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Sample records for sonicate immunoassay based

  1. Hydrogel nanoparticle based immunoassay

    Science.gov (United States)

    Liotta, Lance A; Luchini, Alessandra; Petricoin, Emanuel F; Espina, Virginia

    2015-04-21

    An immunoassay device incorporating porous polymeric capture nanoparticles within either the sample collection vessel or pre-impregnated into a porous substratum within fluid flow path of the analytical device is presented. This incorporation of capture particles within the immunoassay device improves sensitivity while removing the requirement for pre-processing of samples prior to loading the immunoassay device. A preferred embodiment is coreshell bait containing capture nanoparticles which perform three functions in one step, in solution: a) molecular size sieving, b) target analyte sequestration and concentration, and c) protection from degradation. The polymeric matrix of the capture particles may be made of co-polymeric materials having a structural monomer and an affinity monomer, the affinity monomer having properties that attract the analyte to the capture particle. This device is useful for point of care diagnostic assays for biomedical applications and as field deployable assays for environmental, pathogen and chemical or biological threat identification.

  2. Bead-based immunoassays

    NARCIS (Netherlands)

    Wal, van der F.J.; Bergervoet, J.H.W.; Achterberg, R.P.; Haasnoot, W.

    2014-01-01

    Since the first immunoassay with (radioactive) labeled antibodies in the middle of the 20th century [1], many different formats on various platforms have been developed, using antibodies for capture and/or detection. If antibodies are used to capture compounds, a support, such as the wall of a

  3. Monoclonal antibody-based immunoassays.

    Science.gov (United States)

    Appleby, P; Reischl, U

    1998-01-01

    An immunoassay may be defined as an assay that employs an immunological reagent, usually an antibody, to confer specificity for the ligand being measured. As a corollary to this, the discovery, and subsequent development, of monoclonal antibodies (MAbs) has greatly expanded the application and use of immunoassays. Polyclonal reagents, with their associated problems of specificity and quality control, have now been largely replaced by readily available MAbs of potential immortality and well-defined specificity and affinity. This has resulted, in the last two decades, in a great expansion in the range of immunoassays available and also a significant improvement in their reproducibility and reliability.

  4. Feasibility of a simple microsieve-based immunoassay platform

    NARCIS (Netherlands)

    Zweitzig, D.R.; Tibbe, Arjan G.J.; Nguyen, A.T.; van Rijn, C.J.M.; Kopnitsky, M.J.; Cichonski, K.; Terstappen, Leonardus Wendelinus Mathias Marie

    2016-01-01

    The intrinsic properties of silicon microsieves, such as an optically flat surface, high overall porosity, and low flow resistance have led to an increasing number of biotechnology applications. In this report, the feasibility of creating a microsieve-based immunoassay platform was explored.

  5. Feasibility of a simple microsieve-based immunoassay platform

    NARCIS (Netherlands)

    Zweitzig, Daniel R.; Tibbe, Arjan G.; Nguyen, Ai T.; Rijn, van Cees J.M.; Kopnitsky, Mark J.; Cichonski, Kathleen; Terstappen, Leon W.M.M.

    2016-01-01

    The intrinsic properties of silicon microsieves, such as an optically flat surface, high overall porosity, and low flow resistance have led to an increasing number of biotechnology applications. In this report, the feasibility of creating a microsieve-based immunoassay platform was explored.

  6. Rapid micromotor-based naked-eye immunoassay.

    Science.gov (United States)

    de Ávila, Berta Esteban-Fernández; Zhao, Mingjiao; Campuzano, Susana; Ricci, Francesco; Pingarrón, José M; Mascini, Marcello; Wang, Joseph

    2017-05-15

    A dynamic micromotor-based immunoassay, exemplified by cortisol detection, based on the use of tubular micromotors functionalized with a specific antibody is described. The use of antibody-functionalized micromotors offers huge acceleration of both direct and competitive cortisol immunoassays, along with greatly enhanced sensitivity of direct and competitive immunoassays. The dramatically improved speed and sensitivity reflect the greatly increased likelihood of antibody-cortisol contacts and fluid mixing associated with the dynamic movement of these microtube motors and corresponding bubble generation that lead to a highly efficient and rapid recognition process. Rapid naked-eye detection of cortisol in the sample is achieved in connection to use of horseradish peroxidase (HRP) tag and TMB/H 2 O 2 system. Key parameters of the competitive immunoassay (e.g., incubation time and reaction volume) were optimized. This fast visual micromotor-based sensing approach enables "on the move" specific detection of the target cortisol down to 0.1μgmL -1 in just 2min, using ultrasmall (50µL) sample volumes. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. History of inductively coupled plasma mass spectrometry-based immunoassays

    International Nuclear Information System (INIS)

    Giesen, Charlotte; Waentig, Larissa; Panne, Ulrich; Jakubowski, Norbert

    2012-01-01

    The analysis of biomolecules requires highly sensitive and selective detection methods capable of tolerating a complex, biological matrix. First applications of biomolecule detection by ICP-MS relied on the use of heteroelements as a label for quantification. However, the combination of immunoassays and ICP-MS facilitates multiparametric analyses through elemental tagging, and provides a powerful alternative to common bioanalytical methods. This approach extends the detection of biomarkers in clinical diagnosis, and has the potential to provide a deeper understanding of the investigated biological system. The results might lead to the detection of diseases at an early stage, or guide treatment plans. Immunoassays are well accepted and established for diagnostic purposes, albeit ICP-MS is scarcely applied for the detection of immune-based assays. However, the screening of biomarkers demands high throughput and multiplex/multiparametric techniques, considering the variety of analytes to be queried. Finally, quantitative information on the expression level of biomarkers is highly desirable to identify abnormalities in a given organism. Thus, it is the aim of this review to introduce the fundamentals, and to discuss the enormous strength of ICP-MS for the detection of different immunoassays on the basis of selected applications, with a special focus on LA‐ICP‐MS. - Highlights: ► We discuss the fundamentals of elemental tagging for ICP‐MS applications. ► We propose a definition for the expressions “label” and “tag”. ► We highlight LA‐ICP‐MS‐based heteroelement detection. ► We give an historic overview on ICP-MS and LA‐ICP‐MS-based immunoassays. ► In a personal outlook, we discuss future improvements realistically attainable.

  8. Applications of antireflection coatings in sonic crystal-based acoustic devices

    International Nuclear Information System (INIS)

    Wang Yun; Deng Ke; Xu Shengjun; Qiu Chunyin; Yang Hai; Liu Zhengyou

    2011-01-01

    The unwanted reflection seriously baffles the practical applications of sonic crystals, such as for various acoustic lenses designed by utilizing the in-band properties of sonic crystals. Herein we introduce the concept of the antireflection coating into the sonic crystal-based devices. The efficiency of such accessorial structures is demonstrated well by an originally high reflection system. Promising perspectives can be anticipated in extending the antireflection coating layers into more general acoustic applications through a flexible design process.

  9. Micromotor-based lab-on-chip immunoassays

    Science.gov (United States)

    García, Miguel; Orozco, Jahir; Guix, Maria; Gao, Wei; Sattayasamitsathit, Sirilak; Escarpa, Alberto; Merkoçi, Arben; Wang, Joseph

    2013-01-01

    Here we describe the first example of using self-propelled antibody-functionalized synthetic catalytic microengines for capturing and transporting target proteins between the different reservoirs of a lab-on-a-chip (LOC) device. A new catalytic polymer/Ni/Pt microtube engine, containing carboxy moieties on its mixed poly(3,4-ethylenedioxythiophene) (PEDOT)/COOH-PEDOT polymeric outermost layer, is further functionalized with the antibody receptor to selectively recognize and capture the target protein. The new motor-based microchip immunoassay operations are carried out without any bulk fluid flow, replacing the common washing steps in antibody-based protein bioassays with the active transport of the captured protein throughout the different reservoirs, where each step of the immunoassay takes place. A first microchip format involving an `on-the-fly' double-antibody sandwich assay (DASA) is used for demonstrating the selective capture of the target protein, in the presence of excess of non-target proteins. A secondary antibody tagged with a polymeric-sphere tracer allows the direct visualization of the binding events. In a second approach the immuno-nanomotor captures and transports the microsphere-tagged antigen through a microchannel network. An anti-protein-A modified microengine is finally used to demonstrate the selective capture, transport and convenient label-free optical detection of a Staphylococcus aureus target bacteria (containing proteinA in its cell wall) in the presence of a large excess of non-target (Saccharomyces cerevisiae) cells. The resulting nanomotor-based microchip immunoassay offers considerable potential for diverse applications in clinical diagnostics, environmental and security monitoring fields.Here we describe the first example of using self-propelled antibody-functionalized synthetic catalytic microengines for capturing and transporting target proteins between the different reservoirs of a lab-on-a-chip (LOC) device. A new catalytic

  10. Comparison of capillary electrophoresis-based immunoassay with fluorescence polarization immunoassay for the immunodetermination of methamphetamine using various methamphetamine antibodies.

    Science.gov (United States)

    Choi, J; Kim, C; Choi, M J

    1998-11-01

    An accurate and simple immunoassay using capillary electrophoresis (CE) with laser-induced fluorescence (LIF) was performed for the detection of methamphetamine (MA) in urine. The CE-LIF was conducted with an untreated fused-silica column using antiserum and a tracer of fluorescein isothiocyanate (FITC)-labeled MA. This CE-LIF system was compared with fluorescence polarization immunoassay (FPIA) in a TDx analyzer in the photo-check mode using the same FITC-labeled tracer and the same antiserum. Various antibodies, not only those prepared by our own immunogens but also those from commercial sources, were screened and characterized in both assay systems with regard to sensitivity, precision, and cross-reactivity. Both systems satisfied analytical precision and gave similar cross-reactivity patterns. However, the CE-LIF-based immunoassay was approximately one order superior to FPIA in sensitivity, requiring less volume of sample, antiserum, and tracer for the assay. Considering that the FPIA system is well known to be a useful tool for screening antibodies and detecting drugs, the CE-LIF-based immunoassay system, which is seemingly more advantageous than the FPIA system, appears to have great power for the characterization of antibodies and for the detection of MA in urine.

  11. Trends in interfacial design for surface plasmon resonance based immunoassays

    International Nuclear Information System (INIS)

    Shankaran, Dhesingh Ravi; Miura, Norio

    2007-01-01

    Immunosensors based on surface plasmon resonance (SPR) have become a promising tool in sensor technology for biomedical, food, environmental, industrial and homeland security applications. SPR is a surface sensitive optical technique, suitable for real-time and label-free analysis of biorecognition events at functional transducer surfaces. Fabrication of highly active and robust sensing surfaces is an important part in immunoassays because the quality, quantity, chemistry and topography of the interfacial biomembranes play a major role in immunosensor performance. Eventually, a variety of immobilization methods such as physical adsorption, covalent coupling, Langmuir-Blodgett film, polymer thin film, self-assembly, sol-gel, etc, have been introduced over the years for the immobilization of biomolecules (antibody or antigen) on the transducer surfaces. The selection of an immobilization method for an immunoassay is governed by several factors such as nature and stability of the biomolecules, target analyte, application, detection principle, mode of signal transduction, matrix complexity, etc. This paper provides an overview of the various surface modification methods for SPR based immunosensor fabrication. The preparation, structure and application of different functional interfacial surfaces have been discussed along with a brief introduction to the SPR technology, biomolecules and detection principles. (review article)

  12. Trends in interfacial design for surface plasmon resonance based immunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Shankaran, Dhesingh Ravi [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka, 816-8580 (Japan); Miura, Norio [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga-shi, Fukuoka, 816-8580 (Japan)

    2007-12-07

    Immunosensors based on surface plasmon resonance (SPR) have become a promising tool in sensor technology for biomedical, food, environmental, industrial and homeland security applications. SPR is a surface sensitive optical technique, suitable for real-time and label-free analysis of biorecognition events at functional transducer surfaces. Fabrication of highly active and robust sensing surfaces is an important part in immunoassays because the quality, quantity, chemistry and topography of the interfacial biomembranes play a major role in immunosensor performance. Eventually, a variety of immobilization methods such as physical adsorption, covalent coupling, Langmuir-Blodgett film, polymer thin film, self-assembly, sol-gel, etc, have been introduced over the years for the immobilization of biomolecules (antibody or antigen) on the transducer surfaces. The selection of an immobilization method for an immunoassay is governed by several factors such as nature and stability of the biomolecules, target analyte, application, detection principle, mode of signal transduction, matrix complexity, etc. This paper provides an overview of the various surface modification methods for SPR based immunosensor fabrication. The preparation, structure and application of different functional interfacial surfaces have been discussed along with a brief introduction to the SPR technology, biomolecules and detection principles. (review article)

  13. Nanoparticle-based immunosensors and immunoassays for aflatoxins

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xu; Niessner, Reinhard [Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München (Germany); Tang, Dianping [Key Laboratory of Analysis and Detection for Food Safety, MOE & Fujian Province, Department of Chemistry, Fuzhou University, Fuzhou 350108 (China); Knopp, Dietmar, E-mail: dietmar.knopp@ch.tum.de [Institute of Hydrochemistry and Chair of Analytical Chemistry, Technische Universität München, Marchioninistrasse 17, D-81377 München (Germany)

    2016-03-17

    Aflatoxins are naturally existing mycotoxins produced mainly by Aspergillus flavus and Aspergillus parasiticus, present in a wide range of food and feed products. Because of their extremely high toxicity and carcinogenicity, strict control of maximum residue levels of aflatoxins in foodstuff is set by many countries. In daily routine, different chromatographic methods are used almost exclusively. As supplement, in several companies enzyme immunoassay-based sample testing as primary screening is performed. Recently, nanomaterials such as noble metal nanoparticles, magnetic particles, carbon nanomaterials, quantum dots, and silica nanomaterials are increasingly utilized for aflatoxin determination to improve the sensitivity and simplify the detection. They are employed either as supports for the immobilization of biomolecules or as electroactive or optical labels for signal transduction and amplification. Several nanoparticle-based electrochemical, piezoelectric, optical, and immunodipstick assays for aflatoxins have been developed. In this review, we summarize these recent advances and illustrate novel concepts and promising applications in the field of food safety. - Highlights: • Novel concepts and promising applications of nanoparticle-based immunological methods for the determination of aflatoxins. • Inclusion of most important nanomaterials and hybrid nanostructures. • Inclusion of electrochemical, optical and mass-sensitive biosensors as well as optical and immunochromatographic assays.

  14. Graphene-based chemiluminescence resonance energy transfer for homogeneous immunoassay.

    Science.gov (United States)

    Lee, Joon Seok; Joung, Hyou-Arm; Kim, Min-Gon; Park, Chan Beum

    2012-04-24

    We report on chemiluminescence resonance energy transfer (CRET) between graphene nanosheets and chemiluminescent donors. In contrast to fluorescence resonance energy transfer, CRET occurs via nonradiative dipole-dipole transfer of energy from a chemiluminescent donor to a suitable acceptor molecule without an external excitation source. We designed a graphene-based CRET platform for homogeneous immunoassay of C-reactive protein (CRP), a key marker for human inflammation and cardiovascular diseases, using a luminol/hydrogen peroxide chemiluminescence (CL) reaction catalyzed by horseradish peroxidase. According to our results, anti-CRP antibody conjugated to graphene nanosheets enabled the capture of CRP at the concentration above 1.6 ng mL(-1). In the CRET platform, graphene played a key role as an energy acceptor, which was more efficient than graphene oxide, while luminol served as a donor to graphene, triggering the CRET phenomenon between luminol and graphene. The graphene-based CRET platform was successfully applied to the detection of CRP in human serum samples in the range observed during acute inflammatory stress.

  15. Catch and measure-mass spectrometry-based immunoassays in biomarker research.

    Science.gov (United States)

    Weiß, Frederik; van den Berg, Bart H J; Planatscher, Hannes; Pynn, Christopher J; Joos, Thomas O; Poetz, Oliver

    2014-05-01

    Mass spectrometry-based (MS) methods are effective tools for discovering protein biomarker candidates that can differentiate between physiological and pathophysiological states. Promising candidates are validated in studies comprising large patient cohorts. Here, targeted protein analytics are used to increase sample throughput. Methods involving antibodies, such as sandwich immunoassays or Western blots, are commonly applied at this stage. Highly-specific and sensitive mass spectrometry-based immunoassays that have been established in recent years offer a suitable alternative to sandwich immunoassays for quantifying proteins. Mass Spectrometric ImmunoAssays (MSIA) and Stable Isotope Standards and Capture by Anti-Peptide Antibodies (SISCAPA/iMALDI) are two prominent types of MS-based immunoassays in which the capture is done either at the protein or the peptide level. We present an overview of these emerging types of immunoassays and discuss their suitability for the discovery and validation of protein biomarkers. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge. © 2013.

  16. Prediction of sonic boom from experimental near-field overpressure data. Volume 2: Data base construction

    Science.gov (United States)

    Glatt, C. R.; Reiners, S. J.; Hague, D. S.

    1975-01-01

    A computerized method for storing, updating and augmenting experimentally determined overpressure signatures has been developed. A data base of pressure signatures for a shuttle type vehicle has been stored. The data base has been used for the prediction of sonic boom with the program described in Volume I.

  17. Design and Fabrication of a PDMS Microchip Based Immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Guocheng; Wang, Wanjun; Wang, Jun; Lin, Yuehe

    2010-07-01

    In this paper, we describe the design and fabrication process of a polydimethylsiloxane (PDMS) microchip for on-chip multiplex immunoassay application. The microchip consists of a PDMS microfluidic channel layer and a micro pneumatic valve control layer. By selectively pressurizing the pneumatic microvalves, immuno reagents were controlled to flow and react in certain fluidic channel sites. Cross contamination was prevented by tightly closed valves. Our design was proposed to utilize PDMS micro channel surface as the solid phase immunoassay substrate and simultaneously detect four targets antigens on chip. Experiment result shows that 20psi valve pressure is sufficient to tightly close a 200µm wide micro channel with flow rate up to 20µl/min.

  18. Highly sensitive immunoassay based on E. coli with autodisplayed Z-domain

    International Nuclear Information System (INIS)

    Jose, Joachim; Park, Min; Pyun, Jae-Chul

    2010-01-01

    The Z-domain of protein A has been known to bind specifically to the F c region of antibodies (IgGs). In this work, the Z-domain of protein A was expressed on the outer membrane of Escherichia coli by using 'Autodisplay' technology as a fusion protein of autotransport domain. The E. coli with autodisplayed Z-domain was applied to the sandwich-type immunoassay as a solid-support of detection-antibodies against a target analyte. For the feasibility demonstration of the E. coli based immunoassay, C-reactive protein (CRP) assay was carried out by using E. coli with autodisplayed Z-domain. The limit of detection (LOD) and binding capacity of the E. coli based immunoassay were estimated to be far more sensitive than the conventional ELISA. Such a far higher sensitivity of E. coli based immunoassay than conventional ELISA was explained by the orientation control of immobilized antibodies and the mobility of E. coli in assay matrix. From the test results of 45 rheumatoid arthritis (RA) patients' serum and 15 healthy samples, a cut-off value was established to have optimal sensitivity and selectivity values for RA. The CRP test result of each individual sample was compared with ELISA which is the reference method for RA diagnosis. From this work, the E. coli with Z-domain was proved to be feasible for the medical diagnosis based on sandwich-type immunoassay.

  19. Nitrocellulose membrane-based enzyme-linked immunoassay for dengue serotype-1 IgM detection

    International Nuclear Information System (INIS)

    Leon, S.; Guevara, C.; Chunga, A.

    1999-01-01

    To evaluate the sensitivity and specifity of a nitrocellulose membrane-based immunoassay for dengue IgM, with respect to capture enzyme immunoassay, for the diagnosis of dengue virus infection. 101 serum samples were processed and divided into 2 groups: 53 from dengue serotype 1 (DEN1) infected patients, and 48 from healthy subjects. Both groups were tested with a nitrocellulose membrane-based IgM capture enzyme immunoassay (NMB-EIA) and also with an ELISA as referential pattern. NMB-EIA testing detected IgM anti-DEN1 in 94,34% of samples from infected patients, and in 14,58% of control samples, whereas ELISA fails to report false positive or false negative results: NMB-EIA appears to be a good alternative for dengue infection diagnosis. (authors)

  20. Effects of rust in the crack face on crack detection based on Sonic-IR method

    International Nuclear Information System (INIS)

    Harai, Y.; Izumi, Y.; Tanabe, H.; Takamatsu, T.; Sakagami, T.

    2015-01-01

    Sonic-IR, which is based on the thermographic detection of the temperature rise due to frictional heating at the defect faces under ultrasonic excitation, has an advantage in the detection of closed and small defects. However, this method has a lot of nuclear factors relating to heat generation. In this study, effects of rust in the crack faces on the crack detection based on the sonic-IR method is experimentally investigated by using crack specimens. The heat generation by ultrasonic excitation was observed regularly during rust accelerated test using original device. The distribution of temperature change around the crack was changed with the progress of rust. This change in heat generation, it believed to be due to change in the contact state of the crack surface due to rust. As a result, it was found that heat generation by ultrasonic excitation is affected by rust in the crack faces. And it was also found that crack detection can be conducted by sonic-IR even if rust was generated in the crack faces. (author)

  1. An ultrasensitive chemiluminescence immunoassay of chloramphenicol based on gold nanoparticles and magnetic beads.

    Science.gov (United States)

    Tao, Xiaoqi; Jiang, Haiyang; Yu, Xuezhi; Zhu, Jinghui; Wang, Xia; Wang, Zhanhui; Niu, Lanlan; Wu, Xiaoping; Shen, Jianzhong

    2013-05-01

    A competitive, direct, chemiluminescent immunoassay based on a magnetic beads (MBs) separation and gold nanoparticles (AuNPs) labelling technique to detect chloramphenicol (CAP) has been developed. Horseradish peroxidase (HRP)-labelled anti-CAP monoclonal antibody conjugated with AuNPs and antigen-immobilized MBs were prepared. After optimization parameters of immunocomplex MBs, the IC50 values of chemiluminescence magnetic nanoparticles immunoassay (CL-MBs-nano-immunoassay) were 0.017 µg L(-1) for extract method I and 0.17 µg L(-1) for extract method II. The immunoassay with two extract methods was applied to detect CAP in milk. Comparison of these two extract methods showed that extract method I was advantageous in better sensitivity, in which the sensitivity was 10 times compared to that of extract method II, while extract method II was superior in simple operation, suitable for high throughout screen. The recoveries were 86.7-98.0% (extract method I) and 80.0-103.0% (extract method II), and the coefficients of variation (CVs) were all recovery with both extract methods and high correlation with traditional ELISA kit in milk system confirmed that the immunomagnetic assay based on AuNPs exhibited promising potential in rapid field screening for trace CAP analysis. Copyright © 2013 John Wiley & Sons, Ltd.

  2. Microfluidic Platform for Enzyme-Linked and Magnetic Particle-Based Immunoassay

    Directory of Open Access Journals (Sweden)

    Dorota G. Pijanowska

    2013-06-01

    Full Text Available This article presents design and testing of a microfluidic platform for immunoassay. The method is based on sandwiched ELISA, whereby the primary antibody is immobilized on nitrocelluose and, subsequently, magnetic beads are used as a label to detect the analyte. The chip takes approximately 2 h and 15 min to complete the assay. A Hall Effect sensor using 0.35-μm BioMEMS TSMC technology (Taiwan Semiconductor Manufacturing Company Bio-Micro-Electro-Mechanical Systems was fabricated to sense the magnetic field from the beads. Furthermore, florescence detection and absorbance measurements from the chip demonstrate successful immunoassay on the chip. In addition, investigation also covers the Hall Effect simulations, mechanical modeling of the bead–protein complex, testing of the microfluidic platform with magnetic beads averaging 10 nm, and measurements with an inductor-based system.

  3. A Switchable Linker-Based Immunoassay for Ultrasensitive Visible Detection of Salmonella in Tomatoes.

    Science.gov (United States)

    Hahn, Jungwoo; Kim, Eunghee; You, Young Sang; Gunasekaran, Sundaram; Lim, Seokwon; Choi, Young Jin

    2017-10-01

    On-site detection for sensitive identification of foodborne pathogens on fresh produce with minimal use of specialized instrumentation is crucial to the food industry. A switchable linker (SL)-based immunoassay was designed for ultrasensitive on-site detection of Salmonella in tomato samples. The assay is based on large-scale aggregation of gold nanoparticles (GNPs), induced by a quantitative relationship among the biotinylated Salmonella polyclonal antibody (b-Ab) used as the SL, the functionalized GNPs, and Salmonella. Important factors such as the concentration of SLs, time required for large-scale aggregation, and selectivity of b-Ab were optimized to minimize the detection time (within 45 min with gentle agitation) and achieve the lowest limit of detection (LOD; 10 CFU/g in tomato samples) possible. This SL-based immunoassay with its relatively low LOD and short detection time may meet the need for rapid, simple, on-site analysis of pathogens in fresh produce. The novel switchable linker-based immunoassay is a rapid, specific, and sensitive method that has potential applications for routine diagnostics of Salmonella in tomato products. These advantages make it a practical approach for general use in the processing industry to detect Salmonella rapidly and to implement appropriate regulatory procedures. Furthermore, it could be applied to other fresh products including cantaloupe, strawberry, and cucumbers. © 2017 Institute of Food Technologists®.

  4. Comparison of pre-processing methods for multiplex bead-based immunoassays.

    Science.gov (United States)

    Rausch, Tanja K; Schillert, Arne; Ziegler, Andreas; Lüking, Angelika; Zucht, Hans-Dieter; Schulz-Knappe, Peter

    2016-08-11

    High throughput protein expression studies can be performed using bead-based protein immunoassays, such as the Luminex® xMAP® technology. Technical variability is inherent to these experiments and may lead to systematic bias and reduced power. To reduce technical variability, data pre-processing is performed. However, no recommendations exist for the pre-processing of Luminex® xMAP® data. We compared 37 different data pre-processing combinations of transformation and normalization methods in 42 samples on 384 analytes obtained from a multiplex immunoassay based on the Luminex® xMAP® technology. We evaluated the performance of each pre-processing approach with 6 different performance criteria. Three performance criteria were plots. All plots were evaluated by 15 independent and blinded readers. Four different combinations of transformation and normalization methods performed well as pre-processing procedure for this bead-based protein immunoassay. The following combinations of transformation and normalization were suitable for pre-processing Luminex® xMAP® data in this study: weighted Box-Cox followed by quantile or robust spline normalization (rsn), asinh transformation followed by loess normalization and Box-Cox followed by rsn.

  5. Chemiluminescence enzyme immunoassay based on magnetic nanoparticles for detection of hepatocellular carcinoma marker glypican-3

    Directory of Open Access Journals (Sweden)

    Qian-Yun Zhang

    2011-08-01

    Full Text Available Glypican-3 (GPC3 is reported as a great promising tumor marker for hepatocellular carcinoma (HCC diagnosis. Highly sensitive and accurate analysis of serum GPC3 (sGPC3, in combination with or instead of traditional HCC marker alpha-fetoprotein (AFP, is essential for early diagnosis of HCC. Biomaterial-functionalized magnetic particles have been utilized as solid supports with good biological compatibility for sensitive immunoassay. Here, the magnetic nanoparticles (MnPs and magnetic microparticles (MmPs with carboxyl groups were further modified with streptavidin, and applied for the development of chemiluminescence enzyme immunoassay (CLEIA. After comparing between MnPs- and MmPs-based CLEIA, MnPs-based CLEIA was proved to be a better method with less assay time, greater sensitivity, better linearity and longer chemiluminescence platform. MnPs-based CLEIA was applied for detection of sGPC3 in normal liver, hepatocirrhosis, secondary liver cancer and HCC serum samples. The results indicated that sGPC3 was effective in diagnosis of HCC with high performance. Keywords: Magnetic nanoparticle, Magnetic microparticle, Chemiluminescence enzyme immunoassay, Glypican-3, Hepatocellular carcinoma

  6. On-chip signal amplification of magnetic bead-based immunoassay by aviating magnetic bead chains.

    Science.gov (United States)

    Jalal, Uddin M; Jin, Gyeong Jun; Eom, Kyu Shik; Kim, Min Ho; Shim, Joon S

    2017-11-06

    In this work, a Lab-on-a-Chip (LOC) platform is used to electromagnetically actuate magnetic bead chains for an enhanced immunoassay. Custom-made electromagnets generate a magnetic field to form, rotate, lift and lower the magnetic bead chains (MBCs). The cost-effective, disposable LOC platform was made with a polymer substrate and an on-chip electrochemical sensor patterned via the screen-printing process. The movement of the MBCs is controlled to improve the electrochemical signal up to 230% when detecting beta-type human chorionic gonadotropin (β-hCG). Thus, the proposed on-chip MBC-based immunoassay is applicable for rapid, qualitative electrochemical point-of-care (POC) analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Advanced techniques in immunoassay

    International Nuclear Information System (INIS)

    Toth, G.

    1982-01-01

    A brief overview of the development history of radioimmunoassay and related techniques with their theory and practice are given. A comparison of radioimmunoassay (RIA), enzyme immunoassay (EIA), spin immunoassay (SIA), sequential saturation analysis (SSA) etc., based on their main parameters, and their fields of application and recent trends are presented. (Sz.J.)

  8. Sonication-based isolation and enrichment of Chlorella protothecoides chloroplasts for illumina genome sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Angelova, Angelina [University of Arizona; Park, Sang-Hycuk [University of Arizona; Kyndt, John [Bellevue University; Fitzsimmons, Kevin [University of Arizona; Brown, Judith K [University of Arizona

    2013-09-01

    With the increasing world demand for biofuel, a number of oleaginous algal species are being considered as renewable sources of oil. Chlorella protothecoides Krüger synthesizes triacylglycerols (TAGs) as storage compounds that can be converted into renewable fuel utilizing an anabolic pathway that is poorly understood. The paucity of algal chloroplast genome sequences has been an important constraint to chloroplast transformation and for studying gene expression in TAGs pathways. In this study, the intact chloroplasts were released from algal cells using sonication followed by sucrose gradient centrifugation, resulting in a 2.36-fold enrichment of chloroplasts from C. protothecoides, based on qPCR analysis. The C. protothecoides chloroplast genome (cpDNA) was determined using the Illumina HiSeq 2000 sequencing platform and found to be 84,576 Kb in size (8.57 Kb) in size, with a GC content of 30.8 %. This is the first report of an optimized protocol that uses a sonication step, followed by sucrose gradient centrifugation, to release and enrich intact chloroplasts from a microalga (C. prototheocoides) of sufficient quality to permit chloroplast genome sequencing with high coverage, while minimizing nuclear genome contamination. The approach is expected to guide chloroplast isolation from other oleaginous algal species for a variety of uses that benefit from enrichment of chloroplasts, ranging from biochemical analysis to genomics studies.

  9. A fast universal immobilization of immunoglobulin G at 4 °C for the development of array-based immunoassays.

    Directory of Open Access Journals (Sweden)

    Shu-Lin Guo

    Full Text Available To maintain the antibody activity and enhance performance of array-based immunoassays, protein G was used to allow a shorter duration of immunoglobulin G immobilization at 4 °C, with the antibody placed in the appropriate orientation. The multiplexed detection of six pain-related message molecules (PRMMs was used as examples for the development of array-based immunoassays: substance P, calcitonin gene-related peptide, nerve growth factor, brain-derived neurotrophic factor, tumor necrosis factor-α, and β-endorphin. Protein G- and non-protein G-coated slides were tested. Compared to non-protein G immunoassays, protein G shortened the antibody immobilization time at 4 °C from overnight to 2 hours. Only protein G-facilitated immunoassays succeeded in simultaneously detecting all six PRMMs with high specificity. Dose-response curves showed that the limits of detection of the protein G-multiplexed immunoassays for the PRMMs was approximately 164, 167, 120, 60, 80, and 92 pg/ml, respectively. Thus, protein G effectively shortens the duration of antibody immobilization at 4 °C, allowing the use of sensitive array-based immunoassays for the simultaneous detection of PRMMs.

  10. Optimizing a waveguide-based sandwich immunoassay for tumor biomarkers

    Energy Technology Data Exchange (ETDEWEB)

    Mukundan, Harshini [Los Alamos National Laboratory; Swanson, Basil I [Los Alamos National Laboratory; Xie, Hongzhi [Los Alamos National Laboratory; Anderson, Aaron S [Los Alamos National Laboratory; Grace, W Kevin [Los Alamos National Laboratory; Shively, John E [NON LANL

    2008-01-01

    The sensor team at the Los Alamos National Laboratory has developed a waveguide-based optical biosensor for the detection of biomarkers associated with the disease. We have previously demonstrated the application of this technology to the sensitive detection of carcinoembryonic antigen in serum and nipple aspirate fluid from breast cancer patients. In this publication, we report improvements to this technology that will facilitate transition to a point-of-care diagnostic system and/or robust research tool.

  11. Magnetic Bead Based Immunoassay for Autonomous Detection of Toxins

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Y; Hara, C A; Knize, M G; Hwang, M H; Venkatesteswaran, K S; Wheeler, E K; Bell, P M; Renzi, R F; Fruetel, J A; Bailey, C G

    2008-05-01

    As a step towards toward the development of a rapid, reliable analyzer for bioagents in the environment, we are developing an automated system for the simultaneous detection of a group of select agents and toxins. To detect toxins, we modified and automated an antibody-based approach previously developed for manual medical diagnostics that uses fluorescent eTag{trademark} reporter molecules and is suitable for highly multiplexed assays. Detection is based on two antibodies binding simultaneously to a single antigen, one of which is labeled with biotin while the other is conjugated to a fluorescent eTag{trademark} through a cleavable linkage. Aqueous samples are incubated with the mixture of antibodies along with streptavidin-coated magnetic beads coupled to a photo-activatable porphyrin complex. In the presence of antigen, a molecular complex is formed where the cleavable linkage is held in proximity to the photoactivable group. Upon excitation at 680 nm, free radicals are generated, which diffuse and cleave the linkage, releasing the eTags{trademark}. Released eTags{trademark} are analyzed using capillary gel electrophoresis with laser-induced fluorescence detection. Limits of detection for ovalbumin and botulinum toxoid individually were 4 ng/mL (or 80 pg) and 16 ng/mL (or 320 pg), respectively, using the manual assay. In addition, we demonstrated the use of pairs of antibodies from different sources in a single assay to decrease the rate of false positives. Automation of the assay was demonstrated on a flow-through format with higher LODs of 125 ng/mL (or 2.5 ng) each of a mixture of ovalbumin and botulinum toxoid. This versatile assay can be easily modified with the appropriate antibodies to detect a wide range of toxins and other proteins.

  12. Development of nanobody-based flow injection chemiluminescence immunoassay for sensitive detection of human prealbumin.

    Science.gov (United States)

    Ma, Lei; Sun, Yanyan; Kang, Xuejun; Wan, Yakun

    2014-11-15

    Nanobodies, derived from camelid heavy-chain antibodies, have novel and impactful applications in clinical diagnostics. Our objective is to develop a nanobody-based chemiluminescence immunoassay for sensitive detection of human prealbumin (PA). In this context, a phage display nanobody library is constructed via immunizing dromedary camel with human prealbumin. Three nanobodies have been identified by five successive bio-panning steps. Based on their high expression level and good affinity, two out of three are chosen for further study. Magnetic beads (MBs) were functionalized with PEI by acylamide bond formed between the carboxyl group on the surface of the MB. Then, an anti-PA nanobody (Nb1) can be effectively immobilized onto the surface of the functionalized MB using glutaradehyde as the link. The modified MBs with Nb1 can specifically capture the target PA and reacted with silica nanoparticles with co-immobilized HRP and anti-PA nanobody (Nb2). The concentration of PA was detected by flow injection chemiluminescence. When using MB/PEI as the carrier of anti-PA Nb1, the CL signal significantly increased to 4-fold compared with the signal using MB without PEI modification. The CL signal was further amplified to 5-fold when Si/Nb2 was used as the signal probe. Under optimized conditions, the present immunoassay exhibited a wide quantitative range from 0.05 to 1000 μg L(-1) with a detection limit of 0.01 μg L(-1). The sensitivity of the proposed immunoassay offers great promises in providing a sensitive, specific, time saving, and potential method for detecting PA in clinical settings. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. A competitive immunoassay for sensitive detection of small molecules chloramphenicol based on luminol functionalized silver nanoprobe.

    Science.gov (United States)

    Yu, Xiuxia; He, Yi; Jiang, Jie; Cui, Hua

    2014-02-17

    Chloramphenicol (CHL) as a broad-spectrum antibiotic has a broad action spectrum against Gram-positive and Gram-negative bacteria, as well as anaerobes. The use of CHL is strictly restricted in poultry because of its toxic effect. However, CHL is still illegally used in animal farming because of its accessibility and low cost. Therefore, sensitive methods are highly desired for the determination of CHL in foodstuffs. The immunoassays based on labeling as an important tool have been reported for the detection of CHL residues in food-producing animals. However, most of the labeling procedures require multi-step reactions and purifications and thus they are complicated and time-consuming. Recently, in our previous work, luminol functionalized silver nanoparticles have been successfully synthesized, which exhibits higher CL efficiency than luminol functionalized gold nanoparticles. In this work, the new luminol functionalized silver nanoparticles have been used for the labeling of small molecules CHL for the first time and a competitive chemiluminescent immunoassay has been developed for the detection of CHL. Owing to the amplification of silver nanoparticles, high sensitivity for CHL could be achieved with a low detection limit of 7.6×10(-9) g mL(-1) and a wide linear dynamic range of 1.0×10(-8)-1.0×10(-6) g mL(-1). This method has also been successfully applied to determine CHL in milk and honey samples with a good recoveries (92% and 102%, 99% and 107% respectively), indicating that the method is feasible for the determination of CHL in real milk and honey samples. The labeling procedure is simple, convenient and fast, superior to previously reported labeling procedures. The immunoassay is also simple, fast, sensitive and selective. It is of application potential for the determination of CHL in foodstuffs. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. False-positive ethyl glucuronide immunoassay screening caused by a propyl alcohol-based hand sanitizer.

    Science.gov (United States)

    Arndt, Torsten; Grüner, Joachim; Schröfel, Stefanie; Stemmerich, Karsten

    2012-11-30

    Urine ethyl glucuronide (EtG) is considered as a specific marker of recent ethanol consumption. We describe false-positive DRI(®) EIA EtG enzyme immunoassay results caused by propyl glucuronides in urine after using a propanol-based hand sanitizer. EtG screening was done with the DRI(®) EIA EtG assay (Microgenics), using a cut-off of 0.5 mg/L as recommended by the manufacturer and of 0.1 mg/L as demanded by the German Regulations for Reissuing Drivers Licenses. Confirmatory EtG analysis was done with the ClinMass(®) EtG LC-MS/MS testkit (Recipe), extended by the mass transitions 235.1→75.1, 235.1→85.1, and 235.1→113.1 for the detection of the 1- and 2-propyl glucuronides. Self-experiments were done by staff members of our lab (n=7), using 3 mL Sterillium(®) Classic Pure (30 g/100 g 1-propanol and 45 g/100 g 2-propanol) for hand sanitation every quarter of an hour for 8 h according to DIN EN 1500:2011-05 with and without an exhauster and by passive inhalation of the sanitizer vapor. Spot urine samples were taken immediately before and up to 24 h after the first sanitizer use. False-positive immunoassay results of up to 4 mg/L or 2.3 mg/g creatinine were obtained after normal use of the sanitizer and also after passive inhalation of the sanitizer vapor (up to 0.89 mg/L or 0.61 mg/g). Immunoassay results were positive even after 4-fold use of the sanitizer (up to 0.14 mg/L or 0.38 mg/g) and up to 6 h after the last sanitizer contact (maximum 0.63 mg/L and 0.33 mg/g for sanitizer users and 0.25 mg/g after passive inhalation). Spiking of EtG-free urine with 1-propyl glucuronide (Athena Environmental Sciences) between 0.05 and 10 mg/L clearly demonstrated a cross reaction of the immunoassay of approx. 10% as compared to EtG. LC-MS/MS of urines with a positive immunoassay EtG result did not show EtG signals, but distinct signals of 1-propyl glucuronide (n-propyl glucuronide) and 2-propyl glucuronide (iso-propyl glucuronide). An exhauster effectively prevented

  15. 340 nm pulsed UV LED system for europium-based time-resolved fluorescence detection of immunoassays

    DEFF Research Database (Denmark)

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter

    2016-01-01

    We report on the design, development and investigation of an optical system based on UV light emitting diode (LED) excitation at 340 nm for time-resolved fluorescence detection of immunoassays. The system was tested to measure cardiac marker Troponin I with a concentration of 200 ng....../L in immunoassay. The signal-to-noise ratio was comparable to state-of-the-art Xenon flash lamp based unit with equal excitation energy and without overdriving the LED. We performed a comparative study of the flash lamp and the LED based system and discussed temporal, spatial, and spectral features of the LED...... excitation for time-resolved fluorimetry. Optimization of the suggested key parameters of the LED promises significant increase of the signal-to-noise ratio and hence of the sensitivity of immunoassay systems....

  16. 340 nm pulsed UV LED system for europium-based time-resolved fluorescence detection of immunoassays.

    Science.gov (United States)

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Petersen, Paul Michael; Pedersen, Christian

    2016-09-19

    We report on the design, development and investigation of an optical system based on UV light emitting diode (LED) excitation at 340 nm for time-resolved fluorescence detection of immunoassays. The system was tested to measure cardiac marker Troponin I with a concentration of 200 ng/L in immunoassay. The signal-to-noise ratio was comparable to state-of-the-art Xenon flash lamp based unit with equal excitation energy and without overdriving the LED. We performed a comparative study of the flash lamp and the LED based system and discussed temporal, spatial, and spectral features of the LED excitation for time-resolved fluorimetry. Optimization of the suggested key parameters of the LED promises significant increase of the signal-to-noise ratio and hence of the sensitivity of immunoassay systems.

  17. Sonication reduces the attachment of Salmonella Typhimurium ATCC 14028 cells to bacterial cellulose-based plant cell wall models and cut plant material.

    Science.gov (United States)

    Tan, Michelle S F; Rahman, Sadequr; Dykes, Gary A

    2017-04-01

    This study investigated the removal of bacterial surface structures, particularly flagella, using sonication, and examined its effect on the attachment of Salmonella Typhimurium ATCC 14028 cells to plant cell walls. S. Typhimurium ATCC 14028 cells were subjected to sonication at 20 kHz to remove surface structures without affecting cell viability. Effective removal of flagella was determined by staining flagella of sonicated cells with Ryu's stain and enumerating the flagella remaining by direct microscopic counting. The attachment of sonicated S. Typhimurium cells to bacterial cellulose-based plant cell wall models and cut plant material (potato, apple, lettuce) was then evaluated. Varying concentrations of pectin and/or xyloglucan were used to produce a range of bacterial cellulose-based plant cell wall models. As compared to the non-sonicated controls, sonicated S. Typhimurium cells attached in significantly lower numbers (between 0.5 and 1.0 log CFU/cm 2 ) to all surfaces except to the bacterial cellulose-only composite without pectin and xyloglucan. Since attachment of S. Typhimurium to the bacterial cellulose-only composite was not affected by sonication, this suggests that bacterial surface structures, particularly flagella, could have specific interactions with pectin and xyloglucan. This study indicates that sonication may have potential applications for reducing Salmonella attachment during the processing of fresh produce. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Rapid bead-based immunoassay for measurement of mannose-binding lectin

    DEFF Research Database (Denmark)

    Bay, J T; Garred, P

    2009-01-01

    have been developed more automated platforms for MBL analysis is urgently needed. To pursue this, we set out to develop a flexible bead-based MBL immunoassay. Serum was obtained from 98 healthy individuals and 50 patients investigated for possible immunodeficiencies. We used the Luminex xMAP bead array...... coefficient were found be 7.88% and 5.70%, respectively. A close correlation between the new assay and a reference MBL measurement ELISA was found (rho 0.9381, P bead-based assay was less sensitive to interfering anti-murine antibodies in the blood samples than when the antibodies employed were...... used in the reference polystyrene-based ELISA. The new assay could be performed in 3 h with less than 25 microl serum required of each sample. These results show that MBL can be measured readily using a bead-based platform, which may form an efficient basis for a multiplex approach to measure different...

  19. Enhanced Plasmonic Biosensors of Hybrid Gold Nanoparticle-Graphene Oxide-Based Label-Free Immunoassay

    Science.gov (United States)

    Chiu, Nan-Fu; Chen, Chi-Chu; Yang, Cheng-Du; Kao, Yu-Sheng; Wu, Wei-Ren

    2018-05-01

    In this study, we propose a modified gold nanoparticle-graphene oxide sheet (AuNP-GO) nanocomposite to detect two different interactions between proteins and hybrid nanocomposites for use in biomedical applications. GO sheets have high bioaffinity, which facilitates the attachment of biomolecules to carboxyl groups and has led to its use in the development of sensing mechanisms. When GO sheets are decorated with AuNPs, they introduce localized surface plasmon resonance (LSPR) in the resonance energy transfer of spectral changes. Our results suggest a promising future for AuNP-GO-based label-free immunoassays to detect disease biomarkers and rapidly diagnose infectious diseases. The results showed the detection of antiBSA in 10 ng/ml of hCG non-specific interfering protein with dynamic responses ranging from 1.45 nM to 145 fM, and a LOD of 145 fM. Considering the wide range of potential applications of GO sheets as a host material for a variety of nanoparticles, the approach developed here may be beneficial for the future integration of nanoparticles with GO nanosheets for blood sensing. The excellent anti-interference characteristics allow for the use of the biosensor in clinical analysis and point-of-care testing (POCT) diagnostics of rapid immunoassay products, and it may also be a potential tool for the measurement of biomarkers in human serum.

  20. Highly sensitive immunoassay of protein molecules based on single nanoparticle fluorescence detection in a nanowell

    Science.gov (United States)

    Han, Jin-Hee; Kim, Hee-Joo; Lakshmana, Sudheendra; Gee, Shirley J.; Hammock, Bruce D.; Kennedy, Ian M.

    2011-03-01

    A nanoarray based-single molecule detection system was developed for detecting proteins with extremely high sensitivity. The nanoarray was able to effectively trap nanoparticles conjugated with biological sample into nanowells by integrating with an electrophoretic particle entrapment system (EPES). The nanoarray/EPES is superior to other biosensor using immunoassays in terms of saving the amounts of biological solution and enhancing kinetics of antibody binding due to reduced steric hindrance from the neighboring biological molecules. The nanoarray patterned onto a layer of PMMA and LOL on conductive and transparent indium tin oxide (ITO)-glass slide by using e-beam lithography. The suspension of 500 nm-fluorescent (green emission)-carboxylated polystyrene (PS) particles coated with protein-A followed by BDE 47 polyclonal antibody was added to the chip that was connected to the positive voltage. The droplet was covered by another ITO-coated-glass slide and connected to a ground terminal. After trapping the particles into the nanowells, the solution of different concentrations of anti-rabbit- IgG labeled with Alexa 532 was added for an immunoassay. A single molecule detection system could quantify the anti-rabbit IgG down to atto-mole level by counting photons emitted from the fluorescent dye bound to a single nanoparticle in a nanowell.

  1. 340 nm pulsed UV LED system for europium-based time-resolved fluorescence detection of immunoassays

    OpenAIRE

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Petersen, Paul Michael; Pedersen, Christian

    2016-01-01

    We report on the design, development and investigation of an optical system based on UV light emitting diode (LED) excitation at 340 nm for time-resolved fluorescence detection of immunoassays. The system was tested to measure cardiac marker Troponin I with a concentration of 200 ng/L in immunoassay. The signal-to-noise ratio was comparable to state-of-the-art Xenon flash lamp based unit with equal excitation energy and without overdriving the LED. We performed a comparative study of the flas...

  2. Detection of Avian Influenza Virus by Fluorescent DNA Barcode-based Immunoassay with Sensitivity Comparable to PCR

    DEFF Research Database (Denmark)

    Cao, Cuong; Dhumpa, Raghuram; Bang, Dang Duong

    2010-01-01

    involves the sandwiching of the target AIV between magnetic immunoprobes and barcode-carrying immunoprobes. Because each barcode-carrying immunoprobe is functionalized with a multitude of fluorophore-DNA barcode strands, many DNA barcodes are released for each positive binding event resulting......In this paper, a coupling of fluorophore-DNA barcode and bead-based immunoassay for detecting avian influenza virus (AIV) with PCR-like sensitivity is reported. The assay is based on the use of sandwich immunoassay and fluorophore-tagged oligonucleotides as representative barcodes. The detection...

  3. Sonic Watermarking

    Directory of Open Access Journals (Sweden)

    Ryuki Tachibana

    2004-10-01

    Full Text Available Audio watermarking has been used mainly for digital sound. In this paper, we extend the range of its applications to live performances with a new composition method for real-time audio watermarking. Sonic watermarking mixes the sound of the watermark signal and the host sound in the air to detect illegal music recordings recorded from auditoriums. We propose an audio watermarking algorithm for sonic watermarking that increases the magnitudes of the host signal only in segmented areas pseudorandomly chosen in the time-frequency plane. The result of a MUSHRA subjective listening test assesses the acoustic quality of the method in the range of “excellent quality.” The robustness is dependent on the type of music samples. For popular and orchestral music, a watermark can be stably detected from music samples that have been sonic-watermarked and then once compressed in an MPEG 1 layer 3 file.

  4. Open noise barriers based on sonic crystals. Advances in noise control in transport infraestructures

    Energy Technology Data Exchange (ETDEWEB)

    Peiro Torres, M.P.; Redondo Pastor, J.; Bravo Plana-Sala, J.M.; Sanchez Perez, J.V.

    2016-07-01

    Noise control is an environmental problem of first magnitude nowadays. In this work, we present a new concept of acoustic screen designed to control the specific noise generated by transport infrastructures, based on new materials called sonic crystals. These materials are formed by arrangements of acoustic scatterers in air, and provide a new and different mechanism in the fight against noise from those of the classical screens. This mechanism is usually called multiple scattering and is due to their structuring in addition to their physical properties. Due to the separation between scatterers, these barriers are transparent to air and water allowing a reduction on their foundations. Tests carried out in a wind tunnel show a reduction of 42% in the overturning momentum compared to classical barriers. The acoustical performance of these barriers is shown in this work, explaining the new characteristics provided in the control of noise. Finally, an example of these barriers is presented and classified according to acoustic standardization tests. The acoustic barrier reported in this work provides a high technological solution in the field of noise control. (Author)

  5. Development of a Nanobody-Based Lateral Flow Immunoassay for Detection of Human Norovirus.

    Science.gov (United States)

    Doerflinger, Sylvie Y; Tabatabai, Julia; Schnitzler, Paul; Farah, Carlo; Rameil, Steffen; Sander, Peter; Koromyslova, Anna; Hansman, Grant S

    2016-01-01

    Human noroviruses are the dominant cause of outbreaks of acute gastroenteritis. These viruses are usually detected by molecular methods, including reverse transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Human noroviruses are genetically and antigenically diverse, with two main genogroups that are further subdivided into over 40 different genotypes. During the past decade, genogroup 2 genotype 4 (GII.4) has dominated in most countries, but recently, viruses belonging to GII.17 have increased in prevalence in a number of countries. A number of commercially available ELISAs and lateral flow immunoassays were found to have lower sensitivities to the GII.17 viruses, indicating that the antibodies used in these methods may not have a high level of cross-reactivity. In this study, we developed a rapid Nanobody-based lateral flow immunoassay (Nano-immunochromatography [Nano-IC]) for the detection of human norovirus in clinical specimens. The Nano-IC assay detected virions from two GII.4 norovirus clusters, which included the current dominant strain and a novel variant strain. The Nano-IC method had a sensitivity of 80% and specificity of 86% for outbreak specimens. Norovirus virus-like particles (VLPs) representing four genotypes (GII.4, GII.10, GII.12, and GII.17) could be detected by this method, demonstrating the potential in clinical screening. However, further modifications to the Nano-IC method are needed in order to improve this sensitivity, which may be achieved by the addition of other broadly reactive Nanobodies to the system. IMPORTANCE We previously identified a Nanobody (termed Nano-85) that bound to a highly conserved region on the norovirus capsid. In this study, the Nanobody was biotinylated and gold conjugated for a lateral flow immunoassay (termed Nano-IC). We showed that the Nano-IC assay was capable of detecting at least four antigenically distinct GII genotypes, including the newly emerging GII.17. In the clinical setting, the

  6. Development and statistical assessment of a paper-based immunoassay for detection of tumor markers

    Energy Technology Data Exchange (ETDEWEB)

    Mazzu-Nascimento, Thiago [Instituto de Química de São Carlos, Universidade de São Paulo, 13566-590, São Carlos, SP (Brazil); Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP (Brazil); Morbioli, Giorgio Gianini [Instituto de Química de São Carlos, Universidade de São Paulo, 13566-590, São Carlos, SP (Brazil); Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP (Brazil); School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Milan, Luis Aparecido [Departamento de Estatística, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Donofrio, Fabiana Cristina [Instituto de Ciências da Saúde, Universidade Federal de Mato Grosso, 78557-267, Sinop, MT (Brazil); Mestriner, Carlos Alberto [Wama Produtos para Laboratório Ltda, 13560-971, São Carlos, SP (Brazil); Carrilho, Emanuel, E-mail: emanuel@iqsc.usp.br [Instituto de Química de São Carlos, Universidade de São Paulo, 13566-590, São Carlos, SP (Brazil); Instituto Nacional de Ciência e Tecnologia de Bioanalítica, Campinas, SP (Brazil)

    2017-01-15

    Paper-based assays are an attractive low-cost option for clinical chemistry testing, due to characteristics such as short time of analysis, low consumption of samples and reagents, and high portability of assays. However, little attention has been given to the evaluation of the performance of these simple tests, which should include the use of a statistical approach to define the choice of best cut-off value for the test. The choice of the cut-off value impacts on the sensitivity and specificity of the bioassay. Here, we developed a paper-based immunoassay for the detection of the carcinoembryonic antigen (CEA) and performed a statistical assessment to establish the assay's cut-off value using the Youden's J index (68.28 A.U.), what allowed for a gain in sensibility (0.86) and specificity (1.0). We also discuss about the importance of defining a gray zone as a safety margin for test (±12% over the cut-off value), eliminating all false positives and false negatives outcomes and avoiding misleading results. The test accuracy was calculated as the area under the curve (AUC) of the receiver operating characteristic (ROC) curve, presenting a value of 0.97, what classifies this test as highly accurate. We propose here a low-cost method capable of detecting carcinoembryonic antigen (CEA) in human serum samples, highlighting the importance of statistical tools to evaluate a new low-cost diagnostic method. - Highlights: • A paper-based sandwich immunoassay protocol for detection of tumor markers. • A statistical approach to define cut-off values and measuring test's sensitivity, specificity and accuracy. • A simple way to create a gray zone, avoiding false positive and false negative outcomes.

  7. Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

    DEFF Research Database (Denmark)

    Brock, I; Weldingh, K; Leyten, EM

    2004-01-01

    Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection.Brock I, Weldingh K, Leyten EM, Arend SM, Ravn P, Andersen P. Department of Infectious Disease Immunology, Statens Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark. The currently used...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...... recently identified antigens (Rv2653, Rv2654, Rv3873, and Rv3878) from genomic regions that are lacking from the Mycobacterium bovis bacillus Calmette-Guerin (BCG) vaccine strains as well as from the most common nontuberculous mycobacteria. The fine specificity of potential epitopes in these molecules...

  8. Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection

    DEFF Research Database (Denmark)

    Brock, I; Weldingh, K; Leyten, EM

    2004-01-01

    Specific T-cell epitopes for immunoassay-based diagnosis of Mycobacterium tuberculosis infection.Brock I, Weldingh K, Leyten EM, Arend SM, Ravn P, Andersen P. Department of Infectious Disease Immunology, Statens Serum Institute, Artillerivej 5, DK-2300 Copenhagen S, Denmark. The currently used...... method for immunological detection of tuberculosis infection, the tuberculin skin test, has low specificity. Antigens specific for Mycobacterium tuberculosis to replace purified protein derivative are therefore urgently needed. We have performed a rigorous assessment of the diagnostic potential of four...... selected and combined the specific peptide stretches from the four proteins not recognized by M. bovis BCG-vaccinated individuals. These peptide stretches were tested with peripheral blood mononuclear cells obtained from patients with microscopy- or culture-confirmed tuberculosis and from healthy M. bovis...

  9. Development of monoclonal antibody-based immunoassays for the analysis of bisphenol A in canned vegetables.

    Science.gov (United States)

    Moreno, María J; D'Arienzo, Pasquale; Manclús, Juan J; Montoya, Angel

    2011-01-01

    The aim of this work was the development of monoclonal antibodies (MAbs) and highly sensitive immunoassays (ELISAs) to bisphenol A (BPA), a well-known endocrine disruptor able to migrate from the internal coating of cans to food contained inside, particularly vegetables. To produce MAbs to BPA, four synthetic compounds were conjugated to proteins and used as immunizing haptens in mice. By applying hybridoma technology, several MAbs were produced and selected. These antibodies were characterized in the conjugate-coated and in the antibody-coated formats, using both homologous and heterologous conjugates. Three indirect ELISA based on the MAbs showing the highest affinity to BPA were selected. The limit of detection of the most sensitive ELISA was 0.22 nM (0.05 ng/mL), with an I₅₀ value of around 1 nM (0.23 ng/mL). An homologous ELISA based on the MAb BPAB-11 was applied to the simple, direct determination of BPA in the liquid portion of canned artichoke, peas, and sweet corn. Only sample dilution in an appropriate saline buffer was required to minimize matrix effects and to enter the ELISA working range. Recovery and precision of the method were evaluated by spiking the liquid portion of these cans with BPA at 20, 50, and 100 ng/mL. Coefficients of variation were below 20% in most cases. With regard to recovery, the analytical data obtained were also acceptable. This immunoassay has therefore proved its potential as a new tool for the rapid, sensitive and accurate determination of BPA in canned food.

  10. Specificity of immunoassays. Pt. 2

    International Nuclear Information System (INIS)

    Pratt, J.J.; Woldring, M.G.; Boonman, R.; Kittikool, J.

    1979-01-01

    Practical aspects of the measurement of the specificity of immunoassay are reviewed. Antibody heterogeneity in an antiserum makes a pragmatic rather than a theoretical approach necessary. A new method for the measurement of immunoassay specificity is described. This method is based on the errors caused by the cross-reacting antigens and is directly relevant to the validity of results obtained by immunoassay methods. The effect of selectively blocking the least specific antibodies in antisera raised against steroid haptens is tested. The practical consequences of these considerations are tested using steroid radioimmunoassay and enzyme-immunoassay. (orig.) [de

  11. 340nm UV LED excitation in time-resolved fluorescence system for europium-based immunoassays detection

    DEFF Research Database (Denmark)

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter

    2017-01-01

    In immunoassay analyzers for in-vitro diagnostics, Xenon flash lamps have been widely used as excitation light sources. Recent advancements in UV LED technology and its advantages over the flash lamps such as smaller footprint, better wall-plug efficiency, narrow emission spectrum......, and no significant afterglow, have made them attractive light sources for gated detection systems. In this paper, we report on the implementation of a 340 nm UV LED based time-resolved fluorescence system based on europium chelate as a fluorescent marker. The system performance was tested with the immunoassay based...... on the cardiac marker, TnI. The same signal-to-noise ratio as for the flash lamp based system was obtained, operating the LED below specified maximum current. The background counts of the system and its main contributors were measured and analyzed. The background of the system of the LED based unit was improved...

  12. Color encoded microbeads-based flow cytometric immunoassay for polycyclic aromatic hydrocarbons in food

    International Nuclear Information System (INIS)

    Meimaridou, Anastasia; Haasnoot, Willem; Noteboom, Linda; Mintzas, Dimitrios; Pulkrabova, Jana; Hajslova, Jana; Nielen, Michel W.F.

    2010-01-01

    Food contamination caused by chemical hazards such as persistent organic pollutants (POPs) is a worldwide public health concern and requires continuous monitoring. The chromatography-based analysis methods for POPs are accurate and quite sensitive but they are time-consuming, laborious and expensive. Thus, there is a need for validated simplified screening tools, which are inexpensive, rapid, have automation potential and can detect multiple POPs simultaneously. In this study we developed a flow cytometry-based immunoassay (FCIA) using a color-encoded microbeads technology to detect benzo[a]pyrene (BaP) and other polycyclic aromatic hydrocarbons (PAHs) in buffer and food extracts as a starting point for the future development of rapid multiplex assays including other POPs in food, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). A highly sensitive assay for BaP was obtained with an IC 50 of 0.3 μg L -1 using a monoclonal antibody (Mab22F12) against BaP, similar to the IC 50 of a previously described enzyme-linked immunosorbent assay (ELISA) using the same Mab. Moreover, the FCIA was 8 times more sensitive for BaP compared to a surface plasmon resonance (SPR)-based biosensor immunoassay (BIA) using the same reagents. The selectivity of the FCIAs was tested, with two Mabs against BaP for 25 other PAHs, including two hydroxyl PAH metabolites. Apart from BaP, the FCIAs can detect PAHs such as indenol[1,2,3-cd]pyrene (IP), benz[a]anthracene (BaA), and chrysene (CHR) which are also appointed by the European Food Safety Authority (EFSA) as suitable indicators of PAH contamination in food. The FCIAs results were in agreement with those obtained with gas chromatography-mass spectrometry (GC-MS) for the detection of PAHs in real food samples of smoked carp and wheat flour and has great potential for the future routine application of this assay in a simplex or multiplex format in combination with simplified extraction procedure which are

  13. Multiplex competitive microbead-based flow cytometric immunoassay using quantum dot fluorescent labels

    International Nuclear Information System (INIS)

    Yu, Hye-Weon; Kim, In S.; Niessner, Reinhard; Knopp, Dietmar

    2012-01-01

    Highlights: ► First time, duplex competitive bead-based flow cytometric immunoassay was developed using ODs. ► Antibody-coated QD detection probes and antigen-immobilized microspheres were synthesized. ► The two model target analytes were low molecular weight compounds of microbial and chemical origin. ► The determination of different water types was possible after simple filtration of samples. - Abstract: In answer to the ever-increasing need to perform the simultaneous analysis of environmental hazards, microcarrier-based multiplex technologies show great promise. Further integration with biofunctionalized quantum dots (QDs) creates new opportunities to extend the capabilities of multicolor flow cytometry with their unique fluorescence properties. Here, we have developed a competitive microbead-based flow cytometric immunoassay using QDs fluorescent labels for simultaneous detection of two analytes, bringing the benefits of sensitive, rapid and easy-of-manipulation analytical tool for environmental contaminants. As model target compounds, the cyanobacterial toxin microcystin-LR and the polycyclic aromatic hydrocarbon compound benzo[a]pyrene were selected. The assay was carried out in two steps: the competitive immunological reaction of multiple targets using their exclusive sensing elements of QD/antibody detection probes and antigen-coated microsphere, and the subsequent flow cytometric analysis. The fluorescence of the QD-encoded microsphere was thus found to be inversely proportional to target analyte concentration. Under optimized conditions, the proposed assay performed well within 30 min for the identification and quantitative analysis of the two environmental contaminants. For microcystin-LR and benzo[a]pyrene, dose–response curves with IC 50 values of 5 μg L −1 and 1.1 μg L −1 and dynamic ranges of 0.52–30 μg L −1 and 0.13–10 μg L −1 were obtained, respectively. Recovery was 92.6–106.5% for 5 types of water samples like bottled

  14. Development of a Smartphone-based reading system for lateral flow immunoassay.

    Science.gov (United States)

    Lee, Sangdae; Kim, Giyoung; Moon, Jihea

    2014-11-01

    This study was conducted to develop and evaluate the performance of the Smartphone-based reading system for the lateral flow immunoassay (LFIA). Smartphone-based reading system consists of a Samsung Galaxy S2 Smartphone, Smartphone application, and a LFIA reader. LFIA reader is composed of the close-up lens with a focal length up to 30 mm, white LED light, lithium polymer battery, and main body. The Smartphone application for image acquisition and data analysis was developed on the Android platform. The standard curve was obtained by plotting the measured P(T)/P(c) or A(T)/A(c) ratio versus Salmonella standard concentration. The mean, standard deviation (SD), recovery, and relative standard deviation (RSD) were also calculated using additional experimental results. These data were compared with that obtained from the benchtop LFIA reader. The LOD in both systems was observed with 10(6) CFU/mL. The results show high accuracy and good reproducibility with a RSD less than 10% in the range of 10(6) to 10(9) CFU/mL. Due to the simple structure, good sensitivity, and high accuracy of the Smartphone-based reading system, this system can be substituted for the benchtop LFIA reader for point-of-care medical diagnostics.

  15. Fluorescently labelled multiplex lateral flow immunoassay based on cadmium-free quantum dots.

    Science.gov (United States)

    Beloglazova, Natalia V; Sobolev, Aleksander M; Tessier, Mickael D; Hens, Zeger; Goryacheva, Irina Yu; De Saeger, Sarah

    2017-03-01

    A sensitive tool for simultaneous qualitative detection of two mycotoxins based on use of non-cadmium quantum dots (QDs) is presented for the first time. QDs have proven themselves as promising fluorescent labels for biolabeling and chemical analysis. With an increasing global tendency to regulate and limit the use of hazardous elements, indium phosphide (InP) QDs are highlighted as environmentally-friendly alternatives to the highly efficient and well-studied, but potentially toxic Cd- and Pb-based QDs. Here, we developed water-soluble InP QDs-based fluorescent nanostructures. They consisted of core/shell InP/ZnS QDs enrobed in a silica shell that allowed the water solubility (QD@SiO 2 ). Then we applied the QD@SiO 2 as novel, silica shell-encapsulated fluorescent labels in immunoassays for rapid multiplexed screening. Two mycotoxins, zearalenone and deoxynivalenol, were simultaneously detected in maize and wheat, since the two QD@SiO 2 labelled conjugates emit at two different, individually detectable wavelengths. The cutoff values for the simultaneous determination were 50 and 500μgkg -1 for zearalenone and deoxynivalenol, respectively, in both maize and wheat. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was used to confirm the result. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. 340nm UV LED excitation in time-resolved fluorescence system for europium-based immunoassays detection

    OpenAIRE

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2017-01-01

    In immunoassay analyzers for in-vitro diagnostics, Xenon flash lamps have been widely used as excitation light sources. Recent advancements in UV LED technology and its advantages over the flash lamps such as smaller footprint, better wall-plug efficiency, narrow emission spectrum, and no significant afterglow, have made them attractive light sources for gated detection systems. In this paper, we report on the implementation of a 340 nm UV LED based time-resolved fluorescence system based on ...

  17. Nanobody-based enzyme immunoassay for ochratoxin A in cereal with high resistance to matrix interference.

    Science.gov (United States)

    Liu, Xing; Tang, Zongwen; Duan, Zhenhua; He, Zhenyun; Shu, Mei; Wang, Xianxian; Gee, Shirley J; Hammock, Bruce D; Xu, Yang

    2017-03-01

    A sensitive indirect competitive nanobody-based enzyme linked immunosorbent assay (Nb-ELISA) for ochratoxin A (OTA) with high resistance to cereal matrix interference was developed. Nanobodies against OTA (Nb15, Nb28, Nb32, Nb36) were expressed in E. coli cells and their thermal stabilities were compared with that of an OTA-specific monoclonal antibody 6H8. All nanobodies could still retain their antigen-binding activity after exposure to temperature 95°C for 5min or to 90°C for 75min. Nb28 that exhibited the highest sensitivity in ELISA was selected for further research. An indirect competitive ELISA based on Nb28 was developed for OTA, with an IC 50 of 0.64ng/mL and a linear range (IC 20 -IC 80 ) of 0.27-1.47ng/mL. Cereal samples were analyzed following a 2.5 fold dilution of sample extracts, showing the good resistance to matrix interference of the Nb-ELSIA. The recovery of spiked cereal samples (rice, oats, barley) ranged from 80% to 105% and the Nb-ELISA results of OTA content in naturally contamined samples were in good agreement with those determined by a commercial ELISA kit. The results indicated the reliablity of nanobody as a promising immunoassay reagent for detection of mycotoxins in food matrix and its potential in biosensor development. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Microsphere-based immunoassay integrated with a microfluidic network to perform logic operations

    International Nuclear Information System (INIS)

    Sabhachandani, Pooja; Cohen, Noa; Sarkar, Saheli; Konry, Tania

    2015-01-01

    Lab on a chip (LOC) intelligent diagnostics can be described by molecular logic-based circuits. We report on the development of an LOC approach with logic capability for screening combinations of antigen and antibody in the same sample. A microsphere-based immunoassay was integrated with a microfluidic network device to perform the logic operations AND and INHIBIT. Using the clinically relevant biomarkers TNF-α cytokine and anti-TNF-α antibody, we obtained a fluorescent output in the presence of both inputs. This results in an AND operation, while the presence of only one specific input results in a different fluorescent signal, thereby indicating the INHIBIT operation. This approach demonstrates the effective use of molecular logic computation for developing portable, point-of-care technologies for diagnostic purposes due to fast detection times, minimal reagent consumption and low costs. This model system may be further expanded to screening of multiple disease markers, combinatorial logic applications, and developing “smart” sensors and therapeutic technologies. (author)

  19. Rapid and Sensitive Lateral Flow Immunoassay Method for Procalcitonin (PCT Based on Time-Resolved Immunochromatography

    Directory of Open Access Journals (Sweden)

    Xiang-Yang Shao

    2017-02-01

    Full Text Available Procalcitonin (PCT is a current, frequently-used marker for severe bacterial infection. The aim of this study was to develop a cost-effective detection kit for rapid quantitative and on-site detection of PCT. To develop the new PCT quantitative detecting kit, a double-antibody sandwich immunofluorescent assay was employed based on time-resolved immunofluorescent assay (TRFIA combined with lateral flow immunoassay (LFIA. The performance of the new developed kit was evaluated in the aspects of linearity, precision, accuracy, and specificity. Two-hundred thirty-four serum samples were enrolled to carry out the comparison test. The new PCT quantitative detecting kit exhibited a higher sensitivity (0.08 ng/mL. The inter-assay coefficient of variation (CV and the intra-assay CV were 5.4%–7.7% and 5.7%–13.4%, respectively. The recovery rates ranged from 93% to 105%. Furthermore, a high correlation (n = 234, r = 0.977, p < 0.0001 and consistency (Kappa = 0.875 were obtained when compared with the PCT kit from Roche Elecsys BRAHMS. Thus, the new quantitative method for detecting PCT has been successfully established. The results indicated that the newly-developed system based on TRFIA combined with LFIA was suitable for rapid and on-site detection for PCT, which might be a useful platform for other biomarkers in point-of-care tests.

  20. The field application of an immunoassay-based test for petroleum fuels contamination in groundwater

    International Nuclear Information System (INIS)

    Carter, K.R.

    1994-01-01

    The recent development of low-cost, rapid field analytical tests for petroleum fuels based on immunoassay technology has provided an on-site tool for the cost-effective, accurate assessment of groundwater contamination. The method allows for rapid, direct measurement of contaminant concentration. The method has been used for a variety of applications including surface water runoff testing and groundwater monitoring well siting. The PETRO RISc Water Test can be used to substantially reduce the cost of monitoring well installation. Current, monitoring wells are placed based on knowledge of the location of the source of contamination, the size of the release, the time elapsed since the release began, and the hydrogeology of the site. While the location of the source is generally known with some precision, the hydrogeology of the site and the timing of the release rarely are. This results in the need for an ''educated guess'' regarding the drilling location for monitoring wells that are installed to provide long term feedback on groundwater contamination. The tests have the greatest sensitivity to aliphatic compounds in the range of six to ten carbons and aromatic compounds such as toluene, xylene, and naphthalene

  1. Capillary electrochromatography immunoassay for alpha-fetoprotein based on poly(guanidinium ionic liquid) monolithic material.

    Science.gov (United States)

    Liu, Cuicui; Deng, Qiliang; Fang, Guozhen; Dang, Meng; Wang, Shuo

    2017-08-01

    Alpha-fetoprotein (AFP) is widely used as a tumor marker for the serum diagnosis of primary hepatoma. Sensitive detection of AFP level plays an important role in the early diagnosis of disease and highly reliable prediction. In this study, a novel non-competitive immunoassay (IA) based on poly(guanidinium ionic liquid) monolithic material was developed for detecting ultra trace levels of AFP in capillary electrochromatography (CEC) mode. The AFP was mixed with an excess amount of fluorescently labeled antibody. After incubation, the immunocomplex was separated from the free labeled antibody and detected by CEC coupled with laser-induced fluorescence detector. Under the optimized conditions, the developed CEC-IA performed a low detection limit of 0.05 μg L -1  (S/N = 3) and a wide linearity ranging from 0.1 to 1000 μg L -1 for AFP, which can be largely attributed to the high separation and enrichment efficiency of poly(guanidinium ionic liquid) monolithic material for the targets. The application of this method was demonstrated by determining AFP in human serum. Copyright © 2017. Published by Elsevier Inc.

  2. Specific detection of Vibrio parahaemolyticus by fluorescence quenching immunoassay based on quantum dots.

    Science.gov (United States)

    Wang, Ling; Zhang, Junxian; Bai, Haili; Li, Xuan; Lv, Pintian; Guo, Ailing

    2014-07-01

    In this study, anti-Vibrio parahaemolyticus polyclonal and monoclonal antibodies were prepared through intradermal injection immune and lymphocyte hybridoma technique respectively. CdTe quantum dots (QDs) were synthesized at pH 9.3, 98 °C for 1 h with stabilizer of 2.7:1. The fluorescence intensity was 586.499, and the yield was 62.43%. QD probes were successfully prepared under the optimized conditions of pH 7.4, 37 °C for 1 h, 250 μL of 50 mg/mL EDC · HCl, 150 μL of 4 mg/mL NHS, buffer system of Na2HPO4-citric acid, and 8 μL of 2.48 mg/mL polyclonal antibodies. As gold nanoparticles could quench fluorescence of quantum dots, the concentration of V. parahaemolyticus could be detected through measuring the reduction of fluorescence intensity in immune sandwich reaction composed of quantum dot probe, gold-labeled antibody, and the sample. For pure culture, fluorescence intensity of the system was proportional with logarithm concentration of antigen, and the correlation coefficient was 99.764%. The fluorescence quenching immunoassay based on quantum dots is established for the first time to detect Vibrio parahaemolyticus. This method may be used as rapid testing procedure due to its high simplicity and sensitivity.

  3. Toward development of a surface-enhanced Raman scattering (SERS)-based cancer diagnostic immunoassay panel.

    Science.gov (United States)

    Granger, Jennifer H; Granger, Michael C; Firpo, Matthew A; Mulvihill, Sean J; Porter, Marc D

    2013-01-21

    Proteomic analyses of readily obtained human fluids (e.g., serum, urine, and saliva) indicate that the diagnosis of complex diseases will be enhanced by the simultaneous measurement of multiple biomarkers from such samples. This paper describes the development of a nanoparticle-based multiplexed platform that has the potential for simultaneous read-out of large numbers of biomolecules. For this purpose, we have chosen pancreatic adenocarcinoma (PA) as a test bed for diagnosis and prognosis. PA is a devastating form of cancer in which an estimated 86% of diagnoses resulted in death in the United States in 2010. The high mortality rate is due, in part, to the asymptomatic development of the disease and the dearth of sensitive diagnostics available for early detection. One promising route lies in the development of a serum biomarker panel that can generate a signature unique to early stage PA. We describe the design and development of a proof-of-concept PA biomarker immunoassay array coupled with surface-enhanced Raman scattering (SERS) as a sensitive readout method.

  4. Detection of liver kidney microsomal type 1 antibody using molecularly based immunoassays.

    Science.gov (United States)

    Kerkar, N; Ma, Y; Davies, E T; Cheeseman, P; Mieli-Vergani, G; Vergani, D

    2002-12-01

    To assess the diagnostic value of two commercial molecularly based immunoassays detecting liver kidney microsomal type 1 antibody (LKM1). The performance of Varelisa and LKM1 enzyme linked immunosorbent assay (ELISA) was compared with immunofluorescence, and two validated research techniques-an in house ELISA and a radioligand assay measuring antibodies to P4502D6. Thirty serum samples from three patients with autoimmune hepatitis type 2 covering immunofluorescence titres of 1/10 to 1/10 240 and 55 LKM1 negative controls were tested. All 30 sera that were LKM1 positive by immunofluorescence were positive by the in house ELISA, the radioligand assay, and LKM1-ELISA, and 29 were also positive by Varelisa. None of the 55 sera negative for LKM1 by immunofluorescence was positive by the in house ELISA and radioligand assay, but one was positive by Varelisa and 14 were positive using the LKM1-ELISA. Agreement between immunofluorescence, the in house ELISA, the radioligand assay, and Varelisa was high (kappa > 0.8), and agreement between immunofluorescence and LKM1-ELISA was moderate (kappa = 0.63). The assay kit marketed as Varelisa allows accurate detection of LKM1.

  5. Sonication-Induced Modification of Carbon Nanotubes: Effect on the Rheological and Thermo-Oxidative Behaviour of Polymer-Based Nanocomposites.

    Science.gov (United States)

    Arrigo, Rossella; Teresi, Rosalia; Gambarotti, Cristian; Parisi, Filippo; Lazzara, Giuseppe; Dintcheva, Nadka Tzankova

    2018-03-05

    The aim of this work is the investigation of the effect of ultrasound treatment on the structural characteristics of carbon nanotubes (CNTs) and the consequent influence that the shortening induced by sonication exerts on the morphology, rheological behaviour and thermo-oxidative resistance of ultra-high molecular weight polyethylene (UHMWPE)-based nanocomposites. First, CNTs have been subjected to sonication for different time intervals and the performed spectroscopic and morphological analyses reveal that a dramatic decrease of the CNT's original length occurs with increased sonication time. The reduction of the initial length of CNTs strongly affects the nanocomposite rheological behaviour, which progressively changes from solid-like to liquid-like as the CNT sonication time increases. The study of the thermo-oxidative behaviour of the investigated nanocomposites reveals that the CNT sonication has a detrimental effect on the thermo-oxidative stability of nanocomposites, especially for long exposure times. The worsening of the thermo-oxidative resistance of sonicated CNT-containing nanocomposites could be attributed to the lower thermal conductivity of low-aspect-ratio CNTs, which causes the increase of the local temperature at the polymer/nanofillers interphase, with the consequent acceleration of the degradative phenomena.

  6. Sonication-Induced Modification of Carbon Nanotubes: Effect on the Rheological and Thermo-Oxidative Behaviour of Polymer-Based Nanocomposites

    Science.gov (United States)

    Teresi, Rosalia; Gambarotti, Cristian; Dintcheva, Nadka Tzankova

    2018-01-01

    The aim of this work is the investigation of the effect of ultrasound treatment on the structural characteristics of carbon nanotubes (CNTs) and the consequent influence that the shortening induced by sonication exerts on the morphology, rheological behaviour and thermo-oxidative resistance of ultra-high molecular weight polyethylene (UHMWPE)-based nanocomposites. First, CNTs have been subjected to sonication for different time intervals and the performed spectroscopic and morphological analyses reveal that a dramatic decrease of the CNT’s original length occurs with increased sonication time. The reduction of the initial length of CNTs strongly affects the nanocomposite rheological behaviour, which progressively changes from solid-like to liquid-like as the CNT sonication time increases. The study of the thermo-oxidative behaviour of the investigated nanocomposites reveals that the CNT sonication has a detrimental effect on the thermo-oxidative stability of nanocomposites, especially for long exposure times. The worsening of the thermo-oxidative resistance of sonicated CNT-containing nanocomposites could be attributed to the lower thermal conductivity of low-aspect-ratio CNTs, which causes the increase of the local temperature at the polymer/nanofillers interphase, with the consequent acceleration of the degradative phenomena. PMID:29510595

  7. Magnetic bead and gold nanoparticle probes based immunoassay for β-casein detection in bovine milk samples.

    Science.gov (United States)

    Li, Y S; Meng, X Y; Zhou, Y; Zhang, Y Y; Meng, X M; Yang, L; Hu, P; Lu, S Y; Ren, H L; Liu, Z S; Wang, X R

    2015-04-15

    In this work, a double-probe based immunoassay was developed for rapid and sensitive determination of β-casein in bovine milk samples. In the method, magnetic beads (MBs), employed as supports for the immobilization of anti-β-casein polyclonal antibody (PAb), were used as the capture probe. Colloidal gold nanoparticles (AuNPs), employed as a bridge for loading anti-β-casein monoclonal antibody (McAb) and horseradish peroxidase (HRP), were used as the amplification probe. The presence of β-casein causes the sandwich structures of MBs-PAb-β-casein-McAb-AuNPs through the interaction between β-casein and the anti-β-casein antibodies. The HRP, used as an enzymatic-amplified tracer, can catalytically oxidize the substrate 3,3',5,5'-tetramethylbenzidine (TMB), generating optical signals that are proportional to the quantity of β-casein. The linear range of the immunoassay was from 6.5 to 1520ngmL(-1). The limit of detection (LOD) was 4.8ngmL(-1) which was 700 times lower than that of MBs-antibody-HRP based immunoassay and 6-7 times lower than that from the microplate-antibody-HRP based assay. The recoveries of β-casein from bovine milk samples were from 95.0% to 104.3% that had a good correlation coefficient (R(2)=0.9956) with those obtained by an official standard Kjeldahl method. For higher sensitivity, simple sample pretreatment and shorter time requirement of the antigen-antibody reaction, the developed immunoassay demonstrated the viability for detection of β-casein in bovine milk samples. Copyright © 2014. Published by Elsevier B.V.

  8. Description of a nanobody-based competitive immunoassay to detect tsetse fly exposure.

    Directory of Open Access Journals (Sweden)

    Guy Caljon

    2015-02-01

    Full Text Available Tsetse flies are the main vectors of human and animal African trypanosomes. The Tsal proteins in tsetse fly saliva were previously identified as suitable biomarkers of bite exposure. A new competitive assay was conceived based on nanobody (Nb technology to ameliorate the detection of anti-Tsal antibodies in mammalian hosts.A camelid-derived Nb library was generated against the Glossina morsitans morsitans sialome and exploited to select Tsal specific Nbs. One of the three identified Nb families (family III, TsalNb-05 and TsalNb-11 was found suitable for anti-Tsal antibody detection in a competitive ELISA format. The competitive ELISA was able to detect exposure to a broad range of tsetse species (G. morsitans morsitans, G. pallidipes, G. palpalis gambiensis and G. fuscipes and did not cross-react with the other hematophagous insects (Stomoxys calcitrans and Tabanus yao. Using a collection of plasmas from tsetse-exposed pigs, the new test characteristics were compared with those of the previously described G. m. moristans and rTsal1 indirect ELISAs, revealing equally good specificities (> 95% and positive predictive values (> 98% but higher negative predictive values and hence increased sensitivity (> 95% and accuracy (> 95%.We have developed a highly accurate Nb-based competitive immunoassay to detect specific anti-Tsal antibodies induced by various tsetse fly species in a range of hosts. We propose that this competitive assay provides a simple serological indicator of tsetse fly presence without the requirement of test adaptation to the vertebrate host species. In addition, the use of monoclonal Nbs for antibody detection is innovative and could be applied to other tsetse fly salivary biomarkers in order to achieve a multi-target immunoprofiling of hosts. In addition, this approach could be broadened to other pathogenic organisms for which accurate serological diagnosis remains a bottleneck.

  9. Monoclonal antibody-based broad-specificity immunoassay for monitoring organophosphorus pesticides in environmental water samples

    Science.gov (United States)

    The extensive use of organophosphorus pesticides (OPs) in agriculture and domestic settings can result in widespread water contamination. The development of easy-to-use and rapid-screening immunoassay methods in a class-selective manner is a topic of considerable environmental interest. In this wo...

  10. High-performance Sonitopia (Sonic Utopia): Hyper intelligent Material-based Architectural Systems for Acoustic Energy Harvesting

    Science.gov (United States)

    Heidari, F.; Mahdavinejad, M.

    2017-08-01

    The rate of energy consumption in all over the world, based on reliable statistics of international institutions such as the International Energy Agency (IEA) shows significant increase in energy demand in recent years. Periodical recorded data shows a continuous increasing trend in energy consumption especially in developed countries as well as recently emerged developing economies such as China and India. While air pollution and water contamination as results of high consumption of fossil energy resources might be consider as menace to civic ideals such as livability, conviviality and people-oriented cities. In other hand, automobile dependency, cars oriented design and other noisy activities in urban spaces consider as threats to urban life. Thus contemporary urban design and planning concentrates on rethinking about ecology of sound, reorganizing the soundscape of neighborhoods, redesigning the sonic order of urban space. It seems that contemporary architecture and planning trends through soundscape mapping look for sonitopia (Sonic + Utopia) This paper is to propose some interactive hyper intelligent material-based architectural systems for acoustic energy harvesting. The proposed architectural design system may be result in high-performance architecture and planning strategies for future cities. The ultimate aim of research is to develop a comprehensive system for acoustic energy harvesting which cover the aim of noise reduction as well as being in harmony with architectural design. The research methodology is based on a literature review as well as experimental and quasi-experimental strategies according the paradigm of designedly ways of doing and knowing. While architectural design has solution-focused essence in problem-solving process, the proposed systems had better be hyper intelligent rather than predefined procedures. Therefore, the steps of the inference mechanism of the research include: 1- understanding sonic energy and noise potentials as energy

  11. IFSA: a microfluidic chip-platform for frit-based immunoassay protocols

    Science.gov (United States)

    Hlawatsch, Nadine; Bangert, Michael; Miethe, Peter; Becker, Holger; Gärtner, Claudia

    2013-03-01

    Point-of-care diagnostics (POC) is one of the key application fields for lab-on-a-chip devices. While in recent years much of the work has concentrated on integrating complex molecular diagnostic assays onto a microfluidic device, there is a need to also put comparatively simple immunoassay-type protocols on a microfluidic platform. In this paper, we present the development of a microfluidic cartridge using an immunofiltration approach. In this method, the sandwich immunoassay takes place in a porous frit on which the antibodies have immobilized. The device is designed to be able to handle three samples in parallel and up to four analytical targets per sample. In order to meet the critical cost targets for the diagnostic market, the microfluidic chip has been designed and manufactured using high-volume manufacturing technologies in mind. Validation experiments show comparable sensitivities in comparison with conventional immunofiltration kits.

  12. 340nm UV LED excitation in time-resolved fluorescence system for europium-based immunoassays detection

    Science.gov (United States)

    Rodenko, Olga; Fodgaard, Henrik; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2017-02-01

    In immunoassay analyzers for in-vitro diagnostics, Xenon flash lamps have been widely used as excitation light sources. Recent advancements in UV LED technology and its advantages over the flash lamps such as smaller footprint, better wall-plug efficiency, narrow emission spectrum, and no significant afterglow, have made them attractive light sources for gated detection systems. In this paper, we report on the implementation of a 340 nm UV LED based time-resolved fluorescence system based on europium chelate as a fluorescent marker. The system performance was tested with the immunoassay based on the cardiac marker, TnI. The same signal-to-noise ratio as for the flash lamp based system was obtained, operating the LED below specified maximum current. The background counts of the system and its main contributors were measured and analyzed. The background of the system of the LED based unit was improved by 39% compared to that of the Xenon flash lamp based unit, due to the LEDs narrower emission spectrum and longer pulse width. Key parameters of the LED system are discussed to further optimize the signal-to-noise ratio and signal-to-background, and hence the sensitivity of the instrument.

  13. Wide-band all-angle acoustic self-collimation by rectangular sonic crystals with elliptical bases

    International Nuclear Information System (INIS)

    Cicek, Ahmet; Kaya, Olgun Adem; Ulug, Bulent

    2011-01-01

    Self-collimation of acoustic waves in the whole angular range of ±90 0 in the second and third bands of a two-dimensional rectangular sonic crystal with elliptical basis is demonstrated by examining the band structure and equifrequency contours. 70% and 77% of the second and third bands are available for wide-band all-angle self-collimation spanning a bandwidth of approximately 29% and 25% of the central frequencies of the all-angle self-collimation frequency ranges, respectively. Self-collimation of waves over large distances with a small divergence of beam width in the transverse direction is demonstrated through computations based on the finite element method. The second and third bands available for self-collimation are seen to vary linearly in the vast mid-range where a small group velocity dispersion prevents temporal divergence of waves with different frequencies.

  14. Nanoparticle-based sandwich electrochemical immunoassay for carbohydrate antigen 125 with signal enhancement using enzyme-coated nanometer-sized enzyme-doped silica beads.

    Science.gov (United States)

    Tang, Dianping; Su, Biling; Tang, Juan; Ren, Jingjing; Chen, Guonan

    2010-02-15

    A novel nanoparticle-based electrochemical immunoassay of carbohydrate antigen 125 (CA125) as a model was designed to couple with a microfluidic strategy using anti-CA125-functionalized magnetic beads as immunosensing probes. To construct the immunoassay, thionine-horseradish peroxidase conjugation (TH-HRP) was initially doped into nanosilica particles using the reverse micelle method, and then HRP-labeled anti-CA125 antibodies (HRP-anti-CA125) were bound onto the surface of the synthesized nanoparticles, which were used as recognition elements. Different from conventional nanoparticle-based electrochemical immunoassays, the recognition elements of the immunoassay simultaneously contained electron mediator and enzyme labels and simplified the electrochemical measurement process. The sandwich-type immunoassay format was used for the online formation of the immunocomplex in an incubation cell and captured in the detection cell with an external magnet. The electrochemical signals derived from the carried HRP toward the reduction of H(2)O(2) using the doped thionine as electron mediator. Under optimal conditions, the electrochemical immunoassay exhibited a wide working range from 0.1 to 450 U/mL with a detection limit of 0.1 U/mL CA125. The precision, reproducibility, and stability of the immunoassay were acceptable. The assay was evaluated for clinical serum samples, receiving in excellent accordance with results obtained from the standard enzyme-linked immunosorbent assay (ELISA) method. Concluding, the nanoparticle-based assay format provides a promising approach in clinical application and thus represents a versatile detection method.

  15. Sonic Tennis

    DEFF Research Database (Denmark)

    Baldan, Stefano; Götzen, Amalia De; Serafin, Stefania

    2013-01-01

    their movements in order to keep the ball into play. The device can be swung freely and act as a full-fledged motion- based controller, as the game does not rely at all on visual feedback and the device display can thus be ignored. The game aims to be entertaining but also effective for educa- tional purposes......This paper presents an audio-based tennis simulation game for mobile devices, which uses motion input and non-verbal audio feedback as exclusive means of interaction. Players have to listen carefully to the provided auditory clues, like racquet hits and ball bounces, rhythmically synchronizing...

  16. Good performance of an immunoassay based method for nevirapine measurements in human breast milk

    DEFF Research Database (Denmark)

    Salado-Rasmussen, Kirsten; Theilgaard, Zahra Persson; Chiduo, Mercy

    2011-01-01

    from HIV-uninfected women. Clinical samples from HIV-infected women receiving a single-dose of nevirapine were analyzed. Results: Precision and accuracy were evaluated with two concentrations of quality control materials analyzed in three replicates on four different days and was......, requires complicated extraction techniques. The ARK method employs an immunoassay technology and requires a small sample volume (40 μL) and no pre-treatment of the samples. Methods: Commercial enzyme and antibody were used and calibration standards and quality controls were prepared from pooled breast milk...

  17. Universal quantum dot-based sandwich-like immunoassay strategy for rapid and ultrasensitive detection of small molecules using portable and reusable optofluidic nano-biosensing platform

    International Nuclear Information System (INIS)

    Zhou, Liping; Zhu, Anna; Lou, Xuening; Song, Dan; Yang, Rong; Shi, Hanchang; Long, Feng

    2016-01-01

    A universal sandwich-like immunoassay strategy based on quantum-dots immunoprobe (QD-labeled anti-mouse IgG antibody) was developed for rapid and ultrasensitive detection of small molecules. A portable and reusable optofluidic nano-biosensing platform was applied to investigate the sandwich-like immunoassay mechanism and format of small molecules, as well as the binding kinetics between QD immunoprobe and anti-small molecule antibody. A two-step immunoassay method that involves pre-incubation mixture of different concentration of small molecule and anti-small molecule antibody, and subsequent introduction of QD immunoprobe into the optofluidic cell was conducted for small molecule determination. Compared with the one-step immunoassay method, the two-step immunoassay method can obtain higher fluorescence signal and higher sensitivity index, thus improving the nano-biosensing performance. Based on the proposed strategy, two mode targets, namely, microcystin-LR (MC-LR) and Bisphenol A (BPA) were tested with high sensitivity, rapidity, and ease of use. A higher concentration of small molecules in the sample led to less anti-small molecule antibody bound with antigen-carrier protein conjugate immobilized onto the sensor surface, and less QD immunoprobes bound with anti-small molecule antibody. This phenomenon lowered the fluorescence signal detected by nano-biosensing platform. Under optimal operating conditions, MC-LR and BPA exhibited a limit of detection of 0.003 and 0.04 μg/L, respectively. The LODs were better than those of the indirect competitive immunoassay method for small molecules via Cy5.5-labeled anti-small molecule antibody. The proposed QD-based sandwich-like immunoassay strategy was evaluated in spiked water samples, and showed good recovery, precision and accuracy without complicated sample pretreatments. All these results demonstrate that the new detection strategy could be readily applied to the other trace small molecules in real water samples

  18. Universal quantum dot-based sandwich-like immunoassay strategy for rapid and ultrasensitive detection of small molecules using portable and reusable optofluidic nano-biosensing platform

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liping; Zhu, Anna; Lou, Xuening; Song, Dan; Yang, Rong [School of Environment and Natural Resources, Renmin University of China, Beijing (China); Shi, Hanchang [School of Environment, Tsinghua University, Beijing (China); Long, Feng, E-mail: longf04@ruc.edu.cn [School of Environment and Natural Resources, Renmin University of China, Beijing (China)

    2016-01-28

    A universal sandwich-like immunoassay strategy based on quantum-dots immunoprobe (QD-labeled anti-mouse IgG antibody) was developed for rapid and ultrasensitive detection of small molecules. A portable and reusable optofluidic nano-biosensing platform was applied to investigate the sandwich-like immunoassay mechanism and format of small molecules, as well as the binding kinetics between QD immunoprobe and anti-small molecule antibody. A two-step immunoassay method that involves pre-incubation mixture of different concentration of small molecule and anti-small molecule antibody, and subsequent introduction of QD immunoprobe into the optofluidic cell was conducted for small molecule determination. Compared with the one-step immunoassay method, the two-step immunoassay method can obtain higher fluorescence signal and higher sensitivity index, thus improving the nano-biosensing performance. Based on the proposed strategy, two mode targets, namely, microcystin-LR (MC-LR) and Bisphenol A (BPA) were tested with high sensitivity, rapidity, and ease of use. A higher concentration of small molecules in the sample led to less anti-small molecule antibody bound with antigen-carrier protein conjugate immobilized onto the sensor surface, and less QD immunoprobes bound with anti-small molecule antibody. This phenomenon lowered the fluorescence signal detected by nano-biosensing platform. Under optimal operating conditions, MC-LR and BPA exhibited a limit of detection of 0.003 and 0.04 μg/L, respectively. The LODs were better than those of the indirect competitive immunoassay method for small molecules via Cy5.5-labeled anti-small molecule antibody. The proposed QD-based sandwich-like immunoassay strategy was evaluated in spiked water samples, and showed good recovery, precision and accuracy without complicated sample pretreatments. All these results demonstrate that the new detection strategy could be readily applied to the other trace small molecules in real water samples

  19. Trace-level mercury ion (Hg2+) analysis in aqueous sample based on solid-phase extraction followed by microfluidic immunoassay.

    Science.gov (United States)

    Date, Yasumoto; Aota, Arata; Terakado, Shingo; Sasaki, Kazuhiro; Matsumoto, Norio; Watanabe, Yoshitomo; Matsue, Tomokazu; Ohmura, Naoya

    2013-01-02

    Mercury is considered the most important heavy-metal pollutant, because of the likelihood of bioaccumulation and toxicity. Monitoring widespread ionic mercury (Hg(2+)) contamination requires high-throughput and cost-effective methods to screen large numbers of environmental samples. In this study, we developed a simple and sensitive analysis for Hg(2+) in environmental aqueous samples by combining a microfluidic immunoassay and solid-phase extraction (SPE). Using a microfluidic platform, an ultrasensitive Hg(2+) immunoassay, which yields results within only 10 min and with a lower detection limit (LOD) of 0.13 μg/L, was developed. To allow application of the developed immunoassay to actual environmental aqueous samples, we developed an ion-exchange resin (IER)-based SPE for selective Hg(2+) extraction from an ion mixture. When using optimized SPE conditions, followed by the microfluidic immunoassay, the LOD of the assay was 0.83 μg/L, which satisfied the guideline values for drinking water suggested by the United States Environmental Protection Agency (USEPA) (2 μg/L; total mercury), and the World Health Organisation (WHO) (6 μg/L; inorganic mercury). Actual water samples, including tap water, mineral water, and river water, which had been spiked with trace levels of Hg(2+), were well-analyzed by SPE, followed by microfluidic Hg(2+) immunoassay, and the results agreed with those obtained from reduction vaporizing-atomic adsorption spectroscopy.

  20. Development of a highly sensitive and specific immunoassay for enrofloxacin based on heterologous coating haptens.

    Science.gov (United States)

    Wang, Zhanhui; Zhang, Huiyan; Ni, Hengjia; Zhang, Suxia; Shen, Jianzhong

    2014-04-11

    In the paper, an enzyme-linked immunosorbent immunoassay (ELISA) for detection of enrofloxacin was described using one new derivative of enrofloxacin as coating hapten, resulting in surprisingly high sensitivity and specificity. Incorporation of aminobutyric acid (AA) in the new derivative of enrofloxacin had decreased the IC50 of the ELISA for enrofloxacin from 1.3 μg L(-1) to as low as 0.07 μg L(-1). The assay showed neglect cross-reactivity for other fluoroquinolones but ofloxacin (8.23%), marbofloxacin (8.97%) and pefloxacin (7.29%). Analysis of enrofloxacin fortified chicken muscle showed average recoveries from 81 to 115%. The high sensitivity and specificity of the assay makes it a suitable screening method for the determination of low levels of enrofloxacin in chicken muscle without clean-up step. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Synthesis-based approach toward direct sandwich immunoassay for ciguatoxin CTX3C.

    Science.gov (United States)

    Oguri, Hiroki; Hirama, Masahiro; Tsumuraya, Takeshi; Fujii, Ikuo; Maruyama, Megumi; Uehara, Hisatoshi; Nagumo, Yoko

    2003-06-25

    Ciguatoxins are the major causative toxins of ciguatera seafood poisoning. Limited availability of ciguatoxins has hampered the development of a reliable and specific immunoassay for detecting these toxins in contaminated fish. Monoclonal antibodies (mAbs) specific against both ends of ciguatoxin CTX3C were prepared by immunization of mice with protein conjugates of rationally designed synthetic haptens, 3 and 4, in place of the natural toxin. Haptenic groups that possess a surface area larger than 400 A(2) were required to produce mAbs that can bind strongly to CTX3C itself. A direct sandwich enzyme-linked immunosorbent assay (ELISA) using these mAbs was established to detect CTX3C at the ppb level with no cross-reactivity against other related marine toxins, including brevetoxin A, brevetoxin B, okadaic acid, or maitotoxin.

  2. Rapid and Low-Cost CRP Measurement by Integrating a Paper-Based Microfluidic Immunoassay with Smartphone (CRP-Chip)

    Science.gov (United States)

    Dong, Meili; Wu, Jiandong; Ma, Zimin; Peretz-Soroka, Hagit; Zhang, Michael; Komenda, Paul; Tangri, Navdeep; Liu, Yong; Rigatto, Claudio; Lin, Francis

    2017-01-01

    Traditional diagnostic tests for chronic diseases are expensive and require a specialized laboratory, therefore limiting their use for point-of-care (PoC) testing. To address this gap, we developed a method for rapid and low-cost C-reactive protein (CRP) detection from blood by integrating a paper-based microfluidic immunoassay with a smartphone (CRP-Chip). We chose CRP for this initial development because it is a strong biomarker of prognosis in chronic heart and kidney disease. The microfluidic immunoassay is realized by lateral flow and gold nanoparticle-based colorimetric detection of the target protein. The test image signal is acquired and analyzed using a commercial smartphone with an attached microlens and a 3D-printed chip–phone interface. The CRP-Chip was validated for detecting CRP in blood samples from chronic kidney disease patients and healthy subjects. The linear detection range of the CRP-Chip is up to 2 μg/mL and the detection limit is 54 ng/mL. The CRP-Chip test result yields high reproducibility and is consistent with the standard ELISA kit. A single CRP-Chip can perform the test in triplicate on a single chip within 15 min for less than 50 US cents of material cost. This CRP-Chip with attractive features of low-cost, fast test speed, and integrated easy operation with smartphones has the potential to enable future clinical PoC chronic disease diagnosis and risk stratification by parallel measurements of a panel of protein biomarkers. PMID:28346363

  3. Biotin IgM Antibodies in Human Blood: A Previously Unknown Factor Eliciting False Results in Biotinylation-Based Immunoassays

    Science.gov (United States)

    Chen, Tingting; Hedman, Lea; Mattila, Petri S.; Jartti, Laura; Jartti, Tuomas; Ruuskanen, Olli; Söderlund-Venermo, Maria; Hedman, Klaus

    2012-01-01

    Biotin is an essential vitamin that binds streptavidin or avidin with high affinity and specificity. As biotin is a small molecule that can be linked to proteins without affecting their biological activity, biotinylation is applied widely in biochemical assays. In our laboratory, IgM enzyme immuno assays (EIAs) of µ-capture format have been set up against many viruses, using as antigen biotinylated virus like particles (VLPs) detected by horseradish peroxidase-conjugated streptavidin. We recently encountered one serum sample reacting with the biotinylated VLP but not with the unbiotinylated one, suggesting in human sera the occurrence of biotin-reactive antibodies. In the present study, we search the general population (612 serum samples from adults and 678 from children) for IgM antibodies reactive with biotin and develop an indirect EIA for quantification of their levels and assessment of their seroprevalence. These IgM antibodies were present in 3% adults regardless of age, but were rarely found in children. The adverse effects of the biotin IgM on biotinylation-based immunoassays were assessed, including four inhouse and one commercial virus IgM EIAs, showing that biotin IgM do cause false positivities. The biotin can not bind IgM and streptavidin or avidin simultaneously, suggesting that these biotin-interactive compounds compete for the common binding site. In competitive inhibition assays, the affinities of biotin IgM antibodies ranged from 2.1×10−3 to 1.7×10−4 mol/L. This is the first report on biotin antibodies found in humans, providing new information on biotinylation-based immunoassays as well as new insights into the biomedical effects of vitamins. PMID:22879954

  4. Sonication-Based Improvement of the Physicochemical Properties of Guar Gum as a Potential Substrate for Modified Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    Siddique Akber Ansari

    2013-01-01

    Full Text Available Guar Gum is a natural polysaccharide that, due to its physicochemical properties, is extensively investigated for biomedical applications as a matrix for modified drug delivery, but it is also used in the food industry as well as in cosmetics. A commercial sample of Guar Gum was sonicated for different periods of time, and the reduction in the average molecular weight was monitored by means of viscometric measurements. At the same time, the rheological behaviour was also followed, in terms of viscoelasticity range, flow curves, and mechanical spectra. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording mechanical spectra, flow curves, and visible absorption spectra of complexes with Congo Red. The anisotropic elongation, observed in previous studies with tablets of Guar Gum and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels.

  5. A sensitive chemiluminescence enzyme immunoassay based on molecularly imprinted polymers solid-phase extraction of parathion.

    Science.gov (United States)

    Chen, Ge; Jin, Maojun; Du, Pengfei; Zhang, Chan; Cui, Xueyan; Zhang, Yudan; She, Yongxin; Shao, Hua; Jin, Fen; Wang, Shanshan; Zheng, Lufei; Wang, Jing

    2017-08-01

    The chemiluminescence enzyme immunoassay (CLEIA) method responds differently to various sample matrices because of the matrix effect. In this work, the CLEIA method was coupled with molecularly imprinted polymers (MIPs) synthesized by precipitation polymerization to study the matrix effect. The sample recoveries ranged from 72.62% to 121.89%, with a relative standard deviation (RSD) of 3.74-18.14%.The ratio of the sample matrix-matched standard curve slope rate to the solvent standard curve slope was 1.21, 1.12, 1.17, and 0.85 for apple, rice, orange and cabbage in samples pretreated with the mixture of PSA and C 18 . However, the ratio of sample (apple, rice, orange, and cabbage) matrix-matched standard-MIPs curve slope rate to the solvent standard curve was 1.05, 0.92, 1.09, and 1.05 in samples pretreated with MIPs, respectively. The results demonstrated that the matrices of the samples greatly interfered with the detection of parathion residues by CLEIA. The MIPs bound specifically to the parathion in the samples and eliminated the matrix interference effect. Therefore, the CLEIA method have successfully applied MIPs in sample pretreatment to eliminate matrix interference effects and provided a new sensitive assay for agro-products. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A magnetic particles-based chemiluminescence enzyme immunoassay for rapid detection of ovalbumin.

    Science.gov (United States)

    Feng, Xiao-Li; Ren, Hong-Lin; Li, Yan-Song; Hu, Pan; Zhou, Yu; Liu, Zeng-Shan; Yan, Dong-Ming; Hui, Qi; Liu, Dong; Lin, Chao; Liu, Nan-Nan; Liu, Yan-Yan; Lu, Shi-Ying

    2014-08-15

    Egg allergy is an important public health and safety concern, so quantification and administration of food or vaccines containing ovalbumin (OVA) are urgently needed. This study aimed to establish a rapid and sensitive magnetic particles-chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of OVA. The proposed method was developed on the basis of a double antibodies sandwich immunoreaction and luminol-H2O2 chemiluminescence system. The MPs served as both the solid phase and separator, the anti-OVA MPs-coated polyclonal antibodies (pAbs) were used as capturing antibody, and the horseradish peroxidase (HRP)-labeled monoclonal antibody (mAb) was taken as detecting antibody. The parameters of the method were evaluated and optimized. The established MPs-CLEIA method had a linear range from 0.31 to 100ng/ml with a detection limit of 0.24ng/ml. The assays showed low reactivities and less than 5% of intraassay and interassay coefficients of variation (CVs), and the average recoveries were between 92 and 97%. Furthermore, the developed method was applied in real samples analysis successfully, and the correlation coefficient with the commercially available OVA kit was 0.9976. Moreover, it was more rapid and sensitive compared with the other methods for testing OVA. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Chemiluminescence immunoassay based on dual signal amplification strategy of Au/mesoporous silica and multienzyme functionalized mesoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Lin Jiehua, E-mail: linjiehua@qust.edu.cn [Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zhao Yue; Wei Zhijing; Wang Wei [Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2011-11-15

    Highlights: > The increased amount of monoclonal antibody in Au/SiO{sub 2} led to a wider linear range. > Due to the increased HRP tags in HRP-Ab{sub 2}/SiO{sub 2}, signal amplification achieved. > A simple dual amplification immunoassay achieved with flow injection analysis. - Abstract: A chemiluminescent dual signal amplification strategy for the determination of {alpha}-fetoprotein (AFP) was proposed based on a sandwich immunoassay format. Monoclonal antibody of AFP immobilized on the gold nanoparticles doped mesoporous SiO{sub 2} (Au/SiO{sub 2}) were prepared and used as a primary antibody. Horseradish peroxidase (HRP) and HRP-labeled secondary antibody (Ab{sub 2}) co-immobilized into the mesoporous SiO{sub 2} nanoparticles (HRP-Ab{sub 2}/SiO{sub 2}) were used as the labeled immunological probe. Due to the high ratio surface areas and pore volumes of the mesoporous SiO{sub 2}, not only the amount of AFP monoclonal antibody but also the amount of the modified HRP and Ab{sub 2} in HRP-Ab{sub 2}/SiO{sub 2} were largely increased. Thus the chemiluminescent signal was amplified by using the system of luminol and H{sub 2}O{sub 2} under the catalysis of HRP. Under the optimal conditions, two linear ranges for AFP were obtained from 0.01 to 0.5 ng mL{sup -1} and 0.5 to 100 ng mL{sup -1} with a detection limit of 0.005 ng mL{sup -1} (3{sigma}). The fabricated signal amplification strategy showed an excellent promise for sensitive detection of AFP and other tumor markers.

  8. False biochemical diagnosis of hyperthyroidism in streptavidin-biotin-based immunoassays: the problem of biotin intake and related interferences.

    Science.gov (United States)

    Piketty, Marie-Liesse; Polak, Michel; Flechtner, Isabelle; Gonzales-Briceño, Laura; Souberbielle, Jean-Claude

    2017-05-01

    Immunoassays are now commonly used for hormone measurement, in high throughput analytical platforms. Immunoassays are generally robust to interference. However, endogenous analytical error may occur in some patients; this may be encountered in biotin supplementation or in the presence of anti-streptavidin antibody, in immunoassays involving streptavidin-biotin interaction. In these cases, the interference may induce both false positive and false negative results, and simulate a seemingly coherent hormonal profile. It is to be feared that this type of errors will be more frequently observed. This review underlines the importance of keeping close interactions between biologists and clinicians to be able to correlate the hormonal assay results with the clinical picture.

  9. New generation of electrochemical immunoassay based on polymeric nanoparticles for early detection of breast cancer

    Directory of Open Access Journals (Sweden)

    Mouffouk F

    2017-04-01

    Full Text Available Fouzi Mouffouk,1 Sihem Aouabdi,2 Entesar Al-Hetlani,1 Hacene Serrai,3 Tareq Alrefae,4 Liaohai Leo Chen5 1Department of Chemistry, Kuwait University, Safat, Kuwait; 2King Abdullah International Medical Research Center (KAIMRC, Jeddah, Kingdom of Saudi Arabia; 3Department of Radiology and Nuclear Medicine, University Hospital of Gent (UZG, Gent, Belgium; 4Department of Physics, Kuwait University, Safat, Kuwait; 5Surgical Precision Research Lab. Department of Surgery, University of Illinois at Chicago, IL, USA Abstract: Screening and early diagnosis are the key factors for the reduction of mortality rate and treatment cost of cancer. Therefore, sensitive and selective methods that can reveal the low abundance of cancer biomarkers in a biological sample are always desired. Here, we report the development of a novel electrochemical biosensor for early detection of breast cancer by using bioconjugated self-assembled pH-responsive polymeric micelles. The micelles were loaded with ferrocene molecules as “tracers” to specifically target cell surface-associated epithelial mucin (MUC1, a biomarker for breast and other solid carcinoma. The synthesis of target-specific, ferrocene-loaded polymeric micelles was confirmed, and the resulting sensor was capable of detecting the presence of MUC1 in a sample containing about 10 cells/mL. Such a high sensitivity was achieved by maximizing the loading capacity of ferrocene inside the polymeric micelles. Every single event of binding between the antibody and antigen was represented by the signal of hundreds of thousands of ferrocene molecules that were released from the polymeric micelles. This resulted in a significant increase in the intensity of the ferrocene signal detected by cyclic voltammetry. Keywords: electrochemical immunoassay, polymeric nanoparticles, breast cancer biomarkers, biosensors 

  10. Highly sensitive FRET-based fluorescence immunoassay for aflatoxin B1 using cadmium telluride quantum dots

    International Nuclear Information System (INIS)

    Zekavati, Roya; Bayat, Mansour; Safi, Shahabeddin; Hashemi, Seyed Jamal; Rahmani-Cherati, Tavoos; Tabatabaei, Meisam; Mohsenifar, Afshin

    2013-01-01

    We report on a competitive immunoassay for the determination of aflatoxin B1 using fluorescence resonance energy transfer (FRET) from anti-aflatoxin B1 antibody (immobilized on the shell of CdTe quantum dots) to Rhodamine 123 (Rho 123-labeled aflatoxin B1 bound to albumin). The highly specific immuno reaction between the antibody against aflatoxin B1 on the QDs and the labeled-aflatoxin B1 brings the Rho 123 fluorophore (acting as the acceptor) and the QDs (acting as the donor) in close spatial proximity and causes FRET to occur upon photoexcitation of the QDs. In the absence of unlabeled aflatoxin B1, the antigen-antibody complex is stable, and strong emission resulting from the FRET from QDs to labeled aflatoxin B1 is observed. In the presence of aflatoxin B1, it will compete with the labeled aflatoxin B1-albumin complex for binding to the antibody-QDs conjugate so that FRET will be increasingly suppressed. The reduction in the fluorescence intensity of the acceptor correlates well with the concentration of aflatoxin B1. The feasibility of the method was established by the detection of aflatoxin B1 in spiked human serum. There is a linear relationship between the increased fluorescence intensity of Rho 123 with increasing concentration of aflatoxin B1 in spike human serum, over the range of 0.1–0.6 μmol·mL −1 . The limit of detection is 2 × 10 −11 M. This homogeneous competitive detection scheme is simple, rapid and efficient, and does not require excessive washing and separation steps. (author)

  11. Diagnostic performance of line-immunoassay based algorithms for incident HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Schüpbach Jörg

    2012-04-01

    Full Text Available Abstract Background Serologic testing algorithms for recent HIV seroconversion (STARHS provide important information for HIV surveillance. We have previously demonstrated that a patient's antibody reaction pattern in a confirmatory line immunoassay (INNO-LIA™ HIV I/II Score provides information on the duration of infection, which is unaffected by clinical, immunological and viral variables. In this report we have set out to determine the diagnostic performance of Inno-Lia algorithms for identifying incident infections in patients with known duration of infection and evaluated the algorithms in annual cohorts of HIV notifications. Methods Diagnostic sensitivity was determined in 527 treatment-naive patients infected for up to 12 months. Specificity was determined in 740 patients infected for longer than 12 months. Plasma was tested by Inno-Lia and classified as either incident ( Results The 10 best algorithms had a mean raw sensitivity of 59.4% and a mean specificity of 95.1%. Adjustment for overrepresentation of patients in the first quarter year of infection further reduced the sensitivity. In the preferred model, the mean adjusted sensitivity was 37.4%. Application of the 10 best algorithms to four annual cohorts of HIV-1 notifications totalling 2'595 patients yielded a mean IIR of 0.35 in 2005/6 (baseline and of 0.45, 0.42 and 0.35 in 2008, 2009 and 2010, respectively. The increase between baseline and 2008 and the ensuing decreases were highly significant. Other adjustment models yielded different absolute IIR, although the relative changes between the cohorts were identical for all models. Conclusions The method can be used for comparing IIR in annual cohorts of HIV notifications. The use of several different algorithms in combination, each with its own sensitivity and specificity to detect incident infection, is advisable as this reduces the impact of individual imperfections stemming primarily from relatively low sensitivities and

  12. Cellphone-based detection platform for rbST biomarker analysis in milk extracts using a microsphere fluorescence immunoassay.

    Science.gov (United States)

    Ludwig, Susann K J; Zhu, Hongying; Phillips, Stephen; Shiledar, Ashutosh; Feng, Steve; Tseng, Derek; van Ginkel, Leendert A; Nielen, Michel W F; Ozcan, Aydogan

    2014-11-01

    Current contaminant and residue monitoring throughout the food chain is based on sampling, transport, administration, and analysis in specialized control laboratories. This is a highly inefficient and costly process since typically more than 99% of the samples are found to be compliant. On-site simplified prescreening may provide a scenario in which only samples that are suspect are transported and further processed. Such a prescreening can be performed using a small attachment on a cellphone. To this end, a cellphone-based imaging platform for a microsphere fluorescence immunoassay that detects the presence of anti-recombinant bovine somatotropin (rbST) antibodies in milk extracts was developed. RbST administration to cows increases their milk production, but is illegal in the EU and a public health concern in the USA. The cellphone monitors the presence of anti-rbST antibodies (rbST biomarker), which are endogenously produced upon administration of rbST and excreted in milk. The rbST biomarker present in milk extracts was captured by rbST covalently coupled to paramagnetic microspheres and labeled by quantum dot (QD)-coupled detection antibodies. The emitted fluorescence light from these captured QDs was then imaged using the cellphone camera. Additionally, a dark-field image was taken in which all microspheres present were visible. The fluorescence and dark-field microimages were analyzed using a custom-developed Android application running on the same cellphone. With this setup, the microsphere fluorescence immunoassay and cellphone-based detection were successfully applied to milk sample extracts from rbST-treated and untreated cows. An 80% true-positive rate and 95% true-negative rate were achieved using this setup. Next, the cellphone-based detection platform was benchmarked against a newly developed planar imaging array alternative and found to be equally performing versus the much more sophisticated alternative. Using cellphone-based on-site analysis in

  13. Sonic Interaction Design

    DEFF Research Database (Denmark)

    ) challenges these prevalent approaches by considering sound as an active medium that can enable novel sensory and social experiences through interactive technologies. This book offers an overview of the emerging SID research, discussing theories, methods, and practices, with a focus on the multisensory......Sound is an integral part of every user experience but a neglected medium in design disciplines. Design of an artifact’s sonic qualities is often limited to the shaping of functional, representational, and signaling roles of sound. The interdisciplinary field of sonic interaction design (SID...... aspects of sonic experience. Sonic Interaction Design gathers contributions from scholars, artists, and designers working at the intersections of fields ranging from electronic music to cognitive science. They offer both theoretical considerations of key themes and case studies of products and systems...

  14. Development of an immunomagnetic bead-based time-resolved fluorescence immunoassay for rapid determination of levels of carcinoembryonic antigen in human serum

    Energy Technology Data Exchange (ETDEWEB)

    Hou Jingyuan; Liu Tiancai; Lin Guanfeng; Li Zhixiong; Zou Liping; Li Ming [Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou 510515 (China); Wu Yingsong, E-mail: wg@fimmu.com [Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou 510515 (China)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer Magnetic beads was used as the solid phase for TRFIA. Black-Right-Pointing-Pointer The linearity range was broadened greatly compared with conventional TRFIA method. Black-Right-Pointing-Pointer The analysis time was significantly shorter compared with conventional TRFIA method. Black-Right-Pointing-Pointer This method could be developed for practical clinical detections of tumor-associated antigens. - Abstract: A novel immunoassay for the determination of tumor markers in human serum was established by combining a time-resolved fluoroimmunoassay (TRFIA) and immunomagnetic separation. Based on a sandwich-type immunoassay format, analytes in samples were captured by magnetic beads coated with one monoclonal antibody and 'sandwiched' by another monoclonal antibody labeled with europium chelates. The immunocomplex was separated and washed by exposure to a magnetic field and treatment with enhancement solution; fluorescence was then measured according to the number of europium ions dissociated. Levels of the model analyte, carcinoembryonic antigen (CEA), were determined in a linear range (1-1000 ng mL{sup -1}) with a limit of detection of 0.5 ng mL{sup -1} under optimal conditions. The reproducibility, recovery, and specificity of the immunoassay were demonstrated to be acceptable. To evaluate this novel assay for clinical applications, 239 serum samples were evaluated. Compared with the conventional TRFIA and chemiluminescence immunoassay (CLIA), the correlation coefficients of the developed immunoassay were 0.985 and 0.975, respectively. These results showed good correlation and confirmed that our method is feasible and could be used for the clinical determination of CEA (or other tumor antigens) in human serum.

  15. Bead-based competitive fluorescence immunoassay for sensitive and rapid diagnosis of cyanotoxin risk in drinking water.

    Science.gov (United States)

    Yu, Hye-Weon; Jang, Am; Kim, Lan Hee; Kim, Sung-Jo; Kim, In S

    2011-09-15

    Due to the increased occurrence of cyanobacterial blooms and their toxins in drinking water sources, effective management based on a sensitive and rapid analytical method is in high demand for security of safe water sources and environmental human health. Here, a competitive fluorescence immunoassay of microcystin-LR (MCYST-LR) is developed in an attempt to improve the sensitivity, analysis time, and ease-of-manipulation of analysis. To serve this aim, a bead-based suspension assay was introduced based on two major sensing elements: an antibody-conjugated quantum dot (QD) detection probe and an antigen-immobilized magnetic bead (MB) competitor. The assay was composed of three steps: the competitive immunological reaction of QD detection probes against analytes and MB competitors, magnetic separation and washing, and the optical signal generation of QDs. The fluorescence intensity was found to be inversely proportional to the MCYST-LR concentration. Under optimized conditions, the proposed assay performed well for the identification and quantitative analysis of MCYST-LR (within 30 min in the range of 0.42-25 μg/L, with a limit of detection of 0.03 μg/L). It is thus expected that this enhanced assay can contribute both to the sensitive and rapid diagnosis of cyanotoxin risk in drinking water and effective management procedures.

  16. Development of a sensitive Luminex xMAP-based microsphere immunoassay for specific detection of Iris yellow spot virus.

    Science.gov (United States)

    Yu, Cui; Yang, Cuiyun; Song, Shaoyi; Yu, Zixiang; Zhou, Xueping; Wu, Jianxiang

    2018-04-04

    Iris yellow spot virus (IYSV) is an Orthotospovirus that infects most Allium species. Very few approaches for specific detection of IYSV from infected plants are available to date. We report the development of a high-sensitive Luminex xMAP-based microsphere immunoassay (MIA) for specific detection of IYSV. The nucleocapsid (N) gene of IYSV was cloned and expressed in Escherichia coli to produce the His-tagged recombinant N protein. A panel of monoclonal antibodies (MAbs) against IYSV was generated by immunizing the mice with recombinant N protein. Five specific MAbs (16D9, 11C6, 7F4, 12C10, and 14H12) were identified and used for developing the Luminex xMAP-based MIA systems along with a polyclonal antibody against IYSV. Comparative analyses of their sensitivity and specificity in detecting IYSV from infected tobacco leaves identified 7F4 as the best-performed MAb in MIA. We then optimized the working conditions of Luminex xMAP-based MIA in specific detection of IYSV from infected tobacco leaves by using appropriate blocking buffer and proper concentration of biotin-labeled antibodies as well as the suitable ratio between the antibodies and the streptavidin R-phycoerythrin (SA-RPE). Under the optimized conditions the Luminex xMAP-based MIA was able to specifically detect IYSV with much higher sensitivity than conventional enzyme-linked immunosorbent assay (ELISA). Importantly, the Luminex xMAP-based MIA is time-saving and the whole procedure could be completed within 2.5 h. We generated five specific MAbs against IYSV and developed the Luminex xMAP-based MIA method for specific detection of IYSV in plants. This assay provides a sensitive, high-specific, easy to perform and likely cost-effective approach for IYSV detection from infected plants, implicating potential broad usefulness of MIA in plant virus diagnosis.

  17. Label-free electrochemical immunoassay for neuron specific enolase based on 3D macroporous reduced graphene oxide/polyaniline film.

    Science.gov (United States)

    Zhang, Qi; Li, Xiaoyan; Qian, Chunhua; Dou, Li; Cui, Feng; Chen, Xiaojun

    2018-01-01

    The content of neuron specific enolase (NSE) in serum is considered to be an essential indicator of small cell lung cancer (SCLC). Here, a novel label-free electrochemical immunoassay for the detection of NSE based on the three dimensionally macroporous reduced graphene oxide/polyaniline (3DM rGO/PANI) film has been proposed. The 3DM rGO/PANI film was constructed by electrochemical co-deposition of GO and aniline into the interspaces of a sacrificial silica opal template modified Au slice. During the co-deposition, GO was successfully reduced by aniline and PANI could be deposited on the surfaces of rGO sheets. The ratio of rGO and PANI in the composite was also optimized to achieve the maximum electrochemical performance. The 3DM rGO/PANI composite provided larger specific surface area for the antibody immobilization, exhibited enhanced conductivity for electron transfer, and more important was that PANI acted as the electroactive probe for indicating the NSE concentration. Under the optimal conditions, a linear current response of PANI to NSE concentration was obtained over 0.5 pg mL -1 -10.0 ng mL -1 with a detection limit of 0.1 pg mL -1 . Moreover, the immunosensor showed excellent selectivity, good stability, satisfactory reproducibility and regeneration, and was employed to detect NSE in clinical serum specimens. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Sensitive chemiluminescence immunoassay for staphylococcal enterotoxin C1 based on the use of dye-encapsulated mesoporous silica nanoparticles

    International Nuclear Information System (INIS)

    Tao, Liang; Zhang, Chunmei; Sun, Yuanjie; Jin, Boquan; Yang, Kun; Li, Xiaohua; Zhang, Zhujun; Zhang, Jinpeng; Yan, Kuocheng

    2016-01-01

    A chemiluminescent immunoassay for the staphylococcal enterotoxin C1 (SEC1) based on the use of dye-encapsulated mesoporous silica nanoparticles (m-SiNPs) as a label is described. The dyes are retained in the m-SiNPs via strong hydrophobic interactions. The assay comprises the following steps: (a) Microplates coated with antibody against SEC1 are filled with sample upon which the SEC antigen will be bound to the surface; (b) following a washing step, secondary antibody linked to m-SiNPs (that were covalently labeled with rhodamine 6G and fluorescein) were added to form the sandwich complex; (c) after another washing step, bis(2,4,6-trichlorophenyl) oxalate, H_2O_2 and imidazole are added to generate chemiluminescence whose intensity is proportional to the number of m-SiNPs and thus to the number of antigen (SEC) molecules. It is found that the use of functionalized m-SiNPs strongly amplifies the signal. Enterotoxin SEC1 can be detected by this method in the 0.025 to 2 ng⋅mL"-"1 concentration range, the detection limit is 19 pg⋅mL"-"1 (at 3σ), and the relative standard deviation (for 11 parallel measurements at a 1 ng⋅mL"-"1 level) is 4.6 %. The use of an automated chemiluminescence analyzer further improves detection. (author)

  19. Evaluation of a magnetic particles-based chemiluminescence enzyme immunoassay for Golgi protein 73 in human serum.

    Science.gov (United States)

    Liu, Xiangyi; Wan, Xiaohua; Lu, Sheng; Zhang, Lijun; Yu, Shaohua; Lu, Xinxin

    2015-05-20

    Golgi protein 73 (GP73) is regarded as a potential serum biomarker for early diagnosis of hepatocellular carcinoma (HCC). We developed a rapid magnetic particles-based chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of serum GP73. Fluorescein isothiocyanate (FITC) and alkaline phosphatase (ALP) were used to label 2 different monoclonal antibodies to GP73. Serum GP73 was captured with labeled antibodies and formed a sandwiched immunoreaction. The magnetic particles (MPs) coated with anti-FITC antibody were used as a means of separation of the GP73 protein from other serum proteins. After adding the enzyme substrate solution, the relative light unit (RLU) was measured. A MPs-CLEIA for serum GP73 was established and evaluated. The RLU was directly proportional to the concentration of GP73. The method linearity was 5-600 μg/l. Limit of the blank was 2.19 μg/l. The intra- and inter-assay imprecision was 73-0.89), and the sensitivity and specificity, with cut-off value of 115.6 μg/l, were 75.4% and 92.1%, respectively. The proposed method demonstrates an acceptable performance for quantifying serum GP73. This assay could be appropriate for routine use in clinical laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Rapid determination of recent cocaine use with magnetic particles-based enzyme immunoassays in serum, saliva, and urine fluids.

    Science.gov (United States)

    Vidal, Juan C; Bertolín, Juan R; Bonel, Laura; Asturias, Laura; Arcos-Martínez, M Julia; Castillo, Juan R

    2016-06-05

    Cocaine is one of the most worldwide used illicit drugs. We report a magnetic particles-based enzyme-linked immunoassay (mpEIA) method for the rapid and sensitive determination of cocaine (COC) in saliva, urine and serum samples. Under optimized conditions, the limits of detections were 0.09ngmL(-1) (urine), 0.15ngmL(-1) (saliva), and 0.06ngmL(-1) COC (human serum). Sensitivities were in the range EC50=0.6-2.5ngmL(-1) COC. The cross-reactivity with the principal metabolite benzoylecgonine (BZE) was only 1.6%. Recovering percentages of doped samples (0, 10, 50, and 100ngmL(-1) of COC) ranged from about 86-111%. Some advantages of the developed mpEIA over conventional ELISA kits are faster incubations, improved reproducibility, and consumption of lower amounts of antibody and enzyme conjugates due to the use of magnetic beads. The reported method was validated following the guidelines on bioanalytical methods of the European Medicines Agency (2011). Unmetabolized COC detection has a great interest in pharmacological, pharmacokinetics, and toxicokinetics studies, and can be used to detect a very recent COC use (1-6h). Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Nanobody Based Immunoassay for Human Soluble Epoxide Hydrolase Detection Using Polymeric Horseradish Peroxidase (PolyHRP) for Signal Enhancement: The Rediscovery of PolyHRP?

    Science.gov (United States)

    Li, Dongyang; Cui, Yongliang; Morisseau, Christophe; Gee, Shirley J; Bever, Candace S; Liu, Xiangjiang; Wu, Jian; Hammock, Bruce D; Ying, Yibin

    2017-06-06

    Soluble epoxide hydrolase (sEH) is a potential pharmacological target for treating hypertension, vascular inflammation, cancer, pain, and multiple cardiovascular related diseases. A variable domain of the heavy chain antibody (termed single domain antibody (sdAb), nanobody, or VHH) possesses the advantages of small size, high stability, ease of genetic manipulation, and ability for continuous manufacture, making such nanobody a superior choice as an immunoreagent. In this work, we developed an ultrasensitive nanobody based immunoassay for human sEH detection using polymeric horseradish peroxidase (PolyHRP) for signal enhancement. Llama nanobodies against human sEH were used as the detection antibody in sandwich enzyme linked immunosorbent assays (ELISA) with polyclonal anti-sEH as the capture antibody. A conventional sandwich ELISA using a horseradish peroxidase (HRP) labeled anti-hemeagglutinin (HA) tag as the tracer showed a marginal sensitivity (0.0015 optical density (OD)·mL/ng) and limit of detection (LOD) of 3.02 ng/mL. However, the introduction of the PolyHRP as the tracer demonstrated a 141-fold increase in the sensitivity (0.21 OD·mL/ng) and 57-fold decrease in LOD (0.05 ng/mL). Systematic comparison of three different tracers in four ELISA formats demonstrated the overwhelming advantage of PolyHRP as a label for nanobody based immunoassay. This enhanced sEH immunoassay was further evaluated in terms of selectivity against other epoxide hydrolases and detection of the target protein in human tissue homogenate samples. Comparison with an enzyme activity based assay and a Western blot for sEH detection reveals good correlation with the immunoassay. This work demonstrates increased competiveness of nanobodies for practical sEH protein detection utilizing PolyHRP. It is worthwhile to rediscover the promising potential of PolyHRP in nanobody and other affinity based methods after its low-profile existence for decades.

  2. Immunoassays in Biotechnology

    Science.gov (United States)

    Immunoassays have broad applications for a wide variety of important biological compounds and environmental contaminants. Immunoassays can detect the presence of an antigen in the human body, a pollutant in the environment, or a critical antibody in a patient’s serum to develop a...

  3. The fabrication of magnetic particle-based chemiluminescence immunoassay for human epididymis protein-4 detection in ovarian cancer

    Directory of Open Access Journals (Sweden)

    Xiaoling Fu

    2018-03-01

    Full Text Available The magnetic particles have a significant influence on the immunoassay detection and cancer therapy. Herein, the chemiluminescence immunoassay combined with the magnetic particles (MPCLIA was presented for the clinical determination and analysis of human epididymis protein 4 (HE4 in the human serum. Under the optimized experiment conditions, the secure MPCLIA method can detect HE4 in the broader range of 0–1000 pmol/L, with a lower detection limit of 1.35 pmol/L. The satisfactory recovery rate of the method in the serum ranged from 83.62% to 105.10%, which was well within the requirement of clinical analysis. Moreover, the results showed the good correlation with enzyme-linked immunosorbent assay (ELISA, with the correlation coefficient of 0.9589. This proposed method has been successfully applied to the clinical determination of HE4 in the human serum. Keywords: Chemiluminescence immunoassay, Magnetic particles, Human epididymis protein 4

  4. Improving the sensitivity of immunoassay based on MBA-embedded Au@SiO2 nanoparticles and surface enhanced Raman spectroscopy

    Science.gov (United States)

    Wei, Chao; Xu, Min-Min; Fang, Cong-Wei; Jin, Qi; Yuan, Ya-Xian; Yao, Jian-Lin

    2017-03-01

    Traditional "sandwich" structure immunoassay is mainly based on the self-assembly of "antibody on solid substrate-antigen-antibody with nanotags" architectures, and the sensitivity of this strategy is critically depended on the surface enhanced Raman scattering (SERS) activities and stability of nanotags. Therefore, the rational design and fabrication on the SERS nanotags attracts the common interests to the bio-related detecting and imaging. Herein, silica encapsulated Au with mercaptobenzoic acid (MBA) core-shell nanoparticles (Au-MBA@SiO2) are fabricated instead of the traditional naked Au or Ag nanoparticles for the SERS-based immunoassay on human and mouse IgG antigens. The MBA molecules facilitate the formation of continuous pinhole-free silica shell and are also used as SERS labels. The silica shell is employed to protect MBA labels and to isolate Au core from the ambient solution for blocking the aggregation. This shell also played the similar role to BSA in inhibiting the nonspecific bindings, which allowed the procedures for constructing "sandwich" structures to be simplified. All of these merits of the Au-MBA@SiO2 brought the high performance in the related immunoassay. Benefiting from the introduction of silica shell to encapsulate MBA labels, the detection sensitivity was improved by about 1- 2 orders of magnitude by comparing with the traditional approach based on naked Au-MBA nanoparticles. This kind of label-embedded core-shell nanoparticles could be developed as the versatile nanotags for the bioanalysis and bioimaging.

  5. First application of a microsphere-based immunoassay to the detection of genetically modified organisms (GMOs): quantification of Cry1Ab protein in genetically modified maize.

    Science.gov (United States)

    Fantozzi, Anna; Ermolli, Monica; Marini, Massimiliano; Scotti, Domenico; Balla, Branko; Querci, Maddalena; Langrell, Stephen R H; Van den Eede, Guy

    2007-02-21

    An innovative covalent microsphere immunoassay, based on the usage of fluorescent beads coupled to a specific antibody, was developed for the quantification of the endotoxin Cry1Ab present in MON810 and Bt11 genetically modified (GM) maize lines. In particular, a specific protocol was developed to assess the presence of Cry1Ab in a very broad range of GM maize concentrations, from 0.1 to 100% [weight of genetically modified organism (GMO)/weight]. Test linearity was achieved in the range of values from 0.1 to 3%, whereas fluorescence signal increased following a nonlinear model, reaching a plateau at 25%. The limits of detection and quantification were equal to 0.018 and 0.054%, respectively. The present study describes the first application of quantitative high-throughput immunoassays in GMO analysis.

  6. Materials for Microfluidic Immunoassays: A Review.

    Science.gov (United States)

    Mou, Lei; Jiang, Xingyu

    2017-08-01

    Conventional immunoassays suffer from at least one of these following limitations: long processing time, high costs, poor user-friendliness, technical complexity, poor sensitivity and specificity. Microfluidics, a technology characterized by the engineered manipulation of fluids in channels with characteristic lengthscale of tens of micrometers, has shown considerable promise for improving immunoassays that could overcome these limitations in medical diagnostics and biology research. The combination of microfluidics and immunoassay can detect biomarkers with faster assay time, reduced volumes of reagents, lower power requirements, and higher levels of integration and automation compared to traditional approaches. This review focuses on the materials-related aspects of the recent advances in microfluidics-based immunoassays for point-of-care (POC) diagnostics of biomarkers. We compare the materials for microfluidic chips fabrication in five aspects: fabrication, integration, function, modification and cost, and describe their advantages and drawbacks. In addition, we review materials for modifying antibodies to improve the performance of the reaction of immunoassay. We also review the state of the art in microfluidic immunoassays POC platforms, from the laboratory to routine clinical practice, and also commercial products in the market. Finally, we discuss the current challenges and future developments in microfluidic immunoassays. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. A high-throughput homogeneous immunoassay based on Förster resonance energy transfer between quantum dots and gold nanoparticles

    International Nuclear Information System (INIS)

    Qian, Jing; Wang, Chengquan; Pan, Xiaohu; Liu, Songqin

    2013-01-01

    Graphical abstract: A Förster resonance energy transfer system by using polyclonal goat anti-CEA antibody labeled luminescent CdTe quantum dots (QDs) as donor and monoclonal goat anti-CEA antibody labeled gold nanoparticles (AuNPs) as acceptor for sensitive detection of tumor marker was proposed. Highlights: ► A homogeneous immunosensing strategy based on FRET for detection of tumor marker was proposed. ► Close of QDs and AuNPs allow the occurrence of quenching the photoluminescence of nano-bio-probes. ► Signal quenching was monitored by a self-developed image analyzer. ► The fluorometric assay format is attractive for widespread carcinoma screening and even field use. -- Abstract: A novel homogeneous immunoassay based on Förster resonance energy transfer for sensitive detection of tumor, e.g., marker with carcinoembryonic antigen (CEA), was proposed. The assay was consisted of polyclonal goat anti-CEA antibody labeled luminescent CdTe quantum dots (QDs) as donor and monoclonal goat anti-CEA antibody labeled gold nanoparticles (AuNPs) as acceptor. In presence of CEA, the bio-affinity between antigen and antibody made the QDs and AuNPs close enough, thus the photoluminescence (PL) quenching of CdTe QDs occurred. The PL properties could be transformed into the fluorometric variation, corresponding to the target antigen concentration, and could be easily monitored and analyzed with the home-made image analysis software. The fluorometric results indicated a linear detection range of 1–110 ng mL −1 for CEA, with a detection limit of 0.3 ng mL −1 . The proposed assay configuration was attractive for carcinoma screening or single sample in point-of-care testing, and even field use. In spite of the limit of available model analyte, this approach could be easily extended to detection of a wide range of biomarkers

  8. Simultaneous detection of IgG antibodies associated with viral hemorrhagic fever by a multiplexed Luminex-based immunoassay.

    Science.gov (United States)

    Wu, Wei; Zhang, Shuo; Qu, Jing; Zhang, Quanfu; Li, Chuan; Li, Jiandong; Jin, Cong; Liang, Mifang; Li, Dexin

    2014-07-17

    Viral hemorrhagic fevers (VHFs) are worldwide diseases caused by several kinds of viruses. With the emergence of new viruses, advanced diagnostic methods are urgently needed for identification of VHFs. Based on Luminex xMAP technology, a rapid, sensitive, multi-pathogen and high-throughput method which could simultaneously detect hemorrhagic fever viruses (HFVs) specific IgG antibodies was developed. Recombinant antigens of nine HFVs including Hantaan virus (HTNV), Seoul virus (SEOV), Puumala virus (PUUV), Andes virus (ANDV), Sin Nombre virus (SNV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) and dengue virus (DENV) were produced and purified from a prokaryotic expression system and the influence of the coupling amount was investigated. Cross-reactions among antigens and their rabbit immune sera were evaluated. Serum samples collected from 51 laboratory confirmed hemorrhagic fever with renal syndrome (HFRS) patients, 43 confirmed SFTS patients and 88 healthy donors were analyzed. Results showed that recombinant nucleocapsid protein of the five viruses belonging to the genus Hantavirus, had serological cross-reactivity with their corresponding rabbit immune sera, but not apparent with immune sera of other four viruses. Evaluation of this new method with clinical serum samples showed 98.04% diagnostic sensitivity for HFRS, 90.70% for SFTS detection and the specificity was ranging from 66.67% to 100.00%. The multiplexed Luminex-based immunoassay has firstly been established in our study, which provides a potentially reliable diagnostic tool for IgG antibody detection of VHFs. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. A high-throughput homogeneous immunoassay based on Förster resonance energy transfer between quantum dots and gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Jing [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); School of Chemistry and Chemical Engineering, Jiangsu University, Zhengjiang 212013 (China); Wang, Chengquan [Changzhou College of Information Technology, Changzhou 213164 (China); Pan, Xiaohu [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Liu, Songqin, E-mail: liusq@seu.edu.cn [School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China)

    2013-02-06

    Graphical abstract: A Förster resonance energy transfer system by using polyclonal goat anti-CEA antibody labeled luminescent CdTe quantum dots (QDs) as donor and monoclonal goat anti-CEA antibody labeled gold nanoparticles (AuNPs) as acceptor for sensitive detection of tumor marker was proposed. Highlights: ► A homogeneous immunosensing strategy based on FRET for detection of tumor marker was proposed. ► Close of QDs and AuNPs allow the occurrence of quenching the photoluminescence of nano-bio-probes. ► Signal quenching was monitored by a self-developed image analyzer. ► The fluorometric assay format is attractive for widespread carcinoma screening and even field use. -- Abstract: A novel homogeneous immunoassay based on Förster resonance energy transfer for sensitive detection of tumor, e.g., marker with carcinoembryonic antigen (CEA), was proposed. The assay was consisted of polyclonal goat anti-CEA antibody labeled luminescent CdTe quantum dots (QDs) as donor and monoclonal goat anti-CEA antibody labeled gold nanoparticles (AuNPs) as acceptor. In presence of CEA, the bio-affinity between antigen and antibody made the QDs and AuNPs close enough, thus the photoluminescence (PL) quenching of CdTe QDs occurred. The PL properties could be transformed into the fluorometric variation, corresponding to the target antigen concentration, and could be easily monitored and analyzed with the home-made image analysis software. The fluorometric results indicated a linear detection range of 1–110 ng mL{sup −1} for CEA, with a detection limit of 0.3 ng mL{sup −1}. The proposed assay configuration was attractive for carcinoma screening or single sample in point-of-care testing, and even field use. In spite of the limit of available model analyte, this approach could be easily extended to detection of a wide range of biomarkers.

  10. Nanobody-based electrochemical immunoassay for Bacillus thuringiensis Cry1Ab toxin by detecting the enzymatic formation of polyaniline

    International Nuclear Information System (INIS)

    Zhu, Min; Li, Guanghui; Li, Min; Zhou, Zikai; Liu, Hong; Lei, Hongtao; Shen, Yanfei; Wan, Yakun

    2015-01-01

    We describe an electrochemical immunoassay for the Cry1Ab toxin that is produced by Bacillus thuringiensis. It is making use of a nanobody (a heavy-chain only antibody) that was selected from an immune phage displayed library. A biotinylated primary nanobody and a HRP-conjugated secondary nanobody were applied in a sandwich immunoassay where horseradish peroxidase (HRP) is used to produce polyaniline (PANI) from aniline. PANI can be easily detected by differential pulse voltammetry at a working voltage as low as 40 mV (vs. Ag/AgCl) which makes the assay fairly selective. This immunoassay for Cry1Ab has an analytical range from 0.1 to 1000 ng∙mL -1 and a 0.07 ng∙mL -1 lower limit of detection. The average recoveries of the toxin from spiked samples are in the range from 102 to 114 %, with a relative standard deviation of <7.5 %. The results demonstrated that the assay represented an attractive alternative to existing immunoassays in enabling affordable, sensitive, robust and specific determination of this toxin. (author)

  11. Detection of hidden hazelnut protein in food by IgY-based indirect competitive enzyme-immunoassay

    NARCIS (Netherlands)

    Baumgartner, S.; Bremer, M.G.E.G.; Kemmers - Voncken, A.E.M.; Smits, N.G.E.; Haasnoot, W.; Banks, J.; Reece, P.; Danks, C.; Tomkies, V.; Immer, U.; Schmitt, K.; Krska, R.

    2004-01-01

    The development of an indirect competitive enzyme-immunoassay for the detection of hidden hazelnut protein in complex food matrices is described. A sensitive and selective polyclonal antibody was raised by immunisation of laying hens with protein extracts from roasted hazelnuts. In contrast to

  12. Fabrication and characterization of tosyl-activated magnetic and nonmagnetic monodisperse microspheres for use in microfluic-based ferritin immunoassay

    Czech Academy of Sciences Publication Activity Database

    Reymond, F.; Vollet, Ch.; Plichta, Zdeněk; Horák, Daniel

    2013-01-01

    Roč. 29, č. 2 (2013), s. 532-542 ISSN 8756-7938 R&D Projects: GA MŠk 7E12053; GA ČR GAP503/10/0664 EU Projects: European Commission(XE) 246513 - NADINE Institutional support: RVO:61389013 Keywords : biosensors * electrochemistry * immunoassays Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.883, year: 2013

  13. Strip-based immunoassay for the simultaneous detection of the neonicotinoid insecticides imidacloprid and thiamethoxam in agricultural products

    Science.gov (United States)

    A semiquantitative strip immunoassay was developed for the rapid detection of imidacloprid and thiamethoxam in agricultural products using specific nanocolloidal gold-labeled monoclonal antibodies. The conjugates of imidacloprid-BSA and thiamethoxam-BSA and goat anti-mouse IgG were coated on the ni...

  14. Consumer-friendly food allergen detection: moving towards smartphone-based immunoassays.

    Science.gov (United States)

    Ross, Georgina M S; Bremer, Monique G E G; Nielen, Michel W F

    2018-03-26

    In this critical review, we provide a comprehensive overview of immunochemical food allergen assays and detectors in the context of their user-friendliness, through their connection to smartphones. Smartphone-based analysis is centered around citizen science, putting analysis into the hands of the consumer. Food allergies represent a significant worldwide health concern and consumers should be able to analyze their foods, whenever and wherever they are, for allergen presence. Owing to the need for a scientific background, traditional laboratory-based detection methods are generally unsuitable for the consumer. Therefore, it is important to develop simple, safe, and rapid assays that can be linked with smartphones as detectors to improve user accessibility. Smartphones make excellent detection systems because of their cameras, embedded flash functions, portability, connectivity, and affordability. Therefore, this review has summarized traditional laboratory-based methods for food allergen detection such as enzyme-linked-immunosorbent assay, flow cytometry, and surface plasmon resonance, and the potential to modernize these methods by interfacing them with a smartphone readout system, based on the aforementioned smartphone characteristics. This is the first review focusing on smartphone-based food-allergen detection methods designed with the intention of being consumer-friendly. Graphical abstract A smartphone-based food allergen detection system in three easy steps (1) sample preparation, (2) allergen detection on a smartphone using antibodies, which then transmits the data wirelessly, (3) analytical results sent straight to smartphone.

  15. Design of a single-step immunoassay principle based on the combination of an enzyme-labeled antibody release coating and a hydrogel copolymerized with a fluorescent enzyme substrate in a microfluidic capillary device.

    Science.gov (United States)

    Wakayama, Hideki; Henares, Terence G; Jigawa, Kaede; Funano, Shun-ichi; Sueyoshi, Kenji; Endo, Tatsuro; Hisamoto, Hideaki

    2013-11-21

    A combination of an enzyme-labeled antibody release coating and a novel fluorescent enzyme substrate-copolymerized hydrogel in a microchannel for a single-step, no-wash microfluidic immunoassay is demonstrated. This hydrogel discriminates the free enzyme-conjugated antibody from an antigen-enzyme-conjugated antibody immunocomplex based on the difference in molecular size. A selective and sensitive immunoassay, with 10-1000 ng mL(-1) linear range, is reported.

  16. Lateral-flow colloidal gold-based immunoassay for the rapid detection of deoxynivalenol with two indicator ranges

    International Nuclear Information System (INIS)

    Kolosova, Anna Yu.; Sibanda, Liberty; Dumoulin, Frederic; Lewis, Janet; Duveiller, Etienne; Van Peteghem, Carlos; Saeger, Sarah de

    2008-01-01

    A lateral-flow immunoassay using a colloidal gold-labelled monoclonal antibody was developed for the rapid detection of deoxynivalenol (DON). Different parameters, such as the amount of immunoreagents, type of the materials, composition of the blocking solution and of the detector reagent mixture, were investigated to provide the optimum assay performance. The experimental results demonstrated that such a visual test had an indicator range rather than a cut-off value. Thus, tests for DON determination with two different indicator ranges of 250-500 and 1000-2000 μg kg -1 were designed. The method allowed detection of DON at low and high concentration levels, which could be useful for research and practical purposes. The assay applied to spiked wheat and pig feed samples demonstrated accurate and reproducible results. The applicability of the developed lateral-flow test was also confirmed under real field conditions. The test strips prepared in Belgium were sent to Mexico, where they were used for the screening of DON contamination in different bread wheat entries from Fusarium Head Blight inoculated plots. The results were compared with those obtained by ELISA and LC-MS/MS. A poor correlation between ELISA and LC-MS/MS was observed. Visual results of the dipstick tests were in a good agreement with the results of the LC-MS/MS method. Coupled with a simple and fast sample preparation, this qualitative one-step test based on the visual evaluation of results did not require any equipment. Results could be obtained within 10 min. The described assay format can be used as a simple, rapid, cost-effective and robust on-site screening tool for mycotoxin contamination in different agricultural commodities

  17. A bare-eye-based lateral flow immunoassay based on the use of gold nanoparticles for simultaneous detection of three pesticides

    International Nuclear Information System (INIS)

    Wang, Limin; Cai, Jia; Wang, Yulong; Fang, Qingkui; Wang, Suyan; Cheng, Qi; Liu, Fengquan; Du, Dan; Lin, Yuehe

    2014-01-01

    We present a novel lateral flow immunoassay (LFIA) for the simultaneous detection of the pesticides imidacloprid, chlorpyrifos-methyl and isocarbophos based on three competitive immunoreactions. In contrast to previously reported LFIAs, the method is based on the use of four strips. Each has three red channels (three test lines dispensed with different capture reagent) to detect imidacloprid, chlorpyrifos-methyl and isocarbophos respectively. Different channels on each strip are the key to multi-detection, and four strips of LFIA are needed for visual and semi-quantitative read-outs. Under optimized conditions, the LFIA was applied to the determination of three pesticides. The detection time is within 7 min and the detection limits are 50, 100, and 100 μg L −1 , respectively. Furthermore, the LFIA was applied to the analysis of spiked Chinese cabbage and soil samples and results were validated by HPLC. (author)

  18. Development of Immunoassay Based on Monoclonal Antibody Reacted with the Neonicotinoid Insecticides Clothianidin and Dinotefuran

    OpenAIRE

    Uchigashima, Mikiko; Watanabe, Eiki; Ito, Shigekazu; Iwasa, Seiji; Miyake, Shiro

    2012-01-01

    Enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody (MoAb) was developed for the neonicotinoid insecticide clothianidin. A new clothianidin hapten (3-[5-(3-methyl-2-nitroguanidinomethyl)-1,3-thiazol-2-ylthio] propionic acid) was synthesized and conjugated to keyhole limpet hemocyanin, and was used for monoclonal antibody preparation. The resulting MoAb CTN-16A3-13 was characterized by a direct competitive ELISA (dc-ELISA). The 50% of inhibition concentration value with cl...

  19. Label-free immunosensor based on Pd nanoplates for amperometric immunoassay of alpha-fetoprotein.

    Science.gov (United States)

    Wang, Huan; Li, He; Zhang, Yihe; Wei, Qin; Ma, Hongmin; Wu, Dan; Li, Yan; Zhang, Yong; Du, Bin

    2014-03-15

    In this paper, Pd nanoplates were used as a kind of electrode materials for fabrication of an electrochemical immunosensor, which was applied for detection of cancer biomarker alpha-fetoprotein (AFP). Thanks to the unique structure and properties of Pd nanoplates, the antibody of AFP (Ab) was effectively immobilized onto the surface of the Pd nanoplates modified glassy carbon electrode (GCE). Moreover, the good electrochemical properties of Pd nanoplates greatly improved the electronic transmission rate and enhanced the electrochemical signal, which led to an increase of the detection sensitivity. Based on the specific antibody-antigen interaction, a label-free immunosensor based on Pd nanoplates was developed for sensing of AFP. The current method allows us to detect AFP over a wide concentration range from 0.01 to 75.0 ng/mL with a detection limit of 4 pg/mL. The proposed immunosensor has been used to determine AFP in human serum with satisfactory results. © 2013 Elsevier B.V. All rights reserved.

  20. Radiolabelling for immunoassay

    International Nuclear Information System (INIS)

    Chapman, R.S.

    1998-01-01

    Since the early 1960s labelled compounds employed in immunoassay techniques, both radioimmunoassay and immunoradiometric assay, have involved radioisotopes typically 3 H (tritium) and 125 Iodine. With the advent of increasingly stringent governmental regulations regarding usage and disposal of radioisotopes and the impetus of research towards improved immunoassay sensitivity following the discovery of monoclonal antibodies and their application to excess reagent immunometric assay methodology, radioisotopic labels are gradually being replaced by non-isotopic labels: enzyme, fluorescence and chemiluminescence

  1. Development of Immunoassay Based on Monoclonal Antibody Reacted with the Neonicotinoid Insecticides Clothianidin and Dinotefuran

    Directory of Open Access Journals (Sweden)

    Seiji Iwasa

    2012-11-01

    Full Text Available Enzyme-linked immunosorbent assay (ELISA based on a monoclonal antibody (MoAb was developed for the neonicotinoid insecticide clothianidin. A new clothianidin hapten (3-[5-(3-methyl-2-nitroguanidinomethyl-1,3-thiazol-2-ylthio] propionic acid was synthesized and conjugated to keyhole limpet hemocyanin, and was used for monoclonal antibody preparation. The resulting MoAb CTN-16A3-13 was characterized by a direct competitive ELISA (dc-ELISA. The 50% of inhibition concentration value with clothianidin was 4.4 ng/mL, and the working range was 1.5–15 ng/mL. The antibody showed high cross-reactivity (64% to dinotefuran among the structurally related neonicotinoid insecticides. The recovery examinations of clothianidin for cucumber, tomato and apple showed highly agreement with the spiked concentrations; the recovery rate was between 104% and 124% and the coefficient of variation value was between 1.8% and 15%. Although the recovery rate of the dc-ELISA was slightly higher than that of HPLC analysis, the difference was small enough to accept the dc-ELISA as a useful method for residue analysis of clothianidin in garden crops.

  2. An automatic enzyme immunoassay based on a chemiluminescent lateral flow immunosensor.

    Science.gov (United States)

    Joung, Hyou-Arm; Oh, Young Kyoung; Kim, Min-Gon

    2014-03-15

    Microfluidic integrated enzyme immunosorbent assay (EIA) sensors are efficient systems for point-of-care testing (POCT). However, such systems are not only relatively expensive but also require a complicated manufacturing process. Therefore, additional fluidic control systems are required for the implementation of EIAs in a lateral flow immunosensor (LFI) strip sensor. In this study, we describe a novel LFI for EIA, the use of which does not require additional steps such as mechanical fluidic control, washing, or injecting. The key concept relies on a delayed-release effect of chemiluminescence substrates (luminol enhancer and hydrogen peroxide generator) by an asymmetric polysulfone membrane (ASPM). When the ASPM was placed between the nitrocellulose (NC) membrane and the substrate pad, substrates encapsulated in the substrate pad were released after 5.3 ± 0.3 min. Using this delayed-release effect, we designed and implemented the chemiluminescent LFI-based automatic EIA system, which sequentially performed the immunoreaction, pH change, substrate release, hydrogen peroxide generation, and chemiluminescent reaction with only 1 sample injection. In a model study, implementation of the sensor was validated by measuring the high sensitivity C-reactive protein (hs-CRP) level in human serum. © 2013 Elsevier B.V. All rights reserved.

  3. Development of immunoassay based on monoclonal antibody reacted with the neonicotinoid insecticides clothianidin and dinotefuran.

    Science.gov (United States)

    Uchigashima, Mikiko; Watanabe, Eiki; Ito, Shigekazu; Iwasa, Seiji; Miyake, Shiro

    2012-11-15

    Enzyme-linked immunosorbent assay (ELISA) based on a monoclonal antibody (MoAb) was developed for the neonicotinoid insecticide clothianidin. A new clothianidin hapten (3-[5-(3-methyl-2-nitroguanidinomethyl)-1,3-thiazol-2-ylthio] propionic acid) was synthesized and conjugated to keyhole limpet hemocyanin, and was used for monoclonal antibody preparation. The resulting MoAb CTN-16A3-13 was characterized by a direct competitive ELISA (dc-ELISA). The 50% of inhibition concentration value with clothianidin was 4.4 ng/mL, and the working range was 1.5–15 ng/mL. The antibody showed high cross-reactivity (64%) to dinotefuran among the structurally related neonicotinoid insecticides. The recovery examinations of clothianidin for cucumber, tomato and apple showed highly agreement with the spiked concentrations; the recovery rate was between 104% and 124% and the coefficient of variation value was between 1.8% and 15%. Although the recovery rate of the dc-ELISA was slightly higher than that of HPLC analysis, the difference was small enough to accept the dc-ELISA as a useful method for residue analysis of clothianidin in garden crops.

  4. Electrochemistry-based approaches to low cost, high sensitivity, automated, multiplexed protein immunoassays for cancer diagnostics.

    Science.gov (United States)

    Dixit, Chandra K; Kadimisetty, Karteek; Otieno, Brunah A; Tang, Chi; Malla, Spundana; Krause, Colleen E; Rusling, James F

    2016-01-21

    Early detection and reliable diagnostics are keys to effectively design cancer therapies with better prognoses. The simultaneous detection of panels of biomarker proteins holds great promise as a general tool for reliable cancer diagnostics. A major challenge in designing such a panel is to decide upon a coherent group of biomarkers which have higher specificity for a given type of cancer. The second big challenge is to develop test devices to measure these biomarkers quantitatively with high sensitivity and specificity, such that there are no interferences from the complex serum or tissue matrices. Lastly, integrating all these tests into a technology that does not require exclusive training to operate, and can be used at point-of-care (POC) is another potential bottleneck in futuristic cancer diagnostics. In this article, we review electrochemistry-based tools and technologies developed and/or used in our laboratories to construct low-cost microfluidic protein arrays for the highly sensitive detection of a panel of cancer-specific biomarkers with high specificity which at the same time has the potential to be translated into POC applications.

  5. Quantum-Dot-Based Lateral Flow Immunoassay for Detection of Neonicotinoid Residues in Tea Leaves.

    Science.gov (United States)

    Wang, Shuangjie; Liu, Ying; Jiao, Shasha; Zhao, Ying; Guo, Yirong; Wang, Mengcen; Zhu, Guonian

    2017-11-22

    Neonicotinoid insecticides are commonly used for pest control on tea plantations as a result of their broad-spectrum activity. However, neonicotinoid residues released from tea leaves into tea infusions pose a dietary risk to consumers. Therefore, a rapid, sensitive, and reliable on-site detection method for neonicotinoids is needed. We developed a quantum-dot-based fluorescent lateral flow immunochromatographic strip (LFICS) combined with a broad-specific antibody for detection of typical neonicotinoids (imidacloprid, imidaclothiz, and clothianidin), with sensitivities [50% inhibitory concentration (IC 50 )] of 0.104-0.33 ng/mL and visual detection limits of 0.5-1 ng/mL. The strip assay could be completed in less than 30 min. Using the LFICS to analyze spiked tea samples (green tea, black tea, and oolong tea), the average recovery of the three neonicotinoids ranged between 71 and 111%, with the coefficient of variation below 12%. The results from the LFICS tests for field samples were consistent with results from ultraperformance liquid chromatography-tandem mass spectrometry. The newly developed strip is a useful tool for the on-site detection of neonicotinoid residues in tea.

  6. The Sound of Stigmatization: Sonic Habitus, Sonic Styles, and Boundary Work in an Urban Slum.

    Science.gov (United States)

    Schwarz, Ori

    2015-07-01

    Based on focus groups and interviews with student renters in an Israeli slum, the article explores the contributions of differences in sonic styles and sensibilities to boundary work, social categorization, and evaluation. Alongside visual cues such as broken windows, bad neighborhoods are characterized by sonic cues, such as shouts from windows. Students understand "being ghetto" as being loud in a particular way and use loudness as a central resource in their boundary work. Loudness is read as a performative index of class and ethnicity, and the performance of middle-class studentship entails being appalled by stigmatized sonic practices and participating in their exoticization. However, the sonic is not merely yet another resource of boundary work. Paying sociological attention to senses other than vision reveals complex interactions between structures anchored in the body, structures anchored in language, and actors' identification strategies, which may refine theorizations of the body and the senses in social theory.

  7. The fabrication of magnetic particle-based chemiluminescence immunoassay for human epididymis protein-4 detection in ovarian cancer.

    Science.gov (United States)

    Fu, Xiaoling; Liu, Yangyang; Qiu, Ruiyun; Foda, Mohamed F; Zhang, Yong; Wang, Tao; Li, Jinshan

    2018-03-01

    The magnetic particles have a significant influence on the immunoassay detection and cancer therapy. Herein, the chemiluminescence immunoassay combined with the magnetic particles (MPCLIA) was presented for the clinical determination and analysis of human epididymis protein 4 (HE4) in the human serum. Under the optimized experiment conditions, the secure MPCLIA method can detect HE4 in the broader range of 0-1000 pmol/L, with a lower detection limit of 1.35 pmol/L. The satisfactory recovery rate of the method in the serum ranged from 83.62% to 105.10%, which was well within the requirement of clinical analysis. Moreover, the results showed the good correlation with enzyme-linked immunosorbent assay (ELISA), with the correlation coefficient of 0.9589. This proposed method has been successfully applied to the clinical determination of HE4 in the human serum.

  8. Europium(III) chelate-dyed nanoparticles as donors in a homogeneous proximity-based immunoassay for estradiol

    International Nuclear Information System (INIS)

    Kokko, Leena; Sandberg, Kaisa; Loevgren, Timo; Soukka, Tero

    2004-01-01

    Nanoparticles containing thousands of fluorescent europium(III) chelates have a very high specific activity compared to traditional lanthanide chelate labels. It can be assumed that if these particles are used in a homogeneous assay as donors, multiple chelates can excite a single acceptor in turns and the energy transfer to the acceptor is increased. The principle was employed in an immunoassay using luminescent resonance energy transfer from a long lifetime europium(III) chelate-dyed nanoparticle to a short lifetime, near-infrared fluorescent molecule. Due to energy transfer fluorescence lifetime of the sensitised emission was prolonged and fluorescence could be measured using a time-resolved detection. A competitive homogeneous immunoassay for estradiol was created using 92 nm europium(III) chelate-dyed nanoparticle coated with 17β-estradiol specific recombinant antibody Fab fragments as a donor and estradiol conjugated with near-infrared dye AlexaFluor 680 as an acceptor. The density of Fab fragments on the surface of the particle influenced the sensitivity of the immunoassay. The optimal Fab density was reached when the entire surface of the particle participated in the energy transfer, but the areas where the energy was transferred to a single acceptor, did not overlap. We were able to detect estradiol concentrations down to 70 pmol l -1 (3xSD of a standard containing 0 nmol l -1 of E2) using a 96-well platform. In this study we demonstrated that nanoparticles containing lanthanide chelates could be used as efficient donors in homogeneous assays

  9. Novel photoluminescence enzyme immunoassay based on supramolecular host-guest recognition using L-arginine/6-aza-2-thiothymine-stabilized gold nanocluster.

    Science.gov (United States)

    Wang, Youmei; Lu, Minghua; Tang, Dianping

    2018-06-30

    A new photoluminescence (PL) enzyme immunoassay was designed for sensitive detection of aflatoxin B 1 (AFB 1 ) via an innovative enzyme substrate, 6-aza-2-thiothymine-stabilized gold nanocluster (AAT-AuNC) with L-arginine. The enzyme substrate with strong PL intensity was formed through supramolecular host-guest assembly between guanidine group of L-arginine and AAT capped on the surface of AuNC. Upon arginase introduction, the captured L-arginine was hydrolyzed into ornithine and urea, thus resulting in the decreasing PL intensity. Based on this principle, a novel competitive-type immunoreaction was first carried out on AFB 1 -bovine serum albumin (AFB 1 -BSA) conjugate-coated microplate, using arginase-labeled anti-AFB 1 antibody as the competitor. Under the optimum conditions, the PL intensity increased with the increment of target AFB 1 , and allowed the detection of the analyte at concentrations as low as 3.2 pg mL -1 (ppt). Moreover, L-arginine-AAT-AuNC-based PL enzyme immunoassay afforded good reproducibility and acceptable specificity. In addition, the accuracy of this methodology, referring to commercial AFB 1 ELISA kit, was evaluated to analyze naturally contaminated or spiked peanut samples, giving well-matched results between two methods, thus representing a useful scheme for practical application in quantitative monitoring of mycotoxins in foodstuff. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Comparison among performances of a ligase chain reaction-based assay and two enzyme immunoassays in detecting Chlamydia trachomatis in urine specimens from men with nongonococcal urethritis.

    Science.gov (United States)

    Deguchi, T; Yasuda, M; Uno, M; Tada, K; Iwata, H; Komeda, H; Maeda, S; Latila, V; Saito, I; Kawada, Y

    1996-01-01

    We evaluated the performances of a ligase chain reaction (LCR)-based assay and two enzyme immunoassays (Chlamydiazyme and IDEIA) in the detection of Chlamydia trachomatis in urine specimens. We compared the results of testing urine specimens by these assays with those of urethral swab culture by examining samples from 131 men with nongonococcal urethritis. Discrepant results were analyzed by testing urethral swab specimens for C. trachomatis by a PCR-based assay. After the resolution of discrepant results, the sensitivity of urethral swab culture was 85.3%, whereas those of the LCR assay, Chlamydiazyme, and IDEIA with urine specimens were 94.1, 82.4, and 94.1%, respectively. The LCR assay and IDEIA were more sensitive than was urethral swab culture. In addition, the LCR assay, with a sensitivity equal to that of IDEIA, was more specific. Overall, the LCR assay proved to be superior to the enzyme immunoassays in detecting C. trachomatis in urine specimens. Testing urine specimens by LCR assay should be a helpful alternative method for diagnosing C. trachomatis urethral infection in men with nongonococcal urethritis. PMID:8784574

  11. Magnetic Particle-Based Immunoassay of Phosphorylated p53 Using Protein-Cage Templated Lead Phosphate and Carbon Nanospheres for Signal Amplification

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Aiqiong; Bao, Yuanwu; Ge, Xiaoxiao; Shin, Yongsoon; Du, Dan; Lin, Yuehe

    2012-11-20

    Phosphorylated p53 at serin 15 (phospho-p53-15) is a potential biomarker of Gamma-radiation exposure. In this paper, we described a new magnetic particles (MPs)-based electrochemical immunoassay of human phospho-p53-15 using carbon nanospheres (CNS) and protein-cage templated lead phosphate nanoparticles for signal amplification. Greatly enhanced sensitivity was achieved by three aspects: 1) The protein-cage nanoparticle (PCN) and p53-15 signal antibody (p53-15 Ab2) are linked to CNS (PCNof each apoferritin; 3) MPs capture a large amount of primary antibodies. Using apoferritin templated metallic phosphate instead of enzyme as label has the advantage of eliminating the addition of mediator or immunoreagents and thus makes the immunoassay system simpler. The subsequent stripping voltammetric analysis of the released lead ions were detected on a disposable screen printed electrode. The response current was proportional to the phospho-p53-15 concentration in the range of 0.02 to 20 ng mL-1 with detection limit of 0.01 ng mL-1. This method shows a good stability, reproducibility and recovery.

  12. The immunoassay handbook

    National Research Council Canada - National Science Library

    Wild, David (David G.)

    2001-01-01

    ... importantly, enabling them to keep current on the basic theory behind immunoassay. Since the publication of the previous edition in 1994, the field has continued to evolve rapidly, and the need for a fully updated version of this book is now paramount. The second edition has been comprehensively updated and new chapters have been added to each section" [publisher's web site].

  13. Paper mechanisms for sonic interaction

    DEFF Research Database (Denmark)

    Delle Monache, Stefano; Rocchesso, Davide; Qi, Ji

    2012-01-01

    Introducing continuous sonic interaction in augmented pop-up books enhances the expressive and performative qualities of movables, making the whole narrative experience more engaging and personal. The SaMPL Spring School on Sounding Popables explored the specific topic of paper-driven sonic...

  14. Rapid and sensitive lateral flow immunoassay method for determining alpha fetoprotein in serum using europium (III) chelate microparticles-based lateral flow test strips

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Rong-Liang; Xu, Xu-Ping; Liu, Tian-Cai; Zhou, Jian-Wei; Wang, Xian-Guo; Ren, Zhi-Qi [Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou 510515, Guangdong (China); Hao, Fen [DaAn Gene Co. Ltd. of Sun Yat-sen University, 19 Xiangshan Road, Guangzhou 510515 (China); Wu, Ying-Song, E-mail: wg@smu.edu.cn [Institute of Antibody Engineering, School of Biotechnology, Southern Medical University, Guangzhou 510515, Guangdong (China)

    2015-09-03

    Alpha-fetoprotein (AFP), a primary marker for many diseases including various cancers, is important in clinical tumor diagnosis and antenatal screening. Most immunoassays provide high sensitivity and accuracy for determining AFP, but they are expensive, often complex, time-consuming procedures. A simple and rapid point-of-care system that integrates Eu (III) chelate microparticles with lateral flow immunoassay (LFIA) has been developed to determine AFP in serum with an assay time of 15 min. The approach is based on a sandwich immunoassay performed on lateral flow test strips. A fluorescence strip reader was used to measure the fluorescence peak heights of the test line (H{sub T}) and the control line (H{sub C}); the H{sub T}/H{sub C} ratio was used for quantitation. The Eu (III) chelate microparticles-based LFIA assay exhibited a wide linear range (1.0–1000 IU mL{sup −1}) for AFP with a low limit of detection (0.1 IU mL{sup −1}) based on 5ul of serum. Satisfactory specificity and accuracy were demonstrated and the intra- and inter-assay coefficients of variation (CV) for AFP were both <10%. Furthermore, in the analysis of human serum samples, excellent correlation (n = 284, r = 0.9860, p < 0.0001) was obtained between the proposed method and a commercially available CLIA kit. Results indicated that the Eu (III) chelate microparticles-based LFIA system provided a rapid, sensitive and reliable method for determining AFP in serum, indicating that it would be suitable for development in point-of-care testing. - Highlights: • Europium (III) chelate microparticles was used as a label for LIFA. • Quantitative detection by using H{sub T}/H{sub C} ratio was achieved. • LIFA for simple and rapid AFP detection in human serum. • The sensitivity and linearity was more excellent compared with QD-based ICTS. • This method could be developed for rapid point-of-care screening.

  15. Fluorometric immunoassay for human serum albumin based on its inhibitory effect on the immunoaggregation of quantum dots with silver nanoparticles

    Science.gov (United States)

    Marukhyan, Seda S.; Gasparyan, Vardan K.

    2017-02-01

    Quantitative determination of HSA was conducted by competitive immunoassay. Inhibition of aggregation of antibody conjugated quantum dots (QD) with albumin conjugated silver nanoparticles (AgNPs) in the presence of HSA was conducted. If antibody-loaded CdSe QDs aggregate with HSA-coated silver nanoparticles the distance between the two kinds of nanoparticles will be reduced enough to cause fluorescence resonance energy transfer (FRET). In this case the yellow fluorescence of the Ab-QDs is quenched. However if HSA (antigen) is added to the Ab-QDs their surface will be blocked and they cannot aggregate any longer with the HSA-AgNPs. Hence, fluorescence will not be quenched. The drop of the intensity of fluorescence (peaking at 570 nm) is inversely correlated with the concentration of HSA in the sample. The method allows to determine HSA in the 30-600 ng·mL-1 concentration range.

  16. Femtomolar detection of 2,4-dichlorophenoxyacetic acid herbicides via competitive immunoassays using microfluidic based carbon nanotube liquid gated transistor.

    Science.gov (United States)

    Wijaya, I Putu Mahendra; Nie, Tey Ju; Gandhi, Sonu; Boro, Robin; Palaniappan, Alagappan; Hau, Goh Wei; Rodriguez, Isabel; Suri, C Raman; Mhaisalkar, Subodh G

    2010-03-07

    Monitoring of environmental pollutants has become increasingly important due to concern over potential health and environmental impact inflicted by these chemicals. In this contribution, we focus on the development of an all-plastic biosensor comprising laminated single-walled carbon nanotubes as the active element and its conductance modulation in a liquid-gated field effect transistor, as the principle of transduction, for the detection of 2,4-dicholorophenoxy acetic acid (2,4-D) herbicide. The reported biosensor is capable of performing real-time label-free detection of analytes in liquid environment. This biosensor which relies on immunoassay principle for specificity is able to detect down to 500 fM levels of 2,4-D in soil samples.

  17. A robust quantitative solid phase immunoassay for the acute phase protein C-reactive protein (CRP) based on cytidine 5 '-diphosphocholine coupled dendrimers

    DEFF Research Database (Denmark)

    Heegaard, Peter M. H.; Pedersen, H. G.; Jensen, A. L.

    2009-01-01

    C-reactive protein (CRP) is an important acute phase protein, being used as a sensitive indicator of inflammation and infection and is also associated with the risk of cardiovascular problems. The present paper describes a robust and sensitive ELISA for CRP, based on the affinity of CRP for phosp......C-reactive protein (CRP) is an important acute phase protein, being used as a sensitive indicator of inflammation and infection and is also associated with the risk of cardiovascular problems. The present paper describes a robust and sensitive ELISA for CRP, based on the affinity of CRP...... was applied to determination of pig and human CRP using commercially available antibodies against human CRP. The assay was shown to be more sensitive than previously published immunoassays employing albumin-coupled cytidine diphosphocholine. The coating was stable for at least 30 days at room temperature...

  18. Proximity hybridization-regulated catalytic DNA hairpin assembly for electrochemical immunoassay based on in situ DNA template-synthesized Pd nanoparticles

    International Nuclear Information System (INIS)

    Zhou, Fuyi; Yao, Yao; Luo, Jianjun; Zhang, Xing; Zhang, Yu; Yin, Dengyang; Gao, Fenglei; Wang, Po

    2017-01-01

    Novel hybridization proximity-regulated catalytic DNA hairpin assembly strategy has been proposed for electrochemical immunoassay based on in situ DNA template-synthesized Pd nanoparticles as signal label. The DNA template-synthesized Pd nanoparticles were characterized with atomic force microscopic and X-ray photoelectron spectroscopy. The highly efficient electrocatalysis by DNA template synthesized Pd nanoparticles for NaBH 4 oxidation produced an intense detection signal. The label-free electrochemical method achieved the detection of carcinoembryonic antigen (CEA) with a linear range from 10 −15 to 10 −11  g mL −1 and a detection limit of 0.43 × 10 −15  g mL −1 . Through introducing a supersandwich reaction to increase the DNA length, the electrochemical signal was further amplified, leading to a detection limit of 0.52 × 10 −16  g mL −1 . And it rendered satisfactory analytical performance for the determination of CEA in serum samples. Furthermore, it exhibited good reproducibility and stability; meanwhile, it also showed excellent specificity due to the specific recognition of antigen by antibody. Therefore, the DNA template synthesized Pd nanoparticles based signal amplification approach has great potential in clinical applications and is also suitable for quantification of biomarkers at ultralow level. - Graphical abstract: A novel label-free and enzyme-free electrochemical immunoassay based on proximity hybridization-regulated catalytic DNA hairpin assemblies for recycling of the CEA. - Highlights: • A novel enzyme-free electrochemical immunosensor was developed for detection of CEA. • The signal amplification was based on catalytic DNA hairpin assembly and DNA-template-synthesized Pd nanoparticles. • The biosensor could detect CEA down to 0.52 × 10 −16  g mL −1 level with a dynamic range spanning 5 orders of magnitude.

  19. Chemiluminescence immunoassay for chloramphenicol

    International Nuclear Information System (INIS)

    Lin Si; Xu Wenge; Liu Yibing

    2007-06-01

    A simple, solid-phase chemiluminescence immunoassay (CLIA) for the measurement of Chloramphenicol(CAP) in foodstuffs is described. A rabbit anti-CAP IgG is passively adsorbed onto the walls of polypropylene plates. The labeled conjugant is horseradish peroxidase(HRP) conjugate of CAP. Luminol solution is used as the substrate of HRP. The light yield is inversely proportional to the concentration of CAP. The method has a similar sensitivity (0.05 ng/mL), specificity, precision, and accuracy to a conventional enzyme immunoassay (EIA). The intra-assay and inter-assay CVs of ten samples were <8 and <20%, respectively, and the analytical recovery of the method was 87% 100%. The experimental correlation coefficient of dilution was found to be 0.999 using milk supernatant as buffer. The assay range for the method was 0.1-10 ng/mL, and it displayed good linearity. (authors)

  20. The sonic borehole logging tool

    International Nuclear Information System (INIS)

    Oelgaard, P.L.

    1990-09-01

    This report deals with the sonic borehole tool. First a review of the various elastic wave types is given and velocity values of compressional waves in various materials listed. Next follows a discussion of 3 models for the relation between transit time and porosity, and a comparison between the 3 models is made. The design of sonic tools is described including their geometry. The path of the sonic signals is discussed. Also the effect of environmental factors on the results of the tools are considered. Finally a number of applications are described. In two appendices the mechanics of deformable bodies and formulas for the velocity of sound are reviewed. (author)

  1. A novel fluorescence immunoassay for the sensitive detection of Escherichia coli O157:H7 in milk based on catalase-mediated fluorescence quenching of CdTe quantum dots.

    Science.gov (United States)

    Chen, Rui; Huang, Xiaolin; Li, Juan; Shan, Shan; Lai, Weihua; Xiong, Yonghua

    2016-12-01

    Immunoassay is a powerful tool for rapid detection of food borne pathogens in food safety monitoring. However, conventional immunoassay always suffers from low sensitivity when it employs enzyme-catalyzing chromogenic substrates to generate colored molecules as signal outputs. In the present study, we report a novel fluorescence immunoassay for the sensitive detection of E. coli O157:H7 through combination of the ultrahigh bioactivity of catalase to hydrogen peroxide (H 2 O 2 ) and H 2 O 2 -sensitive mercaptopropionic acid modified CdTe QDs (MPA-QDs) as a signal transduction. Various parameters, including the concentrations of anti-E. coli O157:H7 polyclonal antibody and biotinylated monoclonal antibody, the amounts of H 2 O 2 and streptavidin labeled catalase (CAT), the hydrolysis temperature and time of CAT to H 2 O 2 , as well as the incubation time between H 2 O 2 and MPA-QDs, were systematically investigated and optimized. With optimal conditions, the catalase-mediated fluorescence quenching immunoassay exhibits an excellent sensitivity for E. coli O157:H7 with a detection limit of 5 × 10 2  CFU/mL, which was approximately 140 times lower than that of horseradish peroxidase-based colorimetric immunoassay. The reliability of the proposed method was further evaluated using E. coli O157:H7 spiked milk samples. The average recoveries of E. coli O157:H7 concentrations from 1.18 × 10 3  CFU/mL to 1.18 × 10 6  CFU/mL were in the range of 65.88%-105.6%. In brief, the proposed immunoassay offers a great potential for rapid and sensitive detection of other pathogens in food quality control. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. State of the art of sonic boom modeling

    Science.gov (United States)

    Plotkin, Kenneth J.

    2002-01-01

    Based on fundamental theory developed through the 1950s and 1960s, sonic boom modeling has evolved into practical tools. Over the past decade, there have been requirements for design tools for an advanced supersonic transport, and for tools for environmental assessment of various military and aerospace activities. This has resulted in a number of advances in the understanding of the physics of sonic booms, including shock wave rise times, propagation through turbulence, and blending sonic boom theory with modern computational fluid dynamics (CFD) aerodynamic design methods. This article reviews the early fundamental theory, recent advances in theory, and the application of these advances to practical models.

  3. Quantitation of estrogen receptor in seventy-five specimens of breast cancer: comparison between an immunoassay (Abbott ER-EIA monoclonal) and a [3H]estradiol binding assay based on isoelectric focusing in polyacrylamide gel

    International Nuclear Information System (INIS)

    Pousette, A.; Gustafsson, S.A.; Thoernblad, A.M.N.; Nordgren, A.; Saellstroem, J.Li.; Lindgren, A.; Sundelin, P.; Gustafsson, J.A.

    1986-01-01

    Quantitation of estrogen receptor has been performed in cytosol prepared from 75 specimens of breast cancer tissue from patients who had not received hormonal therapy. The study was performed in order to compare an immunoassay (Abbott Laboratories, North Chicago, IL) with our currently used method for estrogen receptor analysis based on isoelectric focusing of [ 3 H]estradiol-receptor complex in polyacrylamide gels. Using linear regression analysis, a regression coefficient (slope) of 1.30 and a correlation coefficient of 0.75 were calculated. The differences in results between the two methods are probably partly explained by the fact that the ligand-based method only measures unoccupied receptor, whereas the immunoassay detects the total amount of receptor, resulting in generally slightly higher concentrations with the latter method. However, in five of 75 specimens the ligand-based method gave a considerably higher concentration of estrogen receptor. This was most probably explained by partial proteolysis resulting in the formation of receptor fragment(s), which was undetectable with the immunoassay but detectable with the ligand-based method. These observations underline the importance of careful handling of specimens during the whole immunoassay procedure

  4. Acoustic transparency in two-dimensional sonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Dehesa, Jose; Torrent, Daniel [Wave Phenomena Group, Department of Electronic Engineering, Polytechnic University of Valencia, C/ Camino de Vera s/n, E-46022 Valencia (Spain); Cai Liangwu [Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)], E-mail: jsdehesa@upvnet.upv.es

    2009-01-15

    Acoustic transparency is studied in two-dimensional sonic crystals consisting of hexagonal distributions of cylinders with continuously varying properties. The transparency condition is achieved by selectively closing the acoustic bandgaps, which are governed by the structure factor of the cylindrical scatterers. It is shown here that cylindrical scatterers with the proposed continuously varying properties are physically realizable by using metafluids based on sonic crystals. The feasibility of this proposal is analyzed by a numerical experiment based on multiple scattering theory.

  5. A High-Performance Fluorescence Immunoassay Based on the Relaxation of Quenching, Exemplified by Detection of Cardiac Troponin I

    Directory of Open Access Journals (Sweden)

    Seung-Wan Kim

    2016-05-01

    Full Text Available The intramolecular fluorescence self-quenching phenomenon is a major drawback in developing high-performance fluorometric biosensors which use common fluorophores as signal generators. We propose two strategies involving liberation of the fluorescent molecules by means of enzymatic fragmentation of protein or dehybridization of double-stranded DNA. In the former, bovine serum albumin (BSA was coupled with the fluorescent BODIPY dye (Red BSA, and then immobilized on a solid surface. When the insolubilized Red BSA was treated with proteinase K (10 units/mL for 30 min, the fluorescent signal was significantly increased (3.5-fold compared to the untreated control. In the second case, fluorophore-tagged DNA probes were linked to gold nanoparticles by hybridization with capture DNA strands densely immobilized on the surface. The quenched fluorescence signal was recovered (3.7-fold by thermal dehybridization, which was induced with light of a specific wavelength (e.g., 530 nm for less than 1 min. We next applied the Red BSA self-quenching relaxation technique employing enzymatic fragmentation to a high-performance immunoassay of cardiac troponin I (cTnI in a microtiter plate format. The detection limit was 0.19 ng/mL cTnI, and the fluorescent signal was enhanced approximately 4.1-fold compared with the conventional method of direct measurement of the fluorescent signal from a non-fragmented fluorophore-labeled antibody.

  6. Ultrasensitive colorimetric immunoassay for hCG detection based on dual catalysis of Au@Pt core-shell nanoparticle functionalized by horseradish peroxidase

    Science.gov (United States)

    Wang, Weiguo; Zou, Yake; Yan, Jinwu; Liu, Jing; Chen, Huixiong; Li, Shan; Zhang, Lei

    2018-03-01

    In this paper, an ultrasensitive colorimetric biosensor for human chorionic gonadotrophin (hCG) detection was designed from bottom-up method based on the dual catalysis of the horseradish peroxidase (HRP) and Au@Pt nanoparticles (NPs) relative to H2O2-TEM system. HRP and monoclonal mouse anti-hCG antibody (β-submit, mAb1) were co-immobilized onto the Au@Pt NP surface to improve catalytic efficiency and specificity, which formed a dual functionalized Au@Pt-HRP probe with the mean size of 42.8 nm (D50). The colorimetric immunoassay was developed for the hCG detection, and the Au@Pt-HRP probe featured a higher sensitivity in the concentration range of 0.4-12.8 IU L- 1 with a low limit of detection (LOD) of 0.1 IU L- 1 compared with the LODs of 0.8 IU L- 1 for BA-ELISA and of 2.0 IU L- 1 for Au@Pt, which indicated that the Au@Pt-HRP probe possessed higher catalytic efficiency with 2.8-fold increase over Au@Pt and 33.8-fold increase over HRP. Also, the Au@Pt-HRP probe exhibited good precision and reproducibility, high specificity and acceptable accuracy with CV being less than 15%. The dual functionalized Au@Pt-HRP probe as a type of signal amplified method was firstly applied in the colorimetric immunoassay for the hCG detection.

  7. Quantum dots-based lateral flow immunoassay combined with image analysis for semiquantitative detection of IgE antibody to mite

    Directory of Open Access Journals (Sweden)

    Zhao Y

    2017-07-01

    Full Text Available Yan Zhao,1,* Qiang Zhang,2,* Qingfeng Meng,3 Fenglian Wu,4 Lihua Zhang,1 Yao Tang,1 Yuanyuan Guan,1 Lixin An1 1Department of Allergy, The First Affiliated Hospital, Harbin Medical University, Harbin, 2Department of Otorhinolaryngology Head and Neck Surgery, The Affiliated Yantai Yuhuangding Hospital, Qingdao University, Yantai, 3Department of Ophthalmology, The First Affiliated Hospital, Harbin Medical University, Harbin, 4Department of Burn and Plastic Surgery, The First Affiliated Hospital of Qinhuangdao, Qinhuangdao, People’s Republic of China *These authors contributed equally to this work Abstract: Semiquantitative and rapid detection of specific IgE (sIgE with well clinical relevance to house dust mite (HDM are promising for prevalence rhinitis and asthma patients due to the increasing air pollution. However, the conventional IgE measurement systems are time-consuming, complicated and require special instruments. Herein, we overcome the above limitations of sIgE to HDM detection system by developing a quantum dot nanobeads-based lateral flow immunoassay and an image analysis procedure. The proposed detection system could semiquantitatively measure the IgE in a linear range of 0.2–10 U/mL. Moreover, there is a well correlation between the developed detection system and the clinical symptoms by a comparison study using 56 positive patients’ sera and 40 healthy control sera. The proposed detection system is simple, robust and easy-to-use and promising for in home test. Keywords: lateral flow immunoassay, quantum dots, house dust mite, IgE 

  8. A new strategy for label-free electrochemical immunoassay based on “gate-effect” of β-cyclodextrin modified electrode

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Huan [College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004 (China); Li, Jianping, E-mail: likianping@263.net [College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004 (China); Zhang, Yun; Pan, Hongcheng [College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004 (China); Xu, Guobao, E-mail: guobaoxu@ciac.ac.cn [College of Chemistry and Bioengineering, Guilin University of Technology, Guilin 541004 (China); State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2016-07-05

    A novel label-free electrochemical immunoassay was developed for prostate-specific antigen (PSA) detection via using β-cyclodextrin (β-CD) assembled layer created gates for the electron transfer of probe. To construct the sensor, a gold electrode was self-assembled with monoclonal anti-PSA antibody labeled 6-mercapto-β-cyclodextrin. Interspaces among β-CD molecules in the layer were automatically formed on gold electrode, which act as the channel of the electron transfer of [Fe(CN){sub 6}]{sup 3−/4−} probe. When PSA bind with anti-PSA, it can block these channels on the electrode surface due to their steric hindrance effect, resulting in the decrease in redox current of the probe. Through such a gate-controlled effect, ultra trace amount of PSA may make the currents change greatly after the immunoreaction, which enhanced the signal-to-noise ratio to achieve the amplification effect. By evaluating the logarithm of PSA concentrations, the immunosensor had a good linear response to the current changes with a detection limit of 0.3 pg/mL (S/N = 3) when PSA concentration ranged from 1.0 pg/mL to 1.0 ng/mL. The label-free immunosensor exhibited satisfactory performances in sensitivity, repeatability as well as specificity. - Highlights: • A label-free PSA immunoassay was developed based on “gate-effect” amplification. • Interspaces among β-CD assembled for [Fe(CN){sub 6}]{sup 3−/4−} electron transfer were controlled by the immunoreaction. • Higher sensitivity was achieved with time and cost saving principle.

  9. Determination of avian influenza A (H9N2) virions by inductively coupled plasma mass spectrometry based magnetic immunoassay with gold nanoparticles labeling

    Science.gov (United States)

    Xiao, Guangyang; Chen, Beibei; He, Man; Shi, Kaiwen; Zhang, Xing; Li, Xiaoting; Wu, Qiumei; Pang, Daiwen; Hu, Bin

    2017-12-01

    Avian influenza viruses are the pathogens of global poultry epidemics, and may even cause the human infections. Here, we proposed a novel inductively coupled plasma mass spectrometry (ICP-MS) based immunoassay with gold nanoparticles (Au NPs) labeling for the determination of H9N2 virions. Magnetic-beads modified with anti-influenza A H9N2 hemagglutinin mono-antibody (mAb-HA) were utilized for the capture of H9N2 virions in complex matrix; and Au NPs conjugated with mAb-HA were employed for the specific labeling of H9N2 virions for subsequent ICP-MS detection. With a sandwich immunoassay strategy, this method exhibited a high specificity for H9N2 among other influenza A virions such as H1N1 and H3N2. Under the optimized conditions, this method could detect as low as 0.63 ng mL- 1 H9N2 virions with the linear range of 2-400 ng mL- 1, the relative standard deviation for seven replicate detections of H9N2 virions was 7.2% (c = 10 ng mL- 1). The developed method was applied for the detection of H9N2 virions in real-world chicken dung samples, and the recovery for the spiking samples was 91.4-116.9%. This method is simple, rapid, sensitive, selective, reliable and has a good application potential for virions detection in real-world samples.

  10. Functionalized gold nanorod-based labels for amplified electrochemical immunoassay of E. coli as indicator bacteria relevant to the quality of dairy product.

    Science.gov (United States)

    Zhang, Xinai; Zhang, Fan; Zhang, Hongyin; Shen, Jianzhong; Han, En; Dong, Xiaoya

    2015-01-01

    In this paper, we report an amplified electrochemical immunoassay for Escherichia coli as indicator bacteria relevant to the quality of dairy product using the functionalized gold nanorod-based labels ({dAb-AuNR-FCA}). The {dAb-AuNR-FCA} labels were designed by exploiting silica-functionalized gold nanorods (AuNR@SiO2) as the carriers for immobilization of detection antibody (dAb) and ferrocenecarboxylic acid (FCA), in which dAb was used for recognition of E. coli and FCA tags served as signal-generating molecule. Greatly amplified signal was achieved in the sandwich-type immunoassay when enormous FCA linked to AuNR@SiO2. Compared with the commercially available {dAb-FCA}, the {dAb-AuNR-FCA} labels exhibited a better performance for E. coli assay due to the advantages of AuNR@SiO2 as carriers. Under optimal experimental conditions, it showed a linear relationship between the peak current of FCA and the logarithmic value of E. coli concentration ranging from 1.0×10(2) to 5.0×10(4) cfu mL(-1) with a detection limit of 60 cfu mL(-1) (S/N=3), and the electrochemical detection of E. coli could be achieved in 3h. Moreover, the proposed strategy was used to determine E. coli in dairy product (pure fresh milk, yogurt in shelf-life, and expired yogurt), and the recoveries of standard additions were in the range of 95.1-106%. This proposed strategy exhibited rapid response, high sensitivity and specificity for E. coli assay in dairy product, and could become a promising technique to estimate the quality of dairy product. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. An ultrasensitive chemiluminescence immunoassay for fumonisin B1 detection in cereals based on gold-coated magnetic nanoparticles.

    Science.gov (United States)

    Jie, Mingsha; Yu, Songcheng; Yu, Fei; Liu, Lie; He, Leiliang; Li, Yanqiang; Zhang, Hongquan; Qu, Lingbo; Harrington, Peter de B; Wu, Yongjun

    2018-07-01

    In the present study, a novel highly sensitive magnetic enzyme chemiluminescence immunoassay (MECLIA) was developed to detect fumonisin B 1 (FB 1 ) in cereal samples. The gold-coated magnetic nanoparticles (Fe 3 O 4 @Au, GoldMag) were used as solid phase carrier to develop a competitive CLIA for detecting FB 1 , in which FB 1 in samples would compete with FB 1 -ovalbumin coated on the surface of Fe 3 O 4 @Au nanoparticles for binding with FB 1 antibodies. Successively, horseradish peroxidase labeled goat anti-rabbit IgG (HRP-IgG) was conjugated with FB 1 antibodies on the microplate. In substrate solution containing luminol and H 2 O 2 , HRP-IgG catalyzed luminol oxidation by H 2 O 2 , generating a high chemiluminescence signal. The FB 1 immune GoldMag particles were characterized by Fourier transform infrared spectroscopy, scanning electron microscope and zeta potential analysis, etc. RESULTS: The concentrations and the reaction times of these immunoreagents were optimized to improve the performances of this method. The established method could detect as low as 0.027 ng mL -1 FB 1 from 0.05 ng mL -1 to 25 ng mL -1 , demonstrating little cross-reaction (less than 2.4%) with other structurally related compounds. The average intrassay relative SD (RSD) (n = 6) was 3.4% and the average interassay RSD (n = 6) was 5.4%. This method was successfully applied for the determination of FB 1 in corn and wheat and gave recoveries of between 98-110% and 91-105%, respectively. The results of the present study suggest that the MECLIA approach has potential application for high-throughput fumonisin screening in cereals. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  12. Development of improved enzyme-based and lateral flow immunoassays for rapid and accurate serodiagnosis of canine brucellosis.

    Science.gov (United States)

    Cortina, María E; Novak, Analía; Melli, Luciano J; Elena, Sebastián; Corbera, Natalia; Romero, Juan E; Nicola, Ana M; Ugalde, Juan E; Comerci, Diego J; Ciocchini, Andrés E

    2017-09-01

    Brucellosis is a widespread zoonotic disease caused by Brucella spp. Brucella canis is the etiological agent of canine brucellosis, a disease that can lead to sterility in bitches and dogs causing important economic losses in breeding kennels. Early and accurate diagnosis of canine brucellosis is central to control the disease and lower the risk of transmission to humans. Here, we develop and validate enzyme and lateral flow immunoassays for improved serodiagnosis of canine brucellosis using as antigen the B. canis rough lipopolysaccharide (rLPS). The method used to obtain the rLPS allowed us to produce more homogeneous batches of the antigen that facilitated the standardization of the assays. To validate the assays, 284 serum samples obtained from naturally infected dogs and healthy animals were analyzed. For the B. canis-iELISA and B. canis-LFIA the diagnostic sensitivity was of 98.6%, and the specificity 99.5% and 100%, respectively. We propose the implementation of the B. canis-LFIA as a screening test in combination with the highly accurate laboratory g-iELISA. The B. canis-LFIA is a rapid, accurate and easy to use test, characteristics that make it ideal for the serological surveillance of canine brucellosis in the field or veterinary laboratories. Finally, a blind study including 1040 serum samples obtained from urban dogs showed a prevalence higher than 5% highlighting the need of new diagnostic tools for a more effective control of the disease in dogs and therefore to reduce the risk of transmission of this zoonotic pathogen to humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Novel immunoassay formats for integrated microfluidic circuits: diffusion immunoassays (DIA)

    Science.gov (United States)

    Weigl, Bernhard H.; Hatch, Anson; Kamholz, Andrew E.; Yager, Paul

    2000-03-01

    Novel designs of integrated fluidic microchips allow separations, chemical reactions, and calibration-free analytical measurements to be performed directly in very small quantities of complex samples such as whole blood and contaminated environmental samples. This technology lends itself to applications such as clinical diagnostics, including tumor marker screening, and environmental sensing in remote locations. Lab-on-a-Chip based systems offer many *advantages over traditional analytical devices: They consume extremely low volumes of both samples and reagents. Each chip is inexpensive and small. The sampling-to-result time is extremely short. They perform all analytical functions, including sampling, sample pretreatment, separation, dilution, and mixing steps, chemical reactions, and detection in an integrated microfluidic circuit. Lab-on-a-Chip systems enable the design of small, portable, rugged, low-cost, easy to use, yet extremely versatile and capable diagnostic instruments. In addition, fluids flowing in microchannels exhibit unique characteristics ('microfluidics'), which allow the design of analytical devices and assay formats that would not function on a macroscale. Existing Lab-on-a-chip technologies work very well for highly predictable and homogeneous samples common in genetic testing and drug discovery processes. One of the biggest challenges for current Labs-on-a-chip, however, is to perform analysis in the presence of the complexity and heterogeneity of actual samples such as whole blood or contaminated environmental samples. Micronics has developed a variety of Lab-on-a-Chip assays that can overcome those shortcomings. We will now present various types of novel Lab- on-a-Chip-based immunoassays, including the so-called Diffusion Immunoassays (DIA) that are based on the competitive laminar diffusion of analyte molecules and tracer molecules into a region of the chip containing antibodies that target the analyte molecules. Advantages of this

  14. Interference in immunoassay

    International Nuclear Information System (INIS)

    Chapman, R.S.

    1998-01-01

    Interfering factors are evident in both limited reagent (radioimmunoassay) and excess reagent (immunometric assay) technologies and should be suspected whenever there is a discrepancy between analytical results and clinical findings in the investigation of particular diseases. The overall effect of interference in immunoassay is analytical bias in result, either positive or negative of variable magnitude. The interference maybe caused by a wide spectrum of factors from poor sample collection and handling to physiological factors e.g. lipaemia, heparin treatment, binding protein abnormalities, autoimmunity and drug treatments. The range of interfering factors is extensive and difficult to discuss effectively in a short review

  15. Recent Progress on Sonic Boom Research at NASA

    Science.gov (United States)

    Loubeau, Alexandra

    2012-01-01

    Sonic boom research conducted at NASA through the Supersonics Project of the Fundamental Aeronautics Program is oriented toward understanding the potential impact of sonic boom noise on communities from new low-boom supersonic aircraft designs. Encompassing research in atmospheric propagation, structural response, and human response, NASA research contributes to knowledge in key areas needed to support development of a new noise-based standard for supersonic aircraft certification. Partnerships with several industry, government, and academic institutions have enabled the recent execution of several acoustic field studies on sonic booms. An overview of recent activities funded by NASA includes: focus boom model development and experimental validation, field experiments of structural transmission of sonic booms into large buildings, and low boom community response testing.

  16. Proximity hybridization-regulated catalytic DNA hairpin assembly for electrochemical immunoassay based on in situ DNA template-synthesized Pd nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Fuyi [School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou 221116 (China); Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Department of Pharmaceutical Analysis, School of Pharmacy, Xuzhou Medical College, 221004, Xuzhou (China); Yao, Yao; Luo, Jianjun; Zhang, Xing; Zhang, Yu; Yin, Dengyang [Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Department of Pharmaceutical Analysis, School of Pharmacy, Xuzhou Medical College, 221004, Xuzhou (China); Gao, Fenglei, E-mail: jsxzgfl@sina.com [Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Department of Pharmaceutical Analysis, School of Pharmacy, Xuzhou Medical College, 221004, Xuzhou (China); Wang, Po, E-mail: wangpo@jsnu.edu.cn [School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou 221116 (China)

    2017-05-29

    Novel hybridization proximity-regulated catalytic DNA hairpin assembly strategy has been proposed for electrochemical immunoassay based on in situ DNA template-synthesized Pd nanoparticles as signal label. The DNA template-synthesized Pd nanoparticles were characterized with atomic force microscopic and X-ray photoelectron spectroscopy. The highly efficient electrocatalysis by DNA template synthesized Pd nanoparticles for NaBH{sub 4} oxidation produced an intense detection signal. The label-free electrochemical method achieved the detection of carcinoembryonic antigen (CEA) with a linear range from 10{sup −15} to 10{sup −11} g mL{sup −1} and a detection limit of 0.43 × 10{sup −15} g mL{sup −1}. Through introducing a supersandwich reaction to increase the DNA length, the electrochemical signal was further amplified, leading to a detection limit of 0.52 × 10{sup −16} g mL{sup −1}. And it rendered satisfactory analytical performance for the determination of CEA in serum samples. Furthermore, it exhibited good reproducibility and stability; meanwhile, it also showed excellent specificity due to the specific recognition of antigen by antibody. Therefore, the DNA template synthesized Pd nanoparticles based signal amplification approach has great potential in clinical applications and is also suitable for quantification of biomarkers at ultralow level. - Graphical abstract: A novel label-free and enzyme-free electrochemical immunoassay based on proximity hybridization-regulated catalytic DNA hairpin assemblies for recycling of the CEA. - Highlights: • A novel enzyme-free electrochemical immunosensor was developed for detection of CEA. • The signal amplification was based on catalytic DNA hairpin assembly and DNA-template-synthesized Pd nanoparticles. • The biosensor could detect CEA down to 0.52 × 10{sup −16} g mL{sup −1} level with a dynamic range spanning 5 orders of magnitude.

  17. Procedures for Sensitive Immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Givol, D. [Department of Chemical Immunology, Weizmann Institute of Science, Rehovot (Israel)

    1970-02-15

    Sensitive immunoassay methods should be applied to small molecules of biological importance, which are non-immunogenic by themselves, such as small peptide hormones (e.g. bradykinin), plant hormones (e.g. indoleacetic acid), nucleotides and other small molecules. Methods of binding these small molecules, as haptens, to immunogenic carriers by various cross-linking agents are described (dicyclohexylcarbodiimide, tolylene-diisocyanate and glutaraldehyde), and the considerations involved in relation to the methods of binding and the specificity of the antibodies formed are discussed. Some uses of antibody bound to bromoacetyl cellulose as an immuno adsorbent convenient for assay of immunoglobulins are described. Finally, the sensitive immunoassay method of chemically modified phage is described. This includes methods of binding small molecules (such as the dinitrophenyl group, penicillin, indoleacetic acid) or proteins (such as insulin, immunoglobulins) to phages. Methods of direct chemical conjugation, or an indirect binding via anti-phage Fab, are described. The phage inactivation method by direct plating and its modifications (such as decision technique and complex inactivation) are compared with the more simple end-point titration method. The inhibition of phage inactivation has some advantages as it does not require radioactive material, or expensive radioactive counters, and avoids the need for separation between bound and unbound antigen. Hence, if developed, it could be used as an alternative to radioimmunoassay. (author)

  18. Surface modification of alignment layer by ultraviolet irradiation to dramatically improve the detection limit of liquid-crystal-based immunoassay for the cancer biomarker CA125.

    Science.gov (United States)

    Su, Hui-Wen; Lee, Mon-Juan; Lee, Wei

    2015-05-01

    Liquid crystal (LC)-based biosensing has attracted much attention in recent years. We focus on improving the detection limit of LC-based immunoassay techniques by surface modification of the surfactant alignment layer consisting of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP). The cancer biomarker CA125 was detected with an array of anti-CA125 antibodies immobilized on the ultraviolet (UV)-modified DMOAP monolayer. Compared with a pristine counterpart, UV irradiation enhanced the binding affinity of the CA125 antibody and reproducibility of immunodetection in which a detection limit of 0.01 ng∕ml for the cancer biomarker CA125 was achieved. Additionally, the optical texture observed under a crossed polarized microscope was correlated with the analyte concentration. In a proof-of-concept experiment using CA125-spiked human serum as the analyte, specific binding between the CA125 antigen and the anti-CA125 antibody resulted in a distinct and concentration-dependent optical response despite the high background caused by nonspecific binding of other biomolecules in the human serum. Results from this study indicate that UVmodification of the alignment layer, as well as detection with LCs of large birefringence, contributes to the enhanced performance of the label-free LC-based immunodetection, which may be considered a promising alternative to conventional label-based methods.

  19. An immunoassay for dibutyl phthalate based on direct hapten linkage to the polystyrene surface of microtiter plates.

    Directory of Open Access Journals (Sweden)

    Chenxi Wei

    Full Text Available BACKGROUND: Dibutyl phthalate (DBP is predominantly used as a plasticizer inplastics to make them flexible. Extensive use of phthalates in both industrial processes and other consumer products has resulted in the ubiquitous presence of phthalates in the environment. In order to better determine the level of pollution in the environment and evaluate the potential adverse effects of exposure to DBP, immunoassay for DBP was developed. METHODOLOGY/PRINCIPAL FINDINGS: A monoclonal antibody specific to DBP was produced from a stable hybridoma cell line generated by lymphocyte hybridoma technique. An indirect competitive enzyme-linked immunosorbent assay (icELISA employing direct coating of hapten on polystyrene microtiter plates was established for the detection of DBP. Polystyrene surface was first oxidized by permanganate in dilute sulfuric acid to generate carboxyl groups. Then dibutyl 4-aminophthalate, which is an analogue of DBP, was covalently linked to the carboxyl groups of polystyrene surface with 1-ethyl-3-(3-dimethylaminopropyl carbodiimide hydrochloride (EDC. Compared with conjugate coated format (IC(50=106 ng/mL, the direct hapten coated format (IC(50=14.6 ng/mL improved assay sensitivity after careful optimization of assay conditions. The average recovery of DBP from spiked water sample was 104.4% and the average coefficient of variation was 9.95%. Good agreement of the results obtained by the hapten coated icELISA and gas chromatography-mass spectrometry further confirmed the reliability and accuracy of the icELISA for the detection of DBP in certain plastic and cosmetic samples. CONCLUSIONS/SIGNIFICANCE: The stable and efficient hybridoma cell line obtained is an unlimited source of sensitive and specific antibody to DBP. The hapten coated format is proposed as generally applicable because the carboxyl groups on modified microtiter plate surface enables stable immobilization of aminated or hydroxylated hapten with EDC. The developed

  20. A novel fluorescence immunoassay for the sensitive detection of Escherichia coli O157:H7 in milk based on catalase-mediated fluorescence quenching of CdTe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Rui [College of Life Science, Nanchang University, Nanchang, 330031 (China); State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047 (China); Huang, Xiaolin; Li, Juan; Shan, Shan; Lai, Weihua [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047 (China); Xiong, Yonghua, E-mail: yhxiongchen@163.com [College of Life Science, Nanchang University, Nanchang, 330031 (China); State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047 (China)

    2016-12-01

    Immunoassay is a powerful tool for rapid detection of food borne pathogens in food safety monitoring. However, conventional immunoassay always suffers from low sensitivity when it employs enzyme-catalyzing chromogenic substrates to generate colored molecules as signal outputs. In the present study, we report a novel fluorescence immunoassay for the sensitive detection of E. coli O157:H7 through combination of the ultrahigh bioactivity of catalase to hydrogen peroxide (H{sub 2}O{sub 2}) and H{sub 2}O{sub 2}-sensitive mercaptopropionic acid modified CdTe QDs (MPA-QDs) as a signal transduction. Various parameters, including the concentrations of anti-E. coli O157:H7 polyclonal antibody and biotinylated monoclonal antibody, the amounts of H{sub 2}O{sub 2} and streptavidin labeled catalase (CAT), the hydrolysis temperature and time of CAT to H{sub 2}O{sub 2}, as well as the incubation time between H{sub 2}O{sub 2} and MPA-QDs, were systematically investigated and optimized. With optimal conditions, the catalase-mediated fluorescence quenching immunoassay exhibits an excellent sensitivity for E. coli O157:H7 with a detection limit of 5 × 10{sup 2} CFU/mL, which was approximately 140 times lower than that of horseradish peroxidase-based colorimetric immunoassay. The reliability of the proposed method was further evaluated using E. coli O157:H7 spiked milk samples. The average recoveries of E. coli O157:H7 concentrations from 1.18 × 10{sup 3} CFU/mL to 1.18 × 10{sup 6} CFU/mL were in the range of 65.88%–105.6%. In brief, the proposed immunoassay offers a great potential for rapid and sensitive detection of other pathogens in food quality control. - Highlights: • A novel fluorescence immunoassay was developed for the ultrasensitive detection of E. coli O157:H7. • This detection was achieved through the combination of the high bioactivity of CAT and H{sub 2}O{sub 2}-sensitive QDs. • The activity of CAT to H{sub 2}O{sub 2} is 1000 folds higher than that of the HRP

  1. A novel fluorescence immunoassay for the sensitive detection of Escherichia coli O157:H7 in milk based on catalase-mediated fluorescence quenching of CdTe quantum dots

    International Nuclear Information System (INIS)

    Chen, Rui; Huang, Xiaolin; Li, Juan; Shan, Shan; Lai, Weihua; Xiong, Yonghua

    2016-01-01

    Immunoassay is a powerful tool for rapid detection of food borne pathogens in food safety monitoring. However, conventional immunoassay always suffers from low sensitivity when it employs enzyme-catalyzing chromogenic substrates to generate colored molecules as signal outputs. In the present study, we report a novel fluorescence immunoassay for the sensitive detection of E. coli O157:H7 through combination of the ultrahigh bioactivity of catalase to hydrogen peroxide (H_2O_2) and H_2O_2-sensitive mercaptopropionic acid modified CdTe QDs (MPA-QDs) as a signal transduction. Various parameters, including the concentrations of anti-E. coli O157:H7 polyclonal antibody and biotinylated monoclonal antibody, the amounts of H_2O_2 and streptavidin labeled catalase (CAT), the hydrolysis temperature and time of CAT to H_2O_2, as well as the incubation time between H_2O_2 and MPA-QDs, were systematically investigated and optimized. With optimal conditions, the catalase-mediated fluorescence quenching immunoassay exhibits an excellent sensitivity for E. coli O157:H7 with a detection limit of 5 × 10"2 CFU/mL, which was approximately 140 times lower than that of horseradish peroxidase-based colorimetric immunoassay. The reliability of the proposed method was further evaluated using E. coli O157:H7 spiked milk samples. The average recoveries of E. coli O157:H7 concentrations from 1.18 × 10"3 CFU/mL to 1.18 × 10"6 CFU/mL were in the range of 65.88%–105.6%. In brief, the proposed immunoassay offers a great potential for rapid and sensitive detection of other pathogens in food quality control. - Highlights: • A novel fluorescence immunoassay was developed for the ultrasensitive detection of E. coli O157:H7. • This detection was achieved through the combination of the high bioactivity of CAT and H_2O_2-sensitive QDs. • The activity of CAT to H_2O_2 is 1000 folds higher than that of the HRP to tetramethylbenzidine. • The limit of detection of the proposed method could

  2. Subjective Response to Simulated Sonic Booms in Homes

    Science.gov (United States)

    McCurdy, David A.; Brown, Sherilyn A.

    1996-01-01

    One of the environmental issues affecting the development of a second-generation supersonic commercial transport is the impact of sonic booms on people. Aircraft designers are attempting to design the transport to produce sonic boom signatures that will have minimum impact on the public. Current supersonic commercial aircraft produce an 'N-wave' sonic boom pressure signature that is considered unacceptable by the public. This has resulted in first-generation supersonic transports being banned from flying supersonic over land in the United States, a severe economic constraint. By tailoring aircraft volume and lift distributions, designers hope to produce sonic boom signatures having specific shapes other than 'N-wave' that may be more acceptable to the public. As part of the effort to develop a second-generation supersonic commercial transport, Langley Research Center is conducting research to study people's subjective response to sonic booms. As part of that research, a system was developed for performing studies of the subjective response of people to the occurrence of simulated sonic booms in their homes. The In-Home Noise Generation/Response System (IHONORS) provides a degree of situational realism not available in the laboratory and a degree of control over the noise exposure not found in community surveys. The computer-controlled audio system generates the simulated sonic booms, measures the noise levels, and records the subjects' ratings and can be placed and operated in individual homes for extended periods of time. The system was used to conduct an in-home study of subjective response to simulated sonic booms. The primary objective of the study was to determine the effect on annoyance of the number of sonic boom occurrences in a realistic environment. The effects on annoyance of several other parameters were also examined. Initially, data analyses were based on all the data collected. However, further analyser found that test subjects adapted to the sonic

  3. Polyelectrolyte-based electrochemiluminescence enhancement for Ru(bpy){sub 3}{sup 2+} loaded by SiO{sub 2} nanoparticle carrier and its high sensitive immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Zhi-Li; Song, Tian-Mei; Chen, Zhe [College of Pharmaceutical Science, Soochow University, Suzhou 215123 (China); Guo, Wu-Run [College of Pharmaceutical Science, Soochow University, Suzhou 215123 (China); College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002 (China); Xie, Hong-Ping, E-mail: hpxie@suda.edu.cn [College of Pharmaceutical Science, Soochow University, Suzhou 215123 (China); Xie, Lian, E-mail: xielian@suda.edu.cn [College of Pharmaceutical Science, Soochow University, Suzhou 215123 (China)

    2015-03-03

    Highlights: • Preparation of strong ECL nanoparticles PAA–Ru@SiO{sub 2}/[PAA⋯Ru&Nafion⋯Ru]. • Ion-pair macromolecule PAA–Ru formed to greatly increase the doping amount. • PAA&Nafion membrane increased the amount of ion-exchanged Ru(bpy){sub 3}{sup 2+}. • PAA&Nafion membrane enhanced the ability of electron transfer. • Realized antibody labeling and established a high-sensitive immunoassay. - Abstract: In this paper the strong electrochemiluminescence (ECL) nanoparticles have been prepared based on the anionic polyelectrolyte sodium polyacrylate (PAA)-ECL enhancement for Ru(bpy){sub 3}{sup 2+}, which were loaded by the carrier of SiO{sub 2} nanoparticle. There were two kinds of Ru(bpy){sub 3}{sup 2+} for the as-prepared nanoparticles, the doped one and the exchanged one. The former was loaded inside the ECL nanoparticles by doping, in a form of ion-pair macromolecules PAA–Ru(bpy){sub 3}{sup 2+}. The corresponding ECL was enhanced about 2 times owing to the doping increase of Ru(bpy){sub 3}{sup 2+}. The latter was loaded on the PAA-doped Nafion membrane by ion exchange. The corresponding ECL was enhanced about 3 times owing to the ion-exchanging increase of Ru(bpy){sub 3}{sup 2+}. At the same time, ECL intensity of the doped-inside Ru(bpy){sub 3}{sup 2+} was further enhanced 13 times because polyelectrolyte PAA in the doped membrane could obviously enhance electron transfer between the doped Ru(bpy){sub 3}{sup 2+} and the working electrode. Furthermore, based on hydrophobic regions of the doped membrane antibody labeling could be easily realized by the as-prepared nanoparticles and then a high sensitive ECL immunoassay for HBsAg was developed. The linear range was between 1.0 and 100 pg mL{sup −1} (R{sup 2} = 0.9912). The detection limit could be as low as 0.11 pg mL{sup −1} (signal-to-noise ratio = 3)

  4. Silver Nanoparticle-Based Fluorescence-Quenching Lateral Flow Immunoassay for Sensitive Detection of Ochratoxin A in Grape Juice and Wine

    Science.gov (United States)

    Jiang, Hu; Li, Xiangmin; Xiong, Ying; Pei, Ke; Nie, Lijuan; Xiong, Yonghua

    2017-01-01

    A silver nanoparticle (AgNP)-based fluorescence-quenching lateral flow immunoassay with competitive format (cLFIA) was developed for sensitive detection of ochratoxin A (OTA) in grape juice and wine samples in the present study. The Ru(phen)32+-doped silica nanoparticles (RuNPs) were sprayed on the test and control line zones as background fluorescence signals. The AgNPs were designed as the fluorescence quenchers of RuNPs because they can block the exciting light transferring to the RuNP molecules. The proposed method exhibited high sensitivity for OTA detection, with a detection limit of 0.06 µg/L under optimized conditions. The method also exhibited a good linear range for OTA quantitative analysis from 0.08 µg/L to 5.0 µg/L. The reliability of the fluorescence-quenching cLFIA method was evaluated through analysis of the OTA-spiked red grape wine and juice samples. The average recoveries ranged from 88.0% to 110.0% in red grape wine and from 92.0% to 110.0% in grape juice. Meanwhile, less than a 10% coefficient variation indicated an acceptable precision of the cLFIA method. In summary, the new AgNP-based fluorescence-quenching cLFIA is a simple, rapid, sensitive, and accurate method for quantitative detection of OTA in grape juice and wine or other foodstuffs. PMID:28264472

  5. Silver Nanoparticle-Based Fluorescence-Quenching Lateral Flow Immunoassay for Sensitive Detection of Ochratoxin A in Grape Juice and Wine

    Directory of Open Access Journals (Sweden)

    Hu Jiang

    2017-02-01

    Full Text Available A silver nanoparticle (AgNP-based fluorescence-quenching lateral flow immunoassay with competitive format (cLFIA was developed for sensitive detection of ochratoxin A (OTA in grape juice and wine samples in the present study. The Ru(phen 3 2 + -doped silica nanoparticles (RuNPs were sprayed on the test and control line zones as background fluorescence signals. The AgNPs were designed as the fluorescence quenchers of RuNPs because they can block the exciting light transferring to the RuNP molecules. The proposed method exhibited high sensitivity for OTA detection, with a detection limit of 0.06 µg/L under optimized conditions. The method also exhibited a good linear range for OTA quantitative analysis from 0.08 µg/L to 5.0 µg/L. The reliability of the fluorescence-quenching cLFIA method was evaluated through analysis of the OTA-spiked red grape wine and juice samples. The average recoveries ranged from 88.0% to 110.0% in red grape wine and from 92.0% to 110.0% in grape juice. Meanwhile, less than a 10% coefficient variation indicated an acceptable precision of the cLFIA method. In summary, the new AgNP-based fluorescence-quenching cLFIA is a simple, rapid, sensitive, and accurate method for quantitative detection of OTA in grape juice and wine or other foodstuffs.

  6. Immunoassay separation technique

    International Nuclear Information System (INIS)

    1977-01-01

    A method for effecting the immunoassay of a multiplicity of samples, each possibly containing an antigen or an antibody to be assayed, is discussed. Each sample is incubated with a solution containing a detectable antigen or antibody to form a multiplicity of mixtures, each mixture containing as components antigen-antibody, non-complexed antigen and non-complexed antibody. At least one of the components of the said mixture is separated by adsorption. There after, quantity of detectable antigen or antibody is detected in one of the non-adsorbed portions of the mixture. An improvement, compared to other techniques, is the continuous and sequential separation of at least one component, which is intended to be separated from each said multiplicity of mixtures

  7. A highly sensitive immunoassay for atrazine based on covalently linking the small molecule hapten to a urea-glutaraldehyde network on a polystyrene surface.

    Science.gov (United States)

    Sai, Na; Sun, Wenjing; Wu, Yuntang; Sun, Zhong; Yu, Guanggui; Huang, Guowei

    2016-11-01

    A new enzyme-linked immunosorbent assay (ELISA) for atrazine was developed based on covalent bonding of the small molecule hapten, 2-mercaptopropionic acid-4-ethylamino-6-isopropylamino-1,3,5-triazine (MPA-atrazine), to urea-glutaraldehyde (UGA)-treated microtiter plates. In this assay, the microtiter plate surface was treated with the UGA network to both introduce amino groups, which were used to cross-link with the hapten carboxylate groups, and efficiently prevent non-specific adsorption of antibodies, which successfully eliminated the time-consuming routine blocking step. Compared with HNO 3 -H 2 SO 4 -APTES-hapten coated ELISA (modified with a HNO 3 -H 2 SO 4 -APTES mixture and covalent-linked hapten) and conventional ELISA (coated with hapten-carrier protein conjugates), the novel ELISA format increased the sensitivity by approximately 3.5-fold and 7.5-fold, respectively, and saved 2.5h and 34h of coating hapten time, respectively. The method's 50% inhibition concentration for atrazine was 5.54ngmL -1 , and the limit of detection was 0.16ngmL -1 after optimization of reaction conditions. Furthermore, the ELISA was adapted for analysis of atrazine in corn, rice, and water samples, demonstrating recoveries of 90%-108%. Thus, the assay provides a convenient alternative to conventional, laborious immunoassays for routine supervision of residue detection in food and the environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Highly sensitive determination of diclofenac based on resin beads and a novel polyclonal antibody by using flow injection chemiluminescence competitive immunoassay

    Science.gov (United States)

    Shi, Jing; Xu, Mingxia; Tang, Qinghui; Zhao, Kang; Deng, Anping; Li, Jianguo

    2018-02-01

    A novel flow injection chemiluminescence immunoassay for simple, sensitive and low-cost detection of diclofenac was established based on specific binding of antigen and antibody. Carboxylic resin beads used as solid phase carrier materials provided good biocompatibility and large surface-to-volume ratio for modifying more coating antigen. There was a competitive process between the diclofenac in solution and the immobilized coating antigen to react with the limited binding sites of the polyclonal antibody to form the immunocomplex. The second antibody labelled with horseradish peroxidase was introduced into the immunosensor and trapped by captured polyclonal antibody against diclofenac, which could effectively amplify chemiluminescence signals of luminol-PIP-H2O2. Under optimal conditions, the diclofenac could be detected quantitatively. The chemiluminescence intensity decreased linearly with the logarithm of the diclofenac concentration in the range of 0.1-100 ng mL- 1 with a detection limit of 0.05 ng mL- 1 at a signal-to-noise ratio of 3. The immunosensor exhibited high sensitivity, specificity and acceptable stability. This easy-operated and cost-effective analytical method could be valuable for the diclofenac determination in real water samples.

  9. Utilization of a lateral flow colloidal gold immunoassay strip based on surface-enhanced Raman spectroscopy for ultrasensitive detection of antibiotics in milk

    Science.gov (United States)

    Shi, Qiaoqiao; Huang, Jie; Sun, Yaning; Yin, Mengqi; Hu, Mei; Hu, Xiaofei; Zhang, Zhijun; Zhang, Gaiping

    2018-05-01

    An ultrasensitive method for the detection of antibiotics in milk is developed based on inexpensive, simple, rapid and portable lateral flow immunoassay (LFI) strip, in combination with high sensitivity surface-enhanced Raman spectroscopy (SERS). In our strategy, an immunoprobe was prepared from colloidal gold (AuNPs) conjugated with both a monoclonal antibody against neomycin (NEO-mAb) and a Raman probe molecule 4-aminothiophenol (PATP). The competitive interaction with immunoprobe between free NEO and the coated antigen (NEO-OVA) resulted in the change of the amount of the immobilized immunoprobe on the paper substrate. The LFI procedure was completed within 15 min. The Raman intensity of PATP on the test line of the LFI strip was measured for the quantitative determination of NEO. The IC50 and the limit of detection (LOD) of this assay are 0.04 ng/mL and 0.216 pg/mL of NEO, respectively. There is no cross-reactivity (CR) of the assay with other compounds, showing high specificity of the assay. The recoveries for milk samples with added NEO are in the range of 89.7%-105.6% with the relative standard deviations (RSD) of 2.4%-5.3% (n = 3). The result reveals that this method possesses high specificity, sensitivity, reproducibility and stability, and can be used to detect a variety of antibiotic residues in milk samples.

  10. Establishment of a novel immunoassay system for rapid detection of 2,4-dichlorophenoxyacetic acid residues based on magnetic-fluorescent probes

    Directory of Open Access Journals (Sweden)

    WANG Yuanfeng

    2014-12-01

    Full Text Available A novel immunoassay system based on magnetic-fluorescent probes was established to detect 2.4-dichlorophenoxyacetic acid (2,4-D residue in liquid system in food and agricultural products.The composites of anti-2,4-D antibody bound to Fe3O4@SiO2-NH2 was employed as the solid phase as well as magnetic probe.The composites composed of 2,4-D-OVA labeled with CdTe@SiO2-NH2 as the fluorescent probe was used to produce fluorescent signal.2,4-D and its fluorescent probe competed binding the antibody on the surface of the magnetic probe.The optimization of 2,4-D-OVA dosage,coupling PH and reaction time in preparing the fluorescent probe were investigated.It showed that in the synthesis of fluorescent probe 8.2 was the optimal pH,70 min was the optimal coupling time,500 μL amount of 2,4-D-OVA.The standard curve was obtained with the concentration of 2,4-D and the maximum fluorescence intensity.The detection limit of the assay was gotten and it was 3.55×10-8.One reaction step and one washing step were needed.The assay significantly shortened the testing time and amplified the detection signal compared with classic ELISA.

  11. Sonic mediations: body, sound, technology

    NARCIS (Netherlands)

    Birdsall, C.; Enns, A.

    2008-01-01

    Sonic Mediations: Body, Sound, Technology is a collection of original essays that represents an invaluable contribution to the burgeoning field of sound studies. While sound is often posited as having a bridging function, as a passive in-between, this volume invites readers to rethink the concept of

  12. Sonic journeys with the dead

    DEFF Research Database (Denmark)

    Sabra, Jakob Borrits

    This audio-paper is a site-specific investigation of relations between a gravesite at Vor Frelser Cemetery (Cemetery of Our Saviour), Copenhagen, Denmark, its cultural history and publicly co-constructed memories. The audio-paper follows a non-representational approach to sonic media and the meta...

  13. AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF THREE IMMUNOASSAY TEST KITS FOR ANTHRAX, BOTULINUM TOXIN AND RICIN

    Science.gov (United States)

    Immunoassay test kits are based on immunoassay methods, where specific antibodies are used to detect and measure the contaminants of interest. Immunoassay test kits rely on the reaction of a contaminant or antigen with a selective antibody to give a product that can be measures....

  14. Development of an immunoassay for determination of 2,4-dichlorophenoxyacetic acid (2,4-D) based upon the recombinant Fab fragment of 2,4-D specific antibody

    Science.gov (United States)

    Nguyen, Van C.; Nguyen, Thi D. T.; Dau, Hung A.; Tham, Thu N.; Quyen, Dinh T.; Bachmman, Till; Schmid, Rolf D.

    2001-09-01

    To develop an immunoassay and further an immunosensor for 2,4-D based upon recombinant antibody, the Fab fragments of 2,4-D specific antibody were expressed in E. coli. Western blotting analysis of the periplasmic cell fractions shown that under the non-reducing condition only a single protein band at a molecular mass of 45-kDa, corresponding to the whole Fab fragment was detected. Antigen binding activity for 2,4-D was found only in the extract of cells bearing the 2,4-D plasmid. An immunoassay based on the competitive reaction of 2,4-D and enzyme tracer with 2,4-D Fab fragments immobilized on micro titer plates via rabbit anti-mouse IgC was developed. Using this assay, 2,4-D could be detected at concentration range of 0.5 (mu) g/1 to 10(mu) g/1. The center point of the 2,4-D test was found at a concentration of 5 (mu) g/l. The assay was applied for detection of 2,4-D in spiked orange samples, resulting in recovery rate of 90 percent. The immunoassay could be applied to monitor human exposure to 2,4-D from contamination in fruit samples.

  15. Immunoassay for thymopoietin

    International Nuclear Information System (INIS)

    Goldstein, G.

    1979-01-01

    The patent describes the development of a radio-immunoassay for thymopoietin in biological samples. The method of raising antibodies to this polypeptide hormone is described. This is achieved by injecting a host animal with an antigen consisting of thymopoietin covalently bonded by glutaraldehyde to a carrier protein such as bovine serum albumin and equine globulin. Different methods of radiolabelling thymopoietin with 125 I for use as the tracer antigen are described. The Bolton-Hunter procedure was preferred to the chloramine-T method since direct iodination of the tyrosyl moieties of thymopoietin resulted in some loss of immunoreactivity. Systems for separating the antigen-antibody complex and unbound antigen are compared. Binding-inhibition curves for unlabelled thymopoietin in the assay employing polyethylene glycol separation showed a sensitivity of 5 ng thymopoietin/ml. However, using the double antibody or dextran coated charcoal separation techniques, the sensitivity of thymopoietin was 0.1 ng/ml. Thus these latter two procedures are thus especially suitable for measuring thymopoietin levels in serum or plasma samples. The assay was shown to be specific for thymopoietin, no significant displacement being produced by control polypeptides. (U.K.)

  16. A versatile SERS-based immunoassay for immunoglobulin detection using antigen-coated gold nanoparticles and malachite green-conjugated protein A/G

    Science.gov (United States)

    A surface enhanced Raman scattering (SERS) immunoassay for antibody detection in serum is described in the present work. The developed assay is conducted in solution and utilizes Au nanoparticles coated with the envelope (E) protein of West Nile Virus (WNV) as the SERS-active substrate and malachite...

  17. Development of a chip-based multiplexed immunoassay using liposomal nanovesicles and its application in the detection of pathogens causing female lower genital tract infections

    Directory of Open Access Journals (Sweden)

    Wen-Hsiang Su

    2013-03-01

    Conclusion: This microarray chip was a rapid, easy, inexpensive and sensitive tool for detecting female lower genital tract Candida infection in a one-time vaginal sampling process, although the data on the four other pathogens were still unavailable. A larger population study is encouraged to test the validity of this multiplexed immunoassay chip.

  18. Shuttle sonic boom - Technology and predictions. [environmental impact

    Science.gov (United States)

    Holloway, P. F.; Wilhold, G. A.; Jones, J. H.; Garcia, F., Jr.; Hicks, R. M.

    1973-01-01

    Because the shuttle differs significantly in both geometric and operational characteristics from conventional supersonic aircraft, estimation of sonic boom characteristics required a new technology base. The prediction procedures thus developed are reviewed. Flight measurements obtained for both the ascent and entry phases of the Apollo 15 and 16 and for the ascent phase only of the Apollo 17 missions are presented which verify the techniques established for application to shuttle. Results of extensive analysis of the sonic boom overpressure characteristics completed to date are presented which indicate that this factor of the shuttle's environmental impact is predictable, localized, of short duration and acceptable. Efforts are continuing to define the shuttle sonic boom characteristics to a fine level of detail based on the final system design.

  19. Optimizing sonication parameters for dispersion of single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Haibo [Fraunhofer Institute for Electronic Nano Systems (Fraunhofer ENAS), 09126 Chemnitz (Germany); Graduate University of the Chinese Academy of Sciences, Beijing (China); State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, 110016 Shenyang (China); Hermann, Sascha, E-mail: sascha.hermann@zfm.tu-chemnitz.de [Center for Microtechnologies (ZfM), Chemnitz University of Technology, 09126 Chemnitz (Germany); Schulz, Stefan E.; Gessner, Thomas [Fraunhofer Institute for Electronic Nano Systems (Fraunhofer ENAS), 09126 Chemnitz (Germany); Center for Microtechnologies (ZfM), Chemnitz University of Technology, 09126 Chemnitz (Germany); Dong, Zaili [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, 110016 Shenyang (China); Li, Wen J., E-mail: wenjungli@gmail.com [State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, 110016 Shenyang (China); Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Hong Kong SAR (China)

    2012-10-26

    Graphical abstract: We study the dispersing behavior of SWCNTs based on the surfactant and the optimization of sonication parameters including the sonication power and running time. Highlights: Black-Right-Pointing-Pointer We study the optimization of sonication for the surfactant-based dispersion of SWCNTs. Black-Right-Pointing-Pointer The absorption spectrum of SWCNT solution strongly depend on the sonication conditions. Black-Right-Pointing-Pointer The sonication process has an important influence on the average length and diameters of SWCNTs in solution. Black-Right-Pointing-Pointer Centrifugation mainly contributes to the decrease of nonresonant absorption background. Black-Right-Pointing-Pointer Under the same sonication parameters, the large-diameter tip performs dispersion of SWCNTs better than the small-diameter tip. -- Abstract: Non-covalent functionalization based on surfactants has become one of the most common methods for dispersing of single-walled carbon nanotubes (SWCNTs). Previously, efforts have mainly been focused on experimenting with different surfactant systems, varying their concentrations and solvents. However sonication plays a very important role during the surfactant-based dispersion process for SWCNTs. The sonication treatment enables the surfactant molecules to adsorb onto the surface of SWCNTs by overcoming the interactions induced by the hydrophobic, electrostatic and van der Waals forces. This work describes a systematic study of the influence of the sonication power and time on the dispersion of SWCNTs. UV-vis-NIR absorption spectra is used to analyze and to evaluate the dispersion of SWCNTs in an aqueous solution of 1 w/v% sodium deoxycholate (DOC) showing that the resonant and nonresonant background absorption strongly depends on the sonication conditions. Furthermore, the diameter and length of SWCNTs under different sonication parameters are investigated using atomic force microscopy (AFM).

  20. A polyclonal antibody based immunoassay detects seven subtypes of Shiga toxin 2 produced by Escherichia coli in human and environmental samples.

    Directory of Open Access Journals (Sweden)

    Xiaohua He

    Full Text Available BACKGROUND: Shiga toxin-producing Escherichia coli (STEC are frequent causes of severe human diseases ranging from diarrhea to hemolytic uremic syndrome. The existing strategy for detection of STEC relies on the unique sorbitol-negative fermentation property of the O157 strains, the most commonly identified serotype has been E. coli O157. It is becoming increasingly evident, however, that numerous non-O157 STEC serotypes also cause outbreaks and severe illnesses. It is necessary to have new methods that are capable of detecting all STEC strains. METHODS AND FINDINGS: Here we describe the development of a sandwich ELISA assay for detecting both O157 and non-O157 STECs by incorporating a novel polyclonal antibody (pAb against Stx2. The newly established immunoassay was capable of detecting Stx2a spiked in environmental samples with a limit of detection between 10 and 100 pg/mL in soil and between 100 and 500 pg/mL in feces. When applied to 36 bacterial strains isolated from human and environmental samples, this assay detected Stx2 in all strains that were confirmed to be stx2-positive by real-time PCR, demonstrating a 100% sensitivity and specificity. CONCLUSIONS: The sandwich ELISA developed in this study will enable any competent laboratory to identify and characterize Stx2-producing O157 and non-O157 strains in human and environmental samples, resulting in rapid diagnosis and patient care. The results of epitope mapping from this study will be useful for further development of a peptide-based antibody and vaccine.

  1. Lateral flow test strip based on colloidal selenium immunoassay for rapid detection of melamine in milk, milk powder, and animal feed

    Directory of Open Access Journals (Sweden)

    Wang ZZ

    2014-04-01

    Full Text Available Zhizeng Wang,1 Dejuan Zhi,2 Yang Zhao,1 Hailong Zhang,2 Xin Wang,2 Yi Ru,1 Hongyu Li1,2 1MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, People's Republic of China; 2Institute of Microbiology and Biochemical Pharmacy, School of Pharmaceutics, Lanzhou University, Lanzhou, People's Republic of China Abstract: Although high melamine (MEL intake has been proven to cause serious health problems, MEL is sometimes illegally added to milk products and animal feed, arousing serious food safety concerns. A satisfactory method of detecting MEL in onsite or in-home testing is in urgent need of development. This work aimed to explore a rapid, convenient, and cost-effective method of identifying MEL in milk products or other food by colloidal selenium-based lateral flow immunoassay. Colloidal selenium was synthesized by L-ascorbic acid to reduce seleninic acid at room temperature. After conjugation with a monoclonal antibody anti-MEL, a test strip was successfully prepared. The detection limit of the test strip reached 150 µg/kg, 1,000 µg/kg, and 800 µg/kg in liquid milk, milk powder, and animal feed, respectively. No cross-reactions with homologues cyanuric acid, cyanurodiamide, or ammelide were found. Moreover, the MEL test strip can remain stable after storage for 1 year at room temperature. Our results demonstrate that the colloidal selenium MEL test strip can detect MEL in adulterated milk products or animal feed conveniently, rapidly, and sensitively. In contrast with a colloidal gold MEL test strip, the colloidal selenium MEL test strip was easy to prepare and more cost-efficient. Keywords: melamine, selenium nanoparticles, test strip, milk, animal feed, dairy food

  2. Cellphone-based detection platform for rbST biomerker analysis in milk extracts using a microsphere fluorescence immunoassay

    NARCIS (Netherlands)

    Ludwig, S.K.J.; Zhu, H.; Phillips, S.; Shiledar, A.; Feng, S.; Tseng, D.; Ginkel, van L.A.; Nielen, M.W.F.; Ozcan, A.

    2014-01-01

    Current contaminant and residue monitoring throughout the food chain is based on sampling, transport, administration, and analysis in specialized control laboratories. This is a highly inefficient and costly process since typically more than 99 % of the samples are found to be compliant. On-site

  3. Development and validation of a genotype 3 recombinant protein-based immunoassay for hepatitis E virus serology in swine

    Directory of Open Access Journals (Sweden)

    W.H.M. van der Poel

    2014-04-01

    Full Text Available Hepatitis E virus (HEV is classified within the family Hepeviridae, genus Hepevirus. HEV genotype 3 (Gt3 infections are endemic in pigs in Western Europe and in North and South America and cause zoonotic infections in humans. Several serological assays to detect HEV antibodies in pigs have been developed, at first mainly based on HEV genotype 1 (Gt1 antigens. To develop a sensitive HEV Gt3 ELISA, a recombinant baculovirus expression product of HEV Gt3 open reading frame-2 was produced and coated onto polystyrene ELISA plates. After incubation of porcine sera, bound HEV antibodies were detected with anti-porcine anti-IgG and anti-IgM conjugates. For primary estimation of sensitivity and specificity of the assay, sets of sera were used from pigs experimentally infected with HEV Gt3. For further validation of the assay and to set the cutoff value, a batch of 1100 pig sera was used. All pig sera were tested using the developed HEV Gt3 assay and two other serologic assays based on HEV Gt1 antigens. Since there is no gold standard available for HEV antibody testing, further validation and a definite setting of the cutoff of the developed HEV Gt3 assay were performed using a statistical approach based on Bayes' theorem. The developed and validated HEV antibody assay showed effective detection of HEV-specific antibodies. This assay can contribute to an improved detection of HEV antibodies and enable more reliable estimates of the prevalence of HEV Gt3 in swine in different regions.

  4. The antibody-based magnetic microparticle immunoassay using p-FET sensing platform for Alzheimer's disease pathogenic factor

    Science.gov (United States)

    Kim, Chang-Beom; Kim, Kwan-Soo; Song, Ki-Bong

    2013-05-01

    The importance of early Alzheimer's disease (AD) detection has been recognized to diagnose people at high risk of AD. The existence of intra/extracellular beta-amyloid (Aβ) of brain neurons has been regarded as the most archetypal hallmark of AD. The existing computed-image-based neuroimaging tools have limitations on accurate quantification of nanoscale Aβ peptides due to optical diffraction during imaging processes. Therefore, we propose a new method that is capable of evaluating a small amount of Aβ peptides by using photo-sensitive field-effect transistor (p-FET) integrated with magnetic force-based microbead collecting platform and selenium(Se) layer (thickness ~700 nm) as an optical filter. This method demonstrates a facile approach for the analysis of Aβ quantification using magnetic force and magnetic silica microparticles (diameter 0.2~0.3 μm). The microbead collecting platform mainly consists of the p-FET sensing array and the magnet (diameter ~1 mm) which are placed beneath each sensing region of the p-FET, which enables the assembly of the Aβ antibody conjugated microbeads, captures the Aβ peptides from samples, measures the photocurrents generated by the Q-dot tagged with Aβ peptides, and consequently results in the effective Aβ quantification.

  5. Comparison and flowering valuation of New Guinea Impatiens cultivars from Sonic and Super Sonic groups

    Directory of Open Access Journals (Sweden)

    Ludmiła Startek

    2012-12-01

    Full Text Available In the years 2002-2003 the flowering of four New Guinea Impatiens cultivars from Sonic and Super Sonic groups were compared. They were the following cultivars: 'Sonic Pink', 'Sonic Sweet Cherry', 'Super Sonic Cherry Cream' and 'Super Sonic Hot Pink'. The experiments were carried out from the middle of April till the middle of October. Neutralised sphagnum peat with slow release fertiliser Osmocote Plus 5/6 was used as medium. It was found that the cultivar 'Sonic Pink' began blooming 1-4 weeks earlier than the other cultivars. The cultivars 'Sonic Sweet Cherry' and 'Super Sonic Cherry Cream' had significantly more abundant flowering (105.3-113.3 flowers per plant than the cultivars 'Sonic Pink' and 'Super Sonic Hot Pink' (72.0-92.8 flowers per plant. All the cultivars had big flowers (6.3-7.8 cm in diameter. The most similar flowers were found in 'Sonic Sweet Cherry' and the least similar in 'Super Sonic Hot Pink'.

  6. Detection of palytoxin-like compounds by a flow cytometry-based immunoassay supported by functional and analytical methods.

    Science.gov (United States)

    Fraga, María; Vilariño, Natalia; Louzao, M Carmen; Fernández, Diego A; Poli, Mark; Botana, Luis M

    2016-01-15

    Palytoxin (PLTX) is a complex marine toxin produced by zoanthids (i.e. Palythoa), dinoflagellates (Ostreopsis) and cyanobacteria (Trichodesmium). PLTX outbreaks are usually associated with Indo-Pacific waters, however their recent repeated occurrence in Mediterranean-European Atlantic coasts demonstrate their current worldwide distribution. Human sickness and fatalities have been associated with toxic algal blooms and ingestion of seafood contaminated with PLTX-like molecules. These toxins represent a serious threat to human health. There is an immediate need to develop easy-to-use, rapid detection methods due to the lack of validated protocols for their detection and quantification. We have developed an immuno-detection method for PLTX-like molecules based on the use of microspheres coupled to flow-cytometry detection (Luminex 200™). The assay consisted of the competition between free PLTX-like compounds in solution and PLTX immobilized on the surface of microspheres for binding to a specific monoclonal anti-PLTX antibody. This method displays an IC50 of 1.83 ± 0.21 nM and a dynamic range of 0.47-6.54 nM for PLTX. An easy-to-perform extraction protocol, based on a mixture of methanol and acetate buffer, was applied to spiked mussel samples providing a recovery rate of 104 ± 8% and a range of detection from 374 ± 81 to 4430 ± 150 μg kg(-1) when assayed with this method. Extracts of Ostreopsis cf. siamensis and Palythoa tuberculosa were tested and yielded positive results for PLTX-like molecules. However, the data obtained for the coral sample suggested that this antibody did not detect 42-OH-PLTX efficiently. The same samples were further analyzed using a neuroblastoma cytotoxicity assay and UPLC-IT-TOF spectrometry, which also pointed to the presence of PLTX-like compounds. Therefore, this single detection method for PLTX provides a semi-quantitative tool useful for the screening of PLTX-like molecules in different matrixes. Copyright © 2015

  7. Detection of Bacillus anthracis spores by super-paramagnetic lateral-flow immunoassays based on "Road Closure".

    Science.gov (United States)

    Wang, Dian-Bing; Tian, Bo; Zhang, Zhi-Ping; Wang, Xu-Ying; Fleming, Joy; Bi, Li-Jun; Yang, Rui-Fu; Zhang, Xian-En

    2015-05-15

    Detection of Bacillus anthracis in the field, whether as a natural infection or as a biothreat remains challenging. Here we have developed a new lateral-flow immunochromatographic assay (LFIA) for B. anthracis spore detection based on the fact that conjugates of B. anthracis spores and super-paramagnetic particles labeled with antibodies will block the pores of chromatographic strips and form retention lines on the strips, instead of the conventionally reported test lines and control lines in classic LFIA. As a result, this new LFIA can simultaneously realize optical, magnetic and naked-eye detection by analyzing signals from the retention lines. As few as 500-700 pure B. anthracis spores can be recognized with CV values less than 8.31% within 5 min of chromatography and a total time of 20 min. For powdery sample tests, this LFIA can endure interference from 25% (w/v) milk, 10% (w/v) baking soda and 10% (w/v) starch without any sample pre-treatment, and has a corresponding detection limit of 6×10(4) spores/g milk powder, 2×10(5) spores/g starch and 5×10(5) spores/g baking soda. Compared with existing methods, this new approach is very competitive in terms of sensitivity, specificity, cost and ease of operation. This proof-of-concept study can also be extended for detection of many other large-sized analytes. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Colloidal gold-McAb probe-based rapid immunoassay strip for simultaneous detection of fumonisins in maize.

    Science.gov (United States)

    Yao, Jingjing; Sun, Yaning; Li, Qingmei; Wang, Fangyu; Teng, Man; Yang, Yanyan; Deng, Ruiguang; Hu, Xiaofei

    2017-05-01

    Fumonisins are a kind of toxic and carcinogenic mycotoxin. A rapid immunochromatographic test strip has been developed for simultaneous detection of fumonisin B 1 , B 2 and B 3 (FB 1 , FB 2 and FB 3 ) in maize based on colloidal gold-labelled monoclonal antibody (McAb) against FB 1 probe. The anti-FB 1 McAb (2E11-H3) was produced through immunisation and cell fusion, and identified as high affinity, specificity and sensitivity. The cross-reaction ratios with fumonisin B 2 and B 3 were accordingly 385% and 72.4%, while none with other analogues. The colloid gold-labelled anti-FB 1 McAb probe was successfully prepared and used for establishing the immunochromatographic strip. The test strip showed high sensitivity and specificity, the IC 50 for FB 1 was 58.08 ng mL -1 , LOD was 11.24 ng mL -1 , calculated from standard curve. Moreover, the test strip exhibited high cross-reactivity with FB 2 and FB 3 , and could be applied to the simultaneous detection of FBs (FB 1 :FB 2 :FB 3 = 12:4:1) in maize sample with high accuracy and precision. The average recoveries of FBs in maize ranged from 90.42% to 95.29%, and CVs were 1.25-3.77%. The results of the test strip for FBs samples showed good correlation with high-performance liquid chromatography analysis. The immunochromatographic test strip could be employed in the rapid simultaneous detection of FB 1 , FB 2 and FB 3 in maize samples on-site. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. The detectability of cracks using sonic IR

    Science.gov (United States)

    Morbidini, Marco; Cawley, Peter

    2009-05-01

    This paper proposes a methodology to study the detectability of fatigue cracks in metals using sonic IR (also known as thermosonics). The method relies on the validation of simple finite-element thermal models of the cracks and specimens in which the thermal loads have been defined by means of a priori measurement of the additional damping introduced in the specimens by each crack. This estimate of crack damping is used in conjunction with a local measurement of the vibration strain during ultrasonic excitation to retrieve the power released at the crack; these functions are then input to the thermal model of the specimens to find the resulting temperature rises (sonic IR signals). The method was validated on mild steel beams with two-dimensional cracks obtained in the low-cycle fatigue regime as well as nickel-based superalloy beams with three-dimensional "thumbnail" cracks generated in the high-cycle fatigue regime. The equivalent 40kHz strain necessary to obtain a desired temperature rise was calculated for cracks in the nickel superalloy set, and the detectability of cracks as a function of length in the range of 1-5mm was discussed.

  10. Sonic Virtuality, Environment, and Presence

    DEFF Research Database (Denmark)

    Grimshaw, Mark

    2018-01-01

    The article presents a brief introduction to the concept of sonic virtuality, a view of sound as a multi-modal, emergent perception that provides a framework that has since been used to provide an explanation of the formation of environments. Additionally, the article uses such concepts to explain...... the phenomenon of presence, not only in virtual worlds but also in actual worlds. The view put forward is that environment is an emergent perception, formed from the hypothetical modelling of salient worlds of sensory things, and it is in the environment that we feel present. The article ends with some thoughts...

  11. Mass cytometry: technique for real time single cell multitarget immunoassay based on inductively coupled plasma time-of-flight mass spectrometry.

    Science.gov (United States)

    Bandura, Dmitry R; Baranov, Vladimir I; Ornatsky, Olga I; Antonov, Alexei; Kinach, Robert; Lou, Xudong; Pavlov, Serguei; Vorobiev, Sergey; Dick, John E; Tanner, Scott D

    2009-08-15

    A novel instrument for real time analysis of individual biological cells or other microparticles is described. The instrument is based on inductively coupled plasma time-of-flight mass spectrometry and comprises a three-aperture plasma-vacuum interface, a dc quadrupole turning optics for decoupling ions from neutral components, an rf quadrupole ion guide discriminating against low-mass dominant plasma ions, a point-to-parallel focusing dc quadrupole doublet, an orthogonal acceleration reflectron analyzer, a discrete dynode fast ion detector, and an 8-bit 1 GHz digitizer. A high spectrum generation frequency of 76.8 kHz provides capability for collecting multiple spectra from each particle-induced transient ion cloud, typically of 200-300 micros duration. It is shown that the transients can be resolved and characterized individually at a peak frequency of 1100 particles per second. Design considerations and optimization data are presented. The figures of merit of the instrument are measured under standard inductively coupled plasma (ICP) operating conditions ( 900 for m/z = 159, the sensitivity with a standard sample introduction system of >1.4 x 10(8) ion counts per second per mg L(-1) of Tb and an abundance sensitivity of (6 x 10(-4))-(1.4 x 10(-3)) (trailing and leading masses, respectively) are shown. The mass range (m/z = 125-215) and abundance sensitivity are sufficient for elemental immunoassay with up to 60 distinct available elemental tags. When 500) can be used, which provides >2.4 x 10(8) cps per mg L(-1) of Tb, at (1.5 x 10(-3))-(5.0 x 10(-3)) abundance sensitivity. The real-time simultaneous detection of multiple isotopes from individual 1.8 microm polystyrene beads labeled with lanthanides is shown. A real time single cell 20 antigen expression assay of model cell lines and leukemia patient samples immuno-labeled with lanthanide-tagged antibodies is presented.

  12. Ultrasonic/Sonic Rotary-Hammer Drills

    Science.gov (United States)

    Badescu, Mircea; Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi; Kassab, Steve

    2010-01-01

    Ultrasonic/sonic rotary-hammer drill (USRoHD) is a recent addition to the collection of apparatuses based on ultrasonic/sonic drill corer (USDC). As described below, the USRoHD has several features, not present in a basic USDC, that increase efficiency and provide some redundancy against partial failure. USDCs and related apparatuses were conceived for boring into, and/or acquiring samples of, rock or other hard, brittle materials of geological interest. They have been described in numerous previous NASA Tech Briefs articles. To recapitulate: A USDC can be characterized as a lightweight, lowpower, piezoelectrically driven jackhammer in which ultrasonic and sonic vibrations are generated and coupled to a tool bit. A basic USDC includes a piezoelectric stack, an ultrasonic transducer horn connected to the stack, a free mass ( free in the sense that it can bounce axially a short distance between hard stops on the horn and the bit), and a tool bit. The piezoelectric stack creates ultrasonic vibrations that are mechanically amplified by the horn. The bouncing of the free mass between the hard stops generates the sonic vibrations. The combination of ultrasonic and sonic vibrations gives rise to a hammering action (and a resulting chiseling action at the tip of the tool bit) that is more effective for drilling than is the microhammering action of ultrasonic vibrations alone. The hammering and chiseling actions are so effective that unlike in conventional twist drilling, little applied axial force is needed to make the apparatus advance into the material of interest. There are numerous potential applications for USDCs and related apparatuses in geological exploration on Earth and on remote planets. In early USDC experiments, it was observed that accumulation of cuttings in a drilled hole causes the rate of penetration of the USDC to decrease steeply with depth, and that the rate of penetration can be increased by removing the cuttings. The USRoHD concept provides for

  13. Research on Test-bench for Sonic Logging Tool

    Directory of Open Access Journals (Sweden)

    Xianping Liu

    2016-01-01

    Full Text Available In this paper, the test-bench for sonic logging tool is proposed and designed to realize automatic calibration and testing of the sonic logging tool. The test-bench System consists of Host Computer, Embedded Controlling Board, and functional boards. The Host Computer serves as the Human Machine Interface (HMI and processes uploaded data. The software running on Host Computer is designed on VC++, which is developed based on multithreading, Dynamic Linkable Library (DLL and Multiple Document Interface (MDI techniques. The Embedded Controlling Board uses ARM7 as the microcontroller and communicates with Host Computer via Ethernet. The Embedded Controlling Board software is realized based on embedded uclinux operating system with a layered architecture. The functional boards are designed based on Field Programmable Gate Array (FPGA and provide test interfaces for the logging tool. The functional board software is divided into independent sub-modules that can repeatedly be used by various functional boards and then integrated those sub-modules in the top layer. With the layered architecture and modularized design, the software system is highly reliable and extensible. With the help of designed system, a test has been conducted quickly and successfully on the electronic receiving cabin of the sonic logging tool. It demonstrated that the system could greatly improve the production efficiency of the sonic logging tool.

  14. Using homogenization, sonication and thermo-sonication to inactivate fungi

    Science.gov (United States)

    Bevilacqua, Antonio; Sinigaglia, Milena; Corbo, Maria Rosaria

    2016-01-01

    Ultrasound (US), Thermo-sonication (TS) and High Pressure Homogenization (HPH) were studied as tools to inactivate the spores of Penicillium spp. and Mucor spp. inoculated in distilled water. For US, the power ranged from 40% to 100%, pulse from 2 to 10 s, and duration of the treatment from 2 to 10 min. TS was performed combining US (40–80% of power, for 8 min and pulse of 2 s) with a thermal treatment (50, 55 and 60°C at 4, 8 and 12 min). Homogenization was done at 30–150 MPa for 1, 2 and 3 times. Power was the most important factors to determine the antifungal effect of US and TS towards the conidia of Penicillium spp.; on the other hand, in US treatments Mucor spp. was also affected by pulse and time. HPH exerted a significant antifungal effect only if the highest pressures were applied for 2–3 times. PMID:27375964

  15. A conventional chemical reaction for use in an unconventional assay: A colorimetric immunoassay for aflatoxin B1 by using enzyme-responsive just-in-time generation of a MnO2 based nanocatalyst.

    Science.gov (United States)

    Lai, Wenqiang; Zeng, Qiao; Tang, Juan; Zhang, Maosheng; Tang, Dianping

    2018-01-10

    The authors describe a colorimetric immunoassay for the model nalyte aflatoxin B 1 (AFB 1 ). It is based on the just-in-time generation of an MnO 2 nanocatalyst. Unlike previously developed immunoassay, the chromogenic reaction relies on the just-in-time formation of an oxidase mimic without the aid of the substrate. Potassium permanganate (KMnO 4 ) is converted into manganese dioxide (MnO 2 ) which acts as an oxidase mimic that catalyzes the oxidation 3,3',5,5'-tetramethylbenzidine (TMB) by oxygen to give a blue colored product. In the presence of ascorbic acid (AA), KMnO 4 is reduced to Mn(II) ions. This results in a decrease in the amount of MnO 2 nanocatalyst. Hence, the oxidation of TMB does not take place. By adding ascorbate oxidase, AA is converted into dehydroascorbic acid which cannot reduce KMnO 4 . Based on these observations, a colorimetric competitive enzyme immunoassay was developed where ascorbate oxidase and gold nanoparticle-labeled antibody against AFB 1 and magnetic beads carrying bovine serum albumin conjugated to AFB 1 are used for the determination of AFB 1 . In presence of AFB 1 , it will compete with the BSA-conjugated AFB 1 (on the magnetic beads) for the labeled antibody against AFB 1 on the gold nanoparticles. This makes the amount of ascorbate oxidase/anti-AFB 1 antibody-labeled gold nanoparticles, which conjugated on magnetic beads, reduce, and resulted in an increase of ascorbic acid. Under optimal conditions, the absorbance (measured at 652 nm) decreases with increasing AFB 1 concentrations in the range from 0.1 to 100 ng mL -1 , with a 0.1 ng mL -1 detection limit (at the 3S blank level). The accuracy of the assay was validated by analyzing spiked peanut samples. The results matched well with those obtained with a commercial ELISA kit. Conceivably, the method is not limited to aflatoxins but has a wide scope in that it may be applied to many other analytes for which respective antibodies are available. Graphical abstract

  16. An Ultrasensitive Electrochemiluminescence Immunoassay for Carbohydrate Antigen 19-9 in Serum Based on Antibody Labeled Fe3O4 Nanoparticles as Capture Probes and Graphene/CdTe Quantum Dot Bionanoconjugates as Signal Amplifiers

    Science.gov (United States)

    Gan, Ning; Zhou, Jing; Xiong, Ping; Li, Tianhua; Jiang, Shan; Cao, Yuting; Jiang, Qianli

    2013-01-01

    The CdTe quantum dots (QDs), graphene nanocomposite (CdTe-G) and dextran–Fe3O4 magnetic nanoparticles have been synthesized for developing an ultrasensitive electrochemiluminescence (ECL) immunoassay for Carcinoembryonic antigen 19-9 (CA 19-9) in serums. Firstly, the capture probes (CA 19-9 Ab1/Fe3O4) for enriching CA 19-9 were synthesized by immobilizing the CA 19-9’s first antibody (CA 19-9 Ab1) on magnetic nanoparticles (dextran-Fe3O4). Secondly, the signal probes (CA 19-9 Ab2/CdTe-G), which can emit an ECL signal, were formed by attaching the secondary CA 19-9 antibody (CA 19-9 Ab2) to the surface of the CdTe-G. Thirdly, the above two probes were used for conjugating with a serial of CA 19-9 concentrations. Graphene can immobilize dozens of CdTe QDs on their surface, which can emit stronger ECL intensity than CdTe QDs. Based on the amplified signal, ultrasensitive antigen detection can be realized. Under the optimal conditions, the ECL signal depended linearly on the logarithm of CA 19-9 concentration from 0.005 to 100 pg/mL, and the detection limit was 0.002 pg/mL. Finally, five samples of human serum were tested, and the results were compared with a time-resolved fluorescence assay (TRFA). The novel immunoassay provides a stable, specific and highly sensitive immunoassay protocol for tumor marker detection at very low levels, which can be applied in early diagnosis of tumor. PMID:23685872

  17. Stakeholder acceptance analysis ResonantSonic drilling

    International Nuclear Information System (INIS)

    Peterson, T.

    1995-12-01

    This report presents evaluations, recommendations, and requirements concerning ResonantSonic Drilling (Sonic Drilling), derived from a three-year program of stakeholder involvement. Sonic Drilling is an innovative method to reach contamination in soil and groundwater. The resonant sonic drill rig uses counter-rotating weights to generate energy, which causes the drill pipe to vibrate elastically along its entire length. In the resonant condition, forces of up to 200,000 pounds are transmitted to the drill bit face to create a cutting action. The resonant energy causes subsurface materials to move back into the adjacent formation, permitting the drill pipe to advance. This report is for technology developers and those responsible for making decisions about the use of technology to remediate contamination by volatile organic compounds. Stakeholders' perspectives help those responsible for technology deployment to make good decisions concerning the acceptability and applicability of sonic drilling to the remediation problems they face

  18. The sonic window: second generation results

    Science.gov (United States)

    Walker, William F.; Fuller, Michael I.; Brush, Edward V.; Eames, Matthew D. C.; Owen, Kevin; Ranganathan, Karthik; Blalock, Travis N.; Hossack, John A.

    2006-03-01

    Medical Ultrasound Imaging is widely used clinically because of its relatively low cost, portability, lack of ionizing radiation, and real-time nature. However, even with these advantages ultrasound has failed to permeate the broad array of clinical applications where its use could be of value. A prime example of this untapped potential is the routine use of ultrasound to guide intravenous access. In this particular application existing systems lack the required portability, low cost, and ease-of-use required for widespread acceptance. Our team has been working for a number of years to develop an extremely low-cost, pocket-sized, and intuitive ultrasound imaging system that we refer to as the "Sonic Window." We have previously described the first generation Sonic Window prototype that was a bench-top device using a 1024 element, fully populated array operating at a center frequency of 3.3 MHz. Through a high degree of custom front-end integration combined with multiplexing down to a 2 channel PC based digitizer this system acquired a full set of RF data over a course of 512 transmit events. While initial results were encouraging, this system exhibited limitations resulting from low SNR, relatively coarse array sampling, and relatively slow data acquisition. We have recently begun assembling a second-generation Sonic Window system. This system uses a 3600 element fully sampled array operating at 5.0 MHz with a 300 micron element pitch. This system extends the integration of the first generation system to include front-end protection, pre-amplification, a programmable bandpass filter, four sample and holds, and four A/D converters for all 3600 channels in a set of custom integrated circuits with a combined area smaller than the 1.8 x 1.8 cm footprint of the transducer array. We present initial results from this front-end and present benchmark results from a software beamformer implemented on the Analog Devices BF-561 DSP. We discuss our immediate plans for further

  19. Immunoassay for determination of trilobolide

    Czech Academy of Sciences Publication Activity Database

    Huml, L.; Jurášek, M.; Mikšátková, P.; Zimmermann, T.; Tomanová, P.; Buděšínský, Miloš; Rottnerová, Z.; Šimková, M.; Harmatha, Juraj; Kmoníčková, Eva; Lapčík, O.; Drašar, P. B.

    2017-01-01

    Roč. 117, Jan (2017), s. 105-111 ISSN 0039-128X. [Conference on Isoprenoids /23./. Minsk, 04.09.2016-07.09.2016] Institutional support: RVO:61388963 ; RVO:68378041 Keywords : trilobolide * avidin-biotin * ELISA * Laser trilobum * synthesis * immunoassay Subject RIV: CE - Biochemistry; FR - Pharmacology ; Medidal Chemistry (UEM-P) OBOR OECD: Biochemical research methods; Pharmacology and pharmacy (UEM-P) Impact factor: 2.282, year: 2016

  20. Intensification of transesterification via sonication numerical simulation and sensitivity study

    International Nuclear Information System (INIS)

    Janajreh, Isam; ElSamad, Tala; Noorul Hussain, Mohammed

    2017-01-01

    Highlights: • 3D numerical simulation of transesterification is accomplished. • A non-isothermal, reactive Navier–stokes was carried out. • Conventional and sonicated process was compared as far as reaction kinetics and yield. • Higher kinetic rates are achieved at lower molar ratios in sonicated process. • It validates feasibility of numerical simulation for transesterification assessment. - Abstract: Transesterification is known as slow reaction that can take over several hours to complete. The process involves two immiscible reactants to produce the biodiesel and the byproduct glycerol. Biodiesel commercialization has always been hindered by the long process times of the transesterification reaction. Catalyzing the process and increasing the agitation rate is the mode of intensifying the process additional to the increase of the molar ratio, temperature, circulation that all penalize the overall process metrics. Finding shorter path by reducing the reaction into a few minutes and ensures high quality biodiesel, in economically viable way is coming along with sonication. This drastic reduction moves the technology from the slow batch process into the high throughput continuous process. In a practical sense this means a huge optimization for the biodiesel production process which opens pathways for faster, voluminous and cheaper production. The mechanism of sonication assisted reaction is explained by the creation of microbubbles which increases the interfacial surface reaction areas and the presence of high localized temperature and turbulence as these microbubbles implode. As a result the reaction kinetics of sonicated transesterification as inferred by several authors is much faster. The aim of this work is to implement the inferred rates in a high fidelity numerical reactive flow simulation model while considering the reactor geometry. It is based on Navier–Stokes equations coupled with energy equation for non-isothermal flow and the transport

  1. Evaluation of the C6 Lyme Enzyme Immunoassay for the Diagnosis of Lyme Disease in Children and Adolescents.

    Science.gov (United States)

    Lipsett, Susan C; Branda, John A; McAdam, Alexander J; Vernacchio, Louis; Gordon, Caroline D; Gordon, Catherine R; Nigrovic, Lise E

    2016-10-01

    The commercially-available C6 Lyme enzyme immunoassay (EIA) has been approved to replace the standard whole-cell sonicate EIA as a first-tier test for the diagnosis of Lyme disease and has been suggested as a stand-alone diagnostic. However, the C6 EIA has not been extensively studied in pediatric patients undergoing evaluation for Lyme disease. We collected discarded serum samples from children and adolescents (aged ≤21 years) undergoing conventional 2-tiered testing for Lyme disease at a single hospital-based clinical laboratory located in an area endemic for Lyme disease. We performed a C6 EIA on all collected specimens, followed by a supplemental immunoblot if the C6 EIA result was positive but the whole-cell sonicate EIA result was negative. We defined a case of Lyme disease as either a clinician-diagnosed erythema migrans lesion or a positive standard 2-tiered serologic result in a patient with symptoms compatible with Lyme disease. We then compared the performance of the C6 EIA alone and as a first-tier test followed by immunoblot, with that of standard 2-tiered serology for the diagnosis of Lyme disease. Of the 944 specimens collected, 114 (12%) were from patients with Lyme disease. The C6 EIA alone had sensitivity similar to that of standard 2-tiered testing (79.8% vs 81.6% for standard 2-tiered testing; P = .71) with slightly lower specificity (94.2% vs 98.8% 2; P Lyme disease, the C6 EIA could guide initial clinical decision making, although a supplemental immunoblot should still be performed. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  2. Fake news? Biotin interference in thyroid immunoassays.

    Science.gov (United States)

    Koehler, Viktoria F; Mann, Ulrike; Nassour, Ayham; Alexander Mann, W

    2018-05-29

    We report on a 47 year old male patient with multiple sclerosis (MS) presenting in our outpatient neurology clinic in Frankfurt/Main for therapy evaluation. Before change of treatment laboratory investigations were performed. Thyroid function tests (TFTs) with a streptavidin/biotin based immunoassay revealed severe hyperthyroidism with positive thyroid autoantibodies suggestive for Graves' disease. Clinical presentation and thyroid sonography were unremarkable. Due to the discordance between clinical presentation and TFTs, we repeated medical history, in which the patient reported taking high-doses of biotin (300 mg/day) for MS. Recent studies with patients suffering from primary and secondary progressive MS, indicated promising effects of high-dose biotin on MS-related disability. In immunoassays relaying on streptavidin-biotin interaction, biotin intake can cause falsely high or low results. Two weeks after withdrawing biotin, biotin/streptavidin dependant assays showed no longer the biochemical picture of severe hyperthyroidism. Biotin intake should be paused for at least two to five days prior to the use of biotin/streptavidin dependant assays. Alternatively, non-biotin/streptavidin dependant assays (radioimmunoassay, gas chromatography-mass spectrometry/liquid chromatography-mass spectrometry) may be used. Copyright © 2017. Published by Elsevier B.V.

  3. High Precision UTDR Measurements by Sonic Velocity Compensation with Reference Transducer

    Directory of Open Access Journals (Sweden)

    Sam Stade

    2014-07-01

    Full Text Available An ultrasonic sensor design with sonic velocity compensation is developed to improve the accuracy of distance measurement in membrane modules. High accuracy real-time distance measurements are needed in membrane fouling and compaction studies. The benefits of the sonic velocity compensation with a reference transducer are compared to the sonic velocity calculated with the measured temperature and pressure using the model by Belogol’skii, Sekoyan et al. In the experiments the temperature was changed from 25 to 60 °C at pressures of 0.1, 0.3 and 0.5 MPa. The set measurement distance was 17.8 mm. Distance measurements with sonic velocity compensation were over ten times more accurate than the ones calculated based on the model. Using the reference transducer measured sonic velocity, the standard deviations for the distance measurements varied from 0.6 to 2.0 µm, while using the calculated sonic velocity the standard deviations were 21–39 µm. In industrial liquors, not only the temperature and the pressure, which were studied in this paper, but also the properties of the filtered solution, such as solute concentration, density, viscosity, etc., may vary greatly, leading to inaccuracy in the use of the Belogol’skii, Sekoyan et al. model. Therefore, calibration of the sonic velocity with reference transducers is needed for accurate distance measurements.

  4. A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer.

    Science.gov (United States)

    Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

    2015-05-22

    Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10(-4) to 10(2) ng/mL).

  5. Improving the sludge disintegration efficiency of sonication by combining with alkalization and thermal pre-treatment methods.

    Science.gov (United States)

    Şahinkaya, S; Sevimli, M F; Aygün, A

    2012-01-01

    One of the most serious problems encountered in biological wastewater treatment processes is the production of waste activated sludge (WAS). Sonication, which is an energy-intensive process, is the most powerful sludge pre-treatment method. Due to lack of information about the combined pre-treatment methods of sonication, the combined pre-treatment methods were investigated and it was aimed to improve the disintegration efficiency of sonication by combining sonication with alkalization and thermal pre-treatment methods in this study. The process performances were evaluated based on the quantities of increases in soluble chemical oxygen demand (COD), protein and carbohydrate. The releases of soluble COD, carbohydrate and protein by the combined methods were higher than those by sonication, alkalization and thermal pre-treatment alone. Degrees of sludge disintegration in various options of sonication were in the following descending order: sono-alkalization > sono-thermal pre-treatment > sonication. Therefore, it was determined that combining sonication with alkalization significantly improved the sludge disintegration and decreased the required energy to reach the same yield by sonication. In addition, effects on sludge settleability and dewaterability and kinetic mathematical modelling of pre-treatment performances of these methods were investigated. It was proven that the proposed model accurately predicted the efficiencies of ultrasonic pre-treatment methods.

  6. Sonic Hedgehog Signaling Promotes Tumor Growth

    National Research Council Canada - National Science Library

    Bushman, Wade

    2007-01-01

    ... of the DOD New Investigator award indicate that Shh signaling promotes tumor growth. This proposal addresses the hypothesis that Sonic hedgehog signaling promotes tumor growth by activating stromal cell gene expression...

  7. Dispersion characteristics of negative refraction sonic crystals

    International Nuclear Information System (INIS)

    Wu, L.-Y.; Chen, L.-W.; Wang, R.C.-C.

    2008-01-01

    Dispersion characteristics of negative refraction sonic crystals are investigated. The plane wave expansion method is used to calculate the equifrequency surface; the dependences of refractive direction on frequencies and incident angles for triangular lattices are shown. There exist the positive and negative refractive waves which include k.V g ≥0 and k.V g ≤0 in the second band for the triangular system. We also use the finite element method to demonstrate that the relative intensity of the transmitted acoustic waves is dependent on incident frequencies and angles. The positions of the partial band gaps obtained by the plane wave expansion method are in good agreement with those obtained by the finite element method. The sonic crystals with negative effective index are shown to have higher transmission intensities. By using the negative refraction behavior, we can design a sonic crystal plane lens to focus a sonic wave

  8. Phase I ResonantSonic CRADA report

    International Nuclear Information System (INIS)

    Richterich, L.R.; Amos, L.O.; Fancher, J.D.; McLellan, G.W.; Setzer, W.V.; Tuttle, B.G.; Hockey, R.L.; Ferris, R.H.; Riechers, D.M.; Pitman, S.G.

    1994-01-01

    This test report describes the Phase 1 testing and results of the ResonantSonic drilling method. This effort was conducted as part of a Cooperative Research and Development Agreement (CRADA) between the US Department of Energy, Pacific Northwest Laboratory, Westinghouse Hanford Company and Water Development Corporation. The purpose of this demonstration was to evaluate the Water Development Corporation's ResonantSonic drilling system, modify components as necessary and determine compatible drilling applications for the ResonantSonic drilling method for use at facilities in the DOE complex and private industry. Initially, the ResonantSonic drill was used to drill several test holes at the Drilling Technology Test Site to assess the feasibility of drilling vertical and angle holes. After this initial phase, a 45 degree angle vapor extraction well was drilled to a depth of 168 feet at the 200 West Carbon Tetrachloride Site. This well was drilled and completed in nine days. Extensive geologic and vapor sampling were conducted while drilling this well. In addition, testing was also conducted at the test site to evaluated drilling with larger diameter casing (8 5/8 inch). Evaluation of the Resonant Sonic drilling method will be continued during the Phase 2 portion of testing to determine if improvements to the ResonantSonic system will make it a more viable method for drilling and sampling

  9. [Automated analyzer of enzyme immunoassay].

    Science.gov (United States)

    Osawa, S

    1995-09-01

    Automated analyzers for enzyme immunoassay can be classified by several points of view: the kind of labeled antibodies or enzymes, detection methods, the number of tests per unit time, analytical time and speed per run. In practice, it is important for us consider the several points such as detection limits, the number of tests per unit time, analytical range, and precision. Most of the automated analyzers on the market can randomly access and measure samples. I will describe the recent advance of automated analyzers reviewing their labeling antibodies and enzymes, the detection methods, the number of test per unit time and analytical time and speed per test.

  10. Enhanced immunoassay for porcine circovirus type 2 antibody using enzyme-loaded and quantum dots-embedded shell–core silica nanospheres based on enzyme-linked immunosorbent assay

    International Nuclear Information System (INIS)

    Wu, Long; Li, Xuepu; Shao, Kang; Ye, Shiyi; Liu, Chen; Zhang, Chenjun; Han, Heyou

    2015-01-01

    Boosting the detection sensitivity of enzyme-linked immunosorbent assay (ELISA) is significant to the early clinical diagnosis of various diseases. Here, we developed a versatile immunosensor using silica nanospheres as carriers for sensitive detection of porcine circovirus type 2 (PCV2) antibody. With HRP enzyme covalently immobilized on the silica nanospheres and CdSe nanocrystals embedded inside, these signal probes were successfully utilized in the sensitive detection of PCV2 antibody by ELISA, fluorometry and square-wave voltammetry (SWV). To further demonstrate the performance of the immunosensor, Human IgG (HIgG) was used as a model analyte. Since more HRP and CdSe QDs were loaded, 5-, 200- and 400-fold enhancements in amplified ELISA, fluorometry and voltammetry responses for HIgG could be achieved compared to conventional ELISA. The respective detection limits of theses methods for HIgG were 3.9, 0.1 and 0.05 ng mL −1 with a RSD below 5% for amplified ELISA, fluorescence and SWV measurements. Additionally, a 100-fold improvement was obtained in the detection sensitivity for PCV2 antibody immunoassay. The versatile immunosensor exhibits good sensitivity, stability and reproducibility, suggesting its potential applications in clinical diagnostics. - Highlights: • A versatile ELISA-based immunoassay for PCV2 antibody was developed. • Enzyme and CdSe QDs modified SiO 2 particles were used to improve sensitivity. • The simultaneous three ELISA-based techniques enhanced the detection reliability. • The biosensors strategy could provide a new avenue to ELISA-based sensors

  11. Enhanced immunoassay for porcine circovirus type 2 antibody using enzyme-loaded and quantum dots-embedded shell–core silica nanospheres based on enzyme-linked immunosorbent assay

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Long; Li, Xuepu; Shao, Kang; Ye, Shiyi; Liu, Chen; Zhang, Chenjun; Han, Heyou, E-mail: hyhan@mail.hzau.edu.cn

    2015-08-05

    Boosting the detection sensitivity of enzyme-linked immunosorbent assay (ELISA) is significant to the early clinical diagnosis of various diseases. Here, we developed a versatile immunosensor using silica nanospheres as carriers for sensitive detection of porcine circovirus type 2 (PCV2) antibody. With HRP enzyme covalently immobilized on the silica nanospheres and CdSe nanocrystals embedded inside, these signal probes were successfully utilized in the sensitive detection of PCV2 antibody by ELISA, fluorometry and square-wave voltammetry (SWV). To further demonstrate the performance of the immunosensor, Human IgG (HIgG) was used as a model analyte. Since more HRP and CdSe QDs were loaded, 5-, 200- and 400-fold enhancements in amplified ELISA, fluorometry and voltammetry responses for HIgG could be achieved compared to conventional ELISA. The respective detection limits of theses methods for HIgG were 3.9, 0.1 and 0.05 ng mL{sup −1} with a RSD below 5% for amplified ELISA, fluorescence and SWV measurements. Additionally, a 100-fold improvement was obtained in the detection sensitivity for PCV2 antibody immunoassay. The versatile immunosensor exhibits good sensitivity, stability and reproducibility, suggesting its potential applications in clinical diagnostics. - Highlights: • A versatile ELISA-based immunoassay for PCV2 antibody was developed. • Enzyme and CdSe QDs modified SiO{sub 2} particles were used to improve sensitivity. • The simultaneous three ELISA-based techniques enhanced the detection reliability. • The biosensors strategy could provide a new avenue to ELISA-based sensors.

  12. Stability of sonicated aqueous suspensions of phospholipids under air.

    Science.gov (United States)

    Almog, R; Forward, R; Samsonoff, C

    1991-12-01

    The stability of phospholipids in liposomal aqueous suspension against oxidative degradation in air was investigated using spectrophotometric indices, glutathione peroxidase reactivity and thin layer chromatography. Zwitterionic phospholipid was found to be susceptible to degradation via oxidation of polyunsaturated hydrocarbon chains and ester hydrolysis, producing oxidized lysophosphatide and free fatty acid derivatives. These products were characterized as hydroperoxides based on their reactivity with the selenium-dependent glutathione peroxidase isolated from human erythrocytes. Lecithin in Tris buffer was more resistant to hydrolysis than in water. The sonication of 8.0 mM of soybean phosphatidylcholine (SB-PC) suspension in 0.1 M Tris (pH 7.5) in the presence of air produced relatively high concentration of conjugated diene hydroperoxide, but a small amount of hydrolyzed products. Anionic phospholipids, such as egg-phosphatidylglycerol (egg-PG), demonstrated higher resistance to air oxidation than the zwitterionic lecithin, but its oxidation was promoted by sonication.

  13. Molecularly Imprinted Polymer as an Antibody Substitution in Pseudo-immunoassays for Chemical Contaminants in Food and Environmental Samples.

    Science.gov (United States)

    Chen, Chaochao; Luo, Jiaxun; Li, Chenglong; Ma, Mingfang; Yu, Wenbo; Shen, Jianzhong; Wang, Zhanhui

    2018-03-21

    The chemical contaminants in food and the environment are quite harmful to food safety and human health. Rapid, accurate, and cheap detection can effectively control the potential risks derived from these chemical contaminants. Among all detection methods, the immunoassay based on the specific interaction of antibody-analyte is one of the most widely used techniques in the field. However, biological antibodies employed in the immunoassay usually cannot tolerate extreme conditions, resulting in an unstable state in both physical and chemical profiles. Molecularly imprinted polymers (MIPs) are a class of polymers with specific molecular recognition abilities, which are highly robust, showing excellent operational stability under a wide variety of conditions. Recently, MIPs have been used in biomimetic immunoassays for chemical contaminants as an antibody substitute in food and the environment. Here, we reviewed these applications of MIPs incorporated in different analytical platforms, such as enzyme-linked immunosorbent assay, fluorescent immunoassay, chemiluminescent immunoassay, electrochemical immunoassay, microfluidic paper-based immunoassay, and homogeneous immunoassay, and discussed current challenges and future trends in the use of MIPs in biomimetic immunoassays.

  14. Nanobody medicated immunoassay for ultrasensitive detection of cancer biomarker alpha-fetoprotein.

    Science.gov (United States)

    Chen, Jing; He, Qing-hua; Xu, Yang; Fu, Jin-heng; Li, Yan-ping; Tu, Zhui; Wang, Dan; Shu, Mei; Qiu, Yu-lou; Yang, Hong-wei; Liu, Yuan-yuan

    2016-01-15

    Immunoassay for cancer biomarkers plays an important role in cancer prevention and early diagnosis. To the development of immunoassay, the quality and stability of applied antibody is one of the key points to obtain reliability and high sensitivity for immunoassay. The main purpose of this study was to develop a novel immunoassay for ultrasensitive detection of cancer biomarker alpha-fetoprotein (AFP) based on nanobody against AFP. Two nanobodies which bind to AFP were selected from a phage display nanobody library by biopanning strategy. The prepared nanobodies are clonable, thermally stable and applied in both sandwich enzyme linked immunoassay (ELISA) and immuno-PCR assay for ultrasensitive detection of AFP. The limit detection of sandwich ELISA setup with optimized nanobodies was 0.48ng mL(-1), and the half of saturation concentration (SC50) value was 6.68±0.56ng mL(-1). These nanobodies were also used to develop an immuno-PCR assay for ultrasensitive detection of AFP, its limit detection values was 0.005ng mL(-1), and the linear range was 0.01-10,000ng mL(-1). These established immunoassays based on nanobodies were highly specific to AFP and with negligible cross reactivity with other tested caner biomarkers. Furthermore, this novel concept of nanobodies mediated immunoassay may provide potential applications in a general method for the ultrasensitive detection of various cancer biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Field intercomparison of prevailing sonic anemometers

    Science.gov (United States)

    Mauder, Matthias; Zeeman, Matthias J.

    2018-01-01

    Three-dimensional sonic anemometers are the core component of eddy covariance systems, which are widely used for micrometeorological and ecological research. In order to characterize the measurement uncertainty of these instruments we present and analyse the results from a field intercomparison experiment of six commonly used sonic anemometer models from four major manufacturers. These models include Campbell CSAT3, Gill HS-50 and R3, METEK uSonic-3 Omni, R. M. Young 81000 and 81000RE. The experiment was conducted over a meadow at the TERENO/ICOS site DE-Fen in southern Germany over a period of 16 days in June of 2016 as part of the ScaleX campaign. The measurement height was 3 m for all sensors, which were separated by 9 m from each other, each on its own tripod, in order to limit contamination of the turbulence measurements by adjacent structures as much as possible. Moreover, the high-frequency data from all instruments were treated with the same post-processing algorithm. In this study, we compare the results for various turbulence statistics, which include mean horizontal wind speed, standard deviations of vertical wind velocity and sonic temperature, friction velocity, and the buoyancy flux. Quantitative measures of uncertainty, such as bias and comparability, are derived from these results. We find that biases are generally very small for all sensors and all computed variables, except for the sonic temperature measurements of the two Gill sonic anemometers (HS and R3), confirming a known transducer-temperature dependence of the sonic temperature measurement. The best overall agreement between the different instruments was found for the mean wind speed and the buoyancy flux.

  16. Survey of immunoassay techniques for biological analysis

    International Nuclear Information System (INIS)

    Burtis, C.A.

    1986-10-01

    Immunoassay is a very specific, sensitive, and widely applicable analytical technique. Recent advances in genetic engineering have led to the development of monoclonal antibodies which further improves the specificity of immunoassays. Originally, radioisotopes were used to label the antigens and antibodies used in immunoassays. However, in the last decade, numerous types of immunoassays have been developed which utilize enzymes and fluorescent dyes as labels. Given the technical, safety, health, and disposal problems associated with using radioisotopes, immunoassays that utilize the enzyme and fluorescent labels are rapidly replacing those using radioisotope labels. These newer techniques are as sensitive, are easily automated, have stable reagents, and do not have a disposal problem. 6 refs., 1 fig., 2 tabs

  17. An accurate, specific, sensitive, high-throughput method based on a microsphere immunoassay for multiplex detection of three viruses and bacterial fruit blotch bacterium in cucurbits.

    Science.gov (United States)

    Charlermroj, Ratthaphol; Makornwattana, Manlika; Himananto, Orawan; Seepiban, Channarong; Phuengwas, Sudtida; Warin, Nuchnard; Gajanandana, Oraprapai; Karoonuthaisiri, Nitsara

    2017-09-01

    To employ a microsphere immunoassay (MIA) to simultaneously detect multiple plant pathogens (potyviruses, Watermelon silver mottle virus, Melon yellow spot virus, and Acidovorax avenae subsp. citrulli) in actual plant samples, several factors need to be optimized and rigorously validated. Here, a simple extraction method using a single extraction buffer was successfully selected to detect the four pathogens in various cucurbit samples (cucumber, cantaloupe, melon, and watermelon). The extraction method and assay performance were validated with inoculated and field cucurbit samples. The MIA showed 98-99% relative accuracy, 97-100% relative specificity and 92-100% relative sensitivity when compared to commercial ELISA kits and reverse transcription PCR. In addition, the MIA was also able to accurately detect multiple-infected field samples. The results demonstrate that one common extraction method for all tested cucurbit samples could be applied to detect multiple pathogens; avoiding the need for multiple protocols to be employed. This multiplex method can therefore be instrumental for high-throughput screening of multiple plant pathogens with many advantages such as a shorter assay time (2.5h) with single assay format, a lower cost of detection ($5 vs $19.7 for 4 pathogens/sample) and less labor requirement. Its multiplex capacity can also be expanded to detect up to 50 different pathogens upon the availability of specific antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Horseradish peroxidase and antibody labeled gold nanoparticle probe for amplified immunoassay of ciguatoxin in fish samples based on capillary electrophoresis with electrochemical detection.

    Science.gov (United States)

    Zhang, Zhaoxiang; Liu, Ying; Zhang, Chaoying; Luan, Wenxiu

    2015-03-01

    This paper describes a new amplified immunoassay with horseradish peroxidase (HRP) and antibody (Ab) labeled gold nanoparticles (AuNPs) probe hyphenated to capillary electrophoresis (CE) with electrochemical (EC) detection for ultrasensitive determination of ciguatoxin CTX1B. AuNPs were conjugated with HRP and Ab, and then incubated with limited amount of CTX1B to produce immunocomplex. The immunoreactive sample was injected into capillary for CE separation and EC detection. Enhanced sensitivity was obtained by adopting the AuNPs as carriers of HRP and Ab at high HRP/Ab molar ratio. The calibration curve of CTX1B was in the range of 0.06-90 ng/mL. The detection limit was 0.045 ng/mL, which is 38-fold lower than that of HPLC-MS method for CTX1B analysis. The proposed method was successfully applied for the quantification of CTX1B in contamined fish samples by simultaneously labeling Ab and HRP on AuNPs. The amplified IA with HRP and Ab labeled AuNPs probe hyphenated to CE and EC detection provides a sensitive analytical approach for the determination of trace ciguatoxin in complex samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Development of a monoclonal antibody-based flow-through immunoassay (FTA) for detection of white spot syndrome virus (WSSV) in black tiger shrimp Penaeus monodon.

    Science.gov (United States)

    Patil, R; Shankar, K M; Kumar, B T N; Kulkarni, A; Patil, P; Moger, N

    2013-09-01

    A flow-through immunoassay (FTA), an improved version of immunodot, was developed using a nitrocellulose membrane baked onto adsorbent pads enclosed in a plastic cassette to detect white spot syndrome virus (WSSV) in shrimp. Sharp purple dots developed with WSSV against the white background of the nitrocellulose membrane. The detection limits of WSSV by the FTA and immunodot were 0.312 and 1.2 μg mL(-1) crude WSSV protein, respectively. The FTA could be completed in 8-10 min compared with 90 min for immunodot. The FTA was 100 times more sensitive than 1-step polymerase chain reaction (PCR) and in between that of the 1- and 2-step PCR protocol recommended by the Office of International Epizootics (OIE). In experimental, orally infected shrimp post-larvae, WSSV was first detected 14, 16 and 18 h post-infection (hpi) by FTA, immunodot and one-step PCR, respectively. The FTA detected WSSV 2 and 4 h earlier than immunodot and one-step PCR, respectively. The FTA was more sensitive (25/27) than one-step PCR (23/27) and immunodot (23/27) for the detection of WSSV from white spot disease outbreak ponds. The reagent components of the FTA were stable giving expected results for 6 m at 4-8 °C. The FTA is available as a rapid test kit called 'RapiDot' for the early detection of WSSV under field conditions. © 2013 John Wiley & Sons Ltd.

  20. Improved porous silicon (P-Si) microarray based PSA (prostate specific antigen) immunoassay by optimized surface density of the capture antibody

    Science.gov (United States)

    Lee, SangWook; Kim, Soyoun; Malm, Johan; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas

    2014-01-01

    Enriching the surface density of immobilized capture antibodies enhances the detection signal of antibody sandwich microarrays. In this study, we improved the detection sensitivity of our previously developed P-Si (porous silicon) antibody microarray by optimizing concentrations of the capturing antibody. We investigated immunoassays using a P-Si microarray at three different capture antibody (PSA - prostate specific antigen) concentrations, analyzing the influence of the antibody density on the assay detection sensitivity. The LOD (limit of detection) for PSA was 2.5ngmL−1, 80pgmL−1, and 800fgmL−1 when arraying the PSA antibody, H117 at the concentration 15µgmL−1, 35µgmL−1 and 154µgmL−1, respectively. We further investigated PSA spiked into human female serum in the range of 800fgmL−1 to 500ngmL−1. The microarray showed a LOD of 800fgmL−1 and a dynamic range of 800 fgmL−1 to 80ngmL−1 in serum spiked samples. PMID:24016590

  1. Production Well Performance Enhancement using Sonication Technology

    Energy Technology Data Exchange (ETDEWEB)

    Adewumi, Michael A; Ityokumbul, M Thaddeus; Watson, Robert W; Eltohami, Eltohami; Farias, Mario; Heckman, Glenn; Houlihan, Brendan; Karoor, Samata Prakash; Miller, Bruce G; Mohammed, Nazia; Olanrewaju, Johnson; Ozdemir, Mine; Rejepov, Dautmamed; Sadegh, Abdallah A; Quammie, Kevin E; Zaghloul, Jose; Hughes, W Jack; Montgomery, Thomas C

    2005-12-31

    The objective of this project was to develop a sonic well performance enhancement technology that focused on near wellbore formation damage. In order to successfully achieve this objective, a three-year project was defined. The entire project was broken into four tasks. The overall objective of all this was to foster a better understanding of the mechanisms involved in sonic energy interactions with fluid flow in porous media and adapt such knowledge for field applications. The fours tasks are: • Laboratory studies • Mathematical modeling • Sonic tool design and development • Field demonstration The project was designed to be completed in three years; however, due to budget cuts, support was only provided for the first year, and hence the full objective of the project could not be accomplished. This report summarizes what was accomplished with the support provided by the US Department of Energy. Experiments performed focused on determining the inception of cavitation, studying thermal dissipation under cavitation conditions, investigating sonic energy interactions with glass beads and oil, and studying the effects of sonication on crude oil properties. Our findings show that the voltage threshold for onset of cavitation is independent of transducer-hydrophone separation distance. In addition, thermal dissipation under cavitation conditions contributed to the mobilization of deposited paraffins and waxes. Our preliminary laboratory experiments suggest that waxes are mobilized when the fluid temperature approaches 40°C. Experiments were conducted that provided insights into the interactions between sonic wave and the fluid contained in the porous media. Most of these studies were carried out in a slim-tube apparatus. A numerical model was developed for simulating the effect of sonication in the nearwellbore region. The numerical model developed was validated using a number of standard testbed problems. However, actual application of the model for scale

  2. Quantification of Radicals Generated in a Sonicator

    Directory of Open Access Journals (Sweden)

    Kassim Badmus

    2016-06-01

    Full Text Available The hydroxyl radical (OH• is a powerful oxidant produced as a consequence of cavitation in water. It can react nonspecifically in breaking down persistent organic pollutants in water into their mineral form. It can also recombine to form hydrogen peroxide which is very useful in water treatment. In this study, terephthalic acid (TA and potassium iodide dosimetry were used to quantify and investigate the behaviour of the generated OH radical in a laboratory scale sonicator. The 2-hydroxyl terephthalic acid (HTA formed during terephthalic acid dosimetry was determined by optical fibre spectrometer. The production rate of HTA served as a means of evaluating and characterizing the OH• generated over given time in a sonicator. The influence of sonicator power intensity, solution pH and irradiation time upon OH• generation were investigated. Approximately 2.2 ´ 10-9 M s-1 of OH radical was generated during the sonication process. The rate of generation of the OH radicals was established to be independent of the concentration of the initial reactant. Thus, the rate of generation of OH• can be predicted by zero order kinetics in a sonicator.

  3. Realism Assessment of Sonic Boom Simulators

    Science.gov (United States)

    Sullivan, Brenda M.; Davies, Patrica; Hodgdon, Kthleen K.; Salamone, Joseph A., III; Pilon, Anthony

    2008-01-01

    Developments in small supersonic aircraft design are predicted to result in low-intensity sonic booms. Booms generated by current aircraft are similar to those that led to the ban on commercial supersonic fli ght over the US, so are unsuitable for parametric studies of psychoac oustic response to low-intensity booms. Therefore, simulators have be en used to study the impact of predicted low-intensity sonic booms. H owever, simulators have been criticized because, when simulating conv entional-level booms, the sounds were observed to be unrealistic by p eople experienced in listening to sonic booms. Thus, two studies were conducted to measure the perceived realism of three sonic boom simul ators. Experienced listeners rated the realism of conventional sonic boom signatures when played in these simulators. The effects on percei ved realism of factors such as duration of post-boom noise, exclusion of very low frequency components, inclusion of ground reflections, a nd type of simulator were examined. Duration of post-boom noise was f ound to have a strong effect on perceived realism, while type of simu lator had a weak effect. It was determined that post-boom noise had t o be at least 1.5 seconds long for the sound to be rated very realist ic. Loudness level did not affect realism for the range of sounds pla yed in the tests (80-93 dB ASEL).

  4. A Remotely Deployable Wind Sonic Anemometer

    Directory of Open Access Journals (Sweden)

    Muhammad Awais

    2017-12-01

    Full Text Available Communication and computing shape up base for explosion of Internet of Things (IoT era. Humans can efficiently control the devices around their environment as per requirements because of IoT, the communication between different devices brings more flexibility in surrounding. Useful data is also gathered from some of these devices to create Big Data; where, further analysis assist in making life easier by developing good business models corresponding to user needs, enhance scientific research, formulating weather prediction or monitoring systems and contributing in other relative fields as well. Thus, in this research a remotely deployable IoT enabled Wind Sonic Anemometer has been designed and deployed to calculate average wind speed, direction, and gust. The proposed design is remotely deployable, user-friendly, power efficient and cost-effective because of opted modules i.e., ultrasonic sensors, GSM module, and solar panel. The testbed was also deployed at the roof of Computer & Information Systems Engineering (CIS department, NED UET. Further, its calibration has been carried out by using long short-term memory (LSTM, a deep learning technique; where ground truth data has been gathered from mechanical wind speed sensor (NRG-40 H deployed at top of Industrial & Manufacturing (IM department of NED UET. The obtained results are satisfactory and the performance of designed sensor is also good under various weather conditions.

  5. Personality Traits Bias the Perceived Quality of Sonic Environments

    Directory of Open Access Journals (Sweden)

    PerMagnus Lindborg

    2016-12-01

    Full Text Available There have been few empirical investigations of how individual differences influence the perception of the sonic environment. The present study included the Big Five traits and noise sensitivity as personality factors in two listening experiments (n = 43, n = 45. Recordings of urban and restaurant soundscapes that had been selected based on their type were rated for Pleasantness and Eventfulness using the Swedish Soundscape Quality Protocol. Multivariate multiple regression analysis showed that ratings depended on the type and loudness of both kinds of sonic environments and that the personality factors made a small yet significant contribution. Univariate models explained 48% (cross-validated adjusted R2 of the variation in Pleasantness ratings of urban soundscapes, and 35% of Eventfulness. For restaurant soundscapes the percentages explained were 22% and 21%, respectively. Emotional stability and noise sensitivity were notable predictors whose contribution to explaining the variation in quality ratings was between one-tenth and nearly half of the soundscape indicators, as measured by squared semipartial correlation. Further analysis revealed that 36% of noise sensitivity could be predicted by broad personality dimensions, replicating previous research. Our study lends empirical support to the hypothesis that personality traits have a significant though comparatively small influence on the perceived quality of sonic environments.

  6. Immunoassay of β-endorphin

    International Nuclear Information System (INIS)

    Hoellt, V.; Gramsch, C.; Herz, A.

    1979-01-01

    The present paper describes the characteristics of a series of antisera against β-endorphin (β-E) developed in our laboratory which all recognize β-lipotropin and their use in (1) the determination of β-E in tissue and in body fluids and in (2) the immunocytochemical localization of β-E containing neurons in the rat brain and in (3) the study of the conversion of the β-E/β-LPH precursor into β-LPH and β-E in the pars intermedia/nervosa of the rat pituitary. It is the purpose of the present report to critically analyze the pitfalls and drawbacks, as well as the advantage, of the use of radioimmunoassay and other immunoassays in the determination of β-E. (Auth.)

  7. Numerical Predictions of Sonic Boom Signatures for a Straight Line Segmented Leading Edge Model

    Science.gov (United States)

    Elmiligui, Alaa A.; Wilcox, Floyd J.; Cliff, Susan; Thomas, Scott

    2012-01-01

    A sonic boom wind tunnel test was conducted on a straight-line segmented leading edge (SLSLE) model in the NASA Langley 4- by 4- Foot Unitary Plan Wind Tunnel (UPWT). The purpose of the test was to determine whether accurate sonic boom measurements could be obtained while continuously moving the SLSLE model past a conical pressure probe. Sonic boom signatures were also obtained using the conventional move-pause data acquisition method for comparison. The continuous data acquisition approach allows for accurate signatures approximately 15 times faster than a move-pause technique. These successful results provide an incentive for future testing with greatly increased efficiency using the continuous model translation technique with the single probe to measure sonic boom signatures. Two widely used NASA codes, USM3D (Navier-Stokes) and CART3D-AERO (Euler, adjoint-based adaptive mesh), were used to compute off-body sonic boom pressure signatures of the SLSLE model at several different altitudes below the model at Mach 2.0. The computed pressure signatures compared well with wind tunnel data. The effect of the different altitude for signature extraction was evaluated by extrapolating the near field signatures to the ground and comparing pressure signatures and sonic boom loudness levels.

  8. Electrochemical sensing platform based on tris(2,2'-bipyridyl)cobalt(III) and multiwall carbon nanotubes-Nafion composite for immunoassay of carcinoma antigen-125

    International Nuclear Information System (INIS)

    Chen Shihong; Yuan Ruo; Chai Yaqin; Min Ligen; Li Wenjuan; Xu Yang

    2009-01-01

    A new strategy for constructing a sensitive mediator-type electrochemical immunosensor for the detection of carcinoma antigen-125 (CA125) was developed. In this strategy, mediator tris(2,2'-bipyridyl)cobalt(III) (Co(bpy) 3 3+ ) was incoporated into the multiwall carbon nanotubes-Nafion (MWNTs-Nafion) composite film via a simple ion-exchange route. Then, gold colloidal nanoparticles (nano-Au) were attached onto Co(bpy) 3 3+ /MWNTs-Nafion film through electrostatic interaction between negatively charged nano-Au and positively charged Co(bpy) 3 3+ . Finally, CA125 monoclonal antibody (anti-CA125), used as a model antibody, was assembled onto the surface of nano-Au to achieve an immunosensor for the determination of CA125 antigen. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to characterize the assembly process of the modified electrode. The resulting immunosensor showed a high sensitivity, wide dynamic range consisting of two linear parts from 1.0 to 30 U mL -1 and 30 to 150 U mL -1 with a low detection limit of 0.36 U mL -1 at 3 times the background noise. Moreover, it displayed good reproducibility and stability, and would be potentially attractive for clinical immunoassay of CA125. The integration of mediator Co(bpy) 3 3+ and MWNTs-Nafion composite would offer potential promise for the fabrication of biosensors and biocatalysts.

  9. Characterization of the anti-factor VIII immunoglobulin profile in patients with hemophilia A by use of a fluorescence-based immunoassay

    Science.gov (United States)

    Boylan, Brian; Rice, Anne S.; Dunn, Amy L.; Tarantino, Michael D.; Brettler, Doreen B.; Barrett, John C.; Miller, Connie H.

    2015-01-01

    Summary Background The development of neutralizing antibodies, referred to as inhibitors, against factor VIII (FVIII) is a major complication associated with FVIII infusion therapy for the treatment of hemophilia A (HA). Previous studies have shown that a subset of HA patients and a low percentage of healthy individuals harbor non-neutralizing anti-FVIII antibodies that do not elicit the clinical manifestations associated with inhibitor development. Objective Assess HA patients' anti-FVIII antibody profiles as potential predictors of clinical outcomes. Methods A fluorescence immunoassay (FLI) was used to detect anti-FVIII antibodies in 491 samples from 371 HA patients. Results Assessments of antibody profiles showed that the presence of anti-FVIII IgG1, IgG2, or IgG4 correlated qualitatively and quantitatively with the presence of a FVIII inhibitor as reported by the Nijmegen-Bethesda assay (NBA). Forty-eight patients with a negative inhibitor history contributed serial samples to the study, including seven patients who had negative NBA titers initially and later converted to NBA-positive. The FLI detected anti-FVIII IgG1 in five of those seven patients prior to their conversion to NBA-positive. Five of 15 serial-sample patients who had a negative inhibitor history and a positive anti-FVIII IgG1 later developed an inhibitor, compared to 2 of 33 patients with a negative inhibitor history without anti-FVIII IgG1. Conclusions These data provide a rationale for future studies designed both to monitor the dynamics of anti-FVIII antibody profiles in HA patients as a potential predictor of future inhibitor development and to assess the value of the anti-FVIII FLI as a supplement to traditional inhibitor testing. PMID:25354263

  10. A competitive immunoassay for ultrasensitive detection of Hg(2+) in water, human serum and urine samples using immunochromatographic test based on surface-enhanced Raman scattering.

    Science.gov (United States)

    She, Pei; Chu, Yanxin; Liu, Chunwei; Guo, Xun; Zhao, Kang; Li, Jianguo; Du, Haijing; Zhang, Xiang; Wang, Hong; Deng, Anping

    2016-02-04

    An immunochromatographic test (ICT) strip was developed for ultrasensitive competitive immunoassay of Hg(2+). This strategy was achieved by combining the easy-operation and rapidity of ICT with the high sensitivity of surface-enhanced Raman scattering (SERS). Monoclonal antibody (mAb) against Hg(2+) and Raman active substance 4-mercaptobenzoic acid (MBA) dual labelled gold nanoparticles (GNPs) were prepared as an immunoprobe. The Raman scattering intensity of MBA on the test line of the ICT strip was measured for quantitative determination of Hg(2+). The ICT was able to directly detect Hg(2+) without complexing due to the specific recognition of the mAb with Hg(2+). The IC50 and limit of detection (LOD) of the assay for Hg(2+) detection were 0.12 ng mL(-1) and 0.45 pg mL(-1), respectively. There was no cross-reactivity (CR) of the assay with other nineteen ions and the ICT strips could be kept for 5 weeks without loss of activity. The recoveries of the assay for water, human serum and urine samples spiked with Hg(2+) were in range of 88.3-107.3% with the relative standard deviations (RSD) of 1.5-9.5% (n = 3). The proposed ICT was used for the detection of Hg(2+) in urine samples collected from Occupational Disease Hospital and the results were confirmed by cold-vapor atomic fluorescence spectroscopy (CV-AFS). The assay exhibited high sensitivity, selectivity, stability, precision and accuracy, demonstrating a promising method for the detection of trace amount of Hg(2+) in environmental water samples and biological serum and urine samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Comparison of clinical performance of antigen based-enzyme immunoassay (EIA) and major outer membrane protein (MOMP)-PCR for detection of genital Chlamydia trachomatis infection.

    Science.gov (United States)

    Nateghi Rostami, Mahmoud; Hossein Rashidi, Batool; Aghsaghloo, Fatemeh; Nazari, Razieh

    2016-06-01

    Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen worldwide. Early detection and treatment of C.trachomatis genital infection prevent serious reproductive complications. Performances of enzyme immunoassay (EIA) and major outer membrane protein (MOMP)-polymerase chain reaction (PCR) for diagnosis of genital C.trachomatis infection in women were compared. In this cross sectional study a total of 518 women volunteers were included (33.67±8.3 yrs) who had been referred to Gynecology clinics of Qom province, Iran, were included. Endocervical swab specimens were collected to detect lipopolysaccharide (LPS) antigen in EIA and to amplify MOMP gene of C.trachomatis in PCR. Results were confirmed using ompI nested-PCR. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were calculated for performance of the tests. Odds ratios were determined using binary logistic regression analysis. In total, 37 (7.14%) cases were positive by EIA and/or MOMP-PCR. All discrepant results were confirmed by nested-PCR. Sensitivity, specificity, PPV and NPV values of EIA were 59.46%, 100%, 100% and 96.98%, and those of MOMP-PCR were 97.30%, 100%, 100%, 99.79%, respectively. Reproductive complications including 2.7% ectopic pregnancy, 5.4% stillbirth, 5.4% infertility, and 10.8% PROM were recorded. The risk of developing chlamydiosis was increased 4.8-fold in volunteers with cervicitis (p<0.05; OR 4.80; 95% CI 1.25-18.48). C.trachomatis infection should be regarded in women of reproductive ages especially those with cervicitis. Primary screening of women by using the low cost antigen-EIA is recommended; however, due to the low sensitivity of Ag-EIA, verification of the negative results by a DNA amplification method is needed.

  12. Environmental Pollution: Noise Pollution - Sonic Boom

    Science.gov (United States)

    1977-06-01

    UNCLASSIFIED AD-A041 400 DDC/BIB-77/06 ENVIRONMENTAL POLLUTION NOISE POLLUTION SONIC BOOM A DDC BIBLIOGRAPHY DDC-TAS Cameron Station Alexandria, Va...rn7Sttio 658S-A041 400 4 TITLE xand r.VuhtlVlia) 2 TA i b- 1iblog ra ph y ENVIRONMENTAL POLLUTION : --. Apr-l IM59-Jul, 7NOISE POLLUTION -SONIC BOOM. 1,976...BIBLIOGRAPHY SEARCH CONTROL NO. /2OM09 AD- 769 970 20/1 1/3 DEFENSE UOCUMENTATION CENTER ALEXANDRIA VA ENVIRONMENTAL POLLUTION : NOISE POLLUTION

  13. A competitive immunoassay for ultrasensitive detection of Hg"2"+ in water, human serum and urine samples using immunochromatographic test based on surface-enhanced Raman scattering

    International Nuclear Information System (INIS)

    She, Pei; Chu, Yanxin; Liu, Chunwei; Guo, Xun; Zhao, Kang; Li, Jianguo; Du, Haijing; Zhang, Xiang; Wang, Hong; Deng, Anping

    2016-01-01

    An immunochromatographic test (ICT) strip was developed for ultrasensitive competitive immunoassay of Hg"2"+. This strategy was achieved by combining the easy-operation and rapidity of ICT with the high sensitivity of surface-enhanced Raman scattering (SERS). Monoclonal antibody (mAb) against Hg"2"+ and Raman active substance 4-mercaptobenzoic acid (MBA) dual labelled gold nanoparticles (GNPs) were prepared as an immunoprobe. The Raman scattering intensity of MBA on the test line of the ICT strip was measured for quantitative determination of Hg"2"+. The ICT was able to directly detect Hg"2"+ without complexing due to the specific recognition of the mAb with Hg"2"+. The IC_5_0 and limit of detection (LOD) of the assay for Hg"2"+ detection were 0.12 ng mL"−"1 and 0.45 pg mL"−"1, respectively. There was no cross-reactivity (CR) of the assay with other nineteen ions and the ICT strips could be kept for 5 weeks without loss of activity. The recoveries of the assay for water, human serum and urine samples spiked with Hg"2"+ were in range of 88.3–107.3% with the relative standard deviations (RSD) of 1.5–9.5% (n = 3). The proposed ICT was used for the detection of Hg"2"+ in urine samples collected from Occupational Disease Hospital and the results were confirmed by cold-vapor atomic fluorescence spectroscopy (CV-AFS). The assay exhibited high sensitivity, selectivity, stability, precision and accuracy, demonstrating a promising method for the detection of trace amount of Hg"2"+ in environmental water samples and biological serum and urine samples. - Highlights: • The proposed ICT was able to directly detect Hg"2"+ without formation of Hg"2"+-ligand complex. • The proposed ICT exhibited high sensitivity, specificity, stability, precision and accuracy for Hg"2"+ detection. • The proposed ICT was applicable for the detection of trace amount of Hg"2"+ in water, human serum and urine samples.

  14. A competitive immunoassay for ultrasensitive detection of Hg{sup 2+} in water, human serum and urine samples using immunochromatographic test based on surface-enhanced Raman scattering

    Energy Technology Data Exchange (ETDEWEB)

    She, Pei; Chu, Yanxin [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Liu, Chunwei; Guo, Xun [OptoTrace (Suzhou) Technologies, Inc., STE 316, Building 4, No. 218, Xinghu Street, bioBAY, Suzhou Industrial Park, Suzhou 215123 (China); Zhao, Kang [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Li, Jianguo, E-mail: lijgsd@suda.edu.cn [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Du, Haijing; Zhang, Xiang [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China); Wang, Hong [OptoTrace (Suzhou) Technologies, Inc., STE 316, Building 4, No. 218, Xinghu Street, bioBAY, Suzhou Industrial Park, Suzhou 215123 (China); Deng, Anping, E-mail: denganping@suda.edu.cn [The Key Lab of Health Chemistry & Molecular Diagnosis of Suzhou, College of Chemistry, Chemical Engineering & Materials Science, Soochow University, Renai Road 199, Suzhou 215123 (China)

    2016-02-04

    An immunochromatographic test (ICT) strip was developed for ultrasensitive competitive immunoassay of Hg{sup 2+}. This strategy was achieved by combining the easy-operation and rapidity of ICT with the high sensitivity of surface-enhanced Raman scattering (SERS). Monoclonal antibody (mAb) against Hg{sup 2+} and Raman active substance 4-mercaptobenzoic acid (MBA) dual labelled gold nanoparticles (GNPs) were prepared as an immunoprobe. The Raman scattering intensity of MBA on the test line of the ICT strip was measured for quantitative determination of Hg{sup 2+}. The ICT was able to directly detect Hg{sup 2+} without complexing due to the specific recognition of the mAb with Hg{sup 2+}. The IC{sub 50} and limit of detection (LOD) of the assay for Hg{sup 2+} detection were 0.12 ng mL{sup −1} and 0.45 pg mL{sup −1}, respectively. There was no cross-reactivity (CR) of the assay with other nineteen ions and the ICT strips could be kept for 5 weeks without loss of activity. The recoveries of the assay for water, human serum and urine samples spiked with Hg{sup 2+} were in range of 88.3–107.3% with the relative standard deviations (RSD) of 1.5–9.5% (n = 3). The proposed ICT was used for the detection of Hg{sup 2+} in urine samples collected from Occupational Disease Hospital and the results were confirmed by cold-vapor atomic fluorescence spectroscopy (CV-AFS). The assay exhibited high sensitivity, selectivity, stability, precision and accuracy, demonstrating a promising method for the detection of trace amount of Hg{sup 2+} in environmental water samples and biological serum and urine samples. - Highlights: • The proposed ICT was able to directly detect Hg{sup 2+} without formation of Hg{sup 2+}-ligand complex. • The proposed ICT exhibited high sensitivity, specificity, stability, precision and accuracy for Hg{sup 2+} detection. • The proposed ICT was applicable for the detection of trace amount of Hg{sup 2+} in water, human serum and urine samples.

  15. Sonication assisted Agrobacterium -mediated transformation of ...

    African Journals Online (AJOL)

    In this study, a protocol was developed to obtain stable lines of the Spring Dendrobium cultivar 'Sanya' via sonication assisted Agrobacterium-mediated transformation (SAAT) of protocorm-like bodies (PLBs). Agrobacterium tumefaciens strain LBA4404 was used with the binary vector AG205 containing the chalcone ...

  16. Hydrogen storage in sonicated carbon materials

    NARCIS (Netherlands)

    Hirscher, M.; Becher, M.; Haluska, M.; Dettlaff-Weglikowska, U.; Quintel, A.; Duesberg, G.S.; Choi, Y.J.; Downes, P.; Hulman, M.; Roth, S.; Stepanek, I.; Bernier, P.

    2001-01-01

    The hydrogen storage in purified single-wall carbon nanotubes (SWNTs), graphite and diamond powder was investigated at room temperature and ambient pressure. The samples were sonicated in 5 M HNO3 for various periods of time using an ultrasonic probe of the alloy Ti-6Al-4V. The goal of this

  17. The Social and Sonic Semantics of Reggae

    DEFF Research Database (Denmark)

    Levisen, Carsten

    2017-01-01

    This study breaks new ground into the emerging discipline of sonic semantics and the study of language ideologies in postcolonial contexts. The case in point is the reggae sociality in Port Vila, Vanuatu, where young Pacific Islanders are forming new ways of socializing on the fragments of kastom...

  18. Sonic morphology: Aesthetic dimensional auditory spatial awareness

    Science.gov (United States)

    Whitehouse, Martha M.

    The sound and ceramic sculpture installation, " Skirting the Edge: Experiences in Sound & Form," is an integration of art and science demonstrating the concept of sonic morphology. "Sonic morphology" is herein defined as aesthetic three-dimensional auditory spatial awareness. The exhibition explicates my empirical phenomenal observations that sound has a three-dimensional form. Composed of ceramic sculptures that allude to different social and physical situations, coupled with sound compositions that enhance and create a three-dimensional auditory and visual aesthetic experience (see accompanying DVD), the exhibition supports the research question, "What is the relationship between sound and form?" Precisely how people aurally experience three-dimensional space involves an integration of spatial properties, auditory perception, individual history, and cultural mores. People also utilize environmental sound events as a guide in social situations and in remembering their personal history, as well as a guide in moving through space. Aesthetically, sound affects the fascination, meaning, and attention one has within a particular space. Sonic morphology brings art forms such as a movie, video, sound composition, and musical performance into the cognitive scope by generating meaning from the link between the visual and auditory senses. This research examined sonic morphology as an extension of musique concrete, sound as object, originating in Pierre Schaeffer's work in the 1940s. Pointing, as John Cage did, to the corporeal three-dimensional experience of "all sound," I composed works that took their total form only through the perceiver-participant's participation in the exhibition. While contemporary artist Alvin Lucier creates artworks that draw attention to making sound visible, "Skirting the Edge" engages the perceiver-participant visually and aurally, leading to recognition of sonic morphology.

  19. Microfluidic "Pouch" Chips for Immunoassays and Nucleic Acid Amplification Tests.

    Science.gov (United States)

    Mauk, Michael G; Liu, Changchun; Qiu, Xianbo; Chen, Dafeng; Song, Jinzhao; Bau, Haim H

    2017-01-01

    Microfluidic cassettes ("chips") for processing and analysis of clinical specimens and other sample types facilitate point-of-care (POC) immunoassays and nucleic acid based amplification tests. These single-use test chips can be self-contained and made amenable to autonomous operation-reducing or eliminating supporting instrumentation-by incorporating laminated, pliable "pouch" and membrane structures for fluid storage, pumping, mixing, and flow control. Materials and methods for integrating flexible pouch compartments and diaphragm valves into hard plastic (e.g., acrylic and polycarbonate) microfluidic "chips" for reagent storage, fluid actuation, and flow control are described. We review several versions of these pouch chips for immunoassay and nucleic acid amplification tests, and describe related fabrication techniques. These protocols thus offer a "toolbox" of methods for storage, pumping, and flow control functions in microfluidic devices.

  20. Variance function estimation for immunoassays

    International Nuclear Information System (INIS)

    Raab, G.M.; Thompson, R.; McKenzie, I.

    1980-01-01

    A computer program is described which implements a recently described, modified likelihood method of determining an appropriate weighting function to use when fitting immunoassay dose-response curves. The relationship between the variance of the response and its mean value is assumed to have an exponential form, and the best fit to this model is determined from the within-set variability of many small sets of repeated measurements. The program estimates the parameter of the exponential function with its estimated standard error, and tests the fit of the experimental data to the proposed model. Output options include a list of the actual and fitted standard deviation of the set of responses, a plot of actual and fitted standard deviation against the mean response, and an ordered list of the 10 sets of data with the largest ratios of actual to fitted standard deviation. The program has been designed for a laboratory user without computing or statistical expertise. The test-of-fit has proved valuable for identifying outlying responses, which may be excluded from further analysis by being set to negative values in the input file. (Auth.)

  1. Competitive Protein-binding assay-based Enzyme-immunoassay Method, Compared to High-pressure Liquid Chromatography, Has a Very Lower Diagnostic Value to Detect Vitamin D Deficiency in 9–12 Years Children

    Science.gov (United States)

    Zahedi Rad, Maliheh; Neyestani, Tirang Reza; Nikooyeh, Bahareh; Shariatzadeh, Nastaran; Kalayi, Ali; Khalaji, Niloufar; Gharavi, Azam

    2015-01-01

    Background: The most reliable indicator of Vitamin D status is circulating concentration of 25-hydroxycalciferol (25(OH) D) routinely determined by enzyme-immunoassays (EIA) methods. This study was performed to compare commonly used competitive protein-binding assays (CPBA)-based EIA with the gold standard, high-pressure liquid chromatography (HPLC). Methods: Concentrations of 25(OH) D in sera from 257 randomly selected school children aged 9–11 years were determined by two methods of CPBA and HPLC. Results: Mean 25(OH) D concentration was 22 ± 18.8 and 21.9 ± 15.6 nmol/L by CPBA and HPLC, respectively. However, mean 25(OH) D concentrations of the two methods became different after excluding undetectable samples (25.1 ± 18.9 vs. 29 ± 14.5 nmol/L, respectively; P = 0.04). Based on predefined Vitamin D deficiency as 25(OH) D < 12.5 nmol/L, CPBA sensitivity and specificity were 44.2% and 60.6%, respectively, compared to HPLC. In receiver operating characteristic curve analysis, the best cut-offs for CPBA was 5.8 nmol/L, which gave 82% sensitivity, but specificity was 17%. Conclusions: Though CPBA may be used as a screening tool, more reliable methods are needed for diagnostic purposes. PMID:26330983

  2. Competitive Protein-binding assay-based Enzyme-immunoassay Method, Compared to High-pressure Liquid Chromatography, Has a Very Lower Diagnostic Value to Detect Vitamin D Deficiency in 9-12 Years Children.

    Science.gov (United States)

    Zahedi Rad, Maliheh; Neyestani, Tirang Reza; Nikooyeh, Bahareh; Shariatzadeh, Nastaran; Kalayi, Ali; Khalaji, Niloufar; Gharavi, Azam

    2015-01-01

    The most reliable indicator of Vitamin D status is circulating concentration of 25-hydroxycalciferol (25(OH) D) routinely determined by enzyme-immunoassays (EIA) methods. This study was performed to compare commonly used competitive protein-binding assays (CPBA)-based EIA with the gold standard, high-pressure liquid chromatography (HPLC). Concentrations of 25(OH) D in sera from 257 randomly selected school children aged 9-11 years were determined by two methods of CPBA and HPLC. Mean 25(OH) D concentration was 22 ± 18.8 and 21.9 ± 15.6 nmol/L by CPBA and HPLC, respectively. However, mean 25(OH) D concentrations of the two methods became different after excluding undetectable samples (25.1 ± 18.9 vs. 29 ± 14.5 nmol/L, respectively; P = 0.04). Based on predefined Vitamin D deficiency as 25(OH) D < 12.5 nmol/L, CPBA sensitivity and specificity were 44.2% and 60.6%, respectively, compared to HPLC. In receiver operating characteristic curve analysis, the best cut-offs for CPBA was 5.8 nmol/L, which gave 82% sensitivity, but specificity was 17%. Though CPBA may be used as a screening tool, more reliable methods are needed for diagnostic purposes.

  3. Ultrasensitive multi-analyte electrochemical immunoassay based on GNR-modified heated screen-printed carbon electrodes and PS@PDA-metal labels for rapid detection of MMP-9 and IL-6.

    Science.gov (United States)

    Shi, Jian-Jun; He, Ting-Ting; Jiang, Fang; Abdel-Halim, E S; Zhu, Jun-Jie

    2014-05-15

    An ultrasensitive electrochemical immunoassay was developed for rapid detection of interleukin-6 (IL-6) and matrix metallopeptidase-9 (MMP-9); the method utilized PS@PDA-metal nanocomposites based on graphene nanoribbon (GNR)-modified heated screen-printed carbon electrode (HSPCE). Because of the good hydrophilicity and low toxicity, GNRs were used to immobilize antibodies (Ab) and amplify the electrochemical signal. PS@PDA-metal was used to label antibodies and generate a strong electrochemical signal in acetic buffer. A sandwich strategy was adopted to achieve simultaneous detection of MMP-9 and IL-6 based on HSPCE without cross-talk between adjacent electrodes in the range of 10(-5) to 10(3) ng mL(-1) with detection limits of 5 fg mL(-1) and 0.1 pg mL(-1) (S/N=3), respectively. The proposed method showed wide detection range, low detection limit, acceptable stability and good reproducibility. Satisfactory results were also obtained in the practical samples, thus showing this is a promising technique for simultaneous clinical detection of biocomponent proteins. © 2013 Elsevier B.V. All rights reserved.

  4. USAF Flight Test Investigation of Focused Sonic Booms: Project Have Bears

    Science.gov (United States)

    Downing, Micah; Zamot, Noel; Moss, Chris; Morin, Daniel; Wolski, Ed; Chung, Sukhwan; Plotkin, Kenneth; Maglieri, Domenic

    1996-01-01

    Supersonic operations from military aircraft generate sonic booms that can affect people, animals and structures. A substantial experimental data base exists on sonic booms for aircraft in steady flight and confidence in the predictive techniques has been established. All the focus sonic boom data that are in existence today were collected during the 60's and 70's as part of the information base to the US Supersonic Transport program and the French Jericho studies for the Concorde. These experiments formed the data base to develop sonic boom propagation and prediction theories for focusing. There is a renewed interest in high-speed transports for civilian application. Moreover, today's fighter aircraft have better performance capabilities, and supersonic flights ars more common during air combat maneuvers. Most of the existing data on focus booms are related to high-speed civil operations such as transitional linear accelerations and mild turns. However, military aircraft operating in training areas perform more drastic maneuvers such as dives and high-g turns. An update and confirmation of USAF prediction capabilities is required to demonstrate the ability to predict and control sonic boom impacts, especially those produced by air combat maneuvers.

  5. Electrochemical immunoassay using magnetic beads for the determination of zearalenone in baby food: an anticipated analytical tool for food safety.

    Science.gov (United States)

    Hervás, Miriam; López, Miguel Angel; Escarpa, Alberto

    2009-10-27

    In this work, electrochemical immunoassay involving magnetic beads to determine zearalenone in selected food samples has been developed. The immunoassay scheme has been based on a direct competitive immunoassay method in which antibody-coated magnetic beads were employed as the immobilisation support and horseradish peroxidase (HRP) was used as enzymatic label. Amperometric detection has been achieved through the addition of hydrogen peroxide substrate and hydroquinone as mediator. Analytical performance of the electrochemical immunoassay has been evaluated by analysis of maize certified reference material (CRM) and selected baby food samples. A detection limit (LOD) of 0.011 microg L(-1) and EC(50) 0.079 microg L(-1) were obtained allowing the assessment of the detection of zearalenone mycotoxin. In addition, an excellent accuracy with a high recovery yield ranging between 95 and 108% has been obtained. The analytical features have shown the proposed electrochemical immunoassay to be a very powerful and timely screening tool for the food safety scene.

  6. Pilot Test of a Novel Method for Assessing Community Response to Low-Amplitude Sonic Booms

    Science.gov (United States)

    Fidell, Sanford; Horonjeff, Richard D.; Harris, Michael

    2012-01-01

    A pilot test of a novel method for assessing residents annoyance to sonic booms was performed. During a two-week period, residents of the base housing area at Edwards Air Force Base provided data on their reactions to sonic booms using Smartphone-based interviews. Noise measurements were conducted at the same time. The report presents information about data collection methods and about test participants reactions to low-amplitude sonic booms. The latter information should not be viewed as definitive for several reasons. It may not be reliably generalized to the wider U.S. residential population (because it was not derived from a representative random sample) and the sample itself was not large.

  7. Electrochemical immunoassay for the carcinoembryonic antigen based on the use of a glassy carbon electrode modified with an octahedral Cu2O-gold nanocomposite and staphylococcal protein for signal amplification.

    Science.gov (United States)

    Qin, Zhen; Xu, Wei; Chen, Shuai; Chen, Jun; Qiu, Jing Fu; Li, Chao Rui

    2018-04-24

    The authors describe an electrochemical immunoassay for ultrasensitive direct determination of the carcinoembryonic antigen (CEA). A nanocomposite consisting of octahedral Cu2O nanocrystals covered with gold nanoparticles was utilized to modify a glassy carbon electrode which gives a strongly enhanced chronoamperometric signal for H 2 O 2 which is used as an electrochemical probe. The morphology and elemental composition of the the nanocomposite was studied by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy. In addition, staphylococcal protein A was placed on the electrode for efficient capture of antibody to further enhance the sensitivity of the assay. Under optimal conditions and at a typical working voltage of -0.4 V (vs. Ag/AgCl), the response covers the 2 pg·mL -1 to 20 ng·mL -1 CEA concentration range with a 200 fg·mL -1 lower detection limit. The method was successfully applied to the determination of CEA in (spiked) human serum. Graphical abstract Schematic of the fabrication of an electrochemical immunosensor for ultrasensitive detection the carcinoembryonic antigen. The sensor is based on the use of a glassy carbon electrode modified with an octahedral Cu 2 O-gold nanocomposite and staphylococcal protein A for signal amplification.

  8. Development of immunoassays for detecting clothianidin residue in agricultural products.

    Science.gov (United States)

    Li, Ming; Sheng, Enze; Cong, Lujing; Wang, Minghua

    2013-04-17

    Two enzyme-linked immunosorbent assays (ELISAs) based on polyclonal antibodies (PcAbs) for clothianidin are described: colorimetric detection format (ELISA) and pattern of chemiluminescent assay (CLEIA). Clothianidin hapten was synthesized and conjugated to bovine serum albumin (BSA) and ovalbumin (OVA) to produce immunogen and coating antigen. Anticlothianidin PcAbs were obtained from immunized New Zealand white rabbits. Under optimal conditions, the half-maximal inhibition concentration (IC₅₀) and the limit of detection (LOD, IC₂₀) of clothianidin were 0.046 and 0.0028 mg/L for the ELISA and 0.015 and 0.0014 mg/L for the CLEIA, respectively. There were no obvious cross-reactivities of the antibodies with its analogues except for dinotefuran. Recoveries of 76.4-116.4% for the immunoassays were achieved from spiked samples. The results of immunoassays for the spiked and authentic samples were largely consistent with gas chromatography. Therefore, the proposed immunoassays would be convenient and satisfactory analytical methods for the monitoring of clothianidin in agricultural products.

  9. Current status and future developments in radiolabelled immunoassays

    International Nuclear Information System (INIS)

    Edwards, R.

    1998-01-01

    Radioisotopes are used extensively in medical practice and their use in RIA or IRMA usually represent a small proportion of the total. Radiolabelled immunoassays based on 125 I constitute a simple didactic, cost effective and robust technology which is still regarded as the reference method in many clinical applications. The IAEA has implemented many successful programmes using the ''bulk reagent'' approach, involving 68 countries in all the different regions. The main achievements have been in technology transfer with self sufficiency in production for some countries; training of large numbers of staff; quality control and quality assurance schemes; devolution of screening programmes for neonatal congenital hypothryoidism. Alternatives to the use of radioisotopic tracers are constrained by many factors and are often only available in restricted commercial packages. They are often not suitable for technology transfer programmes and often lack any didactic component in addition to a relative high cost. The production of radiolabels using 125 I is both simple and adaptable. In addition expertise in their preparation and purification is widespread even in developing countries. Together with the ease of producing antibodies, the facts have made 125 I-radiolabelled immunoassays ideal for investigative procedures for many research activities (30,31) particularly in the medical context where radioisotopes are commonly used. In conclusion, even a superficial examination of public health statistics for various countries throughout the continents indicates a need for a simple, inexpensive and robust analytical tool. In this light, there is a predicted continuing role for radiolabelled immunoassays. (author)

  10. Simple patterned nanofiber scaffolds and its enhanced performance in immunoassay.

    Directory of Open Access Journals (Sweden)

    Jing Wang

    Full Text Available Cancer has become the leading cause of death worldwide; early diagnosis and treatment of cancers is critical for the survival of the patients. The concentration of cancer markers in easy-to-access biological fluids can provide great assistance in screening for occult primary cancers, distinguishing malignant from benign findings, determining prognosis and prediction for cancer patients. The multiplex detection technology of a panel of cancer markers can greatly increase the accuracy of disease diagnosis. Herein, we briefly fabricate a high-throughput micro-immunoassay based on the electrospun polystyrene (PS substrates to improve detection sensitivity. The immunoassay was evaluated by analyzing three different cancer biomarkers (AFP, CEA, VEGF. For AFP, CEA, VEGF immunofluorescence assay, the LOD of assay conducted on electrospun PS substrates before or after plasma and the conventional PS substrates were 0.42, 0.10, 1.12 ng/mL, 0.57, 0.09, 1.24 ng/mL, and 159.75, 26.19, 385.59 pg/mL, respectively (P < 0.05. Due to the high porosity and large surface area-to-volume ratio which is the foremost merit of nanostructures, and the plasma treatment which make the hydrophobic PS nanofibers hydropholic, the nanofibers substrates showed sufficient retention of immunoassay functionality and high potential for capture molecules immobilization. Consequently, the immunofluorescence assay conducted on electrospun PS substrates could significantly enhance the sensitivity and limits of detection.

  11. PRODUCTION WELL PERFORMANCE ENHANCEMENT USING SONICATION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Michael A. Adewumi; M. Thaddeus Ityokumbul; Robert W. Watson; Mario Farias; Glenn Heckman; Johnson Olanrewaju; Eltohami Eltohami; Bruce G. Miller; W. Jack Hughes; Thomas C. Montgomery

    2003-12-17

    The objective of this project is to develop a sonic well performance enhancement technology that focuses on near wellbore formations. In order to successfully achieve this objective, a three-year project has been defined with each year consisting of four tasks. The first task is the laboratory-scale study whose goal is to determine the underlying principles of the technology. The second task will develop a scale-up mathematical model to serve as the design guide for tool development. The third task is to develop effective transducers that can operate with variable frequency so that the most effective frequencies can be applied in any given situation. The system, assembled as part of the production string, ensures delivery of sufficient sonic energy to penetrate the near-wellbore formation. The last task is the actual field testing of the tool. The first year of the project has been completed.

  12. Living Melodies - Coevolution Of Sonic Communication

    DEFF Research Database (Denmark)

    Dahlstedt, Palle; Nordahl, Mats G.

    2001-01-01

    The authors have constructed an artificial world of coevolving communicating agents. The behavior of the agents is described in terms of a simple genetic programming framework, which allows the evolution of foraging behavior and movement in order to reproduce, as well as sonic communication....... The sound of the entire world is used as musical raw material for the work. Musically interesting and useful structures are found to emerge....

  13. Sonic Fiction as the Mapping of Difference

    DEFF Research Database (Denmark)

    Holmboe, Rasmus; Stricker, Jan Høgh

    2015-01-01

    The here proposed audio paper/audio lecture performance is an iteration of a site-specific participatory performance piece by Danish artist, composer and musician, Andreas Führer. The piece, which has the title THE MAP IS NOT THE TERRITORY D’OR, is a scored sound walk, which shows a map designati......) as a discussion and contextualisation of sonic materialist (Cox, 2011) and signifying representationalist (Kim-Cohen, 2009) positions....

  14. Six propositions on the sonics of pornography

    OpenAIRE

    Mowlabocus, Sharif; Medhurst, Andy

    2017-01-01

    Pornography (and all its contentious pleasures, contested politics and attendant problematics) is enjoying a fresh wave of academic attention. The overwhelming majority of these studies, however, focus on the visual discourses of sexually explicit material. This risks the sonic dimensions of pornography being overlooked entirely. Yet porn is anything but silent. This speculative article maps out some of the ways in which the sounds of pornography (and the pornography of sound) might be approa...

  15. Sonic boom predictions using a modified Euler code

    Science.gov (United States)

    Siclari, Michael J.

    1992-04-01

    The environmental impact of a next generation fleet of high-speed civil transports (HSCT) is of great concern in the evaluation of the commercial development of such a transport. One of the potential environmental impacts of a high speed civilian transport is the sonic boom generated by the aircraft and its effects on the population, wildlife, and structures in the vicinity of its flight path. If an HSCT aircraft is restricted from flying overland routes due to excessive booms, the commercial feasibility of such a venture may be questionable. NASA has taken the lead in evaluating and resolving the issues surrounding the development of a high speed civilian transport through its High-Speed Research Program (HSRP). The present paper discusses the usage of a Computational Fluid Dynamics (CFD) nonlinear code in predicting the pressure signature and ultimately the sonic boom generated by a high speed civilian transport. NASA had designed, built, and wind tunnel tested two low boom configurations for flight at Mach 2 and Mach 3. Experimental data was taken at several distances from these models up to a body length from the axis of the aircraft. The near field experimental data serves as a test bed for computational fluid dynamic codes in evaluating their accuracy and reliability for predicting the behavior of future HSCT designs. Sonic boom prediction methodology exists which is based on modified linear theory. These methods can be used reliably if near field signatures are available at distances from the aircraft where nonlinear and three dimensional effects have diminished in importance. Up to the present time, the only reliable method to obtain this data was via the wind tunnel with costly model construction and testing. It is the intent of the present paper to apply a modified three dimensional Euler code to predict the near field signatures of the two low boom configurations recently tested by NASA.

  16. In Situ Monitoring of Dispersion Dynamics of Carbon Nanotubes during Sonication Using Electrical Conductivity Measurements

    Directory of Open Access Journals (Sweden)

    Syed Sadiq Ali

    2015-01-01

    Full Text Available The main challenge in the fabrication of carbon nanotube- (CNT- based composite materials is the optimization of the sonication time in order to obtain homogenous and uniform dispersion of CNTs. Past studies mostly relied on postprocessing characterization techniques to address this issue. In the present, however, in situ monitoring of dispersion dynamics of CNTs in distilled water is carried out using instantaneous conductivity measurements. Using a computer controlled data acquisition system, the time evolution of the solution conductivity was carefully recorded. The data were then used to evaluate the intensity of turbulent fluctuations, which clearly highlighted the existence of three distinct sonication phases. During the first phase, the conductivity fluctuations initially increased attaining ultimately a maximum, thus indicating the occurrence of large agglomerates of CNTs. During the second phase of sonication, the solution conductivity showed a rather steep increase while fluctuations steadily declined. This phenomenon can be attributed to the breakdown of large CNT agglomerates, resulting in greater dispersion homogeneity of CNTs. During the third phase, after almost 650 kJ/L of sonication energy, the conductivity increase was almost negligible. The fluctuation intensity also remained constant during this phase signifying that the further sonication was no longer required.

  17. Three-dimensional nanoflower-like MnO2 functionalized graphene as catalytically promoted nanolabels for ultrasensitive electrochemiluminescence immunoassay

    International Nuclear Information System (INIS)

    Su, Min; Zhang, Yan; Song, Xianrang; Ge, Shenguang; Yan, Mei; Yu, Jinghua; Huang, Jiadong

    2013-01-01

    A novel electrochemiluminescence (ECL) immunosensor based on the peroxydisulfate solution for detection of prostate-specific antigen (PSA) has been developed. In this work, gold nanoparticles (AuNPs) were electrodeposited on the glassy carbon electrode surface, which could increase the surface area to capture a large amount of primary antibodies as well as to improve the electronic transmission rate. The as-prepared bionanolabels, three-dimensional (3D) nanoflower-like MnO 2 functionalized graphene (GN/MnO 2 ), with novel hybrid architecture were initially fabricated via electrostatic interaction. Then, to provide an effective matrix for antibody immobilization with good stability and bioactivity, the novel materials were modified by AuNPs with the aid of poly (diallyldimethylammonium chloride) via a simple sonication-induced assembly method. In this immunosensor, MnO 2 with the characteristics of well electrochemical behavior, low cost, and environmental-friendly, is used as a substitute for horseradish peroxidase to catalyze H 2 O 2 to produce O 2 , and its 3D nanoflower-like structure is beneficial for the unparallel surface-to-volume ratio. Furthermore, a simple, low-cost and portable home-made potential transformer was utilized in this system to take the place of conventional electrochemical workstation. With a sandwich-type immunoassay format, the amount of functionalized GN/MnO 2 labeled antibodies increased with the increment of antigens in the samples, which implied that the ECL signals enhanced with the increase of in situ generated O 2 due to the enhancive catalysis of MnO 2 to the H 2 O 2 . The immunosensor displayed excellent analytical performance for the detection of PSA in the range of 0.005–10 ng mL −1 with a detection limit of 2.5 pg mL −1 at 3σ. Moreover, the proposed method showed good precision, acceptable stability and reproducibility, and could be used for the detection of PSA in real samples. The proposed method provides a new

  18. High-Quality Seismic Observations of Sonic Booms

    Science.gov (United States)

    Wurman, Gilead; Haering, Edward A., Jr.; Price, Michael J.

    2011-01-01

    The SonicBREWS project (Sonic Boom Resistant Earthquake Warning Systems) is a collaborative effort between Seismic Warning Systems, Inc. and NASA Dryden Flight Research Center. This project aims to evaluate the effects of sonic booms on Earthquake Warning Systems in order to prevent such systems from experiencing false alarms due to sonic booms. The airspace above the Antelope Valley, California includes the High Altitude Supersonic Corridor and the Black Mountain Supersonic Corridor. These corridors are among the few places in the US where supersonic flight is permitted, and sonic booms are commonplace in the Antelope Valley. One result of this project is a rich dataset of high-quality accelerometer records of sonic booms which can shed light on the interaction between these atmospheric phenomena and the solid earth. Nearly 100 sonic booms were recorded with low-noise triaxial MEMS accelerometers recording 1000 samples per second. The sonic booms had peak overpressures ranging up to approximately 10 psf and were recorded in three flight series in 2010 and 2011. Each boom was recorded with up to four accelerometers in various array configurations up to 100 meter baseline lengths, both in the built environment and the free field. All sonic booms were also recorded by nearby microphones. We present the results of the project in terms of the potential for sonic-boom-induced false alarms in Earthquake Warning Systems, and highlight some of the interesting features of the dataset.

  19. Multiplex immunoassay for persistent organic pollutants in tilapia: comparison of imaging- and flow cytometry-based platforms using spectrally encoded paramagnetic microspheres

    NARCIS (Netherlands)

    Meimaridou, A.; Haasnoot, W.; Shelver, W.L.; Franek, M.; Nielen, M.W.F.

    2013-01-01

    Recent developments in spectrally encoded microspheres (SEMs)-based technologies provide high multiplexing possibilities. Most SEMs-based assays require a flow cytometer with sophisticated fluidics and optics. A new imaging super-paramagnetic SEMs-based alternative platform transports SEMs with

  20. Sound absorption enhancement of nonwoven felt by using coupled membrane - sonic crystal inclusion

    Science.gov (United States)

    Fitriani, M. C.; Yahya, I.; Harjana; Ubaidillah; Aditya, F.; Siregar, Y.; Moeliono, M.; Sulaksono, S.

    2016-11-01

    The experimental results from laboratory test on the sound absorption performance of nonwoven felt with an array thin tubes and sonic crystal inclusions reported in this paper. The nonwoven felt sample was produced by a local company with 15 mm in its thickness and 900 gsm. The 6.4 mm diameter plastic straw was used to construct the thin tubes array while the sonic crystal is arranged in a 4 × 4 lattice crystal formation. It made from a PVC cylinder with 17 mm and 50 mm in diameter and length respectively. All cylinders have two holes positioned on 10 mm and 25 mm from the base. The results show that both treatments, array of thin tube and sonic crystal inclusions are effectively increased the sound absorption coefficient of the nonwoven felt significantly especially in the low frequency range starting from 200Hz.

  1. Design methodology for a community response questionnaire on sonic boom exposure

    Science.gov (United States)

    Farbry, John E., Jr.; Fields, James M.; Molino, John A.; Demiranda, Gwendolyn A.

    1991-01-01

    A preliminary draft questionnaire concerning community response to sonic booms was developed. Interviews were conducted in two communities that had experienced supersonic overflights of the SR-71 airplane for several years. Even though the overflights had ceased about 6 months prior to the interviews, people clearly remembered hearing sonic booms. A total of 22 people living in central Utah and 23 people living along Idaho/Washington state border took part in these interviews. The draft questionnaire was constantly modified during the study in order to evaluate different versions. Questions were developed which related to annoyance, startle, sleep disturbance, building vibration, and building damage. Based on the data collected, a proposed community response survey response instrument was developed for application in a full-scale sonic boom study.

  2. Recent advancements in the immunoassay domain

    International Nuclear Information System (INIS)

    Pradelles, Ph.

    1997-01-01

    The two types of immunoassay techniques, the competition analysis and the immuno-metric analysis (sandwich type), are described; the tracers used with theses methods have high specific radioactivity levels in order to be traced at extremely low content. Non radioactive tracers have been also developed, such as enzymatic, fluorescent, luminescent tracers, which are simpler and may be used at home. The Cea has recently developed some innovative immunoassay formats, such as acetylcholinesterase as a new enzymatic tracer, and immuno-metric dosage for very small molecules such as haptenes

  3. Enhanced Harnessing of the Graviola Bioactive Components Using a Neoteric Sonication Cum Microwave Coadjuvant Extraction Protocol

    Directory of Open Access Journals (Sweden)

    Se Chul Chun

    2018-02-01

    Full Text Available Graviola is one of the most accomplished natural anticancer therapists gaining popularity in recent times. Harnessing the full benefit from tapping all of its rich bioactive reservoirs is absolutely worthy and mandatory. It is in this regard that a well optimized extraction methodology gains paramount importance. In case of Graviola, no sophistication in terms of extraction methods is reported. A neoteric sonication cum microwave combined extraction technology was introduced that maximized the extraction process and minimized (7 min the extraction time. The extraction efficiency was validated based on the significant enrichment of bioactive ingredients in Graviola extracts following the sonication cum microwave combined protocol.

  4. Auscultation of concrete hydraulic dams by sonic tomography; Auscultation des structures hydrauliques en beton par tomographie sonique

    Energy Technology Data Exchange (ETDEWEB)

    Kharrat, Y.; Rhazi, J.; Ballivy, G. [Sherbrooke Univ., PQ (Canada). Dept. de Genie Civil; Cote, P. [Centre de Nantes, Bouguenais (France)

    1995-12-31

    Sonic tomography, a new nondestructive testing method, was described to document the aging and internal degradation of concrete structures. The method is based on the transmission of sonic waves through concrete structures. New tomographic methodology similar to that used in medical or geophysical imaging was applied to existing sonic auscultation techniques used in civil engineering. In the process the speed of propagation of sonic waves in structures is measured with arrays of detectors. Fissures or zones of degradation can be spatially localized and an internal image of the structure can be constructed. Case studies of two hydraulic dams, one from France, the other in Quebec were presented as illustrations. . The theory and experimental procedures involved were described. 16 refs., 1 tab., 12 figs.

  5. Inversion of Supramolecular Chirality by Sonication-Induced Organogelation

    Science.gov (United States)

    Maity, Sibaprasad; Das, Priyadip; Reches, Meital

    2015-01-01

    Natural helical structures have inspired the formation of well-ordered peptide-based chiral nanostructures in vitro. These structures have drawn much attention owing to their diverse applications in the area of asymmetric catalysts, chiral photonic materials, and nanoplasmonics. The self-assembly of two enantiomeric fluorinated aromatic dipeptides into ordered chiral fibrillar nanostructures upon sonication is described. These fibrils form organogels. Our results clearly indicate that fluorine-fluorine interactions play an important role in self-assembly. Circular dichroism analysis revealed that both peptides (peptides 1 and 2), containing two fluorines, depicted opposite cotton effects in their monomeric form compared with their aggregated form. This shows that supramolecular chirality inversion took place during the stimuli-responsive self-aggregation process. Conversely, peptide 3, containing one fluorine, did not exhibit chirality inversion in sonication-induced organogelation. Therefore, our results clearly indicate that fluorination plays an important role in the organogelation process of these aromatic dipeptides. Our findings may have broad implications regarding the design of chiral nanostructures for possible applications such as chiroptical switches, asymmetric catalysis, and chiral recognitions. PMID:26553508

  6. The Effect of Sonic Booms on Earthquake Warning Systems

    Science.gov (United States)

    Wurman, Gilead; Haering, Edward A, Jr.; Price, Michael J.

    2011-01-01

    Several aerospace companies are designing quiet supersonic business jets for service over the United States. These aircraft have the potential to increase the occurrence of mild sonic booms across the country. This leads to interest among earthquake warning (EQW) developers and the general seismological community in characterizing the effect of sonic booms on seismic sensors in the field, their potential impact on EQW systems, and means of discriminating their signatures from those of earthquakes. The SonicBREWS project (Sonic Boom Resistant Earthquake Warning Systems) is a collaborative effort between Seismic Warning Systems, Inc. (SWS) and NASA Dryden Flight Research Center. This project aims to evaluate the effects of sonic booms on EQW sensors. The study consists of exposing high-sample-rate (1000 sps) triaxial accelerometers to sonic booms with overpressures ranging from 10 to 600 Pa in the free field and the built environment. The accelerometers record the coupling of the sonic boom to the ground and surrounding structures, while microphones record the acoustic wave above ground near the sensor. Sonic booms are broadband signals with more high-frequency content than earthquakes. Even a 1000 sps accelerometer will produce a significantly aliased record. Thus the observed peak ground velocity is strongly dependent on the sampling rate, and increases as the sampling rate is reduced. At 1000 sps we observe ground velocities that exceed those of P-waves from ML 3 earthquakes at local distances, suggesting that sonic booms are not negligible for EQW applications. We present the results of several experiments conducted under SonicBREWS showing the effects of typical-case low amplitude sonic booms and worst-case high amplitude booms. We show the effects of various sensor placements and sensor array geometries. Finally, we suggest possible avenues for discriminating sonic booms from earthquakes for the purposes of EQW.

  7. Chimeric recombinant antibody fragments in cardiac troponin I immunoassay.

    Science.gov (United States)

    Hyytiä, Heidi; Heikkilä, Taina; Brockmann, Eeva-Christine; Kekki, Henna; Hedberg, Pirjo; Puolakanaho, Tarja; Lövgren, Timo; Pettersson, Kim

    2015-03-01

    To introduce a novel nanoparticle-based immunoassay for cardiac troponin I (cTnI) utilizing chimeric antibody fragments and to demonstrate that removal of antibody Fc-part and antibody chimerization decrease matrix related interferences. A sandwich-type immunoassay for cTnI based on recombinant chimeric (mouse variable/human constant) antigen binding (cFab) antibodies and intrinsically fluorescent nanoparticles was developed. To test whether using chimeric antibody fragments helps to avoid matrix related interferences, samples (n=39) with known amounts of triglycerides, bilirubin, rheumatoid factor (RF) or human anti-mouse antibodies (HAMAs) were measured with the novel assay, along with a previously published nanoparticle-based research assay with the same antibody epitopes. The limit of detection (LoD) was 3.30ng/L. Within-laboratory precision for 29ng/L and 2819ng/L cTnI were 13.7% and 15.9%, respectively. Regression analysis with Siemens ADVIA Centaur® yielded a slope (95% confidence intervals) of 0.18 (0.17-1.19) and a y-intercept of 1.94 (-1.28-3.91) ng/L. When compared to a previously published nanoparticle-based assay, the novel assay showed substantially reduced interference in the tested interference prone samples, 15.4 vs. 51.3%. A rheumatoid factor containing sample was decreased from 241ng/L to immunoassay for the detection of cTnI and decreased matrix related interferences, thus resulting in a lower number of falsely elevated cTnI-values. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  8. The right environment for the immunoassay

    International Nuclear Information System (INIS)

    Emon, J.M. Van; Gerlach, C.L.

    1995-01-01

    For the US Environmental Protection Agency (EPA), the first in-house research effort began in 1987, when results of an early immunoassay field study verified the technology's potential for environmental applications. Looking at the fundamental features of immunochemical reactions from the clinical laboratories, analytical chemists realized the potential value of these methods for hazardous waste site characterization and pesticide monitoring. Immunoassays rely on the interaction between an antibody and a target analyte. For environmental purposes, enzyme immunoassays are generally used. After the target analyte binds to the antibody, an enzymatic reaction yields a colorimetric change. This change, read visually or by a spectrophotometer, indicates the concentration of the target analyte. Promising results with assays for compounds (such as paraquat and pentachlorophenol) and compound groups (such as total petroleum hydrocarbons and polychlorinated biphenyls) spurred interest among various entrepreneurs. The first target market for immunoassays was environmental engineers and field crews who needed quick answers on-site to determine the direction of further remediation efforts

  9. Tumor specific lung cancer diagnostics with multiplexed FRET immunoassays

    Science.gov (United States)

    Geißler, D.; Hill, D.; Löhmannsröben, H.-G.; Thomas, E.; Lavigne, A.; Darbouret, B.; Bois, E.; Charbonnière, L. J.; Ziessel, R. F.; Hildebrandt, N.

    2010-02-01

    An optical multiplexed homogeneous (liquid phase) immunoassay based on FRET from a terbium complex to eight different fluorescent dyes is presented. We achieved highly sensitive parallel detection of four different lung cancer specific tumor markers (CEA, NSE, SCC and CYFRA21-1) within a single assay and show a proof-of-principle for 5- fold multiplexing. The method is well suited for fast and low-cost miniaturized point-of-care testing as well as for highthroughput screening in a broad range of in-vitro diagnostic applications.

  10. Boundary layer height estimation by sodar and sonic anemometer measurements

    International Nuclear Information System (INIS)

    Contini, D; Cava, D; Martano, P; Donateo, A; Grasso, F M

    2008-01-01

    In this paper an analysis of different methods for the calculation of the boundary layer height (BLH) using sodar and ultrasonic anemometer measurements is presented. All the methods used are based on single point surface measurements. In particular the automatic spectral routine developed for Remtech sodar is compared with the results obtained with the parameterization of the vertical velocity variance, with the calculation of a prognostic model and with a parameterization based on horizontal velocity spectra. Results indicate that in unstable conditions the different methods provide similar pattern, with BLH relatively low, even if the parameterization of the vertical velocity variance is affected by a large scatter that limits its efficiency in evaluating the BLH. In stable nocturnal conditions the performances of the Remtech routine are lower with respect to the ones in unstable conditions. The spectral method, applied to sodar or sonic anemometer data, seems to be the most promising in order to develop an efficient routine for BLH determination

  11. Sensitivity-Enhancement of FRET Immunoassays by Multiple-Antibody Conjugation on Quantum Dots.

    Science.gov (United States)

    Annio, Giacomo; Jennings, Travis; Tagit, Oya; Hildebrandt, Niko

    2018-05-23

    Quantum dots (QDs) are not only advantageous for color-tuning, improved brightness, and high stability, but their nanoparticle surfaces also allow for the attachment of many biomolecules. Because IgG antibodies (ABs) are in the same size range of biocompatible QDs and the AB orientation after conjugation to the QD is often random, it is difficult to predict if few or many ABs per QD will lead to an efficient AB-QD conjugate. This is particularly true for homogeneous Förster resonance energy transfer (FRET) sandwich immunoassays, for which the ABs on the QD must bind a biomarker that needs to bind a second AB-FRET-conjugate. Here, we investigate the performance of Tb-to-QD FRET immunoassays against total prostate specific antigen (TPSA) by changing the number of ABs per QD while leaving all the other assay components unchanged. We first characterize the AB-QD conjugation by various spectroscopic, microscopic, and chromatographic techniques and then quantify the TPSA immunoassay performance regarding sensitivity, limit of detection, and dynamic range. Our results show that an increasing conjugation ratio leads to significantly enhanced FRET immunoassays. These findings will be highly important for developing QD-based immunoassays in which the concentrations of both ABs and QDs can significantly influence the assay performance.

  12. Contact pin-printing of albumin-fungicide conjugate for silicon nitride-based sensors biofunctionalization: Multi-technique surface analysis for optimum immunoassay performance

    Science.gov (United States)

    Gajos, Katarzyna; Budkowski, Andrzej; Tsialla, Zoi; Petrou, Panagiota; Awsiuk, Kamil; Dąbczyński, Paweł; Bernasik, Andrzej; Rysz, Jakub; Misiakos, Konstantinos; Raptis, Ioannis; Kakabakos, Sotirios

    2017-07-01

    Mass fabrication of integrated biosensors on silicon chips is facilitated by contact pin-printing, applied for biofunctionalization of individual Si3N4-based transducers at wafer-scale. To optimize the biofunctionalization for immunochemical (competitive) detection of fungicide thiabendazole (TBZ), Si3N4 surfaces are modified with (3-aminopropyl)triethoxysilane and examined after: immobilization of BSA-TBZ conjugate (probe) from solutions with different concentration, blocking with bovine serum albumin (BSA), and immunoreaction with a mouse monoclonal antibody against TBZ. Nanostructure, surface density, probe composition and coverage uniformity of protein layers are evaluated with Atomic Force Microscopy, Spectroscopic Ellipsometry, Time-of-Flight Secondary Ion Mass Spectrometry and X-ray Photoelectron Spectroscopy. Contact pin-printing of overlapping probe spots is compared with hand spotted areas. Contact pin-printing resulted in two-fold increase of immobilized probe surface density as compared to hand spotting. Regarding BSA-TBZ immobilization, an incomplete monolayer develops into a bilayer as the concentration of BSA-TBZ molecules in the printing solution increases from 25 to 100 μg/mL. Upon blocking, however, a complete protein monolayer is formed for all the BSA-TBZ concentrations used. Free surface sites are filled with BSA for low surface coverage with BSA-TBZ, whereas loosely bound BSA-TBZ molecules are removed from the BSA-TBZ bilayer. As a consequence immunoreaction efficiency increases with the printing probe concentration.

  13. Contact pin-printing of albumin-fungicide conjugate for silicon nitride-based sensors biofunctionalization: Multi-technique surface analysis for optimum immunoassay performance

    Energy Technology Data Exchange (ETDEWEB)

    Gajos, Katarzyna, E-mail: katarzyna.gajos@doctoral.uj.edu.pl [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza, 11, 30-348 Kraków (Poland); Budkowski, Andrzej [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza, 11, 30-348 Kraków (Poland); Tsialla, Zoi; Petrou, Panagiota [Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR Demokritos, P. Grigoriou & Neapoleos St., Aghia Paraksevi 15310, Athens (Greece); Awsiuk, Kamil; Dąbczyński, Paweł [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza, 11, 30-348 Kraków (Poland); Bernasik, Andrzej [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Kraków (Poland); Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Mickiewicza 30, 30-059 Kraków (Poland); Rysz, Jakub [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza, 11, 30-348 Kraków (Poland); Misiakos, Konstantinos; Raptis, Ioannis [Department of Microelectronics, Institute of Nanoscience and Nanotechnology, NCSR Demokritos, P. Grigoriou & Neapoleos St., Aghia Paraksevi 15310, Athens (Greece); Kakabakos, Sotirios [Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR Demokritos, P. Grigoriou & Neapoleos St., Aghia Paraksevi 15310, Athens (Greece)

    2017-07-15

    Highlights: • Contact pin-printing of overlapping probe spots and spotting by hand are compared. • Contact pin-printing favors probe immobilization with two-fold higher surface density. • Incomplete monolayer develops to bilayer as printing solution concentration increases. • Blocking molecules complete probe monolayer but reduce probe bilayer. • Surface immunoreaction increases with probe concentration in printing solution. - Abstract: Mass fabrication of integrated biosensors on silicon chips is facilitated by contact pin-printing, applied for biofunctionalization of individual Si{sub 3}N{sub 4}-based transducers at wafer-scale. To optimize the biofunctionalization for immunochemical (competitive) detection of fungicide thiabendazole (TBZ), Si{sub 3}N{sub 4} surfaces are modified with (3-aminopropyl)triethoxysilane and examined after: immobilization of BSA-TBZ conjugate (probe) from solutions with different concentration, blocking with bovine serum albumin (BSA), and immunoreaction with a mouse monoclonal antibody against TBZ. Nanostructure, surface density, probe composition and coverage uniformity of protein layers are evaluated with Atomic Force Microscopy, Spectroscopic Ellipsometry, Time-of-Flight Secondary Ion Mass Spectrometry and X-ray Photoelectron Spectroscopy. Contact pin-printing of overlapping probe spots is compared with hand spotted areas. Contact pin-printing resulted in two-fold increase of immobilized probe surface density as compared to hand spotting. Regarding BSA-TBZ immobilization, an incomplete monolayer develops into a bilayer as the concentration of BSA-TBZ molecules in the printing solution increases from 25 to 100 μg/mL. Upon blocking, however, a complete protein monolayer is formed for all the BSA-TBZ concentrations used. Free surface sites are filled with BSA for low surface coverage with BSA-TBZ, whereas loosely bound BSA-TBZ molecules are removed from the BSA-TBZ bilayer. As a consequence immunoreaction efficiency

  14. Mathematical modeling and optimization of sonication remediation of soil polluted with 2-methylpropane-2-thiol

    Directory of Open Access Journals (Sweden)

    pejman roohi

    2015-10-01

    Full Text Available Existence of 2-methylpropane-2-thiol as an organosulfur and odorant compound in the soil could causes environmental problem and social dissatisfaction. In this study, remediation of this type of thiol using ultrasound is investigated. Central Composite Design (CCD based on Response Surface Model (RSM was used to obtain effects of the main factor (Power, sonication time and amount of water and their interactions. Analysis of variance and Pareto analysis shows that all main factors are effective (the percentage effects of 43.30%, 30.35% and 9.62% on removal efficiency for power, sonication time and amount of water respectively. Moreover, interaction between water content and power, and sonication time and power are effective interaction (with P-values of 0.025 and 0.007 respectively. Base on experiment results and analysis of variance effects of the daylight is not significant (P-value=0.825. P-value of lack of fit (0.176 suggested model assessed as a good model and adequately fits data. Highest levels of power and sonication time (86 watt and 38 minute respectively and water content in lower level (27 ml in studied interval lead to maximum removal efficiency (82.83%.

  15. From Ecological Sounding Artifacts Towards Sonic Artifact Ecologies

    DEFF Research Database (Denmark)

    Erkut, Cumhur; Serafin, Stefania

    2016-01-01

    The discipline of sonic interaction design has been focused on the interaction between a single user and an artifact. This strongly limits one of the fundamental aspects of music as a social and interactive experience. In this paper we propose sonic artifact ecologies as a mean to examine interac...

  16. Deoxynivalenol-mimic nanobody isolated from a naïve phage display nanobody library and its application in immunoassay.

    Science.gov (United States)

    Qiu, Yu-Lou; He, Qing-Hua; Xu, Yang; Bhunia, Arun K; Tu, Zhui; Chen, Bo; Liu, Yuan-Yuan

    2015-08-05

    In this study, using mycotoxin deoxynivalenol (DON) as a model hapten, we developed a nanobody-based environmental friendly immunoassay for sensitive detection of DON. Two nanobodies (N-28 and N-31) which bind to anti-DON monoclonal antibody (MAb) were isolated from a naive phage display library. These nanobodies are clonable, thermally stable and mycotoxin-free products and can be served as coating antigen mimetics in heterologous immunoassay. The half inhibition concentration (IC50) of the immunoassay developed with N-28 and N-31 was 8.77 ± 0.41 ng mL(-1) and 19.97 ± 0.84 ng mL(-1), respectively, which were 18- and 8-fold more sensitive than the conventional coating antigen (DON-BSA) based immunoassay. In order to better understand the molecular mechanism of antigen mimicry by nanobody, the 3D structure of "nanobody (N-28) - anti-DON MAb" complex was presented and verified by molecular modeling and alanine-scanning mutagenesis. The results showed that hydrogen bond and hydrophobic interaction formed between Thr 102 - Ser 106 of N-28 and CDR H3 residues of anti-DON antibody may contribute to their binding. This novel concept of enhancing sensitivity of immunoassay for DON based on nanobody may provide potential applications in a general method for immunoassay of various food chemical contaminants. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Sub-sonic thermal explosions investigated by radiography

    Energy Technology Data Exchange (ETDEWEB)

    Smilowitz, Laura B [Los Alamos National Laboratory; Henson, Bryan F [Los Alamos National Laboratory; Romero, Jerry J [Los Alamos National Laboratory; Asay, Blaine W [Los Alamos National Laboratory

    2010-01-01

    This paper reviews the past 5 years of experiments utilizing radiographic techniques to study defiagration in thermal explosions in HMX based formulations. Details of triggering and timing synchronization are given. Radiographic images collected using both protons and x-rays are presented. Comparisons of experiments with varying size, case confinement, binder, and synchronization are presented. Techniques for quantifying the data in the images are presented and a mechanism for post-ignition burn propagation in a thermal explosion is discussed. From these experiments, we have observed a mechanism for sub-sonic defiagration with both gas phase convective and solid phase conductive burning. The convective front velocity is directly measured from the radiographic images and consumes only a small fraction of the HE. It lights the HE as it passes beginning the slower solid state conductive burn process. This mechanism is used to create a model to simulate the radiographic results and a comparison will be shown.

  18. Merging Metallic Catalysts and Sonication: A Periodic Table Overview

    Directory of Open Access Journals (Sweden)

    Claudia E. Domini

    2017-04-01

    Full Text Available This account summarizes and discusses recent examples in which the combination of ultrasonic waves and metal-based reagents, including metal nanoparticles, has proven to be a useful choice in synthetic planning. Not only does sonication often enhance the activity of the metal catalyst/reagent, but it also greatly enhances the synthetic transformation that can be conducted under milder conditions relative to conventional protocols. For the sake of clarity, we have adopted a structure according to the periodic-table elements or families, distinguishing between bulk metal reagents and nanoparticles, as well as the supported variations, thus illustrating the characteristics of the method under consideration in target synthesis. The coverage focuses essentially on the last decade, although the discussion also strikes a comparative balance between the more recent advancements and past literature.

  19. Development of national immunoassay reagent programmes

    International Nuclear Information System (INIS)

    Sufi, S.B.; Micallef, J.V.; Ahsan, R.; Goncharov, N.P.

    1992-01-01

    Despite the existence of networks of fully equipped laboratories with well-trained staff, the availability of immunodiagnostic services in developing countries is often limited by the high cost of imported kits. There are a number of ways of tackling this problem, ranging from bulk purchase of kits or reagents to local development and production of assay systems. Argentina/Chile, China, Cuba/Mexico, and Thailand are amongst the countries which have established local immunoassay reagent programmes to manufacture low cost, high quality immunoassay reagents. Kits from these projects are now beginning to become available, and it is hoped that they will promote national diagnostic services and research, as well as stimulating the development of reagent programmes for other analytes. (author). 4 refs, 1 tab

  20. Studies on direct and indirect electrochemical immunoassays

    OpenAIRE

    Buckley, Eileen

    1989-01-01

    Two approaches to electrochemical immunoassay are reported. The first approach was an indirect method, involving an electroactive, enzyme-catalysed, substrate to product reaction. Conditions were optimised for the amperometric detection of para-aminophenol, the electroactive product of the alkaline phosphatase catalysed hydrolysis of a new substrate, p-aminophenylphosphate, after separation by HPLC. The second approach involved the direct electrochemical detection of an immunoglo...

  1. Geophysical borehole logging in Lavia borehole - results and interpretation of sonic and tube wave measurements

    International Nuclear Information System (INIS)

    Andersson, P.; Stenberg, L.

    1985-02-01

    Swedish Nuclear Fuel and Waste Management Co, SKB has been contracted by Industrial Power Company LTD, TVO to perform geophysical logging in a borehole at Lavia in Western Finland. The logging has been conducted by Swedish Geological Co, SGAB in accordance with an agreement for cooperation with SKB. The depth of the borehole is 1001 m, diameter 56 mm and inclination 10-20 degrees to the vertical. The aim of the logging was to determine the various geophysical parameters in the borehole in order to interpret and understand the rock mass properties in the vicinity of the borehole. According to the contract the report covers the following main objectives: a technical description of the field work and the equipment used; a review of the theoretical base for the sonic and tube wave methods; an interpretation and presentation of the results obtained by sonic and tube wave mesurements. The evaluation of the sonic and tube wave measurements shows good correlation. On a qualitative basis there seems to be a correlation between tube wave generating points, the relative tube wave amplitudes and the hydraulic conductivity measurements performed as hydraulical tests between packers in the borehole. The low velocity anamalies in the sonic log are mainly caused by tectonic features like fractures and fracture zones but to some extent also by contacts between granite and diorite. The estimation of elastic properties of the rock mass from observation of tube wave velocity are in accordance with laboratory determinations made on core samples. (author)

  2. Valley Topological Phases in Bilayer Sonic Crystals

    Science.gov (United States)

    Lu, Jiuyang; Qiu, Chunyin; Deng, Weiyin; Huang, Xueqin; Li, Feng; Zhang, Fan; Chen, Shuqi; Liu, Zhengyou

    2018-03-01

    Recently, the topological physics in artificial crystals for classical waves has become an emerging research area. In this Letter, we propose a unique bilayer design of sonic crystals that are constructed by two layers of coupled hexagonal array of triangular scatterers. Assisted by the additional layer degree of freedom, a rich topological phase diagram is achieved by simply rotating scatterers in both layers. Under a unified theoretical framework, two kinds of valley-projected topological acoustic insulators are distinguished analytically, i.e., the layer-mixed and layer-polarized topological valley Hall phases, respectively. The theory is evidently confirmed by our numerical and experimental observations of the nontrivial edge states that propagate along the interfaces separating different topological phases. Various applications such as sound communications in integrated devices can be anticipated by the intriguing acoustic edge states enriched by the layer information.

  3. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays.

    Science.gov (United States)

    Chen, Hui; Hagström, Anna E V; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C; Atmar, Robert L; Willson, Richard C

    2016-04-14

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 10(6) virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings.

  4. Alkaline phosphatase-fused repebody as a new format of immuno-reagent for an immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Hyo-Deok; Lee, Joong-jae [Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Kim, Yu Jung [Industrial Biotechnology and Bioenergy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon (Korea, Republic of); Hantschel, Oliver [School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Lee, Seung-Goo [Industrial Biotechnology and Bioenergy Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon (Korea, Republic of); Kim, Hak-Sung, E-mail: hskim76@kaist.ac.kr [Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of)

    2017-01-15

    Enzyme-linked immunoassays based on an antibody-antigen interaction are widely used in biological and medical sciences. However, the conjugation of an enzyme to antibodies needs an additional chemical process, usually resulting in randomly cross-linked molecules and a loss of the binding affinity and enzyme activity. Herein, we present the development of an alkaline phosphatase-fused repebody as a new format of immuno-reagent for immunoassays. A repebody specifically binding to human TNF-α (hTNF-α) was selected through a phage display, and its binding affinity was increased up to 49 nM using a modular engineering approach. A monomeric alkaline phosphatase (mAP), which was previously isolated from a metagenome library, was genetically fused to the repebody as a signal generator, and the resulting repebody-mAP fusion protein was used for direct and sandwich immunoassays of hTNF-α. We demonstrate the utility and potential of the repebody-mAP fusion protein as an immuno-reagent by showing the sensitivity of 216 pg mL{sup −1} for hTNF-α in a sandwich immunoassay. Furthermore, this repebody-mAP fusion protein enabled the detection of hTNF-α spiked in a serum-supplemented medium with high accuracy and reproducibility. It is thus expected that a mAP-fused repebody can be broadly used as an immuno-reagent in immunoassays. - Highlights: • A human TNF-α (hTNF-α)-specific repebody was selected using a phage display. • A monomeric alkaline phosphatase (mAP) was genetically fused to the repebody. • mAP-fused repebody enabled detection of hTNF-α with high sensitivity and accuracy. • mAP-fused repebody can be widely used as a new immuno-reagent in immunoassays.

  5. BIOTIN INTERFERENCE WITH ROUTINE CLINICAL IMMUNOASSAYS: UNDERSTAND THE CAUSES AND MITIGATE THE RISKS.

    Science.gov (United States)

    Samarasinghe, Shanika; Meah, Farah; Singh, Vinita; Basit, Arshi; Emanuele, Nicholas; Emanuele, Mary Ann; Mazhari, Alaleh; Holmes, Earle W

    2017-08-01

    The objectives of this report are to review the mechanisms of biotin interference with streptavidin/biotin-based immunoassays, identify automated immunoassay systems vulnerable to biotin interference, describe how to estimate and minimize the risk of biotin interference in vulnerable assays, and review the literature pertaining to biotin interference in endocrine function tests. The data in the manufacturer's "Instructions for Use" for each of the methods utilized by seven immunoassay system were evaluated. We also conducted a systematic search of PubMed/MEDLINE for articles containing terms associated with biotin interference. Available original reports and case series were reviewed. Abstracts from recent scientific meetings were also identified and reviewed. The recent, marked, increase in the use of over-the-counter, high-dose biotin supplements has been accompanied by a steady increase in the number of reports of analytical interference by exogenous biotin in the immunoassays used to evaluate endocrine function. Since immunoassay methods of similar design are also used for the diagnosis and management of anemia, malignancies, autoimmune and infectious diseases, cardiac damage, etc., biotin-related analytical interference is a problem that touches every area of internal medicine. It is important for healthcare personnel to become more aware of immunoassay methods that are vulnerable to biotin interference and to consider biotin supplements as potential sources of falsely increased or decreased test results, especially in cases where a lab result does not correlate with the clinical scenario. FDA = U.S. Food & Drug Administration FT3 = free tri-iodothyronine FT4 = free thyroxine IFUs = instructions for use LH = luteinizing hormone PTH = parathyroid hormone SA/B = streptavidin/biotin TFT = thyroid function test TSH = thyroid-stimulating hormone.

  6. Multiplex detection of plant pathogens using a microsphere immunoassay technology.

    Directory of Open Access Journals (Sweden)

    Ratthaphol Charlermroj

    Full Text Available Plant pathogens are a serious problem for seed export, plant disease control and plant quarantine. Rapid and accurate screening tests are urgently required to protect and prevent plant diseases spreading worldwide. A novel multiplex detection method was developed based on microsphere immunoassays to simultaneously detect four important plant pathogens: a fruit blotch bacterium Acidovorax avenae subsp. citrulli (Aac, chilli vein-banding mottle virus (CVbMV, potyvirus, watermelon silver mottle virus (WSMoV, tospovirus serogroup IV and melon yellow spot virus (MYSV, tospovirus. An antibody for each plant pathogen was linked on a fluorescence-coded magnetic microsphere set which was used to capture corresponding pathogen. The presence of pathogens was detected by R-phycoerythrin (RPE-labeled antibodies specific to the pathogens. The assay conditions were optimized by identifying appropriate antibody pairs, blocking buffer, concentration of RPE-labeled antibodies and assay time. Once conditions were optimized, the assay was able to detect all four plant pathogens precisely and accurately with substantially higher sensitivity than enzyme-linked immunosorbent assay (ELISA when spiked in buffer and in healthy watermelon leaf extract. The assay time of the microsphere immunoassay (1 hour was much shorter than that of ELISA (4 hours. This system was also shown to be capable of detecting the pathogens in naturally infected plant samples and is a major advancement in plant pathogen detection.

  7. Multiplex detection of plant pathogens using a microsphere immunoassay technology.

    Science.gov (United States)

    Charlermroj, Ratthaphol; Himananto, Orawan; Seepiban, Channarong; Kumpoosiri, Mallika; Warin, Nuchnard; Oplatowska, Michalina; Gajanandana, Oraprapai; Grant, Irene R; Karoonuthaisiri, Nitsara; Elliott, Christopher T

    2013-01-01

    Plant pathogens are a serious problem for seed export, plant disease control and plant quarantine. Rapid and accurate screening tests are urgently required to protect and prevent plant diseases spreading worldwide. A novel multiplex detection method was developed based on microsphere immunoassays to simultaneously detect four important plant pathogens: a fruit blotch bacterium Acidovorax avenae subsp. citrulli (Aac), chilli vein-banding mottle virus (CVbMV, potyvirus), watermelon silver mottle virus (WSMoV, tospovirus serogroup IV) and melon yellow spot virus (MYSV, tospovirus). An antibody for each plant pathogen was linked on a fluorescence-coded magnetic microsphere set which was used to capture corresponding pathogen. The presence of pathogens was detected by R-phycoerythrin (RPE)-labeled antibodies specific to the pathogens. The assay conditions were optimized by identifying appropriate antibody pairs, blocking buffer, concentration of RPE-labeled antibodies and assay time. Once conditions were optimized, the assay was able to detect all four plant pathogens precisely and accurately with substantially higher sensitivity than enzyme-linked immunosorbent assay (ELISA) when spiked in buffer and in healthy watermelon leaf extract. The assay time of the microsphere immunoassay (1 hour) was much shorter than that of ELISA (4 hours). This system was also shown to be capable of detecting the pathogens in naturally infected plant samples and is a major advancement in plant pathogen detection.

  8. Diagnosis Of Persistent Infection In Prosthetic Two-Stage Exchange: PCR analysis of Sonication fluid From Bone Cement Spacers.

    Science.gov (United States)

    Mariaux, Sandrine; Tafin, Ulrika Furustrand; Borens, Olivier

    2017-01-01

    Introduction: When treating periprosthetic joint infections with a two-stage procedure, antibiotic-impregnated spacers are used in the interval between removal of prosthesis and reimplantation. According to our experience, cultures of sonicated spacers are most often negative. The objective of our study was to investigate whether PCR analysis would improve the detection of bacteria in the spacer sonication fluid. Methods: A prospective monocentric study was performed from September 2014 to January 2016. Inclusion criteria were two-stage procedure for prosthetic infection and agreement of the patient to participate in the study. Beside tissues samples and sonication, broad range bacterial PCRs, specific S. aureus PCRs and Unyvero-multiplex PCRs were performed on the sonicated spacer fluid. Results: 30 patients were identified (15 hip, 14 knee and 1 ankle replacements). At reimplantation, cultures of tissue samples and spacer sonication fluid were all negative. Broad range PCRs were all negative. Specific S. aureus PCRs were positive in 5 cases. We had two persistent infections and four cases of infection recurrence were observed, with bacteria different than for the initial infection in three cases. Conclusion: The three different types of PCRs did not detect any bacteria in spacer sonication fluid that was culture-negative. In our study, PCR did not improve the bacterial detection and did not help to predict whether the patient will present a persistent or recurrent infection. Prosthetic 2-stage exchange with short interval and antibiotic-impregnated spacer is an efficient treatment to eradicate infection as both culture- and molecular-based methods were unable to detect bacteria in spacer sonication fluid after reimplantation.

  9. Focused ultrasound-mediated noninvasive blood-brain barrier modulation: preclinical examination of efficacy and safety in various sonication parameters.

    Science.gov (United States)

    Shin, Jaewoo; Kong, Chanho; Cho, Jae Sung; Lee, Jihyeon; Koh, Chin Su; Yoon, Min-Sik; Na, Young Cheol; Chang, Won Seok; Chang, Jin Woo

    2018-02-01

    OBJECTIVE The application of pharmacological therapeutics in neurological disorders is limited by the ability of these agents to penetrate the blood-brain barrier (BBB). Focused ultrasound (FUS) has recently gained attention for its potential application as a method for locally opening the BBB and thereby facilitating drug delivery into the brain parenchyma. However, this method still requires optimization to maximize its safety and efficacy for clinical use. In the present study, the authors examined several sonication parameters of FUS influencing BBB opening in small animals. METHODS Changes in BBB permeability were observed during transcranial sonication using low-intensity FUS in 20 adult male Sprague-Dawley rats. The authors examined the effects of FUS sonication with different sonication parameters, varying acoustic pressure, center frequency, burst duration, microbubble (MB) type, MB dose, pulse repetition frequency (PRF), and total exposure time. The focal region of BBB opening was identified by Evans blue dye. Additionally, H & E staining was used to identify blood vessel damage. RESULTS Acoustic pressure amplitude and burst duration were closely associated with enhancement of BBB opening efficiency, but these parameters were also highly correlated with tissue damage in the sonicated region. In contrast, MB types, MB dose, total exposure time, and PRF had an influence on BBB opening without conspicuous tissue damage after FUS sonication. CONCLUSIONS The study aimed to identify these influential conditions and provide safety and efficacy values for further studies. Future work based on the current results is anticipated to facilitate the implementation of FUS sonication for drug delivery in various CNS disease states in the near future.

  10. Cloud Computing for Pharmacometrics: Using AWS, NONMEM, PsN, Grid Engine, and Sonic.

    Science.gov (United States)

    Sanduja, S; Jewell, P; Aron, E; Pharai, N

    2015-09-01

    Cloud computing allows pharmacometricians to access advanced hardware, network, and security resources available to expedite analysis and reporting. Cloud-based computing environments are available at a fraction of the time and effort when compared to traditional local datacenter-based solutions. This tutorial explains how to get started with building your own personal cloud computer cluster using Amazon Web Services (AWS), NONMEM, PsN, Grid Engine, and Sonic.

  11. Device for use in immunoassays

    International Nuclear Information System (INIS)

    Tu, J.I.

    1981-01-01

    A novel double antibody-coated test tube is described for use in radioimmunoassays. The solid phase separation technique of this invention is based on a test tube which has been coated on its internal surface with two antibody layers: a first layer of nonspecific antibodies which is bound to the internal surface of the test tube and a second layer of more specific antibodies which are bound to the nonspecific antibodies. The invention is illustrated in the preparation of double antibody-coated test tubes for use in the radioimmunoassays of plasma digoxin levels and serum triiodothyronine levels. (U.K.)

  12. Massively multi-parametric immunoassays using ICPMS

    International Nuclear Information System (INIS)

    Tanner, S.D.; Ornatsky, O.; Bandura, D.R.; Baranov, V.I.

    2009-01-01

    The use of stable isotopes as tags in immunoassays, and their determination by ICPMS, is poised to have a huge impact on multi-parametric bioanalysis. A new technology, which we term 'mass cytometry', enables high throughput, highly multiplexed individual cell analysis. Preliminary results for T-cell immunophenotyping in peripheral blood mononuclear cells (PBMC), agonist influence on concomitant phosphorylation pathways, and sub-classification of acute myeloid leukemia patients' samples will be presented. The significance of individual cell analysis is demonstrated by the identification of populations of rogue cells in PBMC samples through the use of multidimensional neural network cluster analysis. (author)

  13. Gliadin Detection in Food by Immunoassay

    Science.gov (United States)

    Grant, Gordon; Sporns, Peter; Hsieh, Y.-H. Peggy

    Immunoassays are very sensitive and efficient tests that are commonly used to identify a specific protein. Examples of applications in the food industry include identification of proteins expressed in genetically modified foods, allergens, or proteins associated with a disease, including celiac disease. This genetic disease is associated with Europeans and affects about one in every 200 people in North America. These individuals react immunologically to wheat proteins, and consequently their own immune systems attack and damage their intestines. This disease can be managed if wheat proteins, specifically "gliadins," are avoided in foods.

  14. A redox-mediated chromogenic reaction and application in immunoassay.

    Science.gov (United States)

    Yu, Ru-Jia; Ma, Wei; Peng, Mao-Pan; Bai, Zhi-Shan; Long, Yi-Tao

    2016-08-31

    A novel redox-mediated chromogenic reaction was demonstrated based on the reaction between HAuCl4 and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), which generate various color responses from red to green in the resulting solutions. Various redox substance could be used to mediate the reaction and trigger a distinct color response. We established a sensitive hydrogen peroxide colorimetric sensor based on the redox-mediated chromogenic reaction and depicted the application both in detection of enzyme and in an immunoassay. Combining the traditional chromogenic reagent with gold nanoparticles, our assay has the advantage in short response time (within three minutes), high sensitivity (10(-12) g mL(-1) for HBsAg) and stability. Copyright © 2016. Published by Elsevier B.V.

  15. Epithelial trafficking of Sonic hedgehog by megalin.

    Science.gov (United States)

    Morales, Carlos R; Zeng, Jibin; El Alfy, Mohamed; Barth, Jeremy L; Chintalapudi, Mastan Rao; McCarthy, Robert A; Incardona, John P; Argraves, W Scott

    2006-10-01

    We present here evidence of in vivo epithelial endocytosis and trafficking of non-lipid-modified Sonic hedgehog (ShhN) when infused into rat efferent ducts via microinjection. Initially, exogenous ShhN is detected in endocytic vesicles and early endosomes located near the apical plasma membrane of non-ciliated cells. Within 30-60 min following infusion, ShhN can be detected in lysosomes and at basolateral regions of non-ciliated cells. Basolaterally, ShhN was observed along the extracellular surfaces of interdigitated plasma membranes of adjacent cells and in the extracellular compartment underlying the efferent duct epithelium. Uptake and subcellular trafficking of infused ShhN by non-ciliated cells could be blocked by either anti-megalin IgG or the megalin antagonist, RAP. Ciliated cells, which do not express megalin, displayed little if any apical internalization of ShhN even though they were found to express Patched-1. However, ShhN was found in coated pits of lateral plasma membranes of ciliated cells as well as in underlying endocytic vesicles. We conclude that megalin-mediated endocytosis of ShhN can occur in megalin-expressing epithelia in vivo, and that the internalized ShhN can be targeted to the lysosome or transcytosed in the plane of the epithelium or across the epithelium. These findings highlight the multiple mechanisms by which megalin may influence Shh morphogen gradients in vivo.

  16. Sonic Hedgehog Signaling in Thyroid Cancer

    Directory of Open Access Journals (Sweden)

    Xiulong Xu

    2017-10-01

    Full Text Available Thyroid cancer is the most common malignancy of the endocrine system. The initiation of thyroid cancer is often triggered by a genetic mutation in the phosphortidylinositol-3 kinase (PI3K or mitogen-activated protein kinase (MAPK pathway, such as RAS and BRAF, or by the rearrangement of growth factor receptor tyrosine kinase genes such as RET/PTC. The sonic hedgehog (Shh pathway is evolutionarily conserved and plays an important role in the embryonic development of normal tissues and organs. Gene mutations in the Shh pathway are involved in basal cell carcinomas (BCC. Activation of the Shh pathway due to overexpression of the genes encoding the components of this pathway stimulates the growth and spread of a wide range of cancer types. The Shh pathway also plays an important role in cancer stem cell (CSC self-renewal. GDC-0449 and LDE-225, two inhibitors of this pathway, have been approved for treating BCC and are being tested as a single agent or in combination with other drugs for treating various other cancers. Here, we review the recent findings on activation of the Shh pathway in thyroid cancer and its role in maintaining thyroid CSC self-renewal. We also summarize the recent developments on crosstalk of the Shh pathway with the MAPK and PI3K oncogenic pathways, and its implications for combination therapy.

  17. Sonic Hedgehog Signaling in Thyroid Cancer

    Science.gov (United States)

    Xu, Xiulong; Lu, Yurong; Li, Yi; Prinz, Richard A.

    2017-01-01

    Thyroid cancer is the most common malignancy of the endocrine system. The initiation of thyroid cancer is often triggered by a genetic mutation in the phosphortidylinositol-3 kinase (PI3K) or mitogen-activated protein kinase (MAPK) pathway, such as RAS and BRAF, or by the rearrangement of growth factor receptor tyrosine kinase genes such as RET/PTC. The sonic hedgehog (Shh) pathway is evolutionarily conserved and plays an important role in the embryonic development of normal tissues and organs. Gene mutations in the Shh pathway are involved in basal cell carcinomas (BCC). Activation of the Shh pathway due to overexpression of the genes encoding the components of this pathway stimulates the growth and spread of a wide range of cancer types. The Shh pathway also plays an important role in cancer stem cell (CSC) self-renewal. GDC-0449 and LDE-225, two inhibitors of this pathway, have been approved for treating BCC and are being tested as a single agent or in combination with other drugs for treating various other cancers. Here, we review the recent findings on activation of the Shh pathway in thyroid cancer and its role in maintaining thyroid CSC self-renewal. We also summarize the recent developments on crosstalk of the Shh pathway with the MAPK and PI3K oncogenic pathways, and its implications for combination therapy. PMID:29163356

  18. Fluorescence immunoassay for detecting periodontal bacterial pathogens in plaque.

    OpenAIRE

    Wolff, L F; Anderson, L; Sandberg, G P; Aeppli, D M; Shelburne, C E

    1991-01-01

    A particle concentration fluorescence immunoassay has been modified into a bacterial concentration fluorescence immunoassay (BCFIA) to rapidly detect periodontopathic bacteria in human plaque samples. The BCFIA utilizes fluorescently tagged monoclonal antibodies (MAbs) directed against the lipopolysaccharide of selected gram-negative plaque bacteria. Microorganisms closely associated with periodontal disease that can be identified in plaque with the BCFIA include Porphyromonas gingivalis, Bac...

  19. Review of the biochemical basis of enzyme immunoassays

    International Nuclear Information System (INIS)

    Klingler, W.

    1982-01-01

    The ever increasing number of radioimmunological determination poses problems allied with the handling of radioactive substances. In recent years various non-radioactive methods have been developed, among which the enzyme immunoassay is already in routine use. Homogeneous and heterogeneous enzyme immunoassays are described. Criteria for enzymes, substrates and enzyme-substrate reactions are listed. (orig.) [de

  20. Optimized Lateral Flow Immunoassay Reader for the Detection of Infectious Diseases in Developing Countries.

    Science.gov (United States)

    Pilavaki, Evdokia; Demosthenous, Andreas

    2017-11-20

    Detection and control of infectious diseases is a major problem, especially in developing countries. Lateral flow immunoassays can be used with great success for the detection of infectious diseases. However, for the quantification of their results an electronic reader is required. This paper presents an optimized handheld electronic reader for developing countries. It features a potentially low-cost, low-power, battery-operated device with no added optical accessories. The operation of this proof of concept device is based on measuring the reflected light from the lateral flow immunoassay and translating it into the concentration of the specific analyte of interest. Characterization of the surface of the lateral flow immunoassay has been performed in order to accurately model its response to the incident light. Ray trace simulations have been performed to optimize the system and achieve maximum sensitivity by placing all the components in optimum positions. A microcontroller enables all the signal processing to be performed on the device and a Bluetooth module allows transmission of the results wirelessly to a mobile phone app. Its performance has been validated using lateral flow immunoassays with influenza A nucleoprotein in the concentration range of 0.5 ng/mL to 200 ng/mL.

  1. Optimized Lateral Flow Immunoassay Reader for the Detection of Infectious Diseases in Developing Countries

    Directory of Open Access Journals (Sweden)

    Evdokia Pilavaki

    2017-11-01

    Full Text Available Detection and control of infectious diseases is a major problem, especially in developing countries. Lateral flow immunoassays can be used with great success for the detection of infectious diseases. However, for the quantification of their results an electronic reader is required. This paper presents an optimized handheld electronic reader for developing countries. It features a potentially low-cost, low-power, battery-operated device with no added optical accessories. The operation of this proof of concept device is based on measuring the reflected light from the lateral flow immunoassay and translating it into the concentration of the specific analyte of interest. Characterization of the surface of the lateral flow immunoassay has been performed in order to accurately model its response to the incident light. Ray trace simulations have been performed to optimize the system and achieve maximum sensitivity by placing all the components in optimum positions. A microcontroller enables all the signal processing to be performed on the device and a Bluetooth module allows transmission of the results wirelessly to a mobile phone app. Its performance has been validated using lateral flow immunoassays with influenza A nucleoprotein in the concentration range of 0.5 ng/mL to 200 ng/mL.

  2. Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays: applications, fundamentals, and optimization

    International Nuclear Information System (INIS)

    Jeremy Daniel Driskell

    2006-01-01

    Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments

  3. Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays. Applications, fundamentals, and optimization

    Energy Technology Data Exchange (ETDEWEB)

    Driskell, Jeremy Daniel [Iowa State Univ., Ames, IA (United States)

    2006-08-09

    Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments

  4. Background Pressure Profiles for Sonic Boom Vehicle Testing in the NASA Glenn 8- by 6-Foot Supersonic Wind Tunnel

    Science.gov (United States)

    Castner, Raymond; Shaw, Stephen; Adamson, Eric; Simerly, Stephanie

    2013-01-01

    In an effort to identify test facilities that offer sonic boom measurement capabilities, an exploratory test program was initiated using wind tunnels at NASA research centers. The subject of this report is the sonic boom pressure rail data collected in the Glenn Research Center 8- by 6-Foot Supersonic Wind Tunnel. The purpose is to summarize the lessons learned based on the test activity, specifically relating to collecting sonic boom data which has a large amount of spatial pressure variation. The wind tunnel background pressure profiles are presented as well as data which demonstrated how both wind tunnel Mach number and model support-strut position affected the wind tunnel background pressure profile. Techniques were developed to mitigate these effects and are presented.

  5. Lateral Flow Immunoassays for Ebola Virus Disease Detection in Liberia.

    Science.gov (United States)

    Phan, Jill C; Pettitt, James; George, Josiah S; Fakoli, Lawrence S; Taweh, Fahn M; Bateman, Stacey L; Bennett, Richard S; Norris, Sarah L; Spinnler, David A; Pimentel, Guillermo; Sahr, Phillip K; Bolay, Fatorma K; Schoepp, Randal J

    2016-10-15

    Lateral flow immunoassays (LFIs) are point-of-care diagnostic assays that are designed for single use outside a formal laboratory, with in-home pregnancy tests the best-known example of these tests. Although the LFI has some limitations over more-complex immunoassay procedures, such as reduced sensitivity and the potential for false-positive results when using complex sample matrices, the assay has the benefits of a rapid time to result and ease of use. These benefits make it an attractive option for obtaining rapid results in an austere environment. In an outbreak of any magnitude, a field-based rapid diagnostic assay would allow proper patient transport and for safe burials to be conducted without the delay caused by transport of samples between remote villages and testing facilities. Use of such point-of-care instruments in the ongoing Ebola virus disease (EVD) outbreak in West Africa would have distinct advantages in control and prevention of local outbreaks, but proper understanding of the technology and interpretation of results are important. In this study, a LFI, originally developed by the Naval Medical Research Center for Ebola virus environmental testing, was evaluated for its ability to detect the virus in clinical samples in Liberia. Clinical blood and plasma samples and post mortem oral swabs submitted to the Liberian Institute for Biomedical Research, the National Public Health Reference Laboratory for EVD testing, were tested and compared to results of real-time reverse transcription-polymerase chain reaction (rRT-PCR), using assays targeting Ebola virus glycoprotein and nucleoprotein. The LFI findings correlated well with those of the real-time RT-PCR assays used as benchmarks. Rapid antigen-detection tests such as LFIs are attractive alternatives to traditional immunoassays but have reduced sensitivity and specificity, resulting in increases in false-positive and false-negative results. An understanding of the strengths, weaknesses, and

  6. Room airflow studies using sonic anemometry

    International Nuclear Information System (INIS)

    Wasiolek, P.T.; Whicker, J.J.; Gong, H.; Rodgers, J.C.

    1999-01-01

    To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFD) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of-the-art, three-dimensional sonic anemometer was explored. This instrument allows for the precise measurements of the air-velocity vector components in the range of a few centimeters per second, which is common in many indoor work environments. Measurements of air velocities and directions at selected locations were made for the purpose of providing data for characterizing fundamental aspects of indoor air movement in two ventilated rooms and for comparison to CFD model predictions. One room was a mockup of a plutonium workroom, and the other was an actual functioning plutonium workroom. In the mockup room, air-velocity vector components were measured at 19 locations at three heights (60, 120 and 180 cm) with average velocities varying from 1.4 cm s -1 to 9.7 cm s -1 . There were complex flow patterns observed with turbulence intensities from 39% up to 108%. In the plutonium workroom, measurements were made at the breathing-zone height, recording average velocities ranging from 9.9 cm s -1 to 35.5 cm s -1 with turbulence intensities from 33% to 108%. (au)

  7. CALIBRATION AND TESTING OF SONIC STIMULATION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Roger Turpening; Wayne Pennington; Christopher Schmidt; Sean Trisch

    2005-03-01

    In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are (1) a borehole test site that will remain constant and is available all the time and for any length of time, (2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and (3) a set of procedures that ensures that the amplitude and frequency parameters of a wide range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 x 10{sup -5} cm/sec and a peak to peak pressure of approx. 2.5 x 10{sup -7} microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. Igor Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.

  8. Calibration and Testing of Sonic Stimulation Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Roger M. Turpening; Wayne D.Pennington

    2005-03-31

    In conjunction with Baker Atlas Inc. Michigan Technological University devised a system capable of recording the earth motion and pressure due to downhole and surface seismic sources. The essential elements of the system are 1) a borehole test site that will remain constant and is available all the time and for any length of time, 2) a downhole sonde that will itself remain constant and, because of its downhole digitization feature, does not require the wireline or surface recording components to remain constant, and 3) a set of procedures that ensures that the amplitude and frequency parameters of a wide range of sources can be compared with confidence. This system was used to record four seismic sources, three downhole sources and one surface source. A single activation of each of the downhole sources was not seen on time traces above the ambient noise, however, one sweep of the surface source, a small vertical vibrator, was easily seen in a time trace. One of the downhole sources was seen by means of a spike in its spectrum and a second downhole source was clearly seen after correlation and stacking. The surface vibrator produced a peak to peak particle motion signal of approximately 4.5 X 10-5 cm/sec and a peak to peak pressure of approx. 2.5 X 10-7 microPascals at a depth of 1,485 ft. Theoretical advances were made with our partner, Dr. I. Beresnev at Iowa State University. A theory has been developed to account for the behavior of oil ganglia trapped in pore throats, and their ultimate release through the additional incremental pressure associated with sonic stimulation.

  9. Room airflow studies using sonic anemometry.

    Science.gov (United States)

    Wasiolek, P T; Whicker, J J; Gong, H; Rodgers, J C

    1999-06-01

    To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFD) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of-the art, three-dimensional sonic anemometer was explored. This instrument allows for the precise measurements of the air-velocity vector components in the range of a few centimeters per second, which is common in many indoor work environments. Measurements of air velocities and directions at selected locations were made for the purpose of providing data for characterizing fundamental aspects of indoor air movement in two ventilated rooms and for comparison to CFD model predictions. One room was a mockup of a plutonium workroom, and the other was an actual functioning plutonium workroom. In the mockup room, air-velocity vector components were measured at 19 locations at three heights (60, 120 and 180 cm) with average velocities varying from 1.4 cm s-1 to 9.7 cm s-1. There were complex flow patterns observed with turbulence intensities from 39% up to 108%. In the plutonium workroom, measurements were made at the breathing-zone height, recording average velocities ranging from 9.9 cm s-1 to 35.5 cm s-1 with turbulence intensities from 33% to 108%.

  10. Room airflow studies using sonic anemometry

    Energy Technology Data Exchange (ETDEWEB)

    Wasiolek, P.T.; Whicker, J.J.; Gong, H.; Rodgers, J.C. [Los Alamos National Lab., Health Physics Measurements Group, Los Alamos, NM (United States)

    1999-10-01

    To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFD) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of-the-art, three-dimensional sonic anemometer was explored. This instrument allows for the precise measurements of the air-velocity vector components in the range of a few centimeters per second, which is common in many indoor work environments. Measurements of air velocities and directions at selected locations were made for the purpose of providing data for characterizing fundamental aspects of indoor air movement in two ventilated rooms and for comparison to CFD model predictions. One room was a mockup of a plutonium workroom, and the other was an actual functioning plutonium workroom. In the mockup room, air-velocity vector components were measured at 19 locations at three heights (60, 120 and 180 cm) with average velocities varying from 1.4 cm s{sup -1} to 9.7 cm s{sup -1}. There were complex flow patterns observed with turbulence intensities from 39% up to 108%. In the plutonium workroom, measurements were made at the breathing-zone height, recording average velocities ranging from 9.9 cm s{sup -1} to 35.5 cm s{sup -1} with turbulence intensities from 33% to 108%. (au) 17 refs.

  11. Analysis of Nozzle Jet Plume Effects on Sonic Boom Signature

    Science.gov (United States)

    Bui, Trong

    2010-01-01

    An axisymmetric full Navier-Stokes computational fluid dynamics (CFD) study was conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock (LaNCETS) research airplane, was considered. The highly underexpanded nozzle flow is found to provide significantly more reduction in the tail shock strength in the sonic boom N-wave pressure signature than perfectly expanded and overexpanded nozzle flows. A tail shock train in the sonic boom signature, similar to what was observed in the LaNCETS flight data, is observed for the highly underexpanded nozzle flow. The CFD results provide a detailed description of the nozzle flow physics involved in the LaNCETS nozzle at different nozzle expansion conditions and help in interpreting LaNCETS flight data as well as in the eventual CFD analysis of a full LaNCETS aircraft. The current study also provided important information on proper modeling of the LaNCETS aircraft nozzle. The primary objective of the current CFD research effort was to support the LaNCETS flight research data analysis effort by studying the detailed nozzle exhaust jet plume s imperfect expansion effects on the sonic boom signature of a supersonic aircraft. Figure 1 illustrates the primary flow physics present in the interaction between the exhaust jet plume shock and the sonic boom coming off of an axisymmetric body in supersonic flight. The steeper tail shock from highly expanded jet plume reduces the dip of the sonic boom N-wave signature. A structured finite-volume compressible full Navier-Stokes CFD code was used in the current study. This approach is not limited by the simplifying assumptions inherent in previous sonic boom analysis efforts. Also, this study was the first known jet plume sonic boom CFD study in which the full viscous nozzle flow field was modeled, without

  12. Chemiluminescence immunoassay for prostate-specific antigen

    International Nuclear Information System (INIS)

    Zhang Xuefeng; Liu Yibing; Jia Juanjuan; Xu Wenge; Li Ziying; Chen Yongli; Han Shiquan

    2008-01-01

    The chemiluminescence immunoassay (CLIA) for serum total prostate-specific antigen (T-PSA) was developed. The reaction of luminol with hydrogen peroxide was introduced into this chemiluminescence system. The detection limit is established as 0.12 μg/L (n=10, mean of zero standard + 2SD) and the analytical recovery of PSA is 83.8%-118.7%. The intra-assay and inter-assay CVs vary from 4.4%-5.0% and 6.2%-11.7%, respectively. The experimental correlation coefficient of dilution is found to be 0.999. Compared with immunoradiometric assay (IRMA) kits, the correlative equation is y=1.07x+0.68, and correlation coefficient r=0.97. The standard range for the method is 1.5-80 μg/L, and it presents good linearity. (authors)

  13. An Intermediate in the evolution of superfast sonic muscles

    Directory of Open Access Journals (Sweden)

    Mok Hin-Kiu

    2011-11-01

    Full Text Available Abstract Background Intermediate forms in the evolution of new adaptations such as transitions from water to land and the evolution of flight are often poorly understood. Similarly, the evolution of superfast sonic muscles in fishes, often considered the fastest muscles in vertebrates, has been a mystery because slow bladder movement does not generate sound. Slow muscles that stretch the swimbladder and then produce sound during recoil have recently been discovered in ophidiiform fishes. Here we describe the disturbance call (produced when fish are held and sonic mechanism in an unrelated perciform pearl perch (Glaucosomatidae that represents an intermediate condition in the evolution of super-fast sonic muscles. Results The pearl perch disturbance call is a two-part sound produced by a fast sonic muscle that rapidly stretches the bladder and an antagonistic tendon-smooth muscle combination (part 1 causing the tendon and bladder to snap back (part 2 generating a higher-frequency and greater-amplitude pulse. The smooth muscle is confirmed by electron microscopy and protein analysis. To our knowledge smooth muscle attachment to a tendon is unknown in animals. Conclusion The pearl perch, an advanced perciform teleost unrelated to ophidiiform fishes, uses a slow type mechanism to produce the major portion of the sound pulse during recoil, but the swimbladder is stretched by a fast muscle. Similarities between the two unrelated lineages, suggest independent and convergent evolution of sonic muscles and indicate intermediate forms in the evolution of superfast muscles.

  14. Art and Sonic Mining in the Archives: Methods for Investigating the Wartime History of Birmingham School of Art

    Science.gov (United States)

    Vaughan, Sian

    2018-01-01

    "Absconditi Viscus" (or "Hidden Entries") is a series of sound compositions based on the history of Birmingham School of Art during the First World War. Sound artist Justin Wiggan explored the concept of historical sonic information that although lost could still potentially permeate the archival record and the fabric of the…

  15. High Tensile Strength of Engineered β-Solenoid Fibrils via Sonication and Pulling.

    Science.gov (United States)

    Peng, Zeyu; Parker, Amanda S; Peralta, Maria D R; Ravikumar, Krishnakumar M; Cox, Daniel L; Toney, Michael D

    2017-11-07

    We present estimates of ultimate tensile strength (UTS) for two engineered β-solenoid protein mutant fibril structures (spruce budworm and Rhagium inquisitor antifreeze proteins) derived from sonication-based measurements and from force pulling molecular dynamics simulations, both in water. Sonication experiments generate limiting scissioned fibrils with a well-defined length-to-width correlation for the mutant spruce budworm protein and the resultant UTS estimate is 0.66 ± 0.08 GPa. For fibrils formed from engineered R. inquisitor antifreeze protein, depending upon geometry, we estimate UTSs of 3.5 ± 3.2-5.5 ± 5.1 GPa for proteins with interfacial disulfide bonds, and 1.6 ± 1.5-2.5 ± 2.3 GPa for the reduced form. The large error bars for the R. inquisitor structures are intrinsic to the broad distribution of limiting scission lengths. Simulations provide pulling velocity-dependent UTSs increasing from 0.2 to 1 GPa in the available speed range, and 1.5 GPa extrapolated to the speeds expected in the sonication experiments. Simulations yield low-velocity values for the Young's modulus of 6.0 GPa. Without protein optimization, these mechanical parameters are similar to those of spider silk and Kevlar, but in contrast to spider silk, these proteins have a precisely known sequence-structure relationship. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. Novel quantitative autophagy analysis by organelle flow cytometry after cell sonication.

    Directory of Open Access Journals (Sweden)

    Michael Degtyarev

    Full Text Available Autophagy is a dynamic process of bulk degradation of cellular proteins and organelles in lysosomes. Current methods of autophagy measurement include microscopy-based counting of autophagic vacuoles (AVs in cells. We have developed a novel method to quantitatively analyze individual AVs using flow cytometry. This method, OFACS (organelle flow after cell sonication, takes advantage of efficient cell disruption with a brief sonication, generating cell homogenates with fluorescently labeled AVs that retain their integrity as confirmed with light and electron microscopy analysis. These AVs could be detected directly in the sonicated cell homogenates on a flow cytometer as a distinct population of expected organelle size on a cytometry plot. Treatment of cells with inhibitors of autophagic flux, such as chloroquine or lysosomal protease inhibitors, increased the number of particles in this population under autophagy inducing conditions, while inhibition of autophagy induction with 3-methyladenine or knockdown of ATG proteins prevented this accumulation. This assay can be easily performed in a high-throughput format and opens up previously unexplored avenues for autophagy analysis.

  17. Electrochemical immunoassay using magnetic beads for the determination of zearalenone in baby food: An anticipated analytical tool for food safety

    International Nuclear Information System (INIS)

    Hervas, Miriam; Lopez, Miguel Angel; Escarpa, Alberto

    2009-01-01

    In this work, electrochemical immunoassay involving magnetic beads to determine zearalenone in selected food samples has been developed. The immunoassay scheme has been based on a direct competitive immunoassay method in which antibody-coated magnetic beads were employed as the immobilisation support and horseradish peroxidase (HRP) was used as enzymatic label. Amperometric detection has been achieved through the addition of hydrogen peroxide substrate and hydroquinone as mediator. Analytical performance of the electrochemical immunoassay has been evaluated by analysis of maize certified reference material (CRM) and selected baby food samples. A detection limit (LOD) of 0.011 μg L -1 and EC 50 0.079 μg L -1 were obtained allowing the assessment of the detection of zearalenone mycotoxin. In addition, an excellent accuracy with a high recovery yield ranging between 95 and 108% has been obtained. The analytical features have shown the proposed electrochemical immunoassay to be a very powerful and timely screening tool for the food safety scene.

  18. Electrochemical immunoassay using magnetic beads for the determination of zearalenone in baby food: An anticipated analytical tool for food safety

    Energy Technology Data Exchange (ETDEWEB)

    Hervas, Miriam; Lopez, Miguel Angel [Departamento Quimica Analitica, Universidad de Alcala, Ctra. Madrid-Barcelona, Km. 33600, E-28871 Alcala de Henares, Madrid (Spain); Escarpa, Alberto, E-mail: alberto.escarpa@uah.es [Departamento Quimica Analitica, Universidad de Alcala, Ctra. Madrid-Barcelona, Km. 33600, E-28871 Alcala de Henares, Madrid (Spain)

    2009-10-27

    In this work, electrochemical immunoassay involving magnetic beads to determine zearalenone in selected food samples has been developed. The immunoassay scheme has been based on a direct competitive immunoassay method in which antibody-coated magnetic beads were employed as the immobilisation support and horseradish peroxidase (HRP) was used as enzymatic label. Amperometric detection has been achieved through the addition of hydrogen peroxide substrate and hydroquinone as mediator. Analytical performance of the electrochemical immunoassay has been evaluated by analysis of maize certified reference material (CRM) and selected baby food samples. A detection limit (LOD) of 0.011 {mu}g L{sup -1} and EC{sub 50} 0.079 {mu}g L{sup -1} were obtained allowing the assessment of the detection of zearalenone mycotoxin. In addition, an excellent accuracy with a high recovery yield ranging between 95 and 108% has been obtained. The analytical features have shown the proposed electrochemical immunoassay to be a very powerful and timely screening tool for the food safety scene.

  19. Evaluation of the IRAD flexible probe sonic extensometer

    International Nuclear Information System (INIS)

    Glenn, H.D.; Patrick, W.C.; Rector, N.L.; Butler, L.S.

    1986-08-01

    Evaluation of the IRAD sonic extensometer was initiated with an electronic-circuit analysis which indicated an accuracy of +-0.001 in. (0.025 mm). Readings from two sonic probes consistently were low by 2% for distances between magnetic anchors, but were accurate to +-0.002 and +-0.003 in. (0.051 and 0.076 mm) for small displacements. Although a series of high explosive tests subjected magnetic anchors to peak accelerations of from 2100 g to 32,000 g the anchors generally did not experience detectable damage. Sonic probe readings exhibited a sensitivity to temperature changes with two of the four segments monitored exceeding the correction factor cited by the manufacturer

  20. Effect of sonication on technological properties of beef

    Directory of Open Access Journals (Sweden)

    Z. J. Dolatowski

    2007-06-01

    Full Text Available Ultrasound treatment during rigor mortis period led to an acceleration of aging processes. No significant influence of sonication on acidity during ageing was observed. Ultrasound treatment did not influence the lightness, but according to the shear force measurements, improve meat tenderness. Differentiated technological properties of examined samples may result from influence of ultrasound on protein structures of meat. As a result of ultrasound treatment an increase of free calcium ions concentration occurred. Obtained results pointed out that sonication may be an effective method of formation of technological properties of beef during ageing.

  1. Defatting and Sonication Enhances Protein Extraction from Edible Insects.

    Science.gov (United States)

    Choi, Byoung Deug; Wong, Nathan A K; Auh, Joong-Hyuck

    2017-01-01

    Edible insects are attracting growing interest as a sustainable source of protein for addition to processed meat and dairy products. The current study investigated the optimal method for protein extraction from mealworm larvae ( Tenebrio molitor ), cricket adults ( Gryllus bimaculatus ), and silkworm pupae ( Bombyx mori ), for use in further applications. After defatting with n-hexane for up to 48 h, sonication was applied for 1-20 min and the protein yield was measured. All samples showed a total residual fat percentage below 1.36%, and a 35% to 94% improvement in protein yield (%). In conclusion, defatting with n-hexane combined with sonication improves the protein yield from insect samples.

  2. Dual-Mode SERS-Fluorescence Immunoassay Using Graphene Quantum Dot Labeling on One-Dimensional Aligned Magnetoplasmonic Nanoparticles.

    Science.gov (United States)

    Zou, Fengming; Zhou, Hongjian; Tan, Tran Van; Kim, Jeonghyo; Koh, Kwangnak; Lee, Jaebeom

    2015-06-10

    A novel dual-mode immunoassay based on surface-enhanced Raman scattering (SERS) and fluorescence was designed using graphene quantum dot (GQD) labels to detect a tuberculosis (TB) antigen, CFP-10, via a newly developed sensing platform of linearly aligned magnetoplasmonic (MagPlas) nanoparticles (NPs). The GQDs were excellent bilabeling materials for simultaneous Raman scattering and photoluminescence (PL). The one-dimensional (1D) alignment of MagPlas NPs simplified the immunoassay process and enabled fast, enhanced signal transduction. With a sandwich-type immunoassay using dual-mode nanoprobes, both SERS signals and fluorescence images were recognized in a highly sensitive and selective manner with a detection limit of 0.0511 pg mL(-1).

  3. Can LC and LC-MS ever replace immunoassays?

    Directory of Open Access Journals (Sweden)

    Timothy G. Cross

    2016-10-01

    Full Text Available Immunoassays have been the technology of choice for the analysis of biomolecules for many decades across a wide range of applications in research, diagnostics and infectious disease monitoring. There are good reasons for the wide adoption of immunoassays but even such a well established and characterised technique has limitations and as such investigators are looking at alternative technologies. One such alternative is liquid chromatography (LC and, more specifically, liquid chromatography coupled with mass spectrometry (LC-MS. This article will review both immunoassay and LC and LC-MS technologies and methodologies and discuss the advantages and limitations of both approaches. In addition, the next developments that will need to occur before there is widespread adoption of LC and LC-MS technology preferentially over immunoassays will be examined.

  4. Detection of narcotics with an immunoassay film badge

    International Nuclear Information System (INIS)

    Lukens, H.R.

    1993-01-01

    Efficient personnel performance, a major requirement for a safe nuclear industry, is jeopardized where personnel use narcotics. However, detection of narcotics at nuclear plants is a challenge. The unique specificity and sensitivity of an immunoassay has been implemented in the form of a small, dry immunoassay film badge (IFB) for the detection of vapors emitted by narcotics. The device is suitable as an area monitor, and its characteristics are suitable for use as a breath monitor for the detection of drug use

  5. A Novel Colorimetric Immunoassay Utilizing the Peroxidase Mimicking Activity of Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Hyun Gyu Park

    2013-05-01

    Full Text Available A simple colorimetric immunoassay system, based on the peroxidase mimicking activity of Fe3O4 magnetic nanoparticles (MNPs, has been developed to detect clinically important antigenic molecules. MNPs with ca. 10 nm in diameter were synthesized and conjugated with specific antibodies against target molecules, such as rotaviruses and breast cancer cells. Conjugation of the MNPs with antibodies (MNP-Abs enabled specific recognition of the corresponding target antigenic molecules through the generation of color signals arising from the colorimetric reaction between the selected peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB and H2O2. Based on the MNP-promoted colorimetric reaction, the target molecules were detected and quantified by measuring absorbance intensities corresponding to the oxidized form of TMB. Owing to the higher stabilities and economic feasibilities of MNPs as compared to horseradish peroxidase (HRP, the new colorimetric system employing MNP-Abs has the potential of serving as a potent immunoassay that should substitute for conventional HRP-based immunoassays. The strategy employed to develop the new methodology has the potential of being extended to the construction of simple diagnostic systems for a variety of biomolecules related to human cancers and infectious diseases, particularly in the realm of point-of-care applications.

  6. Status of immunoassay as an analytical tool in environmental investigations

    International Nuclear Information System (INIS)

    Van Emon, J.M.

    2000-01-01

    Immunoassay methods were initially applied in clinical situations where their sensitivity and selectivity were utilized for diagnostic purposes. In the 1970s, pesticide chemists realized the potential benefits of immunoassay methods for compounds difficult to analyze by gas chromatography. This transition of the technology has extended to the analysis of soil, water, food and other matrices of environmental and human exposure significance particularly for compounds difficult to analyze by chromatographic methods. The utility of radioimmunoassays and enzyme immunoassays for environmental investigations was recognized in the 1980s by the U.S. Environmental Protection Agency (U.S. EPA) with the initiation of an immunoassay development programme. The U.S. Department of Agriculture (USDA) and the U.S. Food and Drug Administration (PDA) have investigated immunoassays for the detection of residues in food both from an inspection and a contamination prevention perspective. Environmental immunoassays are providing rapid screening information as well as quantitative information to fulfill rigorous data quality objectives for monitoring programmes

  7. Multiplex dipstick immunoassay for semi-quantitative determination of Fusarium mycotoxins in cereals

    International Nuclear Information System (INIS)

    Lattanzio, Veronica M.T.; Nivarlet, Noan; Lippolis, Vincenzo; Gatta, Stefania Della; Huet, Anne-Catherine; Delahaut, Philippe; Granier, Benoit; Visconti, Angelo

    2012-01-01

    Highlights: ► We developed a rapid method based on a multiplex dipstick immunoassay. ► The assay allowed the determination of major Fusarium toxins in wheat, oats, maize. ► We obtained cut off levels close to EU regulatory levels. - Abstract: A multiplex dipstick immunoassay based method for the simultaneous determination of major Fusarium toxins, namely zearalenone, T-2 and HT-2 toxins, deoxynivalenol and fumonisins in wheat, oats and maize has been developed. The dipstick format was based on an indirect competitive approach. Four test lines (mycotoxin–BSA conjugates) and one control line were located on the strip membrane. Labelled antibodies were freeze-dried within the microwell. Two matrix-related sample preparation protocols have been developed for wheat/oats (not containing fumonisins) and maize (containing fumonisins) respectively. The use of a methanol/water mixture for sample preparation allowed recoveries in the range 73–109% for all mycotoxins in all tested cereals, with relative standard deviation less than 10%. The optimized immunoassay was able to detect target mycotoxins at cut off levels equal to 80% of EU maximum permitted levels, i.e. 280, 400, 1400 and 3200 μg kg −1 , respectively, for zearalenone, T-2/HT-2 toxins, deoxynivalenol and fumonisins in maize, and 80, 400 and 1400 μg kg −1 , respectively, for zearalenone, T-2/HT-2 toxins and deoxynivalenol in wheat and oats. Analysis of naturally contaminated samples resulted in a good agreement between multiplex dipstick and validated confirmatory LC–MS/MS. The percentage of false positive results was less than or equal to 13%, whereas no false negative results were obtained. Data on the presence/absence of 6 mycotoxins at levels close to EU regulatory levels were obtained within 30 min. The proposed immunoassay protocol is rapid, inexpensive, easy-to-use and fit for purpose of rapid screening of mycotoxins in cereals.

  8. Multiplex dipstick immunoassay for semi-quantitative determination of Fusarium mycotoxins in cereals

    Energy Technology Data Exchange (ETDEWEB)

    Lattanzio, Veronica M.T., E-mail: veronica.lattanzio@ispa.cnr.it [National Research Council of Italy, Institute of Sciences of Food Production (ISPA-CNR), Via Amendola 122/O, 70126 Bari (Italy); Nivarlet, Noan [UNISENSOR S.A., Zoning industriel du Dossay, Rue du Dossay no 3, B-4020 Liege (Belgium); Lippolis, Vincenzo; Gatta, Stefania Della [National Research Council of Italy, Institute of Sciences of Food Production (ISPA-CNR), Via Amendola 122/O, 70126 Bari (Italy); Huet, Anne-Catherine; Delahaut, Philippe [Centre d' Economie Rurale (CER Groupe), Rue du Point du Jour no 8, B-6900 Marloie (Belgium); Granier, Benoit [UNISENSOR S.A., Zoning industriel du Dossay, Rue du Dossay no 3, B-4020 Liege (Belgium); Visconti, Angelo [National Research Council of Italy, Institute of Sciences of Food Production (ISPA-CNR), Via Amendola 122/O, 70126 Bari (Italy)

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer We developed a rapid method based on a multiplex dipstick immunoassay. Black-Right-Pointing-Pointer The assay allowed the determination of major Fusarium toxins in wheat, oats, maize. Black-Right-Pointing-Pointer We obtained cut off levels close to EU regulatory levels. - Abstract: A multiplex dipstick immunoassay based method for the simultaneous determination of major Fusarium toxins, namely zearalenone, T-2 and HT-2 toxins, deoxynivalenol and fumonisins in wheat, oats and maize has been developed. The dipstick format was based on an indirect competitive approach. Four test lines (mycotoxin-BSA conjugates) and one control line were located on the strip membrane. Labelled antibodies were freeze-dried within the microwell. Two matrix-related sample preparation protocols have been developed for wheat/oats (not containing fumonisins) and maize (containing fumonisins) respectively. The use of a methanol/water mixture for sample preparation allowed recoveries in the range 73-109% for all mycotoxins in all tested cereals, with relative standard deviation less than 10%. The optimized immunoassay was able to detect target mycotoxins at cut off levels equal to 80% of EU maximum permitted levels, i.e. 280, 400, 1400 and 3200 {mu}g kg{sup -1}, respectively, for zearalenone, T-2/HT-2 toxins, deoxynivalenol and fumonisins in maize, and 80, 400 and 1400 {mu}g kg{sup -1}, respectively, for zearalenone, T-2/HT-2 toxins and deoxynivalenol in wheat and oats. Analysis of naturally contaminated samples resulted in a good agreement between multiplex dipstick and validated confirmatory LC-MS/MS. The percentage of false positive results was less than or equal to 13%, whereas no false negative results were obtained. Data on the presence/absence of 6 mycotoxins at levels close to EU regulatory levels were obtained within 30 min. The proposed immunoassay protocol is rapid, inexpensive, easy-to-use and fit for purpose of rapid screening of mycotoxins

  9. ResonantSonic drilling. Innovative technology summary report

    International Nuclear Information System (INIS)

    1995-04-01

    The technology of ResonantSonic drilling is described. This technique has been demonstrated and deployed as an innovative tool to access the subsurface for installation of monitoring and/or remediation wells and for collection of subsurface materials for environmental restoration applications. The technology uses no drilling fluids, is safe and can be used to drill slant holes

  10. Environmental Pollution: Noise Pollution - Sonic Boom. Volume I.

    Science.gov (United States)

    Defense Documentation Center, Alexandria, VA.

    The unclassified, annotated bibliography is Volume I of a two-volume set on Noise Pollution - Sonic Boom in a series of scheduled bibliographies on Environmental Pollution. Volume II is Confidential. Corporate author-monitoring agency, subject, title, contract, and report number indexes are included. (Author/JR)

  11. Interdisciplinarity in Medialogy with applications to Sonic Interaction Design

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Serafin, Stefania

    2009-01-01

    Medialogy is a novel education developed in Denmark since 2002, whose goal is to combine technology and creativity in the design, contextualization and evaluation of media technology. In this paper we describe the progression of the sonic interaction design curriculum in the Medialogy education, ......, stressing the importance of a transdisciplinary training for engineers working on interactive sound....

  12. Development of a prototype lateral flow immunoassay (LFI for the rapid diagnosis of melioidosis.

    Directory of Open Access Journals (Sweden)

    Raymond L Houghton

    2014-03-01

    Full Text Available Burkholderia pseudomallei is a soil-dwelling bacterium and the causative agent of melioidosis. Isolation of B. pseudomallei from clinical samples is the "gold standard" for the diagnosis of melioidosis; results can take 3-7 days to produce. Alternatively, antibody-based tests have low specificity due to a high percentage of seropositive individuals in endemic areas. There is a clear need to develop a rapid point-of-care antigen detection assay for the diagnosis of melioidosis. Previously, we employed In vivo Microbial Antigen Discovery (InMAD to identify potential B. pseudomallei diagnostic biomarkers. The B. pseudomallei capsular polysaccharide (CPS and numerous protein antigens were identified as potential candidates. Here, we describe the development of a diagnostic immunoassay based on the detection of CPS. Following production of a CPS-specific monoclonal antibody (mAb, an antigen-capture immunoassay was developed to determine the concentration of CPS within a panel of melioidosis patient serum and urine samples. The same mAb was used to produce a prototype Active Melioidosis Detect Lateral Flow Immunoassay (AMD LFI; the limit of detection of the LFI for CPS is comparable to the antigen-capture immunoassay (∼0.2 ng/ml. The analytical reactivity (inclusivity of the AMD LFI was 98.7% (76/77 when tested against a large panel of B. pseudomallei isolates. Analytical specificity (cross-reactivity testing determined that 97.2% of B. pseudomallei near neighbor species (35/36 were not reactive. The non-reactive B. pseudomallei strain and the reactive near neighbor strain can be explained through genetic sequence analysis. Importantly, we show the AMD LFI is capable of detecting CPS in a variety of patient samples. The LFI is currently being evaluated in Thailand and Australia; the focus is to optimize and validate testing procedures on melioidosis patient samples prior to initiation of a large, multisite pre-clinical evaluation.

  13. Targeted selected reaction monitoring mass spectrometric immunoassay for insulin-like growth factor 1.

    Directory of Open Access Journals (Sweden)

    Eric E Niederkofler

    Full Text Available Insulin-like growth factor 1 (IGF1 is an important biomarker of human growth disorders that is routinely analyzed in clinical laboratories. Mass spectrometry-based workflows offer a viable alternative to standard IGF1 immunoassays, which utilize various pre-analytical preparation strategies. In this work we developed an assay that incorporates a novel sample preparation method for dissociating IGF1 from its binding proteins. The workflow also includes an immunoaffinity step using antibody-derivatized pipette tips, followed by elution, trypsin digestion, and LC-MS/MS separation and detection of the signature peptides in a selected reaction monitoring (SRM mode. The resulting quantitative mass spectrometric immunoassay (MSIA exhibited good linearity in the range of 1 to 1,500 ng/mL IGF1, intra- and inter-assay precision with CVs of less than 10%, and lowest limits of detection of 1 ng/mL. The linearity and recovery characteristics of the assay were also established, and the new method compared to a commercially available immunoassay using a large cohort of human serum samples. The IGF1 SRM MSIA is well suited for use in clinical laboratories.

  14. Development and sexual dimorphism of the sonic system in three deep-sea neobythitine fishes and comparisons between upper mid and lower continental slope

    Science.gov (United States)

    Fine, Michael L.; Ali, Heba A.; Nguyen, Thanh Kim; Mok, Hin-Kiu; Parmentier, Eric

    2018-01-01

    Based on morphology, NB Marshall identified cusk-eels (family Ophidiidae) as one of the chief sound-producing groups on the continental slope. Due to food scarcity, we hypothesized that sonic systems will be reduced at great depths despite their potential importance in sexual reproduction. We examined this hypothesis in the cusk-eel subfamily Neobythitinae by comparing sonic morphology in Atlantic species from the upper-mid (Dicrolene intronigra) and deeper continental slope (Porogadus miles and Bathyonus pectoralis) with three Taiwanese species previously described from the upper slope (Hoplobrotula armatus, Neobythites longipes and N. unimaculatus). In all six species, medial muscles are heavier in males than in females. Dicrolene has four pairs of sonic muscles similar to the shallow Pacific species, suggesting neobythitine sonic anatomy is conservative and sufficient food exists to maintain a well-developed system at depths exceeding 1 km. The sonic system in Porogadus and Bathyonus was reduced to a single pair of ventral medial muscles that connects to a smaller and thinner swimbladder via a long tendon. Small muscle fiber diameters, a likely indicator of rapid contraction, were present in males of five of the species. However, in Bathyonus, the deepest species (pale coloration, reduced eye size, shorter sonic muscles and longer tendons), muscle fibers were larger suggesting an adaptation to facilitate rapid bladder movement for sound production while using slower contractions and less metabolic energy. The six species separate into three groups in length-weight regressions: the three upper slope species have the greatest weights per unit length, Dicrolene is lower, and the two deep species are further reduced consistent with the hypothesis that food limitation affects sonic anatomy at great depths.

  15. Turbulence fluxes and variances measured with a sonic anemometer mounted on a tethered balloon

    Science.gov (United States)

    Canut, Guylaine; Couvreux, Fleur; Lothon, Marie; Legain, Dominique; Piguet, Bruno; Lampert, Astrid; Maurel, William; Moulin, Eric

    2016-09-01

    This study presents the first deployment in field campaigns of a balloon-borne turbulence probe, developed with a sonic anemometer and an inertial motion sensor suspended below a tethered balloon. This system measures temperature and horizontal and vertical wind at high frequency and allows the estimation of heat and momentum fluxes as well as turbulent kinetic energy in the lower part of the boundary layer. The system was validated during three field experiments with different convective boundary-layer conditions, based on turbulent measurements from instrumented towers and aircraft.

  16. Sensitive, Fast, and Specific Immunoassays for Methyltestosterone Detection

    Directory of Open Access Journals (Sweden)

    Na Kong

    2015-04-01

    Full Text Available An indirect competitive enzyme-linked immunosorbent assay (icELISA and an immunochromatographic strip assay using a highly specific monoclonal antibody, were developed to detect methyltestosterone (MT residues in animal feed. The optimized icELISA had a half-inhibition concentration value of 0.26 ng/mL and a limit of detection value of 0.045 ng/mL. There was no cross-reactivity with eight analogues, revealing high specificity for MT. Based on icELISA results, the recovery rate of MT in animal feed was 82.4%–100.6%. The results were in accordance with those obtained by gas chromatography-mass spectrometry. The developed immunochromatographic strip assay, as the first report for MT detection, had a visual cut-off value of 1 ng/mL in PBS, 2.5 ng/g in fish feed, and 2.5 ng/g in pig feed. Therefore, these immunoassays are useful and fast tools for MT residue detection in animal feed.

  17. Plasmon enhanced fluoro-immunoassay using egg yolk antibodies for ultra-sensitive detection of herbicide diuron.

    Science.gov (United States)

    Sharma, Priyanka; Kukkar, Manil; Ganguli, Ashok K; Bhasin, Aman; Suri, C Raman

    2013-08-07

    Plasmon enhanced fluorescence immunoassay (PEFI) format has been reported in developing a sensitive heterogeneous fluoroimmunoassay for monitoring the phenylurea herbicide diuron. Computer-assisted molecular modeling was carried out to study the conformational and electrostatic effects of synthesized hapten for producing highly specific egg yolk antibody against a phenyl urea herbicide diuron. The generated antibodies were labeled with fluorescein isothiocyanate at different molar ratios and used as tracer in the developed fluorescence based immunoassay. The sensitivity of the assay format was enhanced by using silver nanoparticles tagged with bovine serum albumin as a new blocking reagent in the developed PEFI format. Enhancer treatment on the developed immunoassay showed a significant improvement of fluorescence signal intensity with approximately 10 fold increase in assay sensitivity. The immunoassay has a detection limit of 0.01 ng mL(-1) with good signal precision (~2%) in the optimum working concentration range between 1 pg mL(-1) to 10 μg mL(-1) of diuron. These findings facilitate high throughput fluorescence-based processes that could be useful in biology, drug discovery and compound screening applications.

  18. Self-collimated slow sound in sonic crystals

    International Nuclear Information System (INIS)

    Kaya, Olgun Adem; Cicek, Ahmet; Ulug, Bulent

    2012-01-01

    Self-collimated slow-sound propagation in a two-dimensional rectangular sonic crystal composed of elliptical scatterers in air is numerically demonstrated. The group velocity at the centre and the edges of the fourth acoustic band is reduced to 45 m s -1 and 30 m s -1 , corresponding to 1/8 and 1/12 of the speed of sound in air, respectively. Elimination of omni-directional reflections encountered in linear waveguides and the reduction of group-velocity dispersion at the mid-band frequencies lead to preservation of pulse shape and amplitude upon traversal of the sonic crystal. Wave transmission is increased from approximately -20 to -2.5 dB, with almost an order of magnitude enhancement, via injector layers optimized through a pattern search algorithm. Self-collimating performance of the system is not degraded under oblique incidence, except for pulse broadening due to increased effective source width.

  19. Potential applications of immunoassays in studies of flatfish recruitment

    Science.gov (United States)

    Feller, Robert J.

    The fisheries recruitment-stock problem, a lack of correlation between measures of reproductive output of the parent stock and recruitment to the fishery, has several potential biotic and abiotic causes. Immunoassays may be useful in examining several aspects of this and several other problems in flatfish ecology: stock identification, parasitism and disease, and trophic interactions. Given stage-specific antisera capable of recognozing antigenic moieties of, for instance, eggs, larvae, or newly-settled juveniles, it is possible to screen stomach contents of many putative predators ( e.g., shrimp or crabs) rapidly for the presence and amounts of platfish prey. This trophic application of immunological methods has great promise for measuring loss of potential recruits to predation. All immunoassays are limited by the quality of antisera used and the researcher's ability to interpret quantitative data in an ecologically meaningful way. Key references for applications of immunoassays in fish-related questions are provided with recommendations for their utilization.

  20. Mixing volume determination in batch transfers through sonic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Renan Martins [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas]. E-mail: renan@cenpes.petrobras.com.br; Rachid, Felipe Bastos de Freitas [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Engenharia Mecanica]. E-mail: rachid@mec.uff.br; Araujo, Jose Henrique Carneiro de [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Ciencia da Computacao]. E-mail: jhca@dcc.ic.uff.br

    2000-07-01

    An experimental methodology to evaluate mixing volumes in batch transfers by means of sonic detectors has been reported in this paper. Mixing volumes have then been computed in a transfer of diesel/gasoline carried out through a pipeline operated by Petrobras for different interface points. It has been shown that an adequate choice of the interface points is crucial for keeping the mixing volume uncertainty within acceptable limits. (author)

  1. Modification of a deoxynivalenol-antigen-mimicking nanobody to improve immunoassay sensitivity by site-saturation mutagenesis.

    Science.gov (United States)

    Qiu, Yu-Lou; He, Qing-Hua; Xu, Yang; Wang, Wei; Liu, Yuan-Yuan

    2016-01-01

    A nanobody (N-28) which can act as a deoxynivalenol (DON) antigen has been generated, and its residues Thr102-Ser106 were identified to bind with anti-DON monoclonal antibody by alanine-scanning mutagenesis. Site-saturation mutagenesis was used to analyze the plasticity of five residues and to improve the sensitivity of the N-28-based immunoassay. After mutagenesis, three mutants were selected by phage immunoassay and were sequenced. The half-maximal inhibitory concentrations of the immunoassay based on mutants N-28-T102Y, N-28-V103L, and N-28-Y105F were 24.49 ± 1.0, 51.83 ± 2.5, and 35.65 ± 1.6 ng/mL, respectively, showing the assay was, respectively, 3.2, 1.5, and 2.2 times more sensitive than the wild-type-based assay. The best mutant, N-28-T102Y, was used to develop a competitive phage ELISA to detect DON in cereals with high specificity and accuracy. In addition, the structural properties of N-28-T102Y and N-28 were investigated, revealing that the affinity of N-28-T102Y decreased because of increased steric hindrance with the large side chain. The lower-binding-affinity antigen mimetic may contribute to the improvement of the sensitivity of competitive immunoassays. These results demonstrate that nanobodies would be a favorable tool for engineering. Moreover, our results have laid a solid foundation for site-saturation mutagenesis of antigen-mimicking nanobodies to improve immunoassay sensitivity for small molecules.

  2. Synthesis of PDLLA/PLLA-bentonite nanocomposite through sonication

    International Nuclear Information System (INIS)

    Sitompul, Johnner; Setyawan, Daru; Kim, Daniel Young Joon; Lee, Hyung Woo

    2016-01-01

    This paper concerns the synthesis of poly(D,L-lactic acid)/poly(L-lactic acid) bentonite nanocomposites. Poly (D,L-lactic acid) (PDLLA) was synthesized using lactic acid through the ZnO-catalyzed direct polycondensation method at vacuum pressure and poly(L-lactic acid) (PLLA) was synthesized with L-lactide by ring-opening polymerization method. The PDLLA/PLLA-bentonite nanocomposite films were synthesized using the solvent casting method. The nanoclay, bentonite, was prepared using the solution-intercalation method by dissolving the nanoparticles into chloroform before sonication. In this study, PDLLA/PLLA-bentonite nanocomposite films were produced using variable amounts of nanoclay and sonication times during the mixing of PDLLA/PLLA and bentonite. The properties of the PDLLA/PLLA nanocomposites were then characterized using the X-ray Diffraction (XRD), Universal Testing Machine (UTM), Water Vapor Permeability (WVP) tests, and the enzymatic biodegradability test. The XRD test was used to measure the intercalation of nanoclay layers in the PDLLA/PLLA matrix and the PDLLA/PLLA-bentonite intercalated nanocomposite films. It was found through these various tests that adding bentonite to the PDLLA/PLLA increases tensile strength to 56.76 MP. Furthermore, the biodegradability increases as well as the barrier properties of the polymers The different sonication time used during the mixing of the polymer solution with bentonite also affected the properties of the PDLLA/PLLA-bentonite nanocomposite films.

  3. Chalk porosity and sonic velocity versus burial depth

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Gommesen, Lars; Krogsbøll, Anette Susanne

    2008-01-01

    Seventy chalk samples from four formations in the overpressured Danish central North Sea have been analyzed to investigate how correlations of porosity and sonic velocity with burial depth are affected by varying mineralogy, fluid pressure, and early introduction of petroleum. The results show th...... for fluid pressure because the cementing ions originate from stylolites, which are mechanically similar to fractures. We find that cementation occurs over a relatively short depth interval.......Seventy chalk samples from four formations in the overpressured Danish central North Sea have been analyzed to investigate how correlations of porosity and sonic velocity with burial depth are affected by varying mineralogy, fluid pressure, and early introduction of petroleum. The results show...... that porosity and sonic velocity follow the most consistent depth trends when fluid pressure and pore-volume compressibility are considered. Quartz content up to 10% has no marked effect, but more than 5% clay causes lower porosity and velocity. The mineralogical effect differs between P-wave and shear velocity...

  4. Synthesis of PDLLA/PLLA-bentonite nanocomposite through sonication

    Energy Technology Data Exchange (ETDEWEB)

    Sitompul, Johnner, E-mail: sitompul@che.itb.ac.id; Setyawan, Daru, E-mail: daru.setyawan@gmail.com; Kim, Daniel Young Joon, E-mail: daniel.kim12321@gmail.com [Department of Chemical Engineering, Faculty of Industrial Technology, Institute of Technology Bandung Jl. Ganesha 10, Bandung, West Java, 40132 (Indonesia); Lee, Hyung Woo, E-mail: leehw@che.itb.ac.id [Department of Chemical Engineering, Faculty of Industrial Technology, Institute of Technology Bandung Jl. Ganesha 10, Bandung, West Java, 40132 (Indonesia); Research and Business Foundation, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi, 440-746 (Korea, Republic of)

    2016-04-19

    This paper concerns the synthesis of poly(D,L-lactic acid)/poly(L-lactic acid) bentonite nanocomposites. Poly (D,L-lactic acid) (PDLLA) was synthesized using lactic acid through the ZnO-catalyzed direct polycondensation method at vacuum pressure and poly(L-lactic acid) (PLLA) was synthesized with L-lactide by ring-opening polymerization method. The PDLLA/PLLA-bentonite nanocomposite films were synthesized using the solvent casting method. The nanoclay, bentonite, was prepared using the solution-intercalation method by dissolving the nanoparticles into chloroform before sonication. In this study, PDLLA/PLLA-bentonite nanocomposite films were produced using variable amounts of nanoclay and sonication times during the mixing of PDLLA/PLLA and bentonite. The properties of the PDLLA/PLLA nanocomposites were then characterized using the X-ray Diffraction (XRD), Universal Testing Machine (UTM), Water Vapor Permeability (WVP) tests, and the enzymatic biodegradability test. The XRD test was used to measure the intercalation of nanoclay layers in the PDLLA/PLLA matrix and the PDLLA/PLLA-bentonite intercalated nanocomposite films. It was found through these various tests that adding bentonite to the PDLLA/PLLA increases tensile strength to 56.76 MP. Furthermore, the biodegradability increases as well as the barrier properties of the polymers The different sonication time used during the mixing of the polymer solution with bentonite also affected the properties of the PDLLA/PLLA-bentonite nanocomposite films.

  5. Influence of Chair Vibrations on Indoor Sonic Boom Annoyance

    Science.gov (United States)

    Rathsam, Jonathan; Klos, Jacob; Loubeau, Alexandra

    2015-01-01

    One goal of NASA’s Commercial Supersonic Technology Project is to identify candidate noise metrics suitable for regulating quiet sonic boom aircraft. A suitable metric must consider the short duration and pronounced low frequency content of sonic booms. For indoor listeners, rattle and creaking sounds and floor and chair vibrations may also be important. The current study examined the effect of such vibrations on the annoyance of test subjects seated indoors. The study involved two chairs exposed to nearly identical acoustic levels: one placed directly on the floor, and the other isolated from floor vibrations by pneumatic elastomeric mounts. All subjects experienced both chairs, sitting in one chair for the first half of the experiment and the other chair for the remaining half. Each half of the experiment consisted of 80 impulsive noises played at the exterior of the sonic boom simulator. When all annoyance ratings were analyzed together there appeared to be no difference in mean annoyance with isolation condition. When the apparent effect of transfer bias was removed, a subtle but measurable effect of vibration on annoyance was identified.

  6. Uranium carbide dissolution in nitric solution: Sonication vs. silent conditions

    International Nuclear Information System (INIS)

    Virot, Matthieu; Szenknect, Stéphanie; Chave, Tony; Dacheux, Nicolas; Moisy, Philippe; Nikitenko, Sergey I.

    2013-01-01

    The dissolution of uranium carbide (UC) in nitric acid media is considered by means of power ultrasound (sonication) or magnetic stirring. The induction period required to initiate UC dissolution was found to be dramatically shortened when sonicating a 3 M nitric solution (Ar, 20 kHz, 18 W cm −2 , 20 °C). At higher acidity, magnetic stirring offers faster dissolution kinetics compared to sonication. Ultrasound-assisted UC dissolution is found to be passivated after ∼60% dissolution and remains incomplete whatever the acidity which is confirmed by ICP–AES, LECO and SEM–EDX analyses. In general, the kinetics of UC dissolution is linked to the in situ generation of nitrous acid in agreement with the general mechanism of UC dissolution; the nitrous acid formation is reported to be faster under ultrasound at low acidity due to the nitric acid sonolysis. The carbon balance shared between the gaseous, liquid, and solid phases is strongly influenced by the applied dissolution procedure and HNO 3 concentration

  7. Uranium carbide dissolution in nitric solution: Sonication vs. silent conditions

    Science.gov (United States)

    Virot, Matthieu; Szenknect, Stéphanie; Chave, Tony; Dacheux, Nicolas; Moisy, Philippe; Nikitenko, Sergey I.

    2013-10-01

    The dissolution of uranium carbide (UC) in nitric acid media is considered by means of power ultrasound (sonication) or magnetic stirring. The induction period required to initiate UC dissolution was found to be dramatically shortened when sonicating a 3 M nitric solution (Ar, 20 kHz, 18 W cm-2, 20 °C). At higher acidity, magnetic stirring offers faster dissolution kinetics compared to sonication. Ultrasound-assisted UC dissolution is found to be passivated after ∼60% dissolution and remains incomplete whatever the acidity which is confirmed by ICP-AES, LECO and SEM-EDX analyses. In general, the kinetics of UC dissolution is linked to the in situ generation of nitrous acid in agreement with the general mechanism of UC dissolution; the nitrous acid formation is reported to be faster under ultrasound at low acidity due to the nitric acid sonolysis. The carbon balance shared between the gaseous, liquid, and solid phases is strongly influenced by the applied dissolution procedure and HNO3 concentration.

  8. Rapid detection of fungal alpha-amylase in the work environment with a lateral flow immunoassay

    NARCIS (Netherlands)

    Bogdanovic, J.; Koets, M.; Sander, I.; Wouters, I.; Meijster, T.; Heederik, D.J.J.; Amerongen, van A.; Doekes, G.

    2006-01-01

    Background Occupational allergen exposure assessment usually requires airborne dust sampling at the worksite followed by dust extraction and enzyme immunoassay (EIA) analysis at the laboratory. Use of semiquantitative lateral flow immunoassays (LFIAs) may allow a more rapid detection procedure with

  9. Preparation by irradiation of a solid support for enzyme immunoassay

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1984-01-01

    Reagents (immobilized anti-α-fetoprotein discs) having a porous structure were prepared for enzyme immunoassay of α-fetoprotein by radiation polymerization at low temperatures. Discs were attached to sticks for easy handling. The activity (determined by absorbance at 492 nm) of the discs varied with the hydrophilic properties and size of the discs. The discs are sufficiently sensitive and precise for enzyme immunoassay of α-fetoprotein. Anti-AFP dissolved in PBS solution was mixed with a monomer solution of hydroxyethyl methacrylate and hydroxypropyl methacrylate. The mixture was frozen to -78 0 C and gamma irradiated. (Auth.)

  10. Multiplex Immunoassay Profiling of Hormones Involved in Metabolic Regulation.

    Science.gov (United States)

    Stephen, Laurie; Guest, Paul C

    2018-01-01

    Multiplex immunoassays are used for rapid profiling of biomarker proteins and small molecules in biological fluids. The advantages over single immunoassays include lower sample consumption, cost, and labor. This chapter details a protocol to develop a 5-plex assay for glucagon-like peptide 1, growth hormone, insulin, leptin, and thyroid-stimulating hormone on the Luminex ® platform. The results of the analysis of insulin in normal control subjects are given due to the important role of this hormone in nutritional programming diseases.

  11. 3D turbulence measurements using three intersecting Doppler LiDAR beams: validation against sonic anemometry

    Science.gov (United States)

    Carbajo Fuertes, Fernando; Valerio Iungo, Giacomo; Porté-Agel, Fernando

    2013-04-01

    Nowadays communities of researchers and industry in the wind engineering and meteorology sectors demand extensive and accurate measurements of atmospheric boundary layer turbulence for a better understanding of its role in a wide range of onshore and offshore applications: wind resource evaluation, wind turbine wakes, meteorology forecast, pollution and urban climate studies, etc. Atmospheric turbulence has been traditionally investigated through sonic anemometers installed on meteorological masts. However, the setup and maintenance of instrumented masts is generally very costly and the available location for the measurements is limited by the fixed position and height of the facility. In order to overcome the above-mentioned shortcomings, a measurement technique is proposed, based on the reconstruction of the three-dimensional velocity vector from simultaneous measurements of three intersecting Doppler wind LiDARs. This measuring technique presents the main advantage of being able to measure the wind velocity at any point in space inside a very large volume, which can be set and optimized for each test. Furthermore, it is very flexible regarding its transportation, installation and operation in any type of terrain. On the other hand, LiDAR measurements are strongly affected by the aerosol concentration in the air, precipitation, and the spatial and temporal resolution is poorer than that of a sonic anemometer. All this makes the comparison between these two kinds of measurements a complex task. The accuracy of the technique has been assessed by this study against sonic anemometer measurements carried out at different heights on the KNMI's meteorological mast at Cabauw's experimental site for atmospheric research (CESAR) in the Netherlands. An early uncertainty analysis shows that one of the most important parameters to be taken into account is the relative angles between the intersecting laser beams, i.e., the position of each LiDAR on the terrain and their

  12. Sonic Boom Pressure Signature Uncertainty Calculation and Propagation to Ground Noise

    Science.gov (United States)

    West, Thomas K., IV; Bretl, Katherine N.; Walker, Eric L.; Pinier, Jeremy T.

    2015-01-01

    The objective of this study was to outline an approach for the quantification of uncertainty in sonic boom measurements and to investigate the effect of various near-field uncertainty representation approaches on ground noise predictions. These approaches included a symmetric versus asymmetric uncertainty band representation and a dispersion technique based on a partial sum Fourier series that allows for the inclusion of random error sources in the uncertainty. The near-field uncertainty was propagated to the ground level, along with additional uncertainty in the propagation modeling. Estimates of perceived loudness were obtained for the various types of uncertainty representation in the near-field. Analyses were performed on three configurations of interest to the sonic boom community: the SEEB-ALR, the 69o DeltaWing, and the LM 1021-01. Results showed that representation of the near-field uncertainty plays a key role in ground noise predictions. Using a Fourier series based dispersion approach can double the amount of uncertainty in the ground noise compared to a pure bias representation. Compared to previous computational fluid dynamics results, uncertainty in ground noise predictions were greater when considering the near-field experimental uncertainty.

  13. Transesterification of waste vegetable oil under pulse sonication using ethanol, methanol and ethanol–methanol mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Guerra, Edith; Gude, Veera Gnaneswar, E-mail: gude@cee.msstate.edu

    2014-12-15

    Highlights: • Pulse sonication effect on transesterification of waste vegetable oil was studied. • Effects of ethanol, methanol, and alcohol mixtures on FAMEs yield were evaluated. • Effect of ultrasonic intensity, power density, and its output rates were evaluated. • Alcohol mixtures resulted in higher biodiesel yields due to better solubility. - Abstract: This study reports on the effects of direct pulse sonication and the type of alcohol (methanol and ethanol) on the transesterification reaction of waste vegetable oil without any external heating or mechanical mixing. Biodiesel yields and optimum process conditions for the transesterification reaction involving ethanol, methanol, and ethanol–methanol mixtures were evaluated. The effects of ultrasonic power densities (by varying sample volumes), power output rates (in W), and ultrasonic intensities (by varying the reactor size) were studied for transesterification reaction with ethanol, methanol and ethanol–methanol (50%-50%) mixtures. The optimum process conditions for ethanol or methanol based transesterification reaction of waste vegetable oil were determined as: 9:1 alcohol to oil ratio, 1% wt. catalyst amount, 1–2 min reaction time at a power output rate between 75 and 150 W. It was shown that the transesterification reactions using ethanol–methanol mixtures resulted in biodiesel yields as high as >99% at lower power density and ultrasound intensity when compared to ethanol or methanol based transesterification reactions.

  14. The Devolution of a Sonic Community Ritual

    Directory of Open Access Journals (Sweden)

    Robin Daniel Z. Rivera

    2014-12-01

    Full Text Available This paper will deal with the changing soundscape of a particular community in the University of the Philippines Diliman Campus, focusing on the weekly Monday morning flag raising ceremony. The paper will compare how it was celebrated in the past, using earwitness accounts, to how it has been rendered more recently based on a soundscape recording taken in February of 2013. As ritual, flag-raising has devolved over the years. This can be traced to the increase in the level of keynote sounds in and around the campus, the malfunctioning and lack of coordination in the use of the sound devices deployed in the original ritual, and the changes in the soundscapes that index the campus community.

  15. Sonic Helium Detectors in the Fermilab Tevatron

    Science.gov (United States)

    Bossert, R. J.

    2006-04-01

    In the Fermilab Tevatron cryogenic system there are many remotely located low-pressure plate relief valves that must vent large volumes of cold helium gas when magnet quenches occur. These valves can occasionally stick open or not reseat completely, resulting in a large helium loss. As such, the need exists for a detector to monitor the relief valve's discharge area for the presence of helium. Due to the quantity needed, cost is an important factor. A unit has been developed and built for this purpose that is quite inexpensive. Its operating principle is based on the speed of sound, where two closely matched tubes operate at their acoustic resonant frequency. When helium is introduced into one of these tubes, the resulting difference in acoustic time of flight is used to trigger an alarm. At present, there are 39 of these units installed and operating in the Tevatron. They have detected many minor and major helium leaks, and have also been found useful in detecting a rise in the helium background in the enclosed refrigerator buildings. This paper covers the construction, usage and operational experience gained with these units over the last several years.

  16. Sonic helium detectors in the Fermilab Tevatron

    International Nuclear Information System (INIS)

    Bossert, R.J.; Fermilab

    2006-01-01

    In the Fermilab Tevatron cryogenic system there are many remotely located low-pressure plate relief valves that must vent large volumes of cold helium gas when magnet quenches occur. These valves can occasionally stick open or not reseat completely, resulting in a large helium loss. As such, the need exists for a detector to monitor the relief valve's discharge area for the presence of helium. Due to the quantity needed, cost is an important factor. A unit has been developed and built for this purpose that is quite inexpensive. Its operating principle is based on the speed of sound, where two closely matched tubes operate at their acoustic resonant frequency. When helium is introduced into one of these tubes, the resulting difference in acoustic time of flight is used to trigger an alarm. At present, there are 39 of these units installed and operating in the Tevatron. They have detected many minor and major helium leaks, and have also been found useful in detecting a rise in the helium background in the enclosed refrigerator buildings. This paper covers the construction, usage and operational experience gained with these units over the last several years

  17. Biosensor immunoassay for flumequine in broiler serum and muscle

    NARCIS (Netherlands)

    Haasnoot, W.; Gercek, H.; Cazemier, G.; Nielen, M.W.F.

    2007-01-01

    Flumequine (Flu) is one of the fluoroquinolones most frequently applied for the treatment of broilers in The Netherlands. For the detection of residues of Flu in blood serum of broilers, a biosensor immunoassay (BIA) was developed which was fast (7.5 min per sample) and specific (no cross-reactivity

  18. Kinase Activity Studied in Living Cells Using an Immunoassay

    Science.gov (United States)

    Bavec, Aljos?a

    2014-01-01

    This laboratory exercise demonstrates the use of an immunoassay for studying kinase enzyme activity in living cells. The advantage over the classical method, in which students have to isolate the enzyme from cell material and measure its activity in vitro, is that enzyme activity is modulated and measured in living cells, providing a more…

  19. IMMUNOASSAYS FOR THE DETECTION OF UROKINASE RECEPTOR FORMS

    DEFF Research Database (Denmark)

    2004-01-01

    amounts of uPAR forms in a sample with data indicative of the presence of the cancer disease. The method can be used for staging, prognosis or diagnosis of prostate cancer. Two novel monoclonal antibodies and a kit and immunoassays for detecting at least one uPAR form(s) are also described in the present...

  20. Direct salivary cortisol radio-immunoassay determination. Clinical applications

    International Nuclear Information System (INIS)

    Simon, C.; Cherfan, J.; Kurtz, F.; Vignon, F.; Schlienger, J.L.; Chabrier, G.

    1987-01-01

    Salivary cortisol levels reflect the biologically active free fraction of blood cortisol. The authors describe the results obtained with the aim of a radio-immunoassay commercial serum cortisol kit, without prealable extraction in different physiological and pathological situations. Salivary cortisol determination appears performant both in nycthemeral studies and in stimulation or freination tests [fr

  1. Evaluation of Six Different Immunoassays for Serum Thyrotropin

    International Nuclear Information System (INIS)

    Ma Donghong; Lu Hankui; Gao Yunchao; Ge Wenli; Xiong Jiang; Liu Qiaoping; Gu Qing

    2010-01-01

    To analyzes the discrepancy and association among six different thyrotropin (TSH) immunoassay methods and to study their impact on the clinical diagnoses of thyroid diseases, the 150 serum samples from three groups consisting of hyperthyroidism, hypothyroidism and healthy subjects, 50 samples in each group were included in this study. The serum TSH levels were measured simultaneously by radioimmunoassay (RIA), immunoradiometric assay (IRMA), three-type chemilumiminescence immunoassay (CLIA) and electrochemiluminescence immunoassay (ECLIA). The results showed that individual serum TSH level varied significantly from one assay to another. There was no correlation between TSH RIA and other five assays in groups of hyperthyroidism and healthy subjects(P>0.05). The correlations between TSH IRMA and four automatic assays in hyperthyroidism group were relatively low (r= 0.38∼0.41). However, among the four automatic assays, TSH levels were well correlated (r= 0.92∼0.99). For clinical diagnoses, TSH RIA alone was not useful in the differentiation of hyperthyroidism and normal subjects, and TSH IRMA was misleading in some hyperthyroidism. There were no significant differences for four TSH automatic immunoassays in differential diagnoses of thyroid diseases. (authors)

  2. Optimization of phycocyanin extraction from microalgae Spirulina platensis by sonication as antioxidant

    Science.gov (United States)

    Dianursanti, Indraputri, Claudia Maya; Taurina, Zarahmaida

    2018-02-01

    Cardiovascular disease is known as an epidemic disease which has high casualty in the world. One of its trigger factors is the amount of reactive oxygen species (ROS) inside the body. In order to regulate its amount, antioxidant ingestion is compulsory. Microalgae can be adopted as a source of antioxidant. Spirulina platensis is one of the consistently produced microalgae. It contains phycocyanin, a blue pigment, which is known as a nutritious food agent. Phycocyanin could be assumed as an antioxidant and has been clinically validated both in vitro and in vivo. This research is proposed to determine the optimum extraction time. The experiment was conducted by sonication at 37 kHz using phosphate buffer as the solvent. The result exhibited that increasing the sonication time would increase the yield until it achieved the optimum yield. Based on the experiment, the optimum extraction time was 25 minutes with yield of 8.25 mg/g dry biomass and purity of 0.6. It can be summarized that extraction time also affected the extraction efficiency and its antioxidant activity. This paper shows a prospect on future development in cultivating micro flora in Indonesia, particularly in Depok.

  3. Thermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses

    Directory of Open Access Journals (Sweden)

    Araceli Peña

    2012-10-01

    Full Text Available The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while thermography provides accurate crop temperature data. Air distribution by means of perforated polyethylene ducts at ground level, widely used in Mediterranean-type greenhouses, can generate heterogeneous temperature distributions inside the greenhouse when the system is not correctly designed. The system analyzed in this work used a polyethylene duct with a row of hot air outlet holes (all of equal diameter that expel warm air toward the ground to avoid plant damage. We have observed that this design (the most widely used in Almería’s greenhouses produces stagnation of hot air in the highest part of the structure, reducing the heating of the crop zone. Using 88 kW heating power (146.7 W∙m−2 the temperature inside the greenhouse is maintained 7.2 to 11.2 °C above the outside temperature. The crop temperature (17.6 to 19.9 °C was maintained above the minimum recommended value of 10 °C.

  4. Thermography and sonic anemometry to analyze air heaters in Mediterranean greenhouses.

    Science.gov (United States)

    López, Alejandro; Valera, Diego L; Molina-Aiz, Francisco; Peña, Araceli

    2012-10-16

    The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while thermography provides accurate crop temperature data. Air distribution by means of perforated polyethylene ducts at ground level, widely used in Mediterranean-type greenhouses, can generate heterogeneous temperature distributions inside the greenhouse when the system is not correctly designed. The system analyzed in this work used a polyethylene duct with a row of hot air outlet holes (all of equal diameter) that expel warm air toward the ground to avoid plant damage. We have observed that this design (the most widely used in Almería's greenhouses) produces stagnation of hot air in the highest part of the structure, reducing the heating of the crop zone. Using 88 kW heating power (146.7 W ∙ m(-2)) the temperature inside the greenhouse is maintained 7.2 to 11.2 °C above the outside temperature. The crop temperature (17.6 to 19.9 °C) was maintained above the minimum recommended value of 10 °C.

  5. Clearly Transparent Nanopaper from Highly Concentrated Cellulose Nanofiber Dispersion Using Dilution and Sonication

    Directory of Open Access Journals (Sweden)

    Takaaki Kasuga

    2018-02-01

    Full Text Available Nanopaper prepared from holocellulose pulp is one of the best substrates for flexible electronics because of its high thermal resistance and high clear transparency. However, the clearness of nanopaper decreases with increasing concentration of the starting cellulose nanofiber dispersion—with the use of a 2.2 wt % dispersion, for example—resulting in translucent nanopaper with a high haze of 44%. To overcome this problem, we show that the dilution of this high-concentration dispersion with water followed by sonication for 10 s reduces the haze to less than 10% while maintaining the high thermal resistance of the nanopaper. Furthermore, the combination of water dilution and a short sonication treatment improves the clearness of the nanopaper, which would translate into cost savings for the transportation and storage of this highly concentrated cellulose nanofiber dispersion. Finally, we demonstrate the improvement of the electrical conductivity of clear transparent nanopaper prepared from an initially high-concentration dispersion by dropping and heating silver nanowire ink on the nanopaper. These achievements will pave the way toward the realization of the mass production of nanofiber-based flexible devices.

  6. The Use of Structural-Acoustic Techniques to Assess Potential Structural Damage From Sonic Booms

    Science.gov (United States)

    Garrelick, Joel; Martini, Kyle

    1996-01-01

    The potential impact of supersonic operations includes structural damage from the sonic boom overpressure. This paper describes a study of how structural-acoustic modeling and testing techniques may be used to assess the potential for such damage in the absence of actual flyovers. Procedures are described whereby transfer functions relating structural response to sonic boom signature may be obtained with a stationary acoustic source and appropriate data processing. Further, by invoking structural-acoustic reciprocity, these transfer functions may also be acquired by measuring the radiated sound from the structure under a mechanical drive. The approach is based on the fundamental assumption of linearity, both with regard to the (acoustic) propagation of the boom in the vicinity of the structure and to the structure's response. Practical issues revolve around acoustic far field and source directivity requirements. The technique was implemented on a specially fabricated test structure at Edwards AFB, CA with the support of Wyle Laboratories, Inc. Blank shots from a cannon served as our acoustic source and taps from an instrumented hammer generated the mechanical drive. Simulated response functions were constructed. Results of comparisons with corresponding measurements recorded during dedicated supersonic flyovers with F-15 aircraft are presented for a number of sensor placements.

  7. Structural basis for the high specificity of a Trypanosoma congolense immunoassay targeting glycosomal aldolase.

    Directory of Open Access Journals (Sweden)

    Joar Pinto

    2017-09-01

    Full Text Available Animal African trypanosomosis (AAT is a neglected tropical disease which imposes a heavy burden on the livestock industry in Sub-Saharan Africa. Its causative agents are Trypanosoma parasites, with T. congolense and T. vivax being responsible for the majority of the cases. Recently, we identified a Nanobody (Nb474 that was employed to develop a homologous sandwich ELISA targeting T. congolense fructose-1,6-bisphosphate aldolase (TcoALD. Despite the high sequence identity between trypanosomatid aldolases, the Nb474-based immunoassay is highly specific for T. congolense detection. The results presented in this paper yield insights into the molecular principles underlying the assay's high specificity.The structure of the Nb474-TcoALD complex was determined via X-ray crystallography. Together with analytical gel filtration, the structure reveals that a single TcoALD tetramer contains four binding sites for Nb474. Through a comparison with the crystal structures of two other trypanosomatid aldolases, TcoALD residues Ala77 and Leu106 were identified as hot spots for specificity. Via ELISA and surface plasmon resonance (SPR, we demonstrate that mutation of these residues does not abolish TcoALD recognition by Nb474, but does lead to a lack of detection in the Nb474-based homologous sandwich immunoassay.The results show that the high specificity of the Nb474-based immunoassay is not determined by the initial recognition event between Nb474 and TcoALD, but rather by its homologous sandwich design. This (i provides insights into the optimal set-up of the assay, (ii may be of great significance for field applications as it could explain the potential detection escape of certain T. congolense strains, and (iii may be of general interest to those developing similar assays.

  8. Dog-Bone Horns for Piezoelectric Ultrasonic/Sonic Actuators

    Science.gov (United States)

    Sherrit, Stewart; Bar-Cohen, Yoseph; Chang, Zensheu; Bao, Xiaoqi

    2007-01-01

    A shape reminiscent of a dog bone has been found to be superior to other shapes for mechanical-amplification horns that are components of piezoelectrically driven actuators used in a series of related devices denoted generally as ultrasonic/sonic drill/corers (USDCs). The first of these devices was reported in Ultrasonic/Sonic Drill/Corers With Integrated Sensors (NPO-20856), NASA Tech Briefs, Vol. 25, No. 1 (January 2001), page 38. The dog-bone shape was conceived especially for use in a more recent device in the series, denoted an ultrasonic/ sonic gopher, that was described in Ultrasonic/Sonic Mechanisms for Drilling and Coring (NPO-30291), NASA Tech Briefs, Vol. 27, No. 9 (September 2003), page 65. The figure shows an example of a dog-bone-shaped horn and other components of an ultrasonic gopher. Prerequisite to a meaningful description of this development is an unavoidably lengthy recapitulation of the principle of operation of a USDC and, more specifically, of the ultrasonic/sonic gopher as described previously in NASA Tech Briefs. The ultrasonic actuator includes a stack of piezoelectric rings, the horn, a metal backing, and a bolt that connects the aforementioned parts and provides compressive pre-strain to the piezoelectric stack to prevent breakage of the rings during extension. The stack of piezoelectric rings is excited at the resonance frequency of the overall ultrasonic actuator. Through mechanical amplification by the horn, the displacement in the ultrasonic vibration reaches tens of microns at the tip of the horn. The horn hammers an object that is denoted the free mass because it is free to move longitudinally over a limited distance between hard stops: The free mass bounces back and forth between the ultrasonic horn and a tool bit (a drill bit or a corer). Because the longitudinal speed of the free mass is smaller than the longitudinal speed of vibration of the tip of the horn, contact between the free mass and the horn tip usually occurs at a

  9. Upconverting nanophosphors as reporters in a highly sensitive heterogeneous immunoassay for cardiac troponin I

    Energy Technology Data Exchange (ETDEWEB)

    Sirkka, Nina, E-mail: nkelon@utu.fi; Lyytikäinen, Annika; Savukoski, Tanja; Soukka, Tero

    2016-06-21

    Photon upconverting nanophosphors (UCNPs) have a unique capability to produce anti-Stokes emission at visible wavelengths via sequential multiphoton absorption upon infrared excitation. Since the anti-Stokes emission can be easily spectrally resolved from the Stokes' shifted autofluorescence, the upconversion luminescence (UCL) is a highly attractive reporter technology for optical biosensors and biomolecular binding assays – potentially enabling unprecedented sensitivity in separation-based solid-phase immunoassays. UCL technology has not previously been applied in sensitive detection of cardiac troponin I (cTnI), which requires highly sensitive detection to enable accurate and timely diagnosis of myocardial infarction. We have developed an UCL-based immunoassay for cTnI using NaYF{sub 4}: Yb{sup 3+}, Er{sup 3+} UCNPs as reporters. Biotinylated anti-cTnI monoclonal antibody (Mab) and Fab fragment immobilized to streptavidin-coated wells were used to capture cTnI. Captured cTnI was detected from dry well surface after a 15 min incubation with poly(acrylic acid) coated UCNPs conjugated to second anti-cTnI Mab. UCL was measured with a dedicated UCL microplate reader. The UCL-based immunoassay allowed sensitive detection of cTnI. The limit of detection was 3.14 ng L{sup −1}. The calibration curve was linear up to cTnI concentration 50,000 ng L{sup −1}. Plasma recoveries of added cTnI were 92–117%. Obtained cTnI concentrations from five normal plasma samples were 4.13–10.7 ng L{sup −1} (median 5.06 ng L{sup −1}). There is yet significant potential for even further improved limit of detection by reducing non-specifically bound fraction of the Mab-conjugated UCNPs. The assay background with zero calibrator was over 40-fold compared to the background obtained from wells where the reporter conjugate had been excluded. - Highlights: • Detection of attomole analyte quantity in microwell using upconversion luminescence. • Upconverting

  10. Design of novel hybrid organic-inorganic nanostructured biomaterials for immunoassay applications

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, G [Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, PO Box 486, 31270.901, Belo Horizonte, MG (Brazil); Barbosa-Stancioli, E F [Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, PO Box 486, 31270.901, Belo Horizonte, MG (Brazil); Piscitelli Mansur, A A [Department of Metallurgical and Materials Engineering, Biomaterials and Tissue Engineering Laboratory, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil); Vasconcelos, W L [Department of Metallurgical and Materials Engineering, Biomaterials and Tissue Engineering Laboratory, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil); Mansur, H S [Department of Metallurgical and Materials Engineering, Biomaterials and Tissue Engineering Laboratory, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil)

    2006-12-01

    The purpose of this study was to develop novel hybrid organic-inorganic materials based on poly(vinyl alcohol) (PVA) polymer chemically crosslinked network to be tested as solid support on bovine herpesvirus immunoassay. Hybrids were synthesized by reacting PVA with three different alkoxysilanes modifying chemical groups: tetraethoxysilane (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and 3-glycidoxypropyltrimethoxysilane (GPTMS). PVA-derived hybrids were also modified by chemically crosslinking with glutaraldehyde (GA) during the synthesis reaction. In order to investigate the structure in the nanometer-scale, PVA-derived hybrids were characterized by using small-angle x-ray scattering synchrotron radiation (SAXS) and x-ray diffraction (XRD). PVA hybrids' chemical functionalities and their interaction with herpesviruses were also characterized by Fourier transform infrared spectroscopy (FTIR). The bioactivity assays were tested through enzyme linked immunosorbent assay (ELISA). SAXS results have indicated nano-ordered disperse domains for PVA hybrids with different x-ray scattering patterns for PVA polymer and PVA-derived hybrids. FTIR spectra have shown major vibration bands associated with organic-inorganic chemical groups present in the PVA, PVA-derived by silane modifier and PVA chemically crosslinked by GA. The immunoassay results have shown that PVA hybrids with chemically functionalized structures regulated to some extent the specific bioimmobilization of herpesvirus onto solid phase. We think that it is due to the overall balance of forces associated with van der Waals interaction, hydrophilic and hydrophobic forces and steric hindrance acting at the surface. PVA and PVA-derived hybrid materials were successfully produced with GA crosslinking in a nanometer-scale network. Also, such a PVA-based material could be advantageously used in immunoassays with enhanced specificity for diagnosis.

  11. Design of novel hybrid organic-inorganic nanostructured biomaterials for immunoassay applications

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, G [Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, PO Box 486, 31270.901, Belo Horizonte, MG (Brazil); Barbosa-Stancioli, E F [Department of Microbiology, Institute of Biological Sciences, Federal University of Minas Gerais, PO Box 486, 31270.901, Belo Horizonte, MG (Brazil); Piscitelli Mansur, A A [Department of Metallurgical and Materials Engineering, Biomaterials and Tissue Engineering Laboratory, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil); Vasconcelos, W L [Department of Metallurgical and Materials Engineering, Biomaterials and Tissue Engineering Laboratory, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil); Mansur, H S [Department of Metallurgical and Materials Engineering, Biomaterials and Tissue Engineering Laboratory, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil)

    2006-12-01

    The purpose of this study was to develop novel hybrid organic-inorganic materials based on poly(vinyl alcohol) (PVA) polymer chemically crosslinked network to be tested as solid support on bovine herpesvirus immunoassay. Hybrids were synthesized by reacting PVA with three different alkoxysilanes modifying chemical groups: tetraethoxysilane (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and 3-glycidoxypropyltrimethoxysilane (GPTMS). PVA-derived hybrids were also modified by chemically crosslinking with glutaraldehyde (GA) during the synthesis reaction. In order to investigate the structure in the nanometer-scale, PVA-derived hybrids were characterized by using small-angle x-ray scattering synchrotron radiation (SAXS) and x-ray diffraction (XRD). PVA hybrids' chemical functionalities and their interaction with herpesviruses were also characterized by Fourier transform infrared spectroscopy (FTIR). The bioactivity assays were tested through enzyme linked immunosorbent assay (ELISA). SAXS results have indicated nano-ordered disperse domains for PVA hybrids with different x-ray scattering patterns for PVA polymer and PVA-derived hybrids. FTIR spectra have shown major vibration bands associated with organic-inorganic chemical groups present in the PVA, PVA-derived by silane modifier and PVA chemically crosslinked by GA. The immunoassay results have shown that PVA hybrids with chemically functionalized structures regulated to some extent the specific bioimmobilization of herpesvirus onto solid phase. We think that it is due to the overall balance of forces associated with van der Waals interaction, hydrophilic and hydrophobic forces and steric hindrance acting at the surface. PVA and PVA-derived hybrid materials were successfully produced with GA crosslinking in a nanometer-scale network. Also, such a PVA-based material could be advantageously used in immunoassays with enhanced specificity for diagnosis.

  12. Evanescent waves and deaf bands in sonic crystals

    Directory of Open Access Journals (Sweden)

    V. Romero-García

    2011-12-01

    Full Text Available The properties of sonic crystals (SC are theoretically investigated in this work by solving the inverse problem k(ω using the extended plane wave expansion (EPWE. The solution of the resulting eigenvalue problem gives the complex band structure which takes into account both the propagating and the evanescent modes. In this work we show the complete mathematical formulation of the EPWE for SC and the supercell approximation for its use in both a complete SC and a SC with defects. As an example we show a novel interpretation of the deaf bands in a complete SC in good agreement with multiple scattering simulations.

  13. Flow tilt angles near forest edges - Part 1: Sonic anemometry

    DEFF Research Database (Denmark)

    Dellwik, Ebba; Mann, Jakob; Larsen, Klaus Steenberg

    2010-01-01

    distortion and vertical alignment, it was only possible to a limited extent to relate sonic anemometer flow tilt angles to upwind forest edges, but the results by the lidar indicated that an internal boundary layer affect flow tilt angles at 21m above the forest. This is in accordance with earlier studies......-flow angles were assumed for neutral flow, the data was interpreted in relation to upstream and downstream forest edges. Uncertainties caused by flow distortion, vertical misalignment and limited sampling time (statistical uncertainty) were evaluated and found to be highly significant. Since the attack angle...... balance, unless all terms in the carbon dioxide conservation equation can be precisely estimated....

  14. Evanescent waves and deaf bands in sonic crystals

    Science.gov (United States)

    Romero-García, V.; Garcia-Raffi, L. M.; Sánchez-Pérez, J. V.

    2011-12-01

    The properties of sonic crystals (SC) are theoretically investigated in this work by solving the inverse problem k(ω) using the extended plane wave expansion (EPWE). The solution of the resulting eigenvalue problem gives the complex band structure which takes into account both the propagating and the evanescent modes. In this work we show the complete mathematical formulation of the EPWE for SC and the supercell approximation for its use in both a complete SC and a SC with defects. As an example we show a novel interpretation of the deaf bands in a complete SC in good agreement with multiple scattering simulations.

  15. Empirical Musicology Review: Serialist Claims versus Sonic Reality

    Directory of Open Access Journals (Sweden)

    William Thomson

    2010-08-01

    Full Text Available This study examines the descriptive mores of Serialism, as found in writings of leading American academics of the past half-century. A serious gap is revealed, especially between claims made for structural conditions rooted in dodecaphonic procedures and the actual kinetics of music as heard. Curious (and debilitating ambiguities and dead ends are noted in terms used to define critical perceptual conditions in such music; some claims of significance for features of 12- tone rows in certain works are revealed as wholly irrelevant to music as sonic event. Most prominent of the writings discussed are those of Milton Babbitt, Allen Forte and David Lewin.

  16. Sonic Kayaks: Environmental monitoring and experimental music by citizens.

    Science.gov (United States)

    Griffiths, Amber G F; Kemp, Kirsty M; Matthews, Kaffe; Garrett, Joanne K; Griffiths, David J

    2017-11-01

    The Sonic Kayak is a musical instrument used to investigate nature and developed during open hacklab events. The kayaks are rigged with underwater environmental sensors, which allow paddlers to hear real-time water temperature sonifications and underwater sounds, generating live music from the marine world. Sensor data is also logged every second with location, time and date, which allows for fine-scale mapping of water temperatures and underwater noise that was previously unattainable using standard research equipment. The system can be used as a citizen science data collection device, research equipment for professional scientists, or a sound art installation in its own right.

  17. Sonic Kayaks: Environmental monitoring and experimental music by citizens.

    Directory of Open Access Journals (Sweden)

    Amber G F Griffiths

    2017-11-01

    Full Text Available The Sonic Kayak is a musical instrument used to investigate nature and developed during open hacklab events. The kayaks are rigged with underwater environmental sensors, which allow paddlers to hear real-time water temperature sonifications and underwater sounds, generating live music from the marine world. Sensor data is also logged every second with location, time and date, which allows for fine-scale mapping of water temperatures and underwater noise that was previously unattainable using standard research equipment. The system can be used as a citizen science data collection device, research equipment for professional scientists, or a sound art installation in its own right.

  18. Pendaphonics: A Tangible Pendulum-based Sonic Interaction Experience

    DEFF Research Database (Denmark)

    Overholt, Daniel; Hansen, Anne-Marie S.; Burleson, Winslow

    2009-01-01

    , presents a strategy for the design and evaluation of a low-cost, flexible, distributed system for public interaction and performance in a large scale tangible system. Pendaphonics has been installed in a public new media arts space, where over 200 people experienced the initial opening of the environment...

  19. Live imaging of individual cell divisions in mouse neuroepithelium shows asymmetry in cilium formation and Sonic hedgehog response

    Directory of Open Access Journals (Sweden)

    Piotrowska-Nitsche Karolina

    2012-05-01

    Full Text Available Abstract Background Primary cilia are microtubule-based sensory organelles that play important roles in developmental signaling pathways. Recent work demonstrated that, in cell culture, the daughter cell that inherits the older mother centriole generates a primary cilium and responds to external stimuli prior to its sister cell. This asynchrony in timing of cilia formation could be especially critical during development as cell divisions are required for both differentiation and maintenance of progenitor cell niches. Methods Here we integrate several fluorescent markers and use ex vivo live imaging of a single cell division within the mouse E8.5 neuroepithelium to reveal both the formation of a primary cilium and the transcriptional response to Sonic hedgehog in the daughter cells. Results We show that, upon cell division, cilia formation and the Sonic hedgehog response are asynchronous between the daughter cells. Conclusions Our results demonstrate that we can directly observe single cell divisions within the developing neuroepithelium and concomitantly monitor cilium formation or Sonic hedgehog response. We expect this method to be especially powerful in examining whether cellular behavior can lead to both differentiation and maintenance of cells in a progenitor niche.

  20. Safety and skin delayed-type hypersensitivity response in vervet monkeys immunized with Leishmania donovani sonicate antigen delivered with adjuvants

    Directory of Open Access Journals (Sweden)

    Joshua M. Mutiso

    2012-02-01

    Full Text Available In this study, we report on the safety and skin delayed-type hypersensitivity (DTH, responses of the Leishmania donovani whole cell sonicate antigen delivered in conjunction with alum-BCG (AlBCG, Montanide ISA 720 (MISA or Monophosphoryl lipid A (MPLA in groups of vervet monkeys. Following three intradermal injections of the inoculums on days 0, 28 and 42, safety and DTH responses were assessed. Preliminary tumor necrosis factor alpha (TNF-α and interferon gamma (IFN-γ levels were also measured and these were compared with DTH. Only those animals immunized with alum-BCG reacted adversely to the inoculum by producing ulcerative erythematous skin indurations. Non-parametric analysis of variance followed by a post-test showed significantly higher DTH responses in the MISA+Ag group compared with other immunized groups (p < 0.001. The MPLA+Ag group indicated significantly lower DTH responses to the sonicate antigen compared with the AlBCG+Ag group. There was a significant correlation between the DTH and cytokine responses (p < 0.0001. Based on this study we conclude that Leishmania donovani sonicate antigen containing MISA 720 is safe and is associated with a strong DTH reaction following immunization.

  1. Real time analysis of brain tissue by direct combination of ultrasonic surgical aspiration and sonic spray mass spectrometry.

    Science.gov (United States)

    Schäfer, Karl-Christian; Balog, Júlia; Szaniszló, Tamás; Szalay, Dániel; Mezey, Géza; Dénes, Júlia; Bognár, László; Oertel, Matthias; Takáts, Zoltán

    2011-10-15

    Direct combination of cavitron ultrasonic surgical aspirator (CUSA) and sonic spray ionization mass spectrometry is presented. A commercially available ultrasonic surgical device was coupled to a Venturi easy ambient sonic-spray ionization (V-EASI) source by directly introducing liquified tissue debris into the Venturi air jet pump. The Venturi air jet pump was found to efficiently nebulize the suspended tissue material for gas phase ion production. The ionization mechanism involving solely pneumatic spraying was associated with that of sonic spray ionization. Positive and negative ionization spectra were obtained from brain and liver samples reflecting the primary application areas of the surgical device. Mass spectra were found to feature predominantly complex lipid-type constituents of tissues in both ion polarity modes. Multiply charged peptide anions were also detected. The influence of instrumental settings was characterized in detail. Venturi pump geometry and flow parameters were found to be critically important in ionization efficiency. Standard solutions of phospholipids and peptides were analyzed in order to test the dynamic range, sensitivity, and suppression effects. The spectra of the intact tissue specimens were found to be highly specific to the histological tissue type. The principal component analysis (PCA) and linear discriminant analysis (LDA) based data analysis method was developed for real-time tissue identification in a surgical environment. The method has been successfully tested on post-mortem and ex vivo human samples including astrocytomas, meningeomas, metastatic brain tumors, and healthy brain tissue. © 2011 American Chemical Society

  2. Optimization of an immunoassay of 2,6-dichlorobenzamide (BAM) and development of regenerative surfaces by immunosorbent modification with newly synthesised BAM hapten library

    DEFF Research Database (Denmark)

    Uthuppu, Basil; Aamand, Jens; Jørgensen, Claus

    2012-01-01

    Dichlobenil is an extensively used herbicide worldwide which is transformed to the mobile 2,6-dichlorobenzamide (BAM) in soil. BAM has been found in many European groundwater resources that are exploited for drinking water. Currently, immunoassay based monitoring technique (plate based ELISA) is ...

  3. Accuracy of immunoassay and mass spectrometry urinary free cortisol in the diagnosis of Cushing's syndrome.

    Science.gov (United States)

    Aranda, G; Careaga, M; Hanzu, F A; Patrascioiu, I; Ríos, P; Mora, M; Morales-Romero, B; Jiménez, W; Halperin, I; Casals, G

    2016-10-01

    Urinary free cortisol (UFC) determination by highly specific methods as mass spectrometry instead of commercially available antibody-based immunoassays is increasingly recommended. However, clinical comparisons of both analytical approaches in the screening of Cushing's syndrome (CS) are not available. The aim of this study was to evaluate the diagnostic value of mass spectrometry versus immunoassay measurements of 24 h-UFC in the screening of CS. Cross-sectional study of 33 histologically confirmed CS patients: 25 Cushing's disease, 5 adrenal CS and 3 ectopic CS; 92 non-CS patients; and 35 healthy controls. UFC by immunoassay (UFCxIA) and mass spectrometry (UFCxMS), urinary free cortisone (UFCo) and UFC:UFCo ratio were measured, together with creatinine-corrected values. Sensitivity, specificity, AUC and Landis and Koch concordance index were determined. AUC for UFCxIA and UFCxMS were 0.77 (CI 0.68-0.87) and 0.77 (CI 0.67-0.87) respectively, with a kappa coefficient 0.60 and strong Landis and Koch concordance index. The best calculated cutoff values were 359 nmol/24 h for UFCxIA (78 % sensitivity, 62 % specificity) and 258.1 nmol/24 h for UCFxMS (53 % sensitivity, 86 % specificity). The upper limit of UFCxIA and UCFxMS reference ranges were 344.7 and 169.5 nmol/24 h respectively. Sensitivity and specificity for CS diagnosis at these cutpoints were 84 and 56 % for UFCxIA and 81 and 54 % for UFCxMS. According to our data, both methods present a very similar diagnostic value. However, results suggest that lower cutoff points for mass spectrometry may be necessary in order to improve clinical sensitivity.

  4. Continuous and pulse sonication effects on transesterification of used vegetable oil

    International Nuclear Information System (INIS)

    Martinez-Guerra, Edith; Gude, Veera Gnaneswar

    2015-01-01

    Highlights: • We studied continuous and pulse sonication effects on transesterification reaction. • Pulse sonication appears to have superior effects on transesterification reaction. • Effects of various process parameters on FAMEs yield were discussed in detail. • Effects of ultrasonic intensity and power density were compared for both conditions. • Continuous sonication may be beneficial for short time and plug-flow conditions. - Abstract: This study reports on the effects of direct application of continuous and pulse sonication on transesterification reaction of used vegetable oil. Specific to this research, thermal effects of ultrasonics in transesterification reaction without external conventional heating along with the effects of different ultrasonic intensities and power densities were reported. Two process parametric evaluation studies were conducted to compare the effects of continuous and pulse sonication. These included methanol to oil ratio, catalyst concentration and reaction time effects on the transesterification reaction. For continuous sonication, a catalyst amount of 0.5% (wt/wt), methanol to oil ratio of 9:1 was sufficient to complete the transesterification reaction in 1–2 min at a power output of 150 W with a biodiesel yield of 93.5%. For pulse sonication, a maximum biodiesel yield of 98% was achieved at 2.5 min of reaction time, 9:1 methanol to oil ratio, and 1.25% catalyst. Generally, higher biodiesel yields were observed for pulse sonication compared to continuous sonication under any given process condition. Power density and ultrasonic intensity tests revealed that biodiesel yields were more sensitive to continuous sonication due to intense mixing. A plug-flow or contact-type reactor design may improve overall ultrasonic utilization in the transesterification reaction under continuous sonication

  5. The De-Noising of Sonic Echo Test Data through Wavelet Transform Reconstruction

    Directory of Open Access Journals (Sweden)

    J.N. Watson

    1999-01-01

    Full Text Available This paper presents the results of feasibility study into the application of the wavelet transform signal processing method to sonic based non-destructive testing techniques. Finite element generated data from cast in situ foundation piles were collated and processed using both continuous and discrete wavelet transform techniques. Results were compared with conventional Fourier based methods. The discrete Daubechies wavelets and the continuous Mexican hat wavelet were used and their relative merits investigated. It was found that both the continuous Mexican hat and discrete Daubechies D8 wavelets were significantly better at locating the pile toe compared than the Fourier filtered case. The wavelet transform method was then applied to field test data and found to be successful in facilitating the detection of the pile toe.

  6. Sonic anemometry to measure natural ventilation in greenhouses.

    Science.gov (United States)

    López, Alejandro; Valera, Diego Luis; Molina-Aiz, Francisco

    2011-01-01

    The present work has developed a methodology for studying natural ventilation in Mediterranean greenhouses by means of sonic anemometry. In addition, specific calculation programmes have been designed to enable processing and analysis of the data recorded during the experiments. Sonic anemometry allows us to study the direction of the airflow at all the greenhouse vents. Knowing through which vents the air enters and leaves the greenhouse enables us to establish the airflow pattern of the greenhouse under natural ventilation conditions. In the greenhouse analysed in this work for Poniente wind (from the southwest), a roof vent designed to open towards the North (leeward) could allow a positive interaction between the wind and stack effects, improving the ventilation capacity of the greenhouse. The cooling effect produced by the mass of turbulent air oscillating between inside and outside the greenhouse at the side vents was limited to 2% (for high wind speed, u(o) ≥ 4 m s(-1)) reaching 36.3% when wind speed was lower (u(o) = 2 m s(-1)).

  7. MRI monitoring of focused ultrasound sonications near metallic hardware.

    Science.gov (United States)

    Weber, Hans; Ghanouni, Pejman; Pascal-Tenorio, Aurea; Pauly, Kim Butts; Hargreaves, Brian A

    2018-07-01

    To explore the temperature-induced signal change in two-dimensional multi-spectral imaging (2DMSI) for fast thermometry near metallic hardware to enable MR-guided focused ultrasound surgery (MRgFUS) in patients with implanted metallic hardware. 2DMSI was optimized for temperature sensitivity and applied to monitor focus ultrasound surgery (FUS) sonications near metallic hardware in phantoms and ex vivo porcine muscle tissue. Further, we evaluated its temperature sensitivity for in vivo muscle in patients without metallic hardware. In addition, we performed a comparison of temperature sensitivity between 2DMSI and conventional proton-resonance-frequency-shift (PRFS) thermometry at different distances from metal devices and different signal-to-noise ratios (SNR). 2DMSI thermometry enabled visualization of short ultrasound sonications near metallic hardware. Calibration using in vivo muscle yielded a constant temperature sensitivity for temperatures below 43 °C. For an off-resonance coverage of ± 6 kHz, we achieved a temperature sensitivity of 1.45%/K, resulting in a minimum detectable temperature change of ∼2.5 K for an SNR of 100 with a temporal resolution of 6 s per frame. The proposed 2DMSI thermometry has the potential to allow MR-guided FUS treatments of patients with metallic hardware and therefore expand its reach to a larger patient population. Magn Reson Med 80:259-271, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  8. Biodiesel from waste cooking oils via direct sonication

    International Nuclear Information System (INIS)

    Gude, Veera Gnaneswar; Grant, Georgene Elizabeth

    2013-01-01

    Highlights: • Thermal effects of direct sonication on transesterification reaction were studied. • Ultrasonics may effectively transesterify waste oils without external heating. • Intense mixing with temperature rise completes transesterification instantly. • Plug flow process reactor design with ultrasound may prove energy efficient. • Process optimization and biodiesel conversion analysis was presented. - Abstract: This study investigates the effect of direct sonication in conversion of waste cooking oil into biodiesel. Waste cooking oils may cause environmental hazards if not disposed properly. However, waste cooking oils can serve as low-cost feedstock for biodiesel production. Ultrasonics, a non-conventional process technique, was applied to directly convert waste cooking oil into biodiesel in a single step. Ultrasonics transesterify waste cooking oils very efficiently due to increased mass/heat transfer phenomena and specific thermal/athermal effects at molecular levels. Thus, energy and chemical consumption in the overall process is greatly reduced compared to conventional biodiesel processes. Specific to this research, thermal effects of ultrasonics in transesterification reaction without external conventional heating along with effects of different ultrasonic, energy intensities and energy density are reported. Optimization of process parameters such as methanol to oil ratio, catalyst concentration and reaction time are also presented. It was observed that small reactor design such as plug-flow or contact-type reactor design may improve overall ultrasonic utilization in the transesterification reaction due to increased energy density and ultrasonic intensity

  9. Cellular and molecular effects of electromagnetic radiation and sonic waves

    Directory of Open Access Journals (Sweden)

    Patricia Froes Meyer

    2013-07-01

    Full Text Available Electromagnetic radiation (in the form of pulsed magnetic fields, radiofrequency and intense pulsed light and mechanical agents (such as sonic waves have been used in physical therapy. The aim of this study was to assess the effects of low-intensity magnetic fields, sonic and radiofrequency waves, and intense pulsed light on the survival of Escherichia coli cultures and on the electrophoretic mobility of plasmid DNA. Exponentially growing E. coli AB1157 cultures and plasmid DNA samples were exposed to these physical agents and 0.9% NaCl (negative control and SnCl2 (positive control solutions. Aliquots of the cultures were diluted and spread onto a solidified rich medium. The colony-forming units were counted after overnight incubation and the survival fraction was calculated. Agarose gel electrophoresis was performed to visualise and quantify the plasmid topological forms. The results suggest that these agents do not alter the survival of E. coli cells or plasmid DNA electrophoresis mobility. Moreover, they do not protect against the lesive action of SnCl2. These physical agents therefore had no cytotoxic or genotoxic effects under the conditions studied.

  10. Morphology and crystallinity of sisal nanocellulose after sonication

    Science.gov (United States)

    Sosiati, H.; Wijayanti, D. A.; Triyana, K.; Kamiel, B.

    2017-09-01

    Different preparation methods on the natural fibers resulted in different morphology. However, the relationships between type of natural fibers, preparation methods and the morphology of produced nanocellulose could not be exactly defined. The sisal nanocellulose was presently prepared by alkalization and bleaching followed by sonication to verify changes in the morphology and crystallinity of nanocellulose related to the formation mechanism. The extracted microcellulose was subjected to scanning electron microscopy (SEM) and x-ray diffraction (XRD) analysis. The isolated cellulose nanospheres were examined with respect to morphology by SEM and transmission electron microscopy (TEM) and, to crystallinity by electron diffraction analysis. Bleaching after alkalization made the microfibrils clearly separated from each other to the individual fiber whose width of the single fiber was ranging from 6 to 13 µm. The XRD crystallinity index (CI) of microcellulose gradually increased after the chemical treatments; 83.12% for raw sisal fiber, 88.57% for alkali treated fiber and 94.03% for bleached fibers. The ultrasonic agitation after bleaching that was carried out at 750 Watt, 20 kHz and amplitude of 39% for 2 h produces homogeneous cellulose nanospheres less than 50 nm in diameter with relatively low crystallinity. The electron diffraction analysis confirmed that the low crystallinity of produced nnocellulose is related to the effect of chemical treatment done before sonication.

  11. A competitive enzyme immunoassay for the quantitative detection of cocaine from banknotes and latent fingermarks.

    Science.gov (United States)

    van der Heide, Susan; Garcia Calavia, Paula; Hardwick, Sheila; Hudson, Simon; Wolff, Kim; Russell, David A

    2015-05-01

    A sensitive and versatile competitive enzyme immunoassay (cEIA) has been developed for the quantitative detection of cocaine in complex forensic samples. Polyclonal anti-cocaine antibody was purified from serum and deposited onto microtiter plates. The concentration of the cocaine antibody adsorbed onto the plates, and the dilution of the cocaine-HRP hapten were both studied to achieve an optimised immunoassay. The method was successfully used to quantify cocaine in extracts taken from both paper currency and latent fingermarks. The limit of detection (LOD) of 0.162ngmL(-1) achieved with the assay compares favourably to that of conventional chromatography-mass spectroscopy techniques, with an appropriate sensitivity for the quantification of cocaine at the low concentrations present in some forensic samples. The cEIA was directly compared to LC-MS for the analysis of ten UK banknote samples. The results obtained from both techniques were statistically similar, suggesting that the immunoassay was unaffected by cross-reactivity with potentially interfering compounds. The cEIA was used also for the detection of cocaine in extracts from latent fingermarks. The results obtained were compared to the cocaine concentrations detected in oral fluid sampled from the same individual. Using the cEIA, we have shown, for the first time, that endogeneously excreted cocaine can be detected and quantified from a single latent fingermark. Additionally, it has been shown that the presence of cocaine, at similar concentrations, in more than one latent fingermark from the same individual can be linked with those concentrations found in oral fluid. These results show that detection of drugs in latent fingermarks could directly indicate whether an individual has consumed the drug. The specificity and feasibility of measuring low concentrations of cocaine in complex forensic samples demonstrate the effectiveness and robustness of the assay. The immunoassay presents a simple and cost

  12. Evaluation of four immunoassays for diagnosis of brucellosis in Cuba

    International Nuclear Information System (INIS)

    Peraza, C.; Valdes, O.; Fonseca, N.; Garcia, M.; Alvarez, M.; Izquierdo, D.L.

    1998-01-01

    Four immunoassays (two indirect and two competitive ones) were evaluated by samples from areas free of disease, free by vaccination and affected areas using as reference techniques the Bengal Rose Tests, the Antigen in Buffered Plate Tests and the Complement Fixation Reaction Test. The evaluated samples demonstrated that the competitive assays (ELISAC-1 and ELISAC-2) detected less false positives than the indirect ones (ELISAI-1 and ELISAI-2). Of the competitive ELISAS, version 2 presented better sensitivity and specificity results in affected areas for 95% confidence: 80.9 - 96.9% and 97.5 - 99.4% respectively with positive predictive value in the range of 76 to 94% and negative predictive one between 98.1 and 99.7%. It was concluded that this assay can be used for brucellosis control because it gives higher assurance than the other evaluated immunoassays and it can discriminate infected from vaccinated animals. (author)

  13. The Impact of Sonication on the Surface Quality of Single-Walled Carbon Nanotubes.

    Science.gov (United States)

    Koh, Byumseok; Cheng, Wei

    2015-08-01

    Sonication process is regularly adopted for dispersing single-walled carbon nanotubes (SWCNTs) in an aqueous medium. This can be achieved by either covalent functionalization of SWCNTs with strong acid or by noncovalent functionalization using dispersants that adsorb onto the surface of SWCNTs during dispersion. Because the dispersion process is usually performed using sonication, unintentional free radical formation during sonication process may induce covalent modification of SWCNT surface. Herein, we have systematically investigated the status of SWCNT surface modification under various sonication conditions using Raman spectroscopy. Comparing ID /IG (Raman intensities between D and G bands) ratio of SWCNTs under various sonication conditions suggests that typical sonication conditions (1-6 h bath sonication with sonication power between 3 and 80 W) in aqueous media do not induce covalent modification of SWCNT surface. In addition, we confirm that SWCNT dispersion with single-stranded DNA (ssDNA) involves noncovalent adsorption of ssDNA onto the surface of SWCNTs, but not covalent linkage between ssDNA and SWCNT surface. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  14. Label-Free Electrochemical Immunoassay for C-Reactive Protein

    Directory of Open Access Journals (Sweden)

    Madasamy Thangamuthu

    2018-03-01

    Full Text Available C-reactive protein (CRP is one of the most expressed proteins in blood during acute phase inflammation, and its minute level increase has also been recognized for the clinical diagnosis of cardio vascular diseases. Unfortunately, the available commercial immunoassays are labour intensive, require large sample volumes, and have practical limitations, such as low stability and high production costs. Hence, we have developed a simple, cost effective, and label-free electrochemical immunoassay for the measurement of CRP in a drop of serum sample using an immunosensor strip made up of a screen printed carbon electrode (SPE modified with anti-CRP functionalized gold nanoparticles (AuNPs. The measurement relies on the decrease of the oxidation current of the redox indicator Fe3+/Fe2+, resulting from the immunoreaction between CRP and anti-CRP. Under optimal conditions, the present immunoassay measures CRP in a linear range from 0.4–200 nM (0.047–23.6 µg mL−1, with a detection limit of 0.15 nM (17 ng mL−1, S/N = 3 and sensitivity of 90.7 nA nM−1, in addition to a good reproducibility and storage stability. The analytical applicability of the presented immunoassay is verified by CRP measurements in human blood serum samples. This work provides the basis for a low-priced, safe, and easy-to-use point-of-care immunosensor assay to measure CRP at clinically relevant concentrations.

  15. Determination of digoxin by enzyme immunoassay and radioimmunoassay

    International Nuclear Information System (INIS)

    Mueller, H.; Braeuer, H.; Foerster, G.; Reinhardt, M.

    1978-01-01

    The results of parallel determinations of digoxin in the sera of non selected patients (n=104) by enzyme immunoassay (EMIT.EIA) and radioimmunoassay (J-125 labeled RIA) were compared with each other. The determinations revealed considerably different concentrations; the values determined by EIA were statistical lower (for EIA 1,09+'0,99ng/ml, for RIA 1,34+'1,01ng/ml, p [de

  16. Towards the development of a radioenzyme-immunoassay

    International Nuclear Information System (INIS)

    Schuurs, A.H.W.M.; Waart, M. v. d.

    1976-01-01

    We have tried to develop a very sensitive enzyme-immunoassay. For this purpose, a very sensitive radiochemical enzyme assay was used. HCG was chosen as test model and AChE as labelling enzyme. The test appeared to be much more sensitive than the normal enzymeimmunoassay. And, in comparison with RIA, it was about as sensitive but less time-consuming, and it makes use, in principle, of stable reagents. (orig./GSE) [de

  17. Characterization of hapten-protein conjugates: antibody generation and immunoassay development for chlorophenoxyacetic acid pesticides.

    Science.gov (United States)

    Boro, Robin C; Singh, K Vikas; Suri, C Raman

    2009-01-01

    The generation of specific and sensitive antibodies against small molecules is greatly dependent upon the characteristics of the hapten-protein conjugates. In this study, we report a new fluorescence-based method for the characterization of hapten-protein conjugates. The method is based on an effect promoted by hapten-protein conjugation density upon the fluorescence intensity of the intrinsic tryptophan chromophore molecules of the protein. The proposed methodology is applied to quantify the hapten-protein conjugation density for two different chlorophenoxyacetic acid pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenoxybutyric acid (2,4-DB), coupled to carrier protein. Highly sensitive anti-2,4-D and anti-2,4-DB antibodies were obtained using these well-characterized hapten-protein conjugates. The generated antibodies were used in an immunoassay format demonstrating inhibitory concentration (IC50) values equal to 30 and 7 ng/mL for 2,4-D and 2,4-DB, respectively. Linearity was observed in the concentration range between 0.1-500 nglmL with LODs around 4 and 3 ng/mL for 2,4-D and 2,4-DB, respectively, in standard water samples. The proposed method was successfully applied for the determination of the extent of hapten-protein conjugation to produce specific antibodies for immunoassay development against pesticides.

  18. Photoelectrochemical detection of enzymatically generated CdS nanoparticles: Application to development of immunoassay.

    Science.gov (United States)

    Barroso, Javier; Saa, Laura; Grinyte, Ruta; Pavlov, Valeri

    2016-03-15

    We report an innovative photoelectrochemical process (PEC) based on graphite electrode modified with electroactive polyvinylpyridine bearing osmium complex (Os-PVP). The system relies on the in situ enzymatic generation of CdS quantum dots (QDs). Alkaline phosphatase (ALP) catalyzes the hydrolisis of sodium thiophosphate (TP) to hydrogen sulfide (H2S) which in the presence Cd(2+) ions yields CdS semiconductor nanoparticles (SNPs). Irradiation of SNPs with the standard laboratory UV-illuminator (wavelength of 365 nm) results in photooxidation of 1-thioglycerol (TG) mediated by Os-PVP complex on the surface of graphite electrode at applied potential of 0.31 V vs. Ag/AgCl. A novel immunoassay based on specific enzyme linked immunosorbent assay (ELISA) combined with the PEC methodology was developed. Having selected the affinity interaction between bovine serum albumine (BSA) with anti-BSA antibody (AB) as a model system, we built the PEC immunoassay for AB. The new assay displays a linear range up to 20 ngmL(-1) and a detection limit (DL) of 2 ngmL(-1) (S/N=3) which is lower 5 times that of the traditional chromogenic ELISA test employing p-nitro-phenyl phosphate (pNPP). Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Comparison of immunoassays for differentiation of herpes simplex virus type 1 and 2 antibodies

    International Nuclear Information System (INIS)

    Klapper, Paul E.; Valley, Pam J.; Cleator, Gerham M.; Mandall, D.; Qutub, Mohammed O.

    2006-01-01

    To asses the commercial available enzyme-linked immunosorbent assays (ELISA) for differentiation of herpes simplex virus type 1 (Hs-1) and type 2 (HSV-2) antibodies. The study was performed between January 1997 to November 2002 in the Division ofVirology,Department of Pathological Sciences, Central Manchester Healthcare Trust and University of Manchester, Manchester, United Kingdom. Assays based upon type-specific glycoprotein G-1 (gG-1) for HSV-1, and glycoprotein G-2 (gG-2) from HSV-2 were evaluated to differentiate between HSV-1 and HSV-2 antibodies. Using 5 different ELISA tests, 2 panels of serum samples were tested. Panel one consisted of 88 sera, selected from the serum bank of the Clinical Virology Laboratory, Manchester Royal Infirmary; panel 2 comprised of 90 sera selected from samples collected from Bangladeshi female commercial workers.The data of this study showed that a high rate of gG-1 based immunoassays ranged from 87.9-100% for sensitivity and 51.5-100% specificity. Although there are several immunoassays were claimed to differentiate between HSV-1 and HSV-2 antibodies, selection of these assays should be carefully interpreted with the overall clinical framework provided by detailed sexual history and genital examination. (author)

  20. Development of a mass spectrometry immunoassay for unambiguous detection of egg allergen traces in wines.

    Science.gov (United States)

    Pilolli, Rosa; Chaudhari, Ravindra; Palmisano, Francesco; Monaci, Linda

    2017-02-01

    A mass spectrometry immunoassay (MSIA) specifically designed for the detection of egg allergens in wines is described. MSIA is based on an immunoaffinity enrichment procedure combined with targeted MS/MS detection of selected egg peptide markers. Polyclonal antibodies raised against native ovalbumin, chosen as the target protein tracing for egg powder, were immobilized onto low backpressure monolithic MSIA customized disposable tips. Ovalbumin-free wine samples were fortified with standard protein at different concentrations in the low microgram-per-milliliter range. A simple protocol was devised consisting of a 1:4 dilution of the wine sample with a basic solution for pH adjustment, followed by a semi-automated purification/enrichment step on MSIA customized disposable tips fitted on a multichannel electronic pipette. Among the main figures of merit, LOD and LOQ values as low as 0.01 and 0.03 μg/mL, respectively, and within-day precision of 18% should be noticed. Noteworthy, the developed assay outperformed current MS-based methods for the detection of allergenic protein in wine matrices, thanks to the immunoaffinity enrichment. In addition, compared to other immunoassays, the present approach boasts the unquestionable advantage of providing an unambiguous identification of the target protein by simultaneous detection of three unique peptide markers each giving three specific MS/MS transitions.

  1. Abbott prism: a multichannel heterogeneous chemiluminescence immunoassay analyzer.

    Science.gov (United States)

    Khalil, O S; Zurek, T F; Tryba, J; Hanna, C F; Hollar, R; Pepe, C; Genger, K; Brentz, C; Murphy, B; Abunimeh, N

    1991-09-01

    We describe a multichannel heterogeneous immunoassay analyzer in which a sample is split between disposable reaction trays in a group of linear tracks. The system's pipettor uses noninvasive sensing of the sample volume and disposable pipet tips. Each assay track has (a) a conveyor belt for moving reaction trays to predetermined functional stations, (b) temperature-controlled tunnels, (c) noncontact transfer of the reaction mixture between incubation and detection wells, and (d) single-photon counting to detect a chemiluminescence (CL) signal from the captured immunochemical product. A novel disposable reaction tray, with separate reaction and detection wells and self-contained fluid removal, is used in conjunction with the transfer device on the track to produce a carryover-free system. The linear immunoassay track has nine predetermined positions for performing individual assay steps. Assay step sequence and timing is selected by changing the location of the assay modules between these predetermined positions. The assay methodology, a combination of microparticle capture and direct detection of a CL signal on a porous matrix, offers excellent sensitivity, specificity, and ease of automation. Immunoassay configurations have been tested for hepatitis B surface antigen and for antibodies to hepatitis B core antigen, hepatitis C virus, human immunodeficiency virus I and II, and human T-cell leukemia virus I and II.

  2. Evaluation of Rheological Properties and Swelling Behaviour of Sonicated Scleroglucan Samples

    Directory of Open Access Journals (Sweden)

    Siddique Akber Ansari

    2012-02-01

    Full Text Available Scleroglucan is a natural polysaccharide that has been proposed for various applications. However there is no investigation on its property variations when the molecular weight of this polymer is reduced. Scleroglucan was sonicated at two different polymer concentrations for different periods of time and the effect of sonication was investigated with respect to molecular weight variations and rheological properties. Molar mass, estimated by viscometric measurements, was drastically reduced already after a sonication for a few min. Sonicated samples were used for the preparation of gels in the presence of borate ions. The effect of borax on the new samples was investigated by recording the mechanical spectra and the flow curves. A comparison with the system prepared with the dialysed polymer was also carried out. The anisotropic elongation, observed with tablets of scleroglucan and borax, was remarkably reduced when the sonicated samples were used for the preparation of the gels.

  3. Increasing of sensitivity of fluorescent immunoassay analysis of alpha-fetoprotein by means of plasmonical silver nanoparticles

    International Nuclear Information System (INIS)

    Vashchenko, S.V.; Min'ko, A.A.; Romanenko, A.A.; Gaponenko, S.V.; Kulakovich, O.S.

    2014-01-01

    A test system is proposed based on metal enhanced fluorescence to analyze low concentrations of alpha-fetoprotein (AFP), a tumor marker. Antigen-antibody reaction was performed on polystyrene plates coated with silver nanoparticles to increase sensitivity of fluorescent immunoassay and signal-to-noise ratio as compared to silver-free system. As compared to widely used ELISA technique and other immunoassay techniques the proposed approach is characterized by smaller probe volume, fast analysis and simplicity. The proposed test system uses layer-by-layer assembly approach, LED excitation and nanowatt photodetection set-up. The proposed test system offers AFP detection at concentrations used in clinical practice. Fluorescence enhancement for labeled AFP antibodies on a silver substrate was found to depend on antibodies concentration and was up to 6 times. (authors)

  4. Effects of Sonic Booms on Marine Mammals: Problem Review and Recommended Research

    Science.gov (United States)

    Bowles, Ann E.

    1996-01-01

    By flying the High-Speed Civil Transport (HSCT) exclusively over uninhabited areas and mo over water, human annoyance will be reduced to acceptable levels. However, this strategy will for HSCT proponents to contend with the potential effects of sonic booms on animals, particularly ma mammals. What follows is a summary of the environmental regulations that must be addressed, the scientific community's concerns about the potential effects of the HSCT, and recommendations fox research to address the most important concerns. The recommendations included herein are based both on existing scientific evidence and regulatory needs. One cannot over-emphasize the importance of obtaining the appropriate information prior to substantial public exposure. Recent controversies over other human-made acoustic sources in the ocean suggest that the HSCT will receive intense scrutiny. It seems certain that an Environmental Impact Statement (EIS) and Incidental Harassment Authorization (IHA) under the Marine Mammal Protection Act (MMPA) or its equivalent will be necessary.

  5. Research on axial total pressure distributions of sonic steam jet in subcooled water

    International Nuclear Information System (INIS)

    Wu Xinzhuang; Li Wenjun; Yan Junjie

    2012-01-01

    The axial total pressure distributions of sonic steam jet in subcooled water were experimentally investigated for three different nozzle diameters (6.0 mm, 8.0 mm and 10.0 mm). The inlet steam pressure, and pool subcooling subcooled water temperature were in the range of 0.2-0.6 MPa and 420-860 ℃, respectively. The effect of steam pressure, subcooling water temperature and nozzle size on the axial pressure distributions were obtained, and also the characteristics of the maximum pressure and its position were studied. The results indicated that the characteristics of the maximum pressure were influenced by the nozzle size for low steam pressure, but the influence could be ignored for high steam pressure. Moreover, a correlation was given to correlate the position of the maximum pressure based on steam pressure and subcooling water temperature, and the discrepancies of predictions and experiments are within ±15%. (authors)

  6. Sonic Interactions in Virtual Reality: State of the Art, Current Challenges, and Future Directions.

    Science.gov (United States)

    Serafin, Stefania; Geronazzo, Michele; Erkut, Cumhur; Nilsson, Niels C; Nordahl, Rolf

    2018-03-01

    A high-fidelity but efficient sound simulation is an essential element of any VR experience. Many of the techniques used in virtual acoustics are graphical rendering techniques suitably modified to account for sound generation and propagation. In recent years, several advances in hardware and software technologies have been facilitating the development of immersive interactive sound-rendering experiences. In this article, we present a review of the state of the art of such simulations, with a focus on the different elements that, combined, provide a complete interactive sonic experience. This includes physics-based simulation of sound effects and their propagation in space together with binaural rendering to simulate the position of sound sources. We present how these different elements of the sound design pipeline have been addressed in the literature, trying to find the trade-off between accuracy and plausibility. Recent applications and current challenges are also presented.

  7. Effect of deregulation of Sonic Hedgehog pathway on responses to DNA damage and cancer predisposition

    International Nuclear Information System (INIS)

    Charazac, Aurelie

    2015-01-01

    The Gorlin syndrome is a rare genetic disorder characterized by several developmental abnormalities. Due to mutations in PTCH1, a key player of the sonic hedgehog signaling pathway, clinical manifestations also includes hyper-radiosensitivity and an increased predisposition to the development of basal cell carcinomas. Given the implication of DNA repair system defects in hyper-radiosensitivity pathologies, we decided to study the effect of PTCH1 mutations on the DNA damage response in order to better understand the cellular and molecular mechanisms leading to Gorlin's phenotype.This study demonstrate a global failure of the DNA damage repair systems in Gorlin fibroblasts with respect to controls. It highlights in particular the collapse of the base excision repair pathway (BER) responsible for the repair of oxidative DNA damage. (author) [fr

  8. A Multiplex Microsphere-Based Immunoassay Increases the Sensitivity of SIV-Specific Antibody Detection in Serum Samples and Mucosal Specimens Collected from Rhesus Macaques Infected with SIVmac239

    OpenAIRE

    Powell, Rebecca L.R.; Ouellette, Ian; Lindsay, Ross W.; Parks, Christopher L.; King, C. Richter; McDermott, Adrian B.; Morrow, Gavin

    2013-01-01

    Abstract Results from recent HIV-1 vaccine studies have indicated that high serum antibody (Ab) titers may not be necessary for Ab-mediated protection, and that Abs localized to mucosal sites might be critical for preventing infection. Enzyme-linked immunosorbent assay (ELISA) has been used for decades as the gold standard for Ab measurement, though recently, highly sensitive microsphere-based assays have become available, with potential utility for improved detection of Abs. In this study, w...

  9. Music, Mechanism, and the "Sonic Turn" in Physical Diagnosis.

    Science.gov (United States)

    Pesic, Peter

    2016-04-01

    The sonic diagnostic techniques of percussion and mediate auscultation advocated by Leopold von Auenbrugger and R. T. H. Laennec developed within larger musical contexts of practice, notation, and epistemology. Earlier, François-Nicolas Marquet proposed a musical notation of pulse that connected felt pulsation with heard music. Though contemporary vitalists rejected Marquet's work, mechanists such as Albrecht von Haller included it into the larger discourse about the physiological manifestations of bodily fluids and fibers. Educated in that mechanistic physiology, Auenbrugger used musical vocabulary to present his work on thoracic percussion; Laennec's musical experience shaped his exploration of the new timbres involved in mediate auscultation. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Sonic Detection and Ranging (SODAR) Wind Profiler Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Coulter, Richard L. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-04-01

    The SODAR (Sonic Detection and Ranging) wind profiler measures wind profiles and backscattered signal strength between (nominally) 15 meters (m) and 500 m. It operates by transmitting acoustic energy into the atmosphere and measuring the strength and frequency of backscattered energy. The strength of the backscattered signal is determined by the strength of temperature inhomogeneities with size on the order of 10 centimeters (cm). Assuming the scattering elements in the atmosphere are moving with the mean wind, the horizontal wind field can be derived. The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Mobile Facility (AMF) has a system developed by Scintec, Inc. that transmits a sequence of frequencies to enhance signal determination.

  11. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan; Samtaney, Ravi; Bull, Joseph L.

    2013-01-01

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  12. Trial of prestressed concrete cable testing by sonic integrity tester

    International Nuclear Information System (INIS)

    Sugimoto, Masanobu

    1997-01-01

    Highway road network of Japan is in good condition. Those roads were constructed as social infrastructures. But some damages were occurred and propagated in concrete structure which passed more than 20 years after construction. As for the damages load caring capacity of bridge was decreased due to fatigue of increasing traffics and bridge vibration. Recently many troubles happened in PC structure as cut off of the main cables by corrosion and flying the non-grouting PC-bar to roadside. Some case can be checked by hammering testing method and X-ray photo cut or not and condition of cement grouting. But another case has not checking method. Now we are testing for the PC cables by sonic integrity tester which is modified from FPDS(Foundation Pile Diagnosis System). We report in this paper on this result and scope of the future of this method.

  13. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan

    2013-01-10

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  14. Acoustic resonances in two-dimensional radial sonic crystal shells

    Energy Technology Data Exchange (ETDEWEB)

    Torrent, Daniel; Sanchez-Dehesa, Jose, E-mail: jsdehesa@upvnet.upv.e [Wave Phenomena Group, Departamento de Ingenieria Electronica, Universidad Politecnica de Valencia, C/Camino de Vera s.n., E-46022 Valencia (Spain)

    2010-07-15

    Radial sonic crystals (RSC) are fluidlike structures infinitely periodic along the radial direction that verify the Bloch theorem and are possible only if certain specially designed acoustic metamaterials with mass density anisotropy can be engineered (see Torrent and Sanchez-Dehesa 2009 Phys. Rev. Lett. 103 064301). A comprehensive analysis of two-dimensional (2D) RSC shells is reported here. A given shell is in fact a circular slab with a central cavity. These finite crystal structures contain Fabry-Perot-like resonances and modes strongly localized at the central cavity. Semi-analytical expressions are developed to obtain the quality factors of the different resonances, their symmetry features and their excitation properties. The results reported here are completely general and can be extended to equivalent 3D spherical shells and to their photonic counterparts.

  15. Acoustic metamaterials for new two-dimensional sonic devices

    Energy Technology Data Exchange (ETDEWEB)

    Torrent, Daniel; Sanchez-Dehesa, Jose [Wave Phenomena Group, Department of Electronic Engineering, Polytechnic University of Valencia, C/Camino de Vera sn, E-46022 Valencia (Spain)

    2007-09-15

    It has been shown that two-dimensional arrays of rigid or fluidlike cylinders in a fluid or a gas define, in the limit of large wavelengths, a class of acoustic metamaterials whose effective parameters (sound velocity and density) can be tailored up to a certain limit. This work goes a step further by considering arrays of solid cylinders in which the elastic properties of cylinders are taken into account. We have also treated mixtures of two different elastic cylinders. It is shown that both effects broaden the range of acoustic parameters available for designing metamaterials. For example, it is predicted that metamaterials with perfect matching of impedance with air are now possible by using aerogel and rigid cylinders equally distributed in a square lattice. As a potential application of the proposed metamaterial, we present a gradient index lens for airborne sound (i.e. a sonic Wood lens) whose functionality is demonstrated by multiple scattering simulations.

  16. New antibody and immunoassay pretreatment strategy to screen polychlorinated biphenyls in Korean transformer oil.

    Science.gov (United States)

    Terakado, Shingo; Ohmura, Naoya; Park, Seok-Un; Lee, Seung-Min; Glass, Thomas R

    2013-01-01

    Development and modifications are described that expand the application of an immunoassay from the detection of Kanechlors (Japanese technical PCBs mixtures) to the detection of Aroclors (U. S. technical PCB mixtures, used in Korea) in contaminated Korean transformer oil. The first necessary modification was the development of a new antibody with a reactivity profile favorable for Aroclors. The second modification was the addition of a second column to the solid-phase extraction method to reduce assay interference caused by the Korean oil matrix. The matrix interference is suspected to be caused by the presence of synthetic oils (or similar materials) present as contaminants. The modified assay was validated by comparison to high-resolution gas chromatography/high-resolution mass spectrometry analysis, and was shown to be tolerant of up to 10% of several common synthetic insulating oils. Finally the screening performance of the modified assay was evaluated using 500 used transformer oil samples of Korean origin, and was shown to have good performance in terms of false positive and false negative rates. This report provides evidence for the first establishment of immunoassay screening for Aroclor based PCB contamination in Korean transformer oil.

  17. [Membrane-filtration immunoassay: reagents, methods and the diagnostic and technical means for detection].

    Science.gov (United States)

    Khramov, E N; Osin, N S; Pomelova, V G; Vikha, I V; Bychenkova, T A; Smirnova, V G; Grakina, G I; Kas'ianova, T A

    1999-01-01

    The comprehensive development of dot-EIA made at the State Research Institute of Biological Instrument-Making Industry has provided devices KIMF-02 and KIMF-03), a base of chemical reagents, immunoassays, test systems for detection of a wide range of causative agents of viral and bacterial infections, that of serodiagnosis of their related diseases. The KIMF-02 kit has undergone engineering and medical tests and recommended for the Ministry of Health of the Russian Federation to produce them in stock. The kit includes all required for analysis even in an ill-equipped laboratory, a set of attached agents ensures a valid visual recording of results. The developed procedures and test systems allow the immunoassay to be as sensitive as TIFA; however, they are laborious and much simpler in design. The simple and rapid procedures of dot-EIA are recommended for incorporation into the a package of laboratory methods for verification of the accumulation of virus-specific antigens in various biological substrata, environmental samples, for control of the activity of antigens and antibodies used in serological tests, for detection of specific antigens in the clinical samples, and for serodiagnosis of infections.

  18. Clinical Validation of a Point-of-Care Multiplexed In Vitro Immunoassay Using Monoclonal Antibodies (the MSD Influenza Test) in Four Hospitals in Vietnam

    NARCIS (Netherlands)

    van Doorn, H. Rogier; Kinh, Nguyen Van; Tuan, Ha Manh; Tuan, Tran Anh; Minh, Ngo Ngoc Quang; Bryant, Juliet E.; Hang, Vu thi Ty; Uyen, Le thi Tham; Thinh, Le Quoc; Anh, Tran thi Ngoc; Lan, Nguyen Phu Huong; Trung, Nguyen Vu; Taylor, Walter; Merson, Laura; Wertheim, Heiman F. L.; Farrar, Jeremy; Wolbers, Marcel; Chau, Nguyen Van Vinh; de Jong, Menno D.

    2012-01-01

    Point-of-care (POC) diagnostic tests for influenza can considerably shorten the time to clinical decision making. An investigational POC test based on a multiplexed immunoassay was developed by Meso Scale Diagnostics, LLC (MSD), with the objective to make a more sensitive rapid test that can also

  19. Local regularity analysis of strata heterogeneities from sonic logs

    Directory of Open Access Journals (Sweden)

    S. Gaci

    2010-09-01

    Full Text Available Borehole logs provide geological information about the rocks crossed by the wells. Several properties of rocks can be interpreted in terms of lithology, type and quantity of the fluid filling the pores and fractures.

    Here, the logs are assumed to be nonhomogeneous Brownian motions (nhBms which are generalized fractional Brownian motions (fBms indexed by depth-dependent Hurst parameters H(z. Three techniques, the local wavelet approach (LWA, the average-local wavelet approach (ALWA, and Peltier Algorithm (PA, are suggested to estimate the Hurst functions (or the regularity profiles from the logs.

    First, two synthetic sonic logs with different parameters, shaped by the successive random additions (SRA algorithm, are used to demonstrate the potential of the proposed methods. The obtained Hurst functions are close to the theoretical Hurst functions. Besides, the transitions between the modeled layers are marked by Hurst values discontinuities. It is also shown that PA leads to the best Hurst value estimations.

    Second, we investigate the multifractional property of sonic logs data recorded at two scientific deep boreholes: the pilot hole VB and the ultra deep main hole HB, drilled for the German Continental Deep Drilling Program (KTB. All the regularity profiles independently obtained for the logs provide a clear correlation with lithology, and from each regularity profile, we derive a similar segmentation in terms of lithological units. The lithological discontinuities (strata' bounds and faults contacts are located at the local extrema of the Hurst functions. Moreover, the regularity profiles are compared with the KTB estimated porosity logs, showing a significant relation between the local extrema of the Hurst functions and the fluid-filled fractures. The Hurst function may then constitute a tool to characterize underground heterogeneities.

  20. YAP regulates neuronal differentiation through Sonic hedgehog signaling pathway

    International Nuclear Information System (INIS)

    Lin, Yi-Ting; Ding, Jing-Ya; Li, Ming-Yang; Yeh, Tien-Shun; Wang, Tsu-Wei; Yu, Jenn-Yah

    2012-01-01

    Tight regulation of cell numbers by controlling cell proliferation and apoptosis is important during development. Recently, the Hippo pathway has been shown to regulate tissue growth and organ size in Drosophila. In mammalian cells, it also affects cell proliferation and differentiation in various tissues, including the nervous system. Interplay of several signaling cascades, such as Notch, Wnt, and Sonic Hedgehog (Shh) pathways, control cell proliferation during neuronal differentiation. However, it remains unclear whether the Hippo pathway coordinates with other signaling cascades in regulating neuronal differentiation. Here, we used P19 cells, a mouse embryonic carcinoma cell line, as a model to study roles of YAP, a core component of the Hippo pathway, in neuronal differentiation. P19 cells can be induced to differentiate into neurons by expressing a neural bHLH transcription factor gene Ascl1. Our results showed that YAP promoted cell proliferation and inhibited neuronal differentiation. Expression of Yap activated Shh but not Wnt or Notch signaling activity during neuronal differentiation. Furthermore, expression of Yap increased the expression of Patched homolog 1 (Ptch1), a downstream target of the Shh signaling. Knockdown of Gli2, a transcription factor of the Shh pathway, promoted neuronal differentiation even when Yap was over-expressed. We further demonstrated that over-expression of Yap inhibited neuronal differentiation in primary mouse cortical progenitors and Gli2 knockdown rescued the differentiation defect in Yap over-expressing cells. In conclusion, our study reveals that Shh signaling acts downstream of YAP in regulating neuronal differentiation. -- Highlights: ► YAP promotes cell proliferation and inhibits neuronal differentiation in P19 cells. ► YAP promotes Sonic hedgehog signaling activity during neuronal differentiation. ► Knockdown of Gli2 rescues the Yap-overexpression phenotype in P19 cells. ► Knockdown of Gli2 rescues the Yap

  1. YAP regulates neuronal differentiation through Sonic hedgehog signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Ting; Ding, Jing-Ya [Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Li, Ming-Yang [Department of Life Science, National Taiwan Normal University, Taipei 116, Taiwan (China); Yeh, Tien-Shun [Department of Anatomy and Cell Biology, National Yang-Ming University, Taipei 112, Taiwan (China); Wang, Tsu-Wei [Department of Life Science, National Taiwan Normal University, Taipei 116, Taiwan (China); Yu, Jenn-Yah [Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Brain Research Center, National Yang-Ming University, Taipei 112, Taiwan (China)

    2012-09-10

    Tight regulation of cell numbers by controlling cell proliferation and apoptosis is important during development. Recently, the Hippo pathway has been shown to regulate tissue growth and organ size in Drosophila. In mammalian cells, it also affects cell proliferation and differentiation in various tissues, including the nervous system. Interplay of several signaling cascades, such as Notch, Wnt, and Sonic Hedgehog (Shh) pathways, control cell proliferation during neuronal differentiation. However, it remains unclear whether the Hippo pathway coordinates with other signaling cascades in regulating neuronal differentiation. Here, we used P19 cells, a mouse embryonic carcinoma cell line, as a model to study roles of YAP, a core component of the Hippo pathway, in neuronal differentiation. P19 cells can be induced to differentiate into neurons by expressing a neural bHLH transcription factor gene Ascl1. Our results showed that YAP promoted cell proliferation and inhibited neuronal differentiation. Expression of Yap activated Shh but not Wnt or Notch signaling activity during neuronal differentiation. Furthermore, expression of Yap increased the expression of Patched homolog 1 (Ptch1), a downstream target of the Shh signaling. Knockdown of Gli2, a transcription factor of the Shh pathway, promoted neuronal differentiation even when Yap was over-expressed. We further demonstrated that over-expression of Yap inhibited neuronal differentiation in primary mouse cortical progenitors and Gli2 knockdown rescued the differentiation defect in Yap over-expressing cells. In conclusion, our study reveals that Shh signaling acts downstream of YAP in regulating neuronal differentiation. -- Highlights: Black-Right-Pointing-Pointer YAP promotes cell proliferation and inhibits neuronal differentiation in P19 cells. Black-Right-Pointing-Pointer YAP promotes Sonic hedgehog signaling activity during neuronal differentiation. Black-Right-Pointing-Pointer Knockdown of Gli2 rescues the Yap

  2. Ecoacoustic Music for Geoscience: Sonic Physiographies and Sound Casting

    Science.gov (United States)

    Burtner, M.

    2017-12-01

    The author describes specific ecoacoustic applications in his original compositions, Sonic Physiography of a Time-Stretched Glacier (2015), Catalog of Roughness (2017), Sound Cast of Matanuska Glacier (2016) and Ecoacoustic Concerto (Eagle Rock) (2014). Ecoacoustic music uses technology to map systems from nature into music through techniques such as sonification, material amplification, and field recording. The author aspires for this music to be descriptive of the data (as one would expect from a visualization) and also to function as engaging and expressive music/sound art on its own. In this way, ecoacoustic music might provide a fitting accompaniment to a scientific presentation (such as music for a science video) while also offering an exemplary concert hall presentation for a dedicated listening public. The music can at once support the communication of scientific research, and help science make inroads into culture. The author discusses how music created using the data, sounds and methods derived from earth science can recast this research into a sonic art modality. Such music can amplify the communication and dissemination of scientific knowledge by broadening the diversity of methods and formats we use to bring excellent scientific research to the public. Music can also open the public's imagination to science, inspiring curiosity and emotional resonance. Hearing geoscience as music may help a non-scientist access scientific knowledge in new ways, and it can greatly expand the types of venues in which this work can appear. Anywhere music is played - concert halls, festivals, galleries, radio, etc - become a venue for scientific discovery.

  3. Dendrosomatic Sonic Hedgehog Signaling in Hippocampal Neurons Regulates Axon Elongation

    Science.gov (United States)

    Petralia, Ronald S.; Ott, Carolyn; Wang, Ya-Xian; Lippincott-Schwartz, Jennifer; Mattson, Mark P.

    2015-01-01

    The presence of Sonic Hedgehog (Shh) and its signaling components in the neurons of the hippocampus raises a question about what role the Shh signaling pathway may play in these neurons. We show here that activation of the Shh signaling pathway stimulates axon elongation in rat hippocampal neurons. This Shh-induced effect depends on the pathway transducer Smoothened (Smo) and the transcription factor Gli1. The axon itself does not respond directly to Shh; instead, the Shh signal transduction originates from the somatodendritic region of the neurons and occurs in neurons with and without detectable primary cilia. Upon Shh stimulation, Smo localization to dendrites increases significantly. Shh pathway activation results in increased levels of profilin1 (Pfn1), an actin-binding protein. Mutations in Pfn1's actin-binding sites or reduction of Pfn1 eliminate the Shh-induced axon elongation. These findings indicate that Shh can regulate axon growth, which may be critical for development of hippocampal neurons. SIGNIFICANCE STATEMENT Although numerous signaling mechanisms have been identified that act directly on axons to regulate their outgrowth, it is not known whether signals transduced in dendrites may also affect axon outgrowth. We describe here a transcellular signaling pathway in embryonic hippocampal neurons in which activation of Sonic Hedgehog (Shh) receptors in dendrites stimulates axon growth. The pathway involves the dendritic-membrane-associated Shh signal transducer Smoothened (Smo) and the transcription factor Gli, which induces the expression of the gene encoding the actin-binding protein profilin 1. Our findings suggest scenarios in which stimulation of Shh in dendrites results in accelerated outgrowth of the axon, which therefore reaches its presumptive postsynaptic target cell more quickly. By this mechanism, Shh may play critical roles in the development of hippocampal neuronal circuits. PMID:26658865

  4. A novel method for soil aggregate stability measurement by laser granulometry with sonication

    Science.gov (United States)

    Rawlins, B. G.; Lark, R. M.; Wragg, J.

    2012-04-01

    Regulatory authorities need to establish rapid, cost-effective methods to measure soil physical indicators - such as aggregate stability - which can be applied to large numbers of soil samples to detect changes of soil quality through monitoring. Limitations of sieve-based methods to measure the stability of soil macro-aggregates include: i) the mass of stable aggregates is measured, only for a few, discrete sieve/size fractions, ii) no account is taken of the fundamental particle size distribution of the sub-sampled material, and iii) they are labour intensive. These limitations could be overcome by measurements with a Laser Granulometer (LG) instrument, but this technology has not been widely applied to the quantification of aggregate stability of soils. We present a novel method to quantify macro-aggregate (1-2 mm) stability. We measure the difference between the mean weight diameter (MWD; μm) of aggregates that are stable in circulating water of low ionic strength, and the MWD of the fundamental particles of the soil to which these aggregates are reduced by sonication. The suspension is circulated rapidly through a LG analytical cell from a connected vessel for ten seconds; during this period hydrodynamic forces associated with the circulating water lead to the destruction of unstable aggregates. The MWD of stable aggregates is then measured by LG. In the next step, the aggregates - which are kept in the vessel at a minimal water circulation speed - are subject to sonication (18W for ten minutes) so the vast majority of the sample is broken down into its fundamental particles. The suspension is then recirculated rapidly through the LG and the MWD measured again. We refer to the difference between these two measurements as disaggregation reduction (DR) - the reduction in MWD on disaggregation by sonication. Soil types with more stable aggregates have larger values of DR. The stable aggregates - which are resistant to both slaking and mechanical breakdown by the

  5. A Multiplex Microsphere-Based Immunoassay Increases the Sensitivity of SIV-Specific Antibody Detection in Serum Samples and Mucosal Specimens Collected from Rhesus Macaques Infected with SIVmac239.

    Science.gov (United States)

    Powell, Rebecca L R; Ouellette, Ian; Lindsay, Ross W; Parks, Christopher L; King, C Richter; McDermott, Adrian B; Morrow, Gavin

    2013-06-01

    Results from recent HIV-1 vaccine studies have indicated that high serum antibody (Ab) titers may not be necessary for Ab-mediated protection, and that Abs localized to mucosal sites might be critical for preventing infection. Enzyme-linked immunosorbent assay (ELISA) has been used for decades as the gold standard for Ab measurement, though recently, highly sensitive microsphere-based assays have become available, with potential utility for improved detection of Abs. In this study, we assessed the Bio-Plex(®) Suspension Array System for the detection of simian immunodeficiency virus (SIV)-specific Abs in rhesus macaques (RMs) chronically infected with SIV, whose serum or mucosal SIV-specific Ab titers were negative by ELISA. We developed a SIVmac239-specific 4-plex bead array for the simultaneous detection of Abs binding to Env, Gag, Pol, and Nef. The 4-plex assay was used to quantify SIV-specific serum IgG and rectal swab IgA titers from control (SIV-naive) and SIVmac239-infected RMs. The Bio-Plex assay specifically detected anti-SIV Abs in specimens from SIV-infected animals for all four analytes when compared to SIV-naive control samples (p≤0.04). Furthermore, in 70% of Env and 79% of Gag ELISA-negative serum samples, specific Ab was detected using the Bio-Plex assay. Similarly, 71% of Env and 48% of Gag ELISA-negative rectal swab samples were identified as positive using the Bio-Plex assay. Importantly, assay specificity (i.e., probability of true positives) was comparable to ELISA (94%-100%). The results reported here indicate that microsphere-based methods provide a substantial improvement over ELISA for the detection of Ab responses, aid in detecting specific Abs when analyzing samples containing low levels of Abs, such as during the early stages of a vaccine trial, and may be valuable in attempts to link protective efficacy of vaccines with induced Ab responses.

  6. NiCoBP-doped carbon nanotube hybrid: A novel oxidase mimetic system for highly efficient electrochemical immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bing; He, Yu; Liu, Bingqian; Tang, Dianping, E-mail: dianping.tang@fzu.edu.cn

    2014-12-03

    Highlights: • We report a new oxidase mimetic system for highly efficient electrochemical immunoassay. • NiCoBP-doped carbon nanotube hybrids were used as the nanocatalysts. • NiCoBP-doped carbon nanotube hybrids were used as the mimic oxidase. - Abstract: NiCoBP-doped multi-walled carbon nanotube (NiCoBP–MWCNT) was first synthesized by using induced electroless-plating method and functionalized with the biomolecules for highly efficient electrochemical immunoassay of prostate-specific antigen (PSA, used as a model analyte). We discovered that the as-synthesized NiCoBP–MWCNT had the ability to catalyze the glucose oxidization with a stable and well-defined redox peak. The catalytic current increased with the increment of the immobilized NiCoBP–MWCNT on the electrode. Transmission electron microscope (TEM) and energy dispersive X-ray spectrometry (EDX) were employed to characterize the as-prepared NiCoBP–MWCNT. Using the NiCoBP–MWCNT-conjugated anti-PSA antibody as the signal-transduction tag, a new enzyme-free electrochemical immunoassay protocol could be designed for the detection of target PSA on the capture antibody-functionalized immunosensing interface. Experimental results revealed that the designed immunoassay system could exhibit good electrochemical responses toward target PSA, and allowed the detection of PSA at a concentration as low as 0.035 ng mL{sup −1}. More importantly, the NiCoBP-MWCNT-based oxidase mimetic system could be further extended for the monitoring of other low-abundance proteins or disease-related biomarkers by tuning the target antibody.

  7. Targeted deposition of antibodies on a multiplex CMOS microarray and optimization of a sensitive immunoassay using electrochemical detection.

    Directory of Open Access Journals (Sweden)

    John Cooper

    2010-03-01

    Full Text Available The CombiMatrix ElectraSense microarray is a highly multiplex, complementary metal oxide semiconductor with 12,544 electrodes that are individually addressable. This platform is commercially available as a custom DNA microarray; and, in this configuration, it has also been used to tether antibodies (Abs specifically on electrodes using complementary DNA sequences conjugated to the Abs.An empirical method is described for developing and optimizing immunoassays on the CombiMatrix ElectraSense microarray based upon targeted deposition of polypyrrole (Ppy and capture Ab. This process was automated using instrumentation that can selectively apply a potential or current to individual electrodes and also measure current generated at the electrodes by an enzyme-enhanced electrochemical (ECD reaction. By designating groups of electrodes on the array for different Ppy deposition conditions, we determined that the sensitivity and specificity of a sandwich immunoassay for staphylococcal enterotoxin B (SEB is influenced by the application of different voltages or currents and the application time. The sandwich immunoassay used a capture Ab adsorbed to the Ppy and a reporter Ab labeled for fluorescence detection or ECD, and results from these methods of detection were different.Using Ppy deposition conditions for optimum results, the lower limit of detection for SEB using the ECD assay was between 0.003 and 0.01 pg/ml, which represents an order of magnitude improvement over a conventional enzyme-linked immunosorbant assay. In the absence of understanding the variables and complexities that affect assay performance, this highly multiplexed electrode array provided a rapid, high throughput, and empirical approach for developing a sensitive immunoassay.

  8. Homogeneous immunoassay for human IgG using oriented hen egg IgY immobilized on gold sol nanoparticles

    International Nuclear Information System (INIS)

    Yeritsyan, H.E.; Gasparyan, V.K.

    2012-01-01

    Homogeneous immunoassays using (red) gold nanoparticles represent an attractive detection scheme because of the option of photometric readout. We have applied oriented immobilization of hen egg immunoglobulin Y (IgY) on gold nanoparticles when developing a homogeneous immunoassay for human IgG. In oriented immobilization, as opposed to random immobilization, the antigen binding capabilities of the antibodies are retained. It is shown that such immunoassay has significantly better sensitivity in comparison with methods based on conventional immobilization of affinity-purified antibodies. It is also shown that hen egg IgY is better suited than rabbit antibodies, because much more antibody can be immobilized on gold nanoparticles without any destabilization, probably because of the more acidic nature of these antibodies. In addition, hen egg IgY can be supplied in higher quantity and can be prepared more easily than IgG from rabbits. Bleeding and slaughtering of animals is not needed. The assay presented here has a wide detection range (30-500 ng. mL -1 ) and a limit of detection as low as 30 ng. mL -1 of human IgG. (author)

  9. Inkjet-printed point-of-care immunoassay on a nanoscale polymer brush enables subpicomolar detection of analytes in blood

    Science.gov (United States)

    Joh, Daniel Y.; Hucknall, Angus M.; Wei, Qingshan; Mason, Kelly A.; Lund, Margaret L.; Fontes, Cassio M.; Hill, Ryan T.; Blair, Rebecca; Zimmers, Zackary; Achar, Rohan K.; Tseng, Derek; Gordan, Raluca; Freemark, Michael; Ozcan, Aydogan; Chilkoti, Ashutosh

    2017-08-01

    The ELISA is the mainstay for sensitive and quantitative detection of protein analytes. Despite its utility, ELISA is time-consuming, resource-intensive, and infrastructure-dependent, limiting its availability in resource-limited regions. Here, we describe a self-contained immunoassay platform (the “D4 assay”) that converts the sandwich immunoassay into a point-of-care test (POCT). The D4 assay is fabricated by inkjet printing assay reagents as microarrays on nanoscale polymer brushes on glass chips, so that all reagents are “on-chip,” and these chips show durable storage stability without cold storage. The D4 assay can interrogate multiple analytes from a drop of blood, is compatible with a smartphone detector, and displays analytical figures of merit that are comparable to standard laboratory-based ELISA in whole blood. These attributes of the D4 POCT have the potential to democratize access to high-performance immunoassays in resource-limited settings without sacrificing their performance.

  10. Production of talc nano sheets via fine grinding and sonication processes

    International Nuclear Information System (INIS)

    Samayamutthirian Palaniandy; Noorina Hidayu Jamil Khairun Azizi Mohd Azizli; Syed Fuad Saiyid Hashim; Hashim Hussin

    2009-01-01

    Fine grinding of high purity talc in jet mill at low grinding pressure was carried out by varying the feed rate and classifier rotational speed. These ground particles were sonicated in laboratory ultrasonic bath by varying the soniction period at five levels. The ground and sonicated particles were characterized in terms of particle size and particle size distribution. Mechanochemical and sonochemical effect of talc was determine via X-ray diffraction. Particle shape and surface texture of the ground and sonicated product was determined via scanning electron microscope and transmission electron microscope. The ground particle size exhibited particle size below 10 μm with narrow size distribution. The reduction of peak intensity in (002) plane indicated the layered structure has been distorted. The sonicated talc shows that the thickness of the talc particles after the sonication process is 20 nm but the lateral particle size still remains in micron range. The reduction of the XRD peak intensity for (002) plane and thickness of sonicated talc as shown in SEM and TEM micrographs proves that fine grinding and sonication process produces talc nano sheets. (author)

  11. Intercostal high intensity focused ultrasound for liver ablation: The influence of beam shaping on sonication efficacy and near-field risks

    Energy Technology Data Exchange (ETDEWEB)

    Greef, M. de, E-mail: m.degreef@umcutrecht.nl; Wijlemans, J. W.; Bartels, L. W.; Moonen, C. T. W.; Ries, M. [Imaging Division, University Medical Center Utrecht, Utrecht 3508GA (Netherlands); Schubert, G.; Koskela, J. [Philips Healthcare, Vantaa FI-01511 (Finland)

    2015-08-15

    Purpose: One of the major issues in high intensity focused ultrasound ablation of abdominal lesions is obstruction of the ultrasound beam by the thoracic cage. Beam shaping strategies have been shown by several authors to increase focal point intensity while limiting rib exposure. However, as rib obstruction leaves only part of the aperture available for energy transmission, conserving total emitted acoustic power, the intensity in the near-field tissues inherently increases after beam shaping. Despite of effective rib sparing, those tissues are therefore subjected to increased risk of thermal damage. In this study, for a number of clinically representative intercostal sonication geometries, modeling clinically available hardware, the effect of beam shaping on both the exposure of the ribs and near-field to acoustic energy was evaluated and the implications for the volumetric ablation rate were addressed. Methods: A relationship between rib temperature rise and acoustic energy density was established by means of in vivo MR thermometry and simulations of the incident acoustic energy for the corresponding anatomies. This relationship was used for interpretation of rib exposure in subsequent numerical simulations in which rib spacing, focal point placement, and the focal point trajectory were varied. The time required to heat a targeted region to 65 °C was determined without and with the application of beam shaping. The required sonication time was used to calculate the acoustic energy density at the fat–muscle interface and at the surface of the ribs. At the fat–muscle interface, exposure was compared to available literature data and rib exposure was interpreted based on the earlier obtained relation between measured temperature rise and simulated acoustic energy density. To estimate the volumetric ablation rate, the cool-down time between periods of energy exposure was estimated using a time-averaged power limit of 100 kJ/h. Results: At the level of the ribs

  12. Theory of elementary excitations in unstable Bose-Einstein condensates and the instability of sonic horizons

    International Nuclear Information System (INIS)

    Leonhardt, U.; Kiss, T.; Oehberg, P.

    2003-01-01

    Like classical fluids, quantum gases may suffer from hydrodynamic instabilities. Our paper develops a quantum version of the classical stability analysis in fluids, the Bogoliubov theory of elementary excitations in unstable Bose-Einstein condensates. In unstable condensates the excitation modes have complex frequencies. We derive the normalization conditions for unstable modes such that they can serve in a mode decomposition of the noncondensed component. Furthermore, we develop approximative techniques to determine the spectrum and the mode functions. Finally, we apply our theory to sonic horizons - sonic black and white holes. For sonic white holes the spectrum of unstable modes turns out to be intrinsically discrete, whereas black holes may be stable

  13. Acoustic energy harvesting by piezoelectric curved beams in the cavity of a sonic crystal

    International Nuclear Information System (INIS)

    Wang, Wei-Chung; Wu, Liang-Yu; Chen, Lien-Wen; Liu, Chia-Ming

    2010-01-01

    Acoustic energy harvesting by piezoelectric curved beams in the cavity of a sonic crystal is investigated. A resonant cavity of the sonic crystal is used to localize the acoustic wave as the acoustic waves are incident into the sonic crystal at the resonant frequency. The piezoelectric curved beam is placed in the resonant cavity and vibrated by the acoustic wave. The energy harvesting can be achieved as the acoustic waves are incident at the resonant frequency. A model for energy harvesting of the piezoelectric curved beam is also developed to predict the output voltage and power of the energy harvesting. The experimental results are compared with the theoretical

  14. Development of a crosshole sonic logging system for the integrity test of cast-in-situ piles

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tai-Sup; Sung, Nak-Hoon; Hwang, Hak-Soo [Korea Institute of Geoscience and Mineral Resources, Taejeon(Korea)

    2001-09-01

    To evaluate the integrity of cast-in-situ concrete piles, a notebook PC-based crosshole sonic logging system which can be handled by one operator was developed using PCMCIA-type analog to digital converter card. User-interactive software for operation of the system were also developed using Labview. The system was tested with the field model pile to confirm the performance of the developed system. The test result shows that the system is very stable and efficient for detecting defects of the pile. (author). 3 refs., 9 figs.

  15. Fast and sensitive detection of enteropathogenic Yersinia by immunoassays.

    Science.gov (United States)

    Laporte, Jérôme; Savin, Cyril; Lamourette, Patricia; Devilliers, Karine; Volland, Hervé; Carniel, Elisabeth; Créminon, Christophe; Simon, Stéphanie

    2015-01-01

    Yersinia enterocolitica and Yersinia pseudotuberculosis, the two Yersinia species that are enteropathogenic for humans, are distributed worldwide and frequently cause diarrhea in inhabitants of temperate and cold countries. Y. enterocolitica is a major cause of foodborne disease resulting from consumption of contaminated pork meat and is further associated with substantial economic cost. However, investigation of enteropathogenic Yersinia species is infrequently performed routinely in clinical laboratories because of their specific growth characteristics, which make difficult their isolation from stool samples. Moreover, current isolation procedures are time-consuming and expensive, thus leading to underestimates of the incidence of enteric yersiniosis, inappropriate prescriptions of antibiotic treatments, and unnecessary appendectomies. The main objective of the study was to develop fast, sensitive, specific, and easy-to-use immunoassays, useful for both human and veterinary diagnosis. Monoclonal antibodies (MAbs) directed against Y. enterocolitica bioserotypes 2/O:9 and 4/O:3 and Y. pseudotuberculosis serotypes I and III were produced. Pairs of MAbs were selected by testing their specificity and affinity for enteropathogenic Yersinia and other commonly found enterobacteria. Pairs of MAbs were selected to develop highly sensitive enzyme immunoassays (EIAs) and lateral flow immunoassays (LFIs or dipsticks) convenient for the purpose of rapid diagnosis. The limit of detection of the EIAs ranged from 3.2 × 10(3) CFU/ml to 8.8 × 10(4) CFU/ml for pathogenic serotypes I and III of Y. pseudotuberculosis and pathogenic bioserotypes 2/O:9 and 4/O:3 of Y. enterocolitica and for the LFIs ranged from 10(5) CFU/ml to 10(6) CFU/ml. A similar limit of detection was observed for artificially contaminated human feces. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Band-type microelectrodes for amperometric immunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ga-Yeon; Chang, Young Wook; Ko, Hyuk [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Kang, Min-Jung [Korea Institute of Science and Technology (KIST), Seoul (Korea, Republic of); Pyun, Jae-Chul, E-mail: jcpyun@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of)

    2016-07-20

    A band-type microelectrode was made using a parylene-N film as a passivation layer. A circular-type, mm-scale electrode with the same diameter as the band-type microelectrode was also made with an electrode area that was 5000 times larger than the band-type microelectrode. By comparing the amperometric signals of 3,5,3′,5′-tetramethylbenzidine (TMB) samples at different optical density (OD) values, the band-type microelectrode was determined to be 9 times more sensitive than the circular-type electrode. The properties of the circular-type and the band-type electrodes (e.g., the shape of their cyclic voltammograms, the type of diffusion layer used, and the diffusion layer thickness per unit electrode area) were characterized according to their electrode area using the COMSOL Multiphysics software. From these simulations, the band-type electrode was estimated to have the conventional microelectrode properties, even when the electrode area was 100 times larger than a conventional circular-type electrode. These results show that both the geometry and the area of an electrode can influence the properties of the electrode. Finally, amperometric analysis based on a band-type electrode was applied to commercial ELISA kits to analyze human hepatitis B surface antigen (hHBsAg) and human immunodeficiency virus (HIV) antibodies. - Highlights: • A band-type microelectrode was made using a parylene-N film as a passivation layer. • The band-type microelectrode was 14-times more sensitive than circular-type electrode. • The influence of geometry on microelectrode properties was simulated using COMSOL. • The band-type electrode was applied to ELISA kits for hHBsAg and hHIV-antibodies.

  17. Linkage of biomolecules to solid phases for immunoassay

    International Nuclear Information System (INIS)

    Chapman, R.S.

    1998-01-01

    Topics covered by this lecture include a brief review of the principal methods of linkage of biomolecules to solid phase matrices. Copies of the key self explanatory slides are presented as figures together with reprints of two publications by the author dealing with a preferred chemistry for the covalent linkage of antibodies to hydroxyl and amino functional groups and the effects of changes in solid phase matrix and antibody coupling chemistry on the performance of a typical excess reagent immunoassay for thyroid stimulating hormone

  18. On-Chip Immunoassay for Determination of Urinary Albumin

    OpenAIRE

    Laiwattanapaisal, Wanida; Songjaroen, Temsiri; Maturos, Thitima; Lomas, Tanom; Sappat, Assawapong; Tuantranont, Adisorn

    2009-01-01

    An immunoassay performed on a portable microfluidic device was evaluated for the determination of urinary albumin. An increase in absorbance at 500 nm resulting from immunoagglutination was monitored directly on the poly(dimethylsiloxane) (PDMS) microchip using a portable miniature fibre-optic spectrometer. A calibration curve was linear up to 10 mg L–1 (r2 = 0.993), with a detection limit of 0.81 mg L–1 (S/N = 3). The proposed system showed good precision, with relative standard deviations (...

  19. Analytical evaluation of the novel Lumipulse G BRAHMS procalcitonin immunoassay

    OpenAIRE

    Ruzzenente, Orazio; Salvagno, Gian Luca; Gelati, Matteo; Lippi, Giuseppe

    2016-01-01

    Objectives: This study was designed to evaluate the analytical performance of the novel Lumipulse G1200 BRAHMS procalcitonin (PCT) immunoassay. Design and methods: This analytical evaluation encompassed the calculation of the limit of blank (LOB), limit of detection (LOD), functional sensitivity, intra- and inter-assay imprecision, confirmation of linearity and a comparison with the Vidas BRAHMS PCT assay. Results: The LOB, LOD and functional sensitivity were 0.0010 ng/mL, 0.0016 ng/mL and ...

  20. Performance of automated multiplex PCR using sonication fluid for diagnosis of periprosthetic joint infection: a prospective cohort.

    Science.gov (United States)

    Renz, Nora; Feihl, Susanne; Cabric, Sabrina; Trampuz, Andrej

    2017-12-01

    Sonication of explanted prostheses improved the microbiological diagnosis of periprosthetic joint infections (PJI). We evaluated the performance of automated multiplex polymerase chain reaction (PCR) using sonication fluid for the microbiological diagnosis of PJI. In a prospective cohort using uniform definition criteria for PJI, explanted joint prostheses were investigated by sonication and the resulting sonication fluid was analyzed by culture and multiplex PCR. McNemar's Chi-squared test was used to compare the performance of diagnostic tests. Among 111 patients, PJI was diagnosed in 78 (70%) and aseptic failure in 33 (30%). For the diagnosis of PJI, the sensitivity and specificity of periprosthetic tissue culture was 51 and 100%, of sonication fluid culture 58 and 100%, and of sonication fluid PCR 51 and 94%, respectively. Among 70 microorganisms, periprosthetic tissue culture grew 52 (74%), sonication fluid culture grew 50 (71%) and sonication fluid PCR detected 37 pathogens (53%). If only organisms are considered, for which primers are included in the test panel, PCR detected 37 of 58 pathogens (64%). The sonication fluid PCR missed 19 pathogens (predominantly oral streptococci and anaerobes), whereas 7 additional microorganisms were detected only by PCR (including Cutibacterium spp. and coagulase-negative staphylococci). The performance of multiplex PCR using sonication fluid is comparable to culture of periprosthetic tissue or sonication fluid. The advantages of PCR are short processing time (PCR, especially of low-virulent organisms.

  1. Sequential injection chemiluminescence immunoassay for nonionic surfactants by using magnetic microbeads

    International Nuclear Information System (INIS)

    Zhang Ruiq; Nakajima, Hizuru; Soh, Nobuaki; Nakano, Koji; Masadome, Takashi; Nagata, Kazumi; Sakamoto, Kazuhira; Imato, Toshihiko

    2007-01-01

    A rapid and sensitive immunoassay based on a sequential injection analysis (SIA) using magnetic microbeads for the determination of alkylphenol polyethoxylates (APnEOs) is described. An SIA system was constructed from a syringe pump, a switching valve, a flow-through type immunoreaction cell equipped with a photon counting unit and a neodymium magnet. Magnetic beads, to which an anti-APnEOs monoclonal antibody was immobilized, were used as a solid support in an immunoassay. The introduction, trapping and release of the magnetic beads in and from the immunoreaction cell were controlled by means of a neodymium magnet and adjusting the flow of a carrier solution. The immunoassay was based on an indirect competitive immunoreaction of an anti-APnEOs monoclonal antibody immobilized on the magnetic beads with a sample APnEOs and a horseradish peroxidase (HRP)-labeled APnEOs in the same sample solution, and was based on the subsequent chemiluminscence reaction of HRP on the magnetic microbeads with a luminol solution containing hydrogen peroxide and p-iodophenol. The anti-APnEOs antibody was immobilized on the magnetic microbeads by coupling the antibody with the magnetic beads after activation of a carboxylate moiety on the surface of the magnetic beads that had been coated with a polylactic acid film. The antibody immobilized magnetic beads were introduced in the immunoreaction cell and trapped in it by the neodymium magnet, which was equipped beneath the immunoreaction cell. An APnEOs sample solution containing the HRP-labeled APnEOs at a constant concentration, and a luminol solution containing hydrogen peroxide and p-iodophenol were sequentially introduced into the immunoreaction cell, according to an SIA programmed sequence. Chemiluminescence emission was monitored by means of a photon counting unit located at the upper side of the immunoreaction cell by collecting the emitted light with a lens. A typical sigmoidal calibration curve was obtained, when the logarithm

  2. Oligopeptide-based enzyme immunoassay for ovine lentivirus antibody detection.

    OpenAIRE

    Kwang, J; Torres, J V

    1994-01-01

    Ovine progressive pneumonia virus (OPPV) is a lentivirus which causes a progressive disease in sheep. Immunodominant epitopes have been identified in the envelope gp40 glycoprotein. Synthetic peptides representing these regions are able to detect the presence of OPPV antibodies in 96% of infected sheep.

  3. Comparative determination of phenytoin by spectrophotometry, gas chromatography, liquid chromatography, enzyme immunoassay, and radioimmunoassay

    International Nuclear Information System (INIS)

    Castro, A.; Ibanez, J.; DiCesare, J.L.; Adams, R.F.; Malkus, H.

    1978-01-01

    Sera from patients being treated with phenytoin were analyzed for the drug by spectrophotometry, gas chromatography, radioimmunoasay, enzyme immunoassay, and liquid chromatography. The assay values obtained were intercompared statistically. Enzyme immunoassay and liquid chromatography appear to be attractive alternatives to the more traditional methods of spectrophotometry and gas chromatography. Our radioimmunoassay data correlated poorly with results by the four other methods

  4. Determining total thyroxine with the aid of the homogeneous enzyme immunoassay

    International Nuclear Information System (INIS)

    Vogt, W.

    1978-01-01

    Total thyrozine values obtained with the aid of the homogeneous enzyme immunoassay are compared with those delivered by the RIA and the efficiency of the EMIT technique is evaluated. Some results obtained via Enzymun-T4, a heterologous enzyme immunoassay, are also given. (VJ) 891 VJ [de

  5. Evaluation of six immunoassays for detection of dengue virus-specific immunoglobulin M and G antibodies

    NARCIS (Netherlands)

    J. Groen (Jan); P. Koraka (Penelope); J. Velzing (Jans); C. Copra (Cederick); A.D.M.E. Osterhaus (Albert)

    2000-01-01

    textabstractThe performance of six commercially available immunoassay systems for the detection of dengue virus-specific immunoglobulin M (IgM) and IgG antibodies in serum was evaluated. These included two IgM and IgG enzyme immunoassays (EIA) from MRL Laboratories and PanBio, a rapid

  6. Development of Indirect Competitive Immuno-Assay Method Using SPR Detection for Rapid and Highly Sensitive Measurement of Salivary Cortisol Levels

    International Nuclear Information System (INIS)

    Tahara, Yusuke; Huang, Zhe; Kiritoshi, Tetsuro; Onodera, Takeshi; Toko, Kiyoshi

    2014-01-01

    The monitoring of salivary cortisol as a key biomarker of an individual’s stress response has been increasingly focused on. This paper describes the development of a novel cortisol immuno-assay method based on an indirect competitive method using a commercially available surface plasmon resonance instrument. The surface of an Au chip was modified with PEG6-COOH aromatic dialkanethiol self-assembled monolayers and hydrocortisone 3-(O-carboxymethyl) oxime (hydrocortisone 3-CMO) as a cortisol analog. A detection limit of 38 ppt range with a measurement range of 10 ppt–100 ppb was accomplished without the incubation of a mixing solution consisting of standard cortisol and an anti-cortisol antibody, and the time for quantification of cortisol concentration was 8 min from the sample injection. We experimentally compared our immuno-assay with a commercialized salivary cortisol enzyme-linked immunosorbent assay (ELISA) kit using human saliva samples. It was found that the results obtained by the cortisol immuno-assay had a good correlation with those obtained by ELISA assay (R = 0.96). Our findings indicate the potential utility of the cortisol immuno-assay for measurements of human salivary cortisol levels.

  7. Development of Indirect Competitive Immuno-Assay Method Using SPR Detection for Rapid and Highly Sensitive Measurement of Salivary Cortisol Levels

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, Yusuke; Huang, Zhe; Kiritoshi, Tetsuro [Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka (Japan); Onodera, Takeshi [Research and Development Center for Taste and Odor Sensing, Kyushu University, Fukuoka (Japan); Toko, Kiyoshi, E-mail: toko@ed.kyushu-u.ac.jp [Graduate School of Information Science and Electrical Engineering, Kyushu University, Fukuoka (Japan); Research and Development Center for Taste and Odor Sensing, Kyushu University, Fukuoka (Japan)

    2014-05-30

    The monitoring of salivary cortisol as a key biomarker of an individual’s stress response has been increasingly focused on. This paper describes the development of a novel cortisol immuno-assay method based on an indirect competitive method using a commercially available surface plasmon resonance instrument. The surface of an Au chip was modified with PEG6-COOH aromatic dialkanethiol self-assembled monolayers and hydrocortisone 3-(O-carboxymethyl) oxime (hydrocortisone 3-CMO) as a cortisol analog. A detection limit of 38 ppt range with a measurement range of 10 ppt–100 ppb was accomplished without the incubation of a mixing solution consisting of standard cortisol and an anti-cortisol antibody, and the time for quantification of cortisol concentration was 8 min from the sample injection. We experimentally compared our immuno-assay with a commercialized salivary cortisol enzyme-linked immunosorbent assay (ELISA) kit using human saliva samples. It was found that the results obtained by the cortisol immuno-assay had a good correlation with those obtained by ELISA assay (R = 0.96). Our findings indicate the potential utility of the cortisol immuno-assay for measurements of human salivary cortisol levels.

  8. ResonantSonic drilling: History, progress and advances in environmental restoration programs

    International Nuclear Information System (INIS)

    Volk, B.W.; McLellan, G.W.; Moak, D.J.; Lerch, R.E.; Thompson, K.M.; Barrow, J.C.

    1993-01-01

    ResonantSonic SM drilling is being used in the environmental industry to drill faster, cheaper, and safer than conventional drilling methodologies. ResonantSonic is a registered service mark of the Water Development Corporation, Woodland, California. The ResonantSonic drilling method, requires no mud, air or water for rapid penetration through geologic materials ranging from rock and clay to sand and boulders. The specialized drill head imparts high frequency vibrations into a steel drill pipe creating a drilling action which allows the retrieval of continuous, undisturbed cores. An added benefit is that the method can be used for angle drilling. The ReasonantSonic method has been used in the past for projects ranging from pile driving to horizontal drilling. Current programs are utilizing the technique as a valuable tool for obtaining in situ, pristine environmental samples. In the future, this drilling technology could be used for remote, automated sampling at hazardous waste sites

  9. AFSC/RACE/SAP/Cummiskey: Red king crab sonic tagging and dive database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is data from a long-term monitoring project which utilized sonic tags to follow aggregations of red king crab in Womens Bay near Kodiak Alaska. The database...

  10. Influence of borehole-eccentred tools on wireline and logging-while-drilling sonic logging measurements

    KAUST Repository

    Pardo, David; Matuszyk, Paweł Jerzy; Torres-Verdí n, Carlos; Mora Cordova, Angel; Muga, Ignacio; Calo, Victor M.

    2013-01-01

    We describe a numerical study to quantify the influence of tool-eccentricity on wireline (WL) and logging-while-drilling (LWD) sonic logging measurements. Simulations are performed with a height-polynomial-adaptive (hp) Fourier finite-element method

  11. Improve the Recovery of Fermentable Sugar from Rice Straw by Sonication and Its Mathematical Modeling

    Science.gov (United States)

    Bhattacharyya, Saurav; Dutta, Somenath; Datta, Sidhartha; Bhattacharjee, Chiranjib

    2012-08-01

    Rice straw is waste renewable agricultural biomass, which contains sufficient amount of fermentable sugars like glucose, galactose fructose, xylose etc. These sugars can be treated with fermentation pathway to produce ethanol. Hydrolysis of pretreated rice straw in dilute sulfuric acid was investigated at different acid concentrations (0.25-0.75 % w/v), and sonication was carried out to improve the extent of sugar extraction. The current work examines the effect of sonication on extraction of total reducing sugar (TRS) and an empirical mathematical model has been established to predict it. Effects of various operating variables of sonication, including amplitude (60-100 %), cycle (0.6-1.0), treatment time (0-15 min) have been analyzed for each acid concentration. Observation shows that on optimization of the sonication conditions (100 % amplitude, 0.8 cycle and 10 min) around 90 % improvement of TRS extraction occurs at 0.5 % (w/v) acid concentration.

  12. Rational design of Raman-labeled nanoparticles for a dual-modality, light scattering immunoassay on a polystyrene substrate.

    Science.gov (United States)

    Israelsen, Nathan D; Wooley, Donald; Hanson, Cynthia; Vargis, Elizabeth

    2016-01-01

    Surface-enhanced Raman scattering (SERS) is a powerful light scattering technique that can be used for sensitive immunoassay development and cell labeling. A major obstacle to using SERS is the complexity of fabricating SERS probes since they require nanoscale characterization and optical uniformity. The light scattering response of SERS probes may also be modulated by the substrate used for SERS analysis. A typical SERS substrate such as quartz can be expensive. Polystyrene is a cheaper substrate option but can decrease the SERS response due to interfering Raman emission peaks and high background fluorescence. The goal of this research is to develop an optimized process for fabricating Raman-labeled nanoparticles for a SERS-based immunoassay on a polystyrene substrate. We have developed a method for fabricating SERS nanoparticle probes for use in a light scattering immunoassay on a polystyrene substrate. The light scattering profile of both spherical gold nanoparticle and gold nanorod SERS probes were characterized using Raman spectroscopy and optical absorbance spectroscopy. The effects of substrate interference and autofluorescence were reduced by selecting a Raman reporter with a strong light scattering response in a spectral region where interfering substrate emission peaks are minimized. Both spherical gold nanoparticles and gold nanorods SERS probes used in the immunoassay were detected at labeling concentrations in the low pM range. This analytical sensitivity falls within the typical dynamic range for direct labeling of cell-surface biomarkers using SERS probes. SERS nanoparticle probes were fabricated to produce a strong light scattering signal despite substrate interference. The optical extinction and inelastic light scattering of these probes was detected by optical absorbance spectroscopy and Raman spectroscopy, respectively. This immunoassay demonstrates the feasibility of analyzing strongly enhanced Raman signals on polystyrene, which is an

  13. Mobile Phone Ratiometric Imaging Enables Highly Sensitive Fluorescence Lateral Flow Immunoassays without External Optical Filters.

    Science.gov (United States)

    Shah, Kamal G; Singh, Vidhi; Kauffman, Peter C; Abe, Koji; Yager, Paul

    2018-05-14

    Paper-based diagnostic tests based on the lateral flow immunoassay concept promise low-cost, point-of-care detection of infectious diseases, but such assays suffer from poor limits of detection. One factor that contributes to poor analytical performance is a reliance on low-contrast chromophoric optical labels such as gold nanoparticles. Previous attempts to improve the sensitivity of paper-based diagnostics include replacing chromophoric labels with enzymes, fluorophores, or phosphors at the expense of increased fluidic complexity or the need for device readers with costly optoelectronics. Several groups, including our own, have proposed mobile phones as suitable point-of-care readers due to their low cost, ease of use, and ubiquity. However, extant mobile phone fluorescence readers require costly optical filters and were typically validated with only one camera sensor module, which is inappropriate for potential point-of-care use. In response, we propose to couple low-cost ultraviolet light-emitting diodes with long Stokes-shift quantum dots to enable ratiometric mobile phone fluorescence measurements without optical filters. Ratiometric imaging with unmodified smartphone cameras improves the contrast and attenuates the impact of excitation intensity variability by 15×. Practical application was shown with a lateral flow immunoassay for influenza A with nucleoproteins spiked into simulated nasal matrix. Limits of detection of 1.5 and 2.6 fmol were attained on two mobile phones, which are comparable to a gel imager (1.9 fmol), 10× better than imaging gold nanoparticles on a scanner (18 fmol), and >2 orders of magnitude better than gold nanoparticle-labeled assays imaged with mobile phones. Use of the proposed filter-free mobile phone imaging scheme is a first step toward enabling a new generation of highly sensitive, point-of-care fluorescence assays.

  14. Aequorin fusion proteins as bioluminescent tracers for competitive immunoassays

    Science.gov (United States)

    Mirasoli, Mara; Michelini, Elisa; Deo, Sapna K.; Dikici, Emre; Roda, Aldo; Daunert, Sylvia

    2004-06-01

    The use of bio- and chemiluminescence for the development of quantitative binding assays offers undoubted advantages over other detection systems, such as spectrophotometry, fluorescence, or radioactivity. Indeed, bio- and chemiluminescence detection provides similar, or even better, sensitivity and detectability than radioisotopes, while avoiding the problems of health hazards, waste disposal, and instability associated with the use of radioisotopes. Among bioluminescent labels, the calcium-activated photoprotein aequorin, originally isolated from Aequorea victoria and today available as a recombinant product, is characterized by very high detectability, down to attomole levels. It has been used as a bioluminescent label for developing a variety of highly sensitive immunoassays, using various analyte-aequorin conjugation strategies. When the analyte is a protein or a peptide, genetic engineering techniques can be used to produce protein fusions where the analyte is in-frame fused with aequorin, thus producing homogeneous one-to-one conjugation products, available in virtually unlimited amount. Various assays were developed using this strategy: a short review of the most interesting applications is presented, as well as the cloning, purification and initial characterization of an endothelin-1-aequorin conjugate suitable for developing a competitive immunoassay for endothelin-1, a potent vasoconstrictor peptide, involved in hypertension.

  15. Determination of phospholipid transfer proteins in rat tissues by immunoassays

    International Nuclear Information System (INIS)

    Teerlink, T.

    1983-01-01

    Several quantitative immunoassays have been developed for two phospholipid transfer proteins from rat liver, i.e. the phosphatidylcholine transfer protein and the non-specific lipid transfer protein. The development of a double-antibody radioimmunoassay for the phosphatidylcholine transfer protein is described. The transfer protein was labelled with iodine-125 by the mild glucose oxidase-lactoperoxidase method. Although less than one tyrosine residue per molecule of transfer protein was labelled, only 20% of the labelled transfer protein was immunoprecipitable. This value could be increased to 80% by purifying the labelled protein by affinity chromatography on a column of anti-phosphatidylcholine transfer protein-IgG coupled to Sepharose 4B. The radioimmunoassay was used to determine the levels of phosphatidylcholine transfer protein in homogenates and 105 000 xg supernatants from various rat tissues as well as several Morris hepatomas. An enzyme immunoassay for the non-specific lipid transfer protein is also described. The antiserum that was raised especially by the author was cross-reactive with the non-specific lipid transfer protein present in 105 000 xg supernatants from human, mouse and bovine liver. The non-specific lipid transfer protein lost its immunoreactivity upon labelling with iodine-125 using different labelling techniques. Therefore, a regular radioimmunoassay could not be developed. The results of these different assays were compared. (Auth.)

  16. Mesencephalic basolateral domain specification is dependent on Sonic Hedgehog

    Science.gov (United States)

    Martinez-Lopez, Jesus E.; Moreno-Bravo, Juan A.; Madrigal, M. Pilar; Martinez, Salvador; Puelles, Eduardo

    2015-01-01

    In the study of central nervous system morphogenesis, the identification of new molecular markers allows us to identify domains along the antero-posterior and dorso-ventral (DV) axes. In the past years, the alar and basal plates of the midbrain have been divided into different domains. The precise location of the alar-basal boundary is still under discussion. We have identified Barhl1, Nhlh1 and Six3 as appropriate molecular markers to the adjacent domains of this transition. The description of their expression patterns and the contribution to the different mesencephalic populations corroborated their role in the specification of these domains. We studied the influence of Sonic Hedgehog on these markers and therefore on the specification of these territories. The lack of this morphogen produced severe alterations in the expression pattern of Barhl1 and Nhlh1 with consequent misspecification of the basolateral (BL) domain. Six3 expression was apparently unaffected, however its distribution changed leading to altered basal domains. In this study we confirmed the localization of the alar-basal boundary dorsal to the BL domain and demonstrated that the development of the BL domain highly depends on Shh. PMID:25741244

  17. Megalin functions as an endocytic sonic hedgehog receptor.

    Science.gov (United States)

    McCarthy, Robert A; Barth, Jeremy L; Chintalapudi, Mastan R; Knaak, Christian; Argraves, W Scott

    2002-07-12

    Embryos deficient in the morphogen Sonic hedgehog (Shh) or the endocytic receptor megalin exhibit common neurodevelopmental abnormalities. Therefore, we have investigated the possibility that a functional relationship exists between the two proteins. During embryonic development, megalin was found to be expressed along the apical surfaces of neuroepithelial cells and was coexpressed with Shh in the ventral floor plate of the neural tube. Using enzyme-linked immunosorbent assay, homologous ligand displacement, and surface plasmon resonance techniques, it was found that the amino-terminal fragment of Shh (N-Shh) bound to megalin with high affinity. Megalin-expressing cells internalized N-Shh through a mechanism that was inhibited by antagonists of megalin, viz. anti-receptor-associated protein and anti-megalin antibodies. Heparin also inhibited N-Shh endocytosis, implicating proteoglycans in the internalization process, as has been described for other megalin ligands. Use of chloroquine to inhibit lysosomal proteinase activity showed that N-Shh endocytosed via megalin was not efficiently targeted to the lysosomes for degradation. The ability of megalin-internalized N-Shh to bypass lysosomes may relate to the finding that the interaction between N-Shh and megalin was resistant to dissociation with low pH. Together, these findings show that megalin is an efficient endocytic receptor for N-Shh. Furthermore, they implicate megalin as a new regulatory component of the Shh signaling pathway.

  18. Mesencephalic basolateral domain specification is dependent on Sonic Hedgehog

    Directory of Open Access Journals (Sweden)

    Jesus E. Martinez-Lopez

    2015-02-01

    Full Text Available In the study of central nervous system morphogenesis, the identification of new molecular markers allows us to identify domains along the antero-posterior and dorso-ventral axes. In the past years, the alar and basal plates of the midbrain have been divided into different domains. The precise location of the alar-basal boundary is still under discussion. We have identified Barhl1, Nhlh1 and Six3 as appropriate molecular markers to the adjacent domains of this transition. The description of their expression patterns and the contribution to the different mesencephalic populations corroborated their role in the specification of these domains. We studied the influence of Sonic Hedgehog on these markers and therefore on the specification of these territories. The lack of this morphogen produced severe alterations in the expression pattern of Barhl1 and Nhlh1 with consequent misspecification of the basolateral domain. Six3 expression was apparently unaffected, however its distribution changed leading to altered basal domains. In this study we confirmed the localization of the alar-basal boundary dorsal to the basolateral domain and demonstrated that the development of the basolateral domain highly depends on Shh.

  19. Sonic hedgehog signaling in the development of the mouse hypothalamus

    Directory of Open Access Journals (Sweden)

    Sandra eBlaess

    2015-01-01

    Full Text Available The expression pattern of Sonic Hedgehog (Shh in the developing hypothalamus changes over time. Shh is initially expressed in the prechordal mesoderm and later in the hypothalamic neuroepithelium-- first medially, and then in two off-medial domains. This dynamic expression suggests that Shh might regulate several aspects of hypothalamic development. To gain insight into them, lineage tracing, (conditional gene inactivation in mouse, in ovo loss- and gain-of-function approaches in chick and analysis of Shh expression regulation have been employed. We will focus on mouse studies and refer to chick and fish when appropriate to clarify. These studies show that Shh-expressing neuroepithelial cells serve as a signaling center for neighboring precursors, and give rise to most of the basal hypothalamus (tuberal and mammillary regions. Shh signaling is initially essential for hypothalamic induction. Later, Shh signaling from the neuroepithelium controls specification of the lateral hypothalamic area and growth-patterning coordination in the basal hypothalamus. To further elucidate the role of Shh in hypothalamic development, it will be essential to understand how Shh regulates the downstream Gli transcription factors.

  20. Ontogenetic expression of Sonic Hedgehog in the chicken subpallium

    Directory of Open Access Journals (Sweden)

    Sylvia M Bardet

    2010-07-01

    Full Text Available Sonic hedgehog (SHH is a secreted signaling factor that is implicated in the molecular patterning of the central nervous system (CNS, somites and limbs in vertebrates. SHH has a crucial role in the generation of ventral cell types along the entire rostrocaudal axis of the neural tube. It is secreted early in development by the axial mesoderm (prechordal plate and notochord and the overlying ventral neural tube. Recent studies clarified the impact of SHH signaling mechanisms on dorsoventral patterning of the spinal cord, but the corresponding phenomena in the rostral forebrain are slightly different and more complex. This notably involves separate Shh expression in the preoptic part of the forebrain alar plate, as well as in the hypothalamic floor and basal plates. The present work includes a detailed spatio-temporal description of the singular alar Shh expression pattern in the rostral preoptic forebrain of chick embryos, comparing it with FoxG1, Dlx5, Nkx2.1 and Nkx2.2 mRNA expression at diverse stages of development. As a result of this mapping, we report a subdivision of the preoptic region in dorsal and ventral zones; only the dorsal part shows Shh expression. The positive area impinges as well upon a median septocommissural preoptic domain. Our study strongly suggests tangential migration of Shh positive cells from the preoptic region into other subpallial domains, particularly into the pallidal mantle and the intermediate septum.

  1. Foretinib is effective therapy for metastatic sonic hedgehog medulloblastoma.

    Science.gov (United States)

    Faria, Claudia C; Golbourn, Brian J; Dubuc, Adrian M; Remke, Marc; Diaz, Roberto J; Agnihotri, Sameer; Luck, Amanda; Sabha, Nesrin; Olsen, Samantha; Wu, Xiaochong; Garzia, Livia; Ramaswamy, Vijay; Mack, Stephen C; Wang, Xin; Leadley, Michael; Reynaud, Denis; Ermini, Leonardo; Post, Martin; Northcott, Paul A; Pfister, Stefan M; Croul, Sidney E; Kool, Marcel; Korshunov, Andrey; Smith, Christian A; Taylor, Michael D; Rutka, James T

    2015-01-01

    Medulloblastoma is the most common malignant pediatric brain tumor, with metastases present at diagnosis conferring a poor prognosis. Mechanisms of dissemination are poorly understood and metastatic lesions are genetically divergent from the matched primary tumor. Effective and less toxic therapies that target both compartments have yet to be identified. Here, we report that the analysis of several large nonoverlapping cohorts of patients with medulloblastoma reveals MET kinase as a marker of sonic hedgehog (SHH)-driven medulloblastoma. Immunohistochemical analysis of phosphorylated, active MET kinase in an independent patient cohort confirmed its correlation with increased tumor relapse and poor survival, suggesting that patients with SHH medulloblastoma may benefit from MET-targeted therapy. In support of this hypothesis, we found that the approved MET inhibitor foretinib could suppress MET activation, decrease tumor cell proliferation, and induce apoptosis in SHH medulloblastomas in vitro and in vivo. Foretinib penetrated the blood-brain barrier and was effective in both the primary and metastatic tumor compartments. In established mouse xenograft or transgenic models of metastatic SHH medulloblastoma, foretinib administration reduced the growth of the primary tumor, decreased the incidence of metastases, and increased host survival. Taken together, our results provide a strong rationale to clinically evaluate foretinib as an effective therapy for patients with SHH-driven medulloblastoma. ©2014 American Association for Cancer Research.

  2. Effect of sonic driving on maximal aerobic performance.

    Science.gov (United States)

    Brilla, L.R.; Hatcher, Stefanie

    2000-07-01

    The study purpose was to evaluate antecedent binaural stimulation (ABS) on maximal aerobic physical performance. Twenty-two healthy, physically active subjects, 21-34 years, randomly received one of two preparations for each session: 15 min of quiet (BLANK) or percussive sonic driving at 200+ beats per minute (bpm) using a recorded compact disc (FSS, Mill Valley, CA) with headphones (ABS). Baseline HR, blood pressure (BP), and breathing frequency (f(br)) were obtained. During each condition, HR and f(br) were recorded at 3-min intervals. The graded maximal treadmill testing was administered immediately postpreparation session on separate days, with at least 48 h rest between sessions. There were significant differences in the antecedent period means between the two conditions, ABS (HR: 70.2 +/- 10.7 bpm; f(br): 18.5 +/- 3.3 br min(-1); BP: 134.5/87.9 +/- 13.6/9.2 mm Hg) and BLANK (HR: 64.6 +/- 7.9; f(br): 14.3 +/- 2.9; BP: 126.7/80.3 +/- 12.1/8.6). Differences were noted for each 3-min interval and pre- postantecedent period. The maximal graded exercise test (GXT) results showed that there was a small but significant (P 0.05). There may be a latency to ABS related to entrainment or imagery-enhanced warm-up. Am. J. Hum. Biol. 12:558-565, 2000. Copyright 2000 Wiley-Liss, Inc.

  3. Generation of toxic degradation products by sonication of Pluronic® dispersants: implications for nanotoxicity testing

    OpenAIRE

    Wang, Ruhung; Hughes, Tyler; Beck, Simon; Vakil, Samee; Li, Synyoung; Pantano, Paul; Draper, Rockford K.

    2012-01-01

    Poloxamers (known by the trade name Pluronic®) are triblock copolymer surfactants that contain two polyethylene glycol blocks and one polypropylene glycol block of various sizes. Poloxamers are widely used as nanoparticle dispersants for nanotoxicity studies wherein nanoparticles are sonicated with a dispersant to prepare suspensions. It is known that poloxamers can be degraded during sonication and that reactive oxygen species contribute to the degradation process. However, the possibility t...

  4. Mechanism of inhibition of the tumor suppressor Patched by Sonic Hedgehog

    OpenAIRE

    Tukachinsky, Hanna; Petrov, Kostadin; Watanabe, Miyako; Salic, Adrian

    2016-01-01

    The Hedgehog-signaling pathway plays key roles in animal development and physiology. Insufficient Hedgehog signaling causes birth defects, whereas uncontrolled signaling is implicated in cancer. Signaling is triggered by the secreted protein, Sonic Hedgehog, which inhibits the membrane protein Patched1, leading to pathway activation. Despite its fundamental importance, we do not understand how Sonic Hedgehog inhibits Patched1. Here, we uncover a critical interaction between the fatty-acid?mod...

  5. [Clinical use of the Sonic Air MM 1500 and the Meca Sonic 1400 in canal preparation in endodontics].

    Science.gov (United States)

    Gaye, F; Ba, I; Kane, A W; Mbaye, M; Ndoye Diop, A; Agboton-Johnson, C A

    1991-03-01

    The preparation for canalisation has remained manual for a long time, technically constrictive and lasting for a long time. The application of ultrasound in Endontony allows us to tackle more calmly the canal course of the teath. The aim of this work is to make a qualitative comparison of the endosonic technique and the manual technique with reference to cases treated in the Dentisterie Opératoire clinic in Dakar. 40 teeth of a complex canal anatomy and or in the posterior position in the buccal cavity were submitted to either a manual canalisation preparation or endosconic followed by monconic canal filling with a paste: 3 inc oxyde eugenol and iodoform. OPERATING FORMULA: Preparatory X rays: Allow us to evaluate the length of the work or the operating length after catheterisation: LO--length PRO, APEX RADIO-IMM LO--operating length PRO - occlusive point of reference The parietal support technique: The "synergetic" effect of ultrasonic oscillations of cavitation and of micro-acoustic currents associated with the action of the irrigation solution allow us to obtain canal incision. the pneumatic Sonic Air MM 1500; the Meca Sonic MMR 1400 coupled to a standard ISO motor; SHAPERS and Meca Shapers. Activated by shaper or Méca Shaper. Classic monoconic canal filling: Wadding paste + zinc oxyde paste-iodoform eugenol. X rays for orthocentric monitoring. RESULTS--DISCUSSION: In 60% of the cases treated, the patients presented with a complete dentition. The third inferior molar was in almost all the cases, the cause of the patient seeking a dental consultation. By endosonic treatment-conservation of teeth which would otherwise have been destined for extraction; biopulectomy or instituted pulpectomy for cases of desdodontite, endosconic amplication and canal sealing after the cooling of the inflammation. Duration of treatment: 2 sessions for gangrenous cases or desmodondite and one session for biopulpectomy or pulpectomy, with 4 sessions in 10% of the cases. Operation

  6. Development of a novel ultrasensitive enzyme immunoassay for human glutamic acid decarboxylase 65 antibody.

    Science.gov (United States)

    Numata, Satoshi; Katakami, Hideki; Inoue, Shinobu; Sawada, Hirotake; Hashida, Seiichi

    2016-07-01

    We developed a novel, ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for determination of glutamic acid decarboxylase autoantibody concentrations in serum samples from patients with type 2 diabetes. We developed an immune complex transfer enzyme immunoassay for glutamic acid decarboxylase autoantibody and measured glutamic acid decarboxylase autoantibody from 22 patients with type 1 diabetes, 29 patients with type 2 diabetes, and 32 healthy controls. A conventional ELISA kit identified 10 patients with type 1 diabetes and one patient with type 2 diabetes as glutamic acid decarboxylase autoantibody positive, whereas 15 patients with type 1 diabetes and six patients with type 2 diabetes were identified as glutamic acid decarboxylase autoantibody positive using immune complex transfer enzyme immunoassay. Immune complex transfer enzyme immunoassay is a highly sensitive and specific assay for glutamic acid decarboxylase autoantibody and might be clinically useful for diabetic onset prediction and early diagnosis. © The Author(s) 2016.

  7. Comparison of enzyme immunoassays for the diagnosis of bovine brucellosis

    International Nuclear Information System (INIS)

    Nielsen, K.; Kelly, L.; Gall, D.; Balsevicius, S.; Bosse, J.; Kelly, W.; Nicoletti, P.

    1998-01-01

    The indirect enzyme immunoassay for measurement of bovine antibody to Brucella abortus was tested on 15,716 Canadian sera to assess the specificity. These sera were also tested by the buffered plate antigen test. Two ELISA formats were used for assessment of data: the targeting procedure using a positive control serum allowed to develop to an optical density of 1.0 and the use of a positive control serum to determine relative positivity at a set time. Two different cut-off values were also assessed for each assay. A total of 763 sera gave reactions above established cut-off values in the ELISA while 216 were positive in the buffered plate antigen test (BPAT). A modification of the indirect ELISA employed divalent cation chelating agents (EDTA/EGTA) incorporated into the serum incubation stage to eliminate some non-specific reactions. This method was applied only to the 763 indirect ELISA reactor sera and it eliminated all but 93 or 37, depending on the cut-off selected, of the reactions. Sensitivity was assessed by testing 424 sera from Brucella abortus culture positive cattle. The indirect ELISA classified all 424 sera as positive by either method of data handling and with or without addition of EDTA/EGTA for a specificity estimate of 100%. In the BPAT, 412 sera gave a positive agglutination reaction. Ten percent of the 15,716 sera were randomly selected and tested by two different competitive ELISAs and by the complement fixation test (CFT). One competitive ELISA used Brucella abortus O-polysaccharide as the antigen and an enzyme conjugated monoclonal antibody to the O-polysaccharide for competition and detection. Of the sera tested, 34 gave false positive reactions. On a retest, the false positive reactions were reduced to 2. The second competitive ELISA used lipopolysaccharide as the antigen, a different monoclonal antibody but also specific for the O-polysaccharide for competition and commercially available goat anti-mouse IgG enzyme conjugate for detection

  8. Homogenous 96-plex PEA immunoassay exhibiting high sensitivity, specificity, and excellent scalability

    DEFF Research Database (Denmark)

    Assarsson, Erika; Lundberg, Martin; Holmquist, Göran

    2014-01-01

    reporters, shown potential to relieve the shortcomings of antibodies and their inherent cross-reactivity in multiplex protein quantification applications. The aim of the present study was to develop a robust 96-plex immunoassay based on the proximity extension assay (PEA) for improved high throughput...... detection of protein biomarkers. This was enabled by: (1) a modified design leading to a reduced number of pipetting steps compared to the existing PEA protocol, as well as improved intra-assay precision; (2) a new enzymatic system that uses a hyper-thermostabile enzyme, Pwo, for uniting the two probes......, such as serum and plasma, and also in xenografted mice and resuspended dried blood spots, consuming only 1 µL sample per test. All-in-all, the development of the current multiplex technique is a step toward robust high throughput protein marker discovery and research....

  9. Enzymatic amplification of a flow-injected thermometric enzyme-linked immunoassay for human insulin.

    Science.gov (United States)

    Mecklenburg, M; Lindbladh, C; Li, H; Mosbach, K; Danielsson, B

    1993-08-01

    A flow-injected thermometric enzyme linked immunoassay for human insulin which employs the lactate dehydrogenase/lactate oxidase (LDH/LOD) substrate recycling system for signal amplification is described. The system is composed of two columns, an immunosorbent column containing immobilized anti-insulin antibodies for sensing and a recycling column containing immobilized LDH/LOD/Catalase for detection. The effect of flow rates, conjugate concentrations, and chromatographic support material upon the sensitivity of the assay are investigated. The assay has a detection limit of 0.025 microgram/ml and a linear range from 0.05 to 2 micrograms/ml. This corresponds to a 10-fold increase in sensitivity over the unamplified system. A recombinant human insulin-proinsulin conjugate was also tested. The results show that enzymatic amplification can be employed to increase the sensitivity and reproducibility of flow injection assay-based biosensors. The implications of these results upon on-line analysis are discussed.

  10. High-resolution proton and carbon-13 NMR of membranes: why sonicate?

    International Nuclear Information System (INIS)

    Oldfield, E.; Bowers, J.L.; Forbes, J.

    1987-01-01

    The authors have obtained high-field (11.7-T) proton and carbon-13 Fourier transform (FT) nuclear magnetic resonance (NMR) spectra of egg lecithin and egg lecithin-chloresterol (1:1) multibilayers, using magic-angle sample spinning (MASS) techniques, and sonicated egg lecithin and egg lecithin-cholesterol (1:1) vesicles, using conventional FT NMR methods. Resolution of the proton and carbon-13 MASS NMR spectra of the pure egg lecithin samples is essentially identical with that of sonicated samples, but spectra of the unsonicated lipid, using MASS, can be obtained very much faster than with the more dilute, sonicated systems. With the 1:1 lecithin-cholesterol system, proton MASS NMR spectra are virtually identical with conventional FT spectra of sonicated samples, while the 13 C NMR, the authors demonstrate that most 13 C nuclei in the cholesterol moiety can be monitored, even though these same nuclei are essentially invisible, i.e., are severely broadened, in the corresponding sonicated systems. In addition, 13 C MASS NMR spectra can again be recorded much faster than with sonicated samples, due to concentration effects. Taken together, these results strongly suggest there will seldom be need in the future to resort to ultransonic disruption of lipid bilayer membranes in order to obtain high-resolution proton or carbon-13 NMR spectra

  11. Sonication technique improves microbiological diagnosis in patients treated with antibiotics before surgery for prosthetic joint infections.

    Science.gov (United States)

    Scorzolini, Laura; Lichtner, Miriam; Iannetta, Marco; Mengoni, Fabio; Russo, Gianluca; Panni, Alfredo Schiavone; Vasso, Michele; Vasto, Michele; Bove, Marco; Villani, Ciro; Mastroianni, Claudio M; Vullo, Vincenzo

    2014-07-01

    Microbiological diagnosis is crucial for the appropriate management of implant-associated orthopedic infections (IAOIs). Sonication of biomaterials for microbiological diagnosis has not yet been introduced in routine clinical practice. Aim of this study was to describe the advantages and feasibility of this procedure in the clinical setting. We prospectively studied 56 consecutive patients undergoing revision because of IAOI and compared the sensitivity of sonication of explanted orthopedic implants with standard cultures. Patients were divided into two groups: those with foreign body infection (FBI, 15 patients) and those with prosthetic joint infection (PJI, 41 patients). Clinical, radiological and microbiological features were recorded. In the PJI group the sensitivity of sonication in detecting bacterial growth was higher than conventional culture (77% vs 34.1% respectively, p0.05). Coagulase-negative Staphylococci accounted for 90% of the bacteria detected by sonication. Moreover, we found that in the PJI group the sensitivity of sonication was not affected by the timing of antibiotic interruption before surgery. Sonication remains an important tool to improve microbiological diagnosis in PJIs, especially in patients who received previous antimicrobial treatment.

  12. Loss of Sonic hedgehog leads to alterations in intestinal secretory cell maturation and autophagy.

    Directory of Open Access Journals (Sweden)

    Jessica Gagné-Sansfaçon

    Full Text Available BACKGROUND: Intestinal epithelial cells express the Sonic and Indian hedgehog ligands. Despite the strong interest in gut hedgehog signaling in GI diseases, no studies have specifically addressed the singular role of intestinal epithelial cell Sonic hedgehog signaling. The aim of this study was to investigate the specific role of Sonic hedgehog in adult ileal epithelial homeostasis. METHODOLOGY/PRINCIPAL FINDINGS: A Sonic hedgehog intestinal epithelial conditional knockout mouse model was generated. Assessment of ileal histological abnormalities, crypt epithelial cell proliferation, epithelial cell fate, junctional proteins, signaling pathways, as well as ultrastructural analysis of intracellular organelles were performed in control and mutant mice. Mice lacking intestinal epithelial Sonic Hedgehog displayed decreased ileal crypt/villus length, decreased crypt proliferation as well as a decrease in the number of ileal mucin-secreting goblet cells and antimicrobial peptide-secreting Paneth cells during adult life. These secretory cells also exhibited disruption of their secretory products in mutant mice. Ultrastructural microscopy analysis revealed a dilated ER lumen in secretory cells. This phenotype was also associated with a decrease in autophagy. CONCLUSIONS/SIGNIFICANCE: Altogether, these findings indicate that the loss of Sonic hedgehog can lead to ileal secretory cell modifications indicative of endoplasmic reticulum stress, accompanied by a significant reduction in autophagy.

  13. Rapid and Highly Sensitive Non-Competitive Immunoassay for Specific Detection of Nodularin

    Directory of Open Access Journals (Sweden)

    Sultana Akter

    2017-09-01

    Full Text Available Nodularin (NOD is a cyclic penta-peptide hepatotoxin mainly produced by Nodularia spumigena, reported from the brackish water bodies of various parts of the world. It can accumulate in the food chain and, for safety reasons, levels of NOD not only in water bodies but also in food matrices are of interest. Here, we report on a non-competitive immunoassay for the specific detection of NOD. A phage display technique was utilized to interrogate a synthetic antibody phage library for binders recognizing NOD bound to an anti-ADDA (3-Amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4(E,6(E-dienoic acid monoclonal antibody (Mab. One of the obtained immunocomplex binders, designated SA32C11, showed very high specificity towards nodularin-R (NOD-R over to the tested 10 different microcystins (microcystin-LR, -dmLR, -RR, -dmRR, -YR, -LY, -LF, -LW, -LA, -WR. It was expressed in Escherichia coli as a single chain antibody fragment (scFv fusion protein and used to establish a time-resolved fluorometry-based assay in combination with the anti-ADDA Mab. The detection limit (blank + 3SD of the immunoassay, with a total assay time of 1 h 10 min, is 0.03 µg/L of NOD-R. This represents the most sensitive immunoassay method for the specific detection of NOD reported so far. The assay was tested for its performance to detect NOD using spiked (0.1 to 3 µg/L of NOD-R water samples including brackish sea and coastal water and the recovery ranged from 79 to 127%. Furthermore, a panel of environmental samples, including water from different sources, fish and other marine tissue specimens, were analyzed for NOD using the assay. The assay has potential as a rapid screening tool for the analysis of a large number of water samples for the presence of NOD. It can also find applications in the analysis of the bioaccumulation of NOD in marine organisms and in the food chain.

  14. Design of a surface plasmon resonance immunoassay for therapeutic drug monitoring of amikacin.

    Science.gov (United States)

    Losoya-Leal, Adrian; Estevez, M-Carmen; Martínez-Chapa, Sergio O; Lechuga, Laura M

    2015-08-15

    The therapeutic drug monitoring (TDM) of pharmaceutical drugs with narrow therapeutic ranges is of great importance in the clinical setting. It provides useful information towards the enhancement of drug therapies, aiding in dosage control and toxicity risk management. Amikacin is an aminoglycoside antibiotic commonly used in neonatal therapies that is indicated for TDM due to the toxicity risks inherent in its use. Current techniques for TDM such as high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) are costly, time consuming, and cannot be performed at the site of action. Over the last decades, surface plasmon resonance (SPR) biosensors have become increasingly popular in clinical diagnostics due to their ability to detect biomolecular interactions in real-time. We present an SPR-based competitive immunoassay for the detection of the antibiotic amikacin, suitable for TDM in both adults and neonates. We have obtained high specificity and sensitivity levels with an IC50 value of 1.4ng/mL and a limit of detection of 0.13ng/mL, which comfortably comply with the drug's therapeutic range. Simple dilution of serum can therefore be sufficient to analyze low-volume real samples from neonates, increasing the potential of the methodology for TDM. Compared to current TDM conventional methods, this SPR-based immunoassay can provide advantages such as simplicity, potential portability, and label-free measurements with the possibility of high throughput. This work is the foundation towards the development of an integrated, simple use, highly sensitive, fast, and point-of-care sensing platform for the opportune TDM of antibiotics and other drugs in a clinical setting. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Sonication contribution to identifying prosthetic joint infection with Ralstonia pickettii: a case report and review of the literature.

    Science.gov (United States)

    Birlutiu, Rares Mircea; Roman, Mihai Dan; Cismasiu, Razvan Silviu; Fleaca, Sorin Radu; Popa, Crina Maria; Mihalache, Manuela; Birlutiu, Victoria

    2017-07-19

    In the context of an increase number of primary and revision total hip and total knee arthroplasty performed yearly, an increased risk of complication is expected. Prosthetic joint infection (PJI) remains the most common and feared arthroplasty complication. Ralstonia pickettii is a Gram-negative bacterium, that has also been identified in biofilms. It remains an extremely rare cause of PJI. There is no report of an identification of R. pickettii on an extracted spacer loaded with antibiotic. We present the case of an 83-years-old Caucasian male patient, that underwent a right cemented total hip replacement surgery. The patient is diagnosed with an early PJI with no isolated microorganism. A debridement and change of mobile parts is performed. At the beginning of 2016, the patient in readmitted into the Orthopedic Department for sever, right abdominal and groin pain and elevated serum erythrocyte sedimentation rate and C-reactive protein. A joint aspiration is performed with a negative microbiological examination. A two-stage exchange with long interval management is adopted, and a preformed spacer loaded with gentamicin was implanted. In July 2016, based on the proinflammatory markers evolution, a shift a three-stage exchange strategy is decided. In September 2016, a debridement, and changing of the preformed spacer loaded with gentamicin with another was carried out. Bacteriological examination of the tissues sampled intraoperatively was positive for Pseudomonas aeruginosa. From the sonication fluid, no bacteria were isolated on culture or identified using the bbFISH assay. During the hospitalization period, the patient received i.v. ceftazidime 3x2g/day and p.o. ciprofloxacin 2x750mg/day, antibiotic therapy that was continued after discharge with p.o. ciprofloxacin 2x750mg/day for 6 weeks. In February 2017, a reimplantation of a revision prosthesis is performed. The retrieved spacer is sonicated, and after 4 days of incubation of the sonication fluid, R

  16. Effect of sonication on particle dispersion, administered dose and metal release of non-functionalized, non-inert metal nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Sulena; Hedberg, Jonas, E-mail: jhed@kth.se; Blomberg, Eva [KTH Royal Institute of Technology, Division of Surface and Corrosion Science, Department of Chemistry (Sweden); Wold, Susanna [KTH Royal Institute of Technology, Division of Applied Physical Chemistry, Department of Chemistry (Sweden); Odnevall Wallinder, Inger [KTH Royal Institute of Technology, Division of Surface and Corrosion Science, Department of Chemistry (Sweden)

    2016-09-15

    In this study, we elucidate the effect of different sonication techniques to efficiently prepare particle dispersions from selected non-functionalized NPs (Cu, Al, Mn, ZnO), and corresponding consequences on the particle dose, surface charge and release of metals. Probe sonication was shown to be the preferred method for dispersing non-inert, non-functionalized metal NPs (Cu, Mn, Al). However, rapid sedimentation during sonication resulted in differences between the real and the administered doses in the order of 30–80 % when sonicating in 1 and 2.56 g/L NP stock solutions. After sonication, extensive agglomeration of the metal NPs resulted in rapid sedimentation of all particles. DLVO calculations supported these findings, showing the strong van der Waals forces of the metal NPs to result in significant NP agglomeration. Metal release from the metal NPs was slightly increased by increased sonication. The addition of a stabilizing agent (bovine serum albumin) had an accelerating effect on the release of metals in sonicated solutions. For Cu and Mn NPs, the extent of particle dissolution increased from <1.6 to ~5 % after sonication for 15 min. A prolonged sonication time (3–15 min) had negligible effects on the zeta potential of the studied NPs. In all, it is shown that it is of utmost importance to carefully investigate how sonication influences the physico-chemical properties of dispersed metal NPs. This should be considered in nanotoxicology investigations of metal NPs.Graphical Abstract.

  17. An anti-phospholipase A2 receptor quantitative immunoassay and epitope analysis in membranous nephropathy reveals different antigenic domains of the receptor.

    Directory of Open Access Journals (Sweden)

    Astrid Behnert

    Full Text Available The phospholipase A2 receptor (PLA2R was recently discovered as a target autoantigen in patients with idiopathic membranous nephropathy (IMN. Published evidence suggests that the autoantibodies directed towards a conformation dependent epitope are currently effectively detected by a cell based assay (CBA utilizing indirect immunofluorescence (IIF on tissue culture cells transfected with the PLA2R cDNA. Limitations of such IIF-CBA assays include observer dependent subjective evaluation of semi-quantitative test results and the protocols are not amenable to high throughput diagnostic testing. We developed a quantitative, observer independent, high throughput capture immunoassay for detecting PLA2R autoantibodies on an addressable laser bead immunoassay (ALBIA platform. Since reactive domains of PLA2R (i.e. epitopes could be used to improve diagnostic tests by using small peptides in various high throughput diagnostic platforms, we identified PLA2R epitopes that bound autoantibodies of IMN patients. These studies confirmed that inter-molecular epitope spreading occurs in IMN but use of the cognate synthetic peptides in immunoassays was unable to conclusively distinguish between IMN patients and normal controls. However, combinations of these peptides were able to effectively absorb anti-PLA2R reactivity in IIF-CBA and an immunoassay that employed a lysate derived from HEK cells tranfected with and overexpressing PLA2R. While we provide evidence of intermolecular epitope spreading, our data indicates that in addition to conformational epitopes, human anti-PLA2R reactivity in a commercially available CBA and an addressable laser bead immunoassay is significantly absorbed by peptides representing epitopes of PLA2R.

  18. Concordance Between Different Amyloid Immunoassays and Visual Amyloid Positron Emission Tomographic Assessment.

    Science.gov (United States)

    Janelidze, Shorena; Pannee, Josef; Mikulskis, Alvydas; Chiao, Ping; Zetterberg, Henrik; Blennow, Kaj; Hansson, Oskar

    2017-12-01

    Visual assessment of amyloid positron emission tomographic (PET) images has been approved by regulatory authorities for clinical use. Several immunoassays have been developed to measure β-amyloid (Aβ) 42 in cerebrospinal fluid (CSF). The agreement between CSF Aβ42 measures from different immunoassays and visual PET readings may influence the use of CSF biomarkers and/or amyloid PET assessment in clinical practice and trials. To determine the concordance between CSF Aβ42 levels measured using 5 different immunoassays and visual amyloid PET analysis. The study included 262 patients with mild cognitive impairment or subjective cognitive decline from the Swedish BioFINDER (Biomarkers for Identifying Neurodegenerative Disorders Early and Reliably) cohort (recruited from September 1, 2010, through December 31, 2014) who had undergone flutemetamol F 18 ([18F]flutemetamol)-labeled PET. Levels of CSF Aβ42 were analyzed using the classic INNOTEST and the newer modified INNOTEST, fully automated Lumipulse (FL), EUROIMMUN (EI), and Meso Scale Discovery (MSD) assays. Concentrations of CSF Aβ were assessed using an antibody-independent mass spectrometry-based reference measurement procedure. The concordance of CSF Aβ42 levels and Aβ42:Aβ40 and Aβ42:tau ratios with visual [18F]flutemetamol PET status. Of 262 participants (mean [SD] age, 70.9 [5.5] years), 108 were women (41.2%) and 154 were men (58.8%). The mass spectrometry-derived Aβ42 values showed higher correlations with the modified Aβ42-INNOTEST (r = 0.97), Aβ42-FL (r = 0.93), Aβ42-EI (r = 0.93), and Aβ42-MSD (r = 0.95) assays compared with the classic Aβ42-INNOTEST assay (r = 0.88; P ≤ .01). The signal in the classic Aβ42-INNOTEST assay was partly quenched by recombinant Aβ1-40 peptide. However, the classic Aβ42-INNOTEST assay showed better concordance with visual [18F]flutemetamol PET status (area under the receiver operating characteristic curve [AUC], 0.92) compared with the

  19. A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

    Science.gov (United States)

    Cliatt, Larry J., II; Haering, Edward A., Jr.; Jones, Thomas P.; Waggoner, Erin R.; Flattery, Ashley K.; Wiley, Scott L.

    2014-01-01

    In support of the ongoing effort by the National Aeronautics and Space Administration (NASA) to bring supersonic commercial travel to the public, the NASA Armstrong Flight Research Center and the NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response (WSPR). Such tests will be applied to building a dataset that governing agencies such as the Federal Aviation Administration and the International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. The WSPR test was the first such effort that studied responses to non-traditional low sonic booms while the subject persons were in their own homes and performing daily activities.The WSPR test was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle (El Segundo, California). Other partners included Gulfstream Aerospace Corporation (Savannah, Georgia); Pennsylvania State University (University Park, Pennsylvania); Tetra Tech, Inc. (Pasadena, California); and Fidell Associates, Inc. (Woodland Hills, California).A major objective of the effort included exposing a community to the sonic boom magnitudes and occurrences that would be expected to occur in high-air traffic regions having a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data were collected using multiple

  20. A Flight Research Overview of WSPR, a Pilot Project for Sonic Boom Community Response

    Science.gov (United States)

    Cliatt, Larry James; Haering, Ed; Jones, Thomas P.; Waggoner, Erin R.; Flattery, Ashley K.; Wiley, Scott L.

    2014-01-01

    In support of NASAs ongoing effort to bring supersonic commercial travel to the public, NASA Dryden Flight Research Center and NASA Langley Research Center, in cooperation with other industry organizations, conducted a flight research experiment to identify the methods, tools, and best practices for a large-scale quiet (or low) sonic boom community human response test. The name of the effort was Waveforms and Sonic boom Perception and Response. Such tests will go towards building a dataset that governing agencies like the Federal Aviation Administration and International Civil Aviation Organization will use to establish regulations for acceptable sound levels of overland sonic booms. Until WSPR, there had never been an effort that studied the response of people in their own homes and performing daily activities to non-traditional, low sonic booms.WSPR was a NASA collaborative effort with several industry partners, in response to a NASA Aeronautics Research Mission Directorate Research Opportunities in Aeronautics. The primary contractor was Wyle. Other partners included Gulfstream Aerospace Corporation, Pennsylvania State University, Tetra Tech, and Fidell Associates, Inc.A major objective of the effort included exposing a community with the sonic boom magnitudes and occurrences expected in high-air traffic regions with a network of supersonic commercial aircraft in place. Low-level sonic booms designed to simulate those produced by the next generation of commercial supersonic aircraft were generated over a small residential community. The sonic boom footprint was recorded with an autonomous wireless microphone array that spanned the entire community. Human response data was collected using multiple survey methods. The research focused on essential elements of community response testing including subject recruitment, survey methods, instrumentation systems, flight planning and operations, and data analysis methods.This paper focuses on NASAs role in the efforts

  1. Analytical validation of Gentian NGAL particle-enhanced enhanced turbidimetric immunoassay (PETIA

    Directory of Open Access Journals (Sweden)

    Gian Luca Salvagno

    2017-08-01

    Full Text Available Objectives: This study was designed to validate the analytical performance of the new Gentian particle-enhanced enhanced turbidimetric immunoassay (PETIA for measuring neutrophil gelatinase-associated lipocalin (NGAL in serum samples. Design and methods: Analytical validation of the Gentian NGAL assay was carried out on a Roche Cobas c501 and was based on assessment of limit of blank (LOB, limit of detection (LOD, functional sensitivity, imprecision, linearity and concordance with the BioPorto NGAL test. Results: The LOB and LOD of Gentian NGAL were found to be 3.8 ng/mL and 6.3 ng/mL, respectively. An analytical coefficient of variation (CV of 20% corresponded to a NGAL value of 10 ng/mL. The intra-assay and inter-assay imprecision (CV was between 0.4 and 5.2% and 0.6 and 7.1% and the total imprecision (CV was 3.7%. The linearity was optimal at NGAL concentrations between 37 and 1420 ng/mL (r=1.00; p<0.001. An excellent correlation was observed between values measured with Gentian NGAL and BioPorto NGAL in 74 routine serum samples (r=0.993. The mean percentage bias of the Gentian assay versus the Bioporto assay was +3.1% (95% CI, +1.6% to +4.5%. Conclusions: These results show that Gentian NGAL may be a viable option to other commercial immunoassays for both routine and urgent assessment of serum NGAL. Keywords: Neutrophil gelatinase-associated lipocalin, NGAL, Analytical validation, Acute kidney injury

  2. A Portable Immunoassay Platform for Multiplexed Detection of Biotoxins in Clinical and Environmental Samples

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Chung-Yan [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Piccini, Matthew Ernest [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Cepheid, Sunnyvale, CA (United States); Schaff, Ulrich Y. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sandstone Diagnostics, Livermore, CA (United States); Stanker, Larry H. [US Dept. of Agriculture, Albany, CA (United States). Western Regional Research Center, Foodborne Contaminants Research Unit; Cheng, Luisa W. [US Dept. of Agriculture, Albany, CA (United States). Western Regional Research Center, Foodborne Contaminants Research Unit; Ravichandran, Easwaran [Univ. of Massachusetts, Dartmouth, MA (United States); Singh, Bal-Ram [Univ. of Massachusetts, Dartmouth, MA (United States); Sommer, Greg J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sandstone Diagnostics, Livermore, CA (United States); Singh, Anup K. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-01-01

    Multiple cases of attempted bioterrorism events using biotoxins have highlighted the urgent need for tools capable of rapid screening of suspect samples in the field (e.g., mailroom and public events). We present a portable microfluidic device capable of analyzing environmental (e.g., white powder), food (e.g., milk) and clinical (e.g., blood) samples for multiplexed detection of biotoxins. The device is rapid (<15-30 min sample-to-answer), sensitive (< 0.08 pg/mL detection limit for botulinum toxin), multiplexed (up to 64 parallel assays) and capable of analyzing small volume samples (< 20 μL total sample input). The immunoassay approach (SpinDx) is based on binding of toxins in a sample to antibody-laden capture particles followed by sedimentation of particles through a density-media in a microfluidic disk and quantification using a laser-induced fluorescence detector. A direct, blinded comparison with a gold standard ELISA revealed a 5-fold more sensitive detection limit for botulinum toxin while requiring 250-fold less sample volume and a 30 minute assay time with a near unity correlation. A key advantage of the technique is its compatibility with a variety of sample matrices with no additional sample preparation required. Ultrasensitive quantification has been demonstrated from direct analysis of multiple clinical, environmental and food samples, including white powder, whole blood, saliva, salad dressing, whole milk, peanut butter, half and half, honey, and canned meat. We believe that this device can met an urgent need in screening both potentially exposed people as well as suspicious samples in mail-rooms, airports, public sporting venues and emergency rooms. The general-purpose immunodiagnostics device can also find applications in screening of infectious and systemic diseases or serve as a lab device for conducting rapid immunoassays.

  3. Simulation of wireline sonic logging measurements acquired with Borehole-Eccentered tools using a high-order adaptive finite-element method

    KAUST Repository

    Pardo, David

    2011-07-01

    The paper introduces a high-order, adaptive finite-element method for simulation of sonic measurements acquired with borehole-eccentered logging instruments. The resulting frequency-domain based algorithm combines a Fourier series expansion in one spatial dimension with a two-dimensional high-order adaptive finite-element method (FEM), and incorporates a perfectly matched layer (PML) for truncation of the computational domain. The simulation method was verified for various model problems, including a comparison to a semi-analytical solution developed specifically for this purpose. Numerical results indicate that for a wireline sonic tool operating in a fast formation, the main propagation modes are insensitive to the distance from the center of the tool to the center of the borehole (eccentricity distance). However, new flexural modes arise with an increase in eccentricity distance. In soft formations, we identify a new dipole tool mode which arises as a result of tool eccentricity. © 2011 Elsevier Inc.

  4. Simulation of wireline sonic logging measurements acquired with Borehole-Eccentered tools using a high-order adaptive finite-element method

    KAUST Repository

    Pardo, David; Matuszyk, Paweł Jerzy; Muga, Ignacio; Torres-Verdí n, Carlos; Mora Cordova, Angel; Calo, Victor M.

    2011-01-01

    The paper introduces a high-order, adaptive finite-element method for simulation of sonic measurements acquired with borehole-eccentered logging instruments. The resulting frequency-domain based algorithm combines a Fourier series expansion in one spatial dimension with a two-dimensional high-order adaptive finite-element method (FEM), and incorporates a perfectly matched layer (PML) for truncation of the computational domain. The simulation method was verified for various model problems, including a comparison to a semi-analytical solution developed specifically for this purpose. Numerical results indicate that for a wireline sonic tool operating in a fast formation, the main propagation modes are insensitive to the distance from the center of the tool to the center of the borehole (eccentricity distance). However, new flexural modes arise with an increase in eccentricity distance. In soft formations, we identify a new dipole tool mode which arises as a result of tool eccentricity. © 2011 Elsevier Inc.

  5. Clinical development of placental malaria vaccines and immunoassays harmonization

    DEFF Research Database (Denmark)

    Chêne, Arnaud; Houard, Sophie; Nielsen, Morten A

    2016-01-01

    Placental malaria caused by Plasmodium falciparum infection constitutes a major health problem manifesting as severe disease and anaemia in the mother, impaired fetal development, low birth weight or spontaneous abortion. Prevention of placental malaria currently relies on two key strategies...... that are losing efficacy due to spread of resistance: long-lasting insecticide-treated nets and intermittent preventive treatment during pregnancy. A placental malaria vaccine would be an attractive, cost-effective complement to the existing control tools. Two placental malaria vaccine candidates are currently...... in Phase Ia/b clinical trials. During two workshops hosted by the European Vaccine Initiative, one in Paris in April 2014 and the other in Brussels in November 2014, the main actors in placental malaria vaccine research discussed the harmonization of clinical development plans and of the immunoassays...

  6. Development of an Ultrasensitive Immunoassay for Detecting Tartrazine

    Directory of Open Access Journals (Sweden)

    Chuanlai Xu

    2013-06-01

    Full Text Available We have developed an ultrasensitive indirect competitive enzyme-linked immunosorbent assay for the determination of tartrazine. Two carboxylated analogues of tartrazine with different spacer lengths, and one derivative from commercial tartrazine after a little chemical modification, were synthesized as haptens in order to produce antibodies specific to tartrazine. The effect of sulfonic acid groups on the hapten structure of tartrazine was also studied carefully for the first time. A most specific monoclonal antibody against tartrazine was created and exhibited an IC50 value of 0.105 ng/mL and a limit of detection of 0.014 ng/mL, with no cross-reactivity to other structurally-related pigments. The established immunoassay was applied to the determination of tartrazine in fortified samples of orange juice and in real positive samples of carbonated beverages.

  7. Integrated immunoassay using tuneable surface acoustic waves and lensfree detection.

    Science.gov (United States)

    Bourquin, Yannyk; Reboud, Julien; Wilson, Rab; Zhang, Yi; Cooper, Jonathan M

    2011-08-21

    The diagnosis of infectious diseases in the Developing World is technologically challenging requiring complex biological assays with a high analytical performance, at minimal cost. By using an opto-acoustic immunoassay technology, integrating components commonly used in mobile phone technologies, including surface acoustic wave (SAW) transducers to provide pressure driven flow and a CMOS camera to enable lensfree detection technique, we demonstrate the potential to produce such an assay. To achieve this, antibody functionalised microparticles were manipulated on a low-cost disposable cartridge using the surface acoustic waves and were then detected optically. Our results show that the biomarker, interferon-γ, used for the diagnosis of diseases such as latent tuberculosis, can be detected at pM concentrations, within a few minutes (giving high sensitivity at a minimal cost). This journal is © The Royal Society of Chemistry 2011

  8. Plasma myelin basic protein assay using Gilford enzyme immunoassay cuvettes.

    Science.gov (United States)

    Groome, N P

    1981-10-01

    The assay of myelin basic protein in body fluids has potential clinical importance as a routine indicator of demyelination. Preliminary details of a competitive enzyme immunoassay for this protein have previously been published by the author (Groome, N. P. (1980) J. Neurochem. 35, 1409-1417). The present paper now describes the adaptation of this assay for use on human plasma and various aspects of routine data processing. A commercially available cuvette system was found to have advantages over microtitre plates but required a permuted arrangement of sample replicates for consistent results. For dose interpolation, the standard curve could be fitted to a three parameter non-linear equation by regression analysis or linearised by the logit/log transformation.

  9. Development of an ultrasensitive immunoassay for detecting tartrazine.

    Science.gov (United States)

    Li, Zhuokun; Song, Shanshan; Xu, Liguang; Kuang, Hua; Guo, Shidong; Xu, Chuanlai

    2013-06-25

    We have developed an ultrasensitive indirect competitive enzyme-linked immunosorbent assay for the determination of tartrazine. Two carboxylated analogues of tartrazine with different spacer lengths, and one derivative from commercial tartrazine after a little chemical modification, were synthesized as haptens in order to produce antibodies specific to tartrazine. The effect of sulfonic acid groups on the hapten structure of tartrazine was also studied carefully for the first time. A most specific monoclonal antibody against tartrazine was created and exhibited an IC50 value of 0.105 ng/mL and a limit of detection of 0.014 ng/mL, with no cross-reactivity to other structurally-related pigments. The established immunoassay was applied to the determination of tartrazine in fortified samples of orange juice and in real positive samples of carbonated beverages.

  10. On-Chip Immunoassay for Determination of Urinary Albumin

    Directory of Open Access Journals (Sweden)

    Adisorn Tuantranont

    2009-12-01

    Full Text Available An immunoassay performed on a portable microfluidic device was evaluated for the determination of urinary albumin. An increase in absorbance at 500 nm resulting from immunoagglutination was monitored directly on the poly(dimethylsiloxane (PDMS microchip using a portable miniature fibre-optic spectrometer. A calibration curve was linear up to 10 mg L–1 (r2 = 0.993, with a detection limit of 0.81 mg L–1 (S/N = 3. The proposed system showed good precision, with relative standard deviations (RSDs of 5.1%, when evaluated with 10 mg L–1 albumin (n = 10. Determination of urinary albumin with the proposed system gave results highly similar to those determined by the conventional spectrophotometric method using immunoturbidimetric detection (r2 = 0.995; n = 15.

  11. Performance of immunoassay kits for site characterization and remediation

    International Nuclear Information System (INIS)

    Waters, L.C.; Palausky, A.; Counts, R.W.; Jenkins, R.A.

    1995-01-01

    The US Department of Energy (DOE) is supporting efforts to identify, validate and implement the use of effective, low-cost alternatives to currently used analytical methods for environmental management. As part of that program, we have evaluated the performances of a number of immunoassay (IA) kits with specificities for environmental contaminants of concern to the DOE. The studies were done in the laboratory using both spiked and field test samples. The analyte specificity and manufacturers of the kits evaluated were the following: mercury, BioNebraska; polychlorinated biphenyls (PCBs), EnSys and Millipore; petroleum fuel hydrocarbons, Millipore and Ohmicron; and polyaromatic hydrocarbons (PAHs), Ohmicron and Millipore. The kits were used in either a semiquantitative or quantitative format according to the preference of the manufacturers