6,722 research outputs found

    Paper and Fiber-Based Bio-Diagnostic Platforms: Current Challenges and Future Needs

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    In this perspective article, some of the latest paper and fiber-based bio-analytical platforms are summarized, along with their fabrication strategies, the processing behind the product development, and the embedded systems in which paper or fiber materials were integrated. The article also reviews bio-recognition applications of paper/fiber-based devices, the detected analytes of interest, applied detection techniques, the related evaluation parameters, the type and duration of the assays, as well as the advantages and disadvantages of each technique. Moreover, some of the existing challenges of utilizing paper and/or fiber materials are discussed. These include control over the physical characteristics (porosity, permeability, wettability) and the chemical properties (surface functionality) of paper/fiber materials are discussed. Other aspects of the review focus on shelf life, the multi-functionality of the platforms, readout strategies, and other challenges that have to be addressed in order to obtain reliable detection outcomes. Keywords: paper-based bio-analytical devices; shelf life; equipment-free bio-recognition; flow rate; readout strategies; multi-functional platform

    NASA SBIR abstracts of 1991 phase 1 projects

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    The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included

    Special issue on 'Terrestrial laser scanning': editors' notes

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    In this editorial, we provide an overview of the content of the special issue on 'Terrestrial Laser Scanning'. The aim of this Special Issue is to bring together innovative developments and applications of terrestrial laser scanning (TLS), understood in a broad sense. Thus, although most contributions mainly involve the use of laser-based systems, other alternative technologies that also allow for obtaining 3D point clouds for the measurement and the 3D characterization of terrestrial targets, such as photogrammetry, are also considered. The 15 published contributions are mainly focused on the applications of TLS to the following three topics: TLS performance and point cloud processing, applications to civil engineering, and applications to plant characterization

    Micro-Biosensor Devices for Biochemical Analysis Applications

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    A biosensor is an analytical device integrating a biological element and a physicochemical transducer that convert a biological response into a measurable signal. The advantages of biosensors include low cost, small size, quick, sensitivity and selectivity greater than the conventional instruments. Biosensors have a wide range of applications ranging from clinical diagnostics through to environmental monitoring, agriculture industry, et al. The different types of biosensors are classified based on the sensor device as well as the biological material. Biosensors can be broadly classified into (piezoelectric, etc.), electrochemical biosensors (potentiometric, amperometric, etc.), and optical types of biosensors (fiber optics, etc.). Here, we introduce a novel microfluidics-integrated biosensor platform system that can be flexibly adapted to form individual biosensors for different applications. In this dissertation, we present five examples of different emerging areas with this biosensor system including anti-cancer drug screening, glucose monitoring, heavy metal elements measurement, obesity healthcare, and waterborne pathogen DNA detection. These micro-biosensors have great potential to be further developed to emerging portable sensing devices especially for the uses in the developing and undeveloped world. At the last chapter, Raman spectroscopy applied to assess gestational status and the potential for pregnancy complications is presented and discussed. This technique could significantly benefit animal reproduction

    Close-Range Sensing and Data Fusion for Built Heritage Inspection and Monitoring - A Review

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    Built cultural heritage is under constant threat due to environmental pressures, anthropogenic damages, and interventions. Understanding the preservation state of monuments and historical structures, and the factors that alter their architectural and structural characteristics through time, is crucial for ensuring their protection. Therefore, inspection and monitoring techniques are essential for heritage preservation, as they enable knowledge about the altering factors that put built cultural heritage at risk, by recording their immediate effects on monuments and historic structures. Nondestructive evaluations with close-range sensing techniques play a crucial role in monitoring. However, data recorded by different sensors are frequently processed separately, which hinders integrated use, visualization, and interpretation. This article’s aim is twofold: i) to present an overview of close-range sensing techniques frequently applied to evaluate built heritage conditions, and ii) to review the progress made regarding the fusion of multi-sensor data recorded by them. Particular emphasis is given to the integration of data from metric surveying and from recording techniques that are traditionally non-metric. The article attempts to shed light on the problems of the individual and integrated use of image-based modeling, laser scanning, thermography, multispectral imaging, ground penetrating radar, and ultrasonic testing, giving heritage practitioners a point of reference for the successful implementation of multidisciplinary approaches for built cultural heritage scientific investigations

    The NASA SBIR product catalog

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    The purpose of this catalog is to assist small business firms in making the community aware of products emerging from their efforts in the Small Business Innovation Research (SBIR) program. It contains descriptions of some products that have advanced into Phase 3 and others that are identified as prospective products. Both lists of products in this catalog are based on information supplied by NASA SBIR contractors in responding to an invitation to be represented in this document. Generally, all products suggested by the small firms were included in order to meet the goals of information exchange for SBIR results. Of the 444 SBIR contractors NASA queried, 137 provided information on 219 products. The catalog presents the product information in the technology areas listed in the table of contents. Within each area, the products are listed in alphabetical order by product name and are given identifying numbers. Also included is an alphabetical listing of the companies that have products described. This listing cross-references the product list and provides information on the business activity of each firm. In addition, there are three indexes: one a list of firms by states, one that lists the products according to NASA Centers that managed the SBIR projects, and one that lists the products by the relevant Technical Topics utilized in NASA's annual program solicitation under which each SBIR project was selected

    Single Harmonic-based Narrowband Magnetic Particle Imaging

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    Visualization of the in vivo spatial distribution of superparamagnetic iron oxide nanoparticles (SPIONs) is crucial to biomedicine. Magnetic particle imaging (MPI) is one of the most promising approaches for direct measurements of the SPION distribution. In this paper, we systematically investigate a single-harmonic-based narrowband MPI approach. Herein, only the 3rd harmonic at 15 kHz of the SPION signal induced in an excitation magnetic field of 5 kHz is measured via a narrowband detection system for imaging during scanning a field-free-point in a field of view. Experiments on spot and line phantoms are performed to evaluate the spatial distribution by the assessment of the full width at half maximum and modulation transfer function at different excitation magnetic fields from 4 to 10 mT. Experimental results demonstrate that reconstructed images have a spatial resolution of 1.6 and 1.5 mm for a gradient field of 2.2 T/m and 4.4 T/m in x- and z-direction, respectively, at an excitation magnetic field of 4 mT. In terms of line gap, two lines with a gap of 0.5 mm are resolved. With increasing the excitation magnetic field to 10 mT, the spatial resolution gets worse to 2.4 and 2.0 mm in x- and z-direction, respectively. Moreover, the custom-built MPI scanner allows a limit of detection of 53 microgram (Fe)/mL (500 ng Fe weight) using perimag SPIONs. In addition, the excellent performance is demonstrated by imaging experiments on an "emg" logo phantom. We believe that the proposed narrowband MPI approach is a promising approach for SPION imaging

    Upconverting diagnostics: Multiplex assays utilizing upconversion luminescence technology

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    Conventional diagnostics tests and technologies typically allow only a single analysis and result per test. The aim of this study was to propose robust and multiplex array-inwell test platforms based on oligonucleotide and protein arrays combining the advantages of simple instrumentation and upconverting phosphor (UCP) reporter technology. The UCPs are luminescent lanthanide-doped crystals that have a unique capability to convert infrared radiation into visible light. No autofluorescence is produced from the sample under infrared excitation enabling the development of highly sensitive assays. In this study, an oligonucleotide array-in-well hybridization assay was developed for the detection and genotyping of human adenoviruses. The study provided a verification of the advantages and potential of the UCP-based reporter technology in multiplex assays as well as anti-Stokes photoluminescence detection with a new anti- Stokes photoluminescence imager. The developed assay was technically improved and used to detect and genotype adenovirus types from clinical specimens. Based on the results of the epidemiological study, an outbreak of adenovirus type B03 was observed in the autumn of 2010. A quantitative array-in-well immunoassay was developed for three target analytes (prostate specific antigen, thyroid stimulating hormone, and luteinizing hormone). In this study, quantitative results were obtained for each analyte and the analytical sensitivities in buffer were in clinically relevant range. Another protein-based array-inwell assay was developed for multiplex serodiagnostics. The developed assay was able to detect parvovirus B19 IgG and adenovirus IgG antibodies simultaneously from serum samples according to reference assays. The study demonstrated that the UCPtechnology is a robust detection method for diverse multiplex imaging-based array-inwell assays.Perinteiset diagnostiset testit mahdollistavat vain yhden analyysin ja tuloksen määritystä kohden. Väitöskirjatyöni tavoitteena oli kehittää uudenlaisia järjestelmä kuopassa tyyppisiä mallintavia monianalyyttimäärityksiä, joissa yhdestä näytteestä yhdessä reaktiokaivossa voidaan mitata samanaikaisesti useita analyyttejä ja niiden pitoisuuksia. Kehitetyt monianalyyttimääritykset perustuvat sekä nukleiinihappojen että proteiinien mittaukseen hyödyntäen leimoina valoa tuottavia epäorgaanisia lantanidi-ioneja sisältäviä loisteainepartikkeleita (UCP). Näillä partikkeleilla on ainutlaatuinen kyky virittyä matalaenergisen infrapunavalon vaikutuksesta ja emittoida korkeaenergisen näkyvän valon aallonpituuksilla, mikä mahdollistaa autofluoresenssista vapaan mittauksen ja näin ollen herkkien määrityksien kehityksen. Väitöskirjatyössäni kehitin adenoviruksille DNA-tyypitysmäärityksen, joka perustui yksinauhaisen PCR-tuotteen ja adenovirus-tyyppispesifisten koettimien väliseen hybridisaatioreaktioon mikrotiitterilevyn kaivon pohjalla. Tulokset osoittivat, että UCP-leimateknologia ja uusi anti-Stokes luminesenssin kuvantamiseen kehitetty laite soveltuvat monianalyttimääritysten kvantitatiiviseen mittaukseen. Teknisesti parannettua adenovirusten DNA-tyypitysmenetelmää hyödynnettiin kliinisesti merkittävien adenovirustyyppien havaitsemisessa ja genotyypityksessä. Adenovirusinfektioiden epidemiologinen seuranta osoitti, että adenovirus tyyppi B03 aiheutti epidemian syksyllä 2010. Väitöskirjatyössäni kehitin myös kvantitatiivisen mallintavan monianalyytti-immunomäärityksen kolmelle antigeenille. Määrityksessä kaikille analyyteille saatiin kvantitatiivinen tulos, ja analyyttiset herkkyydet olivat kliinisesti merkittävällä alueella. Lisäksi väitöskirjatyössäni kehitin serologisen monianalyyttimäärityksen, jonka avulla mitattiin seerumista IgG-luokan adenovirusja parvovirus B19-vasta-aineita samanaikaisesti. Serologinen monianalyyttimääritys validoitiin näytepaneelilla ja tulokset korreloivat hyvin adenovirus IgG ja parvovirus B19 IgG referenssi-entsyymi-immunomäärityksien kanssa. Väitöskirjatyössäni osoitin, että UCP-teknologia soveltuu sekä oligonukleotidi- että proteiini-pohjaisten monianalyyttimääritysten kvantitatiiviseen kuvantamiseen.Siirretty Doriast

    Design, development and characterization of a novel neutron and X-ray combined computed tomography system

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    Visualizing the three dimensional structure of objects (e.g. nuclear fuel, nuclear materials, explosives and bio materials) and phenomena (e.g. particle tracking) can be very important in nondestructive testing applications. Computed tomography systems are indispensable tools for these types of applications because they provide a versatile non-destructive technique for analysis. A novel neutron and X-ray combined computed tomography (NXCT) system has been designed and developed at the Missouri University of Science & Technology. The neutron and X-ray combined computed tomography system holds much promise for non-destructive material detection and analysis where multiple materials having similar atomic number and differing thermal cross section or vice versa may be present within an object, exclusive neutron or X-ray analysis may exhibit shortcomings in distinguishing interfaces. However, fusing neutron image and X-ray image offers the strengths of both and may provide a superior method of analysis. In addition, a feasible design of a sample positioning system which allows the user to remotely and automatically manipulate the objects makes the NXCT system viable for commercial applications. Moreover, characterization of the newly developed digital imaging system is imperative to the performance evaluation, as well as for describing the associated parameters. The performance of a combined neutron/X-ray digital imaging system was evaluated in terms of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE). This dissertation is a complete overview of the design of the NXCT system, operation, algorithms, performance evaluation and results --Abstract, page iii
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