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Sample records for chemiluminescent membrane array

  1. Large scale biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg

    2009-01-01

    To establish planar biomimetic membranes across large scale partition aperture arrays, we created a disposable single-use horizontal chamber design that supports combined optical-electrical measurements. Functional lipid bilayers could easily and efficiently be established across CO2 laser micro...... peptides and proteins. Next, we tested the scalability of the biomimetic membrane design by establishing lipid bilayers in rectangular 24 x 24 and hexagonal 24 x 27 aperture arrays, respectively. The results presented show that the design is suitable for further developments of sensitive biosensor assays...

  2. Multiplex chemiluminescent immunoassay for screening of mycotoxins using photonic crystal microsphere suspension array.

    Science.gov (United States)

    Xu, Kun; Sun, Yue; Li, Wei; Xu, Jie; Cao, Bin; Jiang, Yunkun; Zheng, Tiesong; Li, Jianlin; Pan, Daodong

    2014-02-21

    A novel multiplex chemiluminescent mycotoxin immunoassay suspension array system was developed by combining the silica photonic crystal microspheres (SPCMs) encoding technique and a chemiluminescent immunoassay (CLIA) method. The SPCMs were used as a carrier of the suspension array and encoded by their reflectance peak positions, which overcome fluorescence photobleaching, and the potential interference between the encoding fluorescence and detection fluorescence. Aflatoxin B1 (AFB1), fumonisin B1 (FB1) and ochratoxin A (OTA) artificial antigens were immobilized on the surfaces of SPCMs by using 3-glycidoxypropyltrimethoxysilane as a linker. Horseradish peroxidase (HRP) was used as a labeling enzyme for the secondary antibody in the enzyme-catalyze H2O2-luminol chemiluminescence system. The CLIA detection system was easily integrated with a multifunctional microplate reader and displayed a two to three orders of magnitude dynamic linear detection range from 0.001 to 1, 0.001 to 1, and 0.01 to 1 ng mL(-1) for AFB1, FB1 and OTA with 50% inhibitory concentrations (IC50) of 0.01, 0.036, and 0.04 ng mL(-1), respectively. The recovery rates are in the range of 63.5 to 121.6% for the three mycotoxins in three kinds of spiked cereal samples. The results of detection in 12 naturally contaminated cereal samples were consistent with that of the classic enzyme-linked immunosorbent assay (ELISA) method. This proposed system is simple, rapid, low cost and high throughput for multiplex mycotoxin assay.

  3. Rapid detection of fluorescent and chemiluminescent total coliforms and Escherichia coli on membrane filters.

    Science.gov (United States)

    Van Poucke, S O; Nelis, H J

    2000-11-01

    The detection of fluorescent colonies of Escherichia coli/total coliforms (TC) on a membrane filter is currently carried out using 4-methylumbelliferyl-beta-D-glycosides as enzyme substrates and a UV-lamp for visualization. The most rapid procedures based on this approach for the demonstration of these indicator bacteria in water take 6-7.5 h to complete. As part of efforts to further reduce the detection time, an improved two-step procedure for the fluorescence or chemiluminescence labelling of microcolonies of E. coli/TC on a membrane filter has been developed. Essential features of this approach include a separation of the bacterial propagation and target enzyme induction from the actual enzymatic labelling, the use of improved fluorogenic, i.e., 4-trifluoromethylumbelliferyl-beta-D-glycosides and fluorescein-di-beta-D-glycosides, or chemiluminogenic (i.e., phenylglucuronic- or galactose-substituted adamantyl 1,2-dioxetanes) substrates for beta-glucuronidase/beta-galactosidase, of enzyme inducers, of special membrane filters and of polymyxin B to promote the cellular uptake of the substrate. This labelling procedure has been applied in conjunction with different detection devices including a UV-lamp, CCD-cameras, X-ray film and the ChemScan((R)) RDI. Using the former three, microcolonies of pure cultures could be detected within 5.5-6.5 h, but waterborne E. coli/TC may fail to form microcolonies in this short time period, thus yielding poor sensitivity and a high false-negative rate. In contrast, a quantitative enumeration was feasible in less than 4 h with the ChemScan((R)) RDI, owing to its ability to detect both microcolonies and non-dividing single cells.

  4. Chemiluminescence lateral flow immunoassay cartridge with integrated amorphous silicon photosensors array for human serum albumin detection in urine samples.

    Science.gov (United States)

    Zangheri, Martina; Di Nardo, Fabio; Mirasoli, Mara; Anfossi, Laura; Nascetti, Augusto; Caputo, Domenico; De Cesare, Giampiero; Guardigli, Massimo; Baggiani, Claudio; Roda, Aldo

    2016-12-01

    A novel and disposable cartridge for chemiluminescent (CL)-lateral flow immunoassay (LFIA) with integrated amorphous silicon (a-Si:H) photosensors array was developed and applied to quantitatively detect human serum albumin (HSA) in urine samples. The presented analytical method is based on an indirect competitive immunoassay using horseradish peroxidase (HRP) as a tracer, which is detected by adding the luminol/enhancer/hydrogen peroxide CL cocktail. The system comprises an array of a-Si:H photosensors deposited on a glass substrate, on which a PDMS cartridge that houses the LFIA strip and the reagents necessary for the CL immunoassay was optically coupled to obtain an integrated analytical device controlled by a portable read-out electronics. The method is simple and fast with a detection limit of 2.5 mg L -1 for HSA in urine and a dynamic range up to 850 mg L -1 , which is suitable for measuring physiological levels of HSA in urine samples and their variation in different diseases (micro- and macroalbuminuria). The use of CL detection allowed accurate and objective analyte quantification in a dynamic range that extends from femtomoles to picomoles. The analytical performances of this integrated device were found to be comparable with those obtained using a charge-coupled device (CCD) as a reference off-chip detector. These results demonstrate that integrating the a-Si:H photosensors array with CL-LFIA technique provides compact, sensitive and low-cost systems for CL-based bioassays with a wide range of applications for in-field and point-of-care bioanalyses. Graphical Abstract A novel integrated portable device was developed for direct quantitative detection of human serum albumin (HSA) in urine samples, exploiting a chemiluminescence lateral flow immunoassay (LFIA). The device comprises a cartridge that holds the LFIA strip and all the reagents necessary for the analysis, an array of amorphous silicon photosensors, and a custom read-out electronics.

  5. Surface Modifications of Support Partitions for Stabilizing Biomimetic Membrane Arrays

    DEFF Research Database (Denmark)

    Perry, Mark; Hansen, Jesper Schmidt; Jensen, Karin Bagger Stibius

    2011-01-01

    Black lipid membrane (BLM) formation across apertures in an ethylene tetra-fluoroethylene (ETFE) partition separating two aqueous compartments is an established technique for the creation of biomimetic membranes. Recently multi-aperture BLM arrays have attracted interest and in order to increase...... with a high signal-to-noise (s/n) ratio. We demonstratesd this by reconstituting gA and α-hemolysin (α-HL) into BLM arrays. The improvement in membrane array lifetime and s/n ratio demonstrates that surface plasma polymerization of the supporting partition can be used to increase the stability of biomimetic...

  6. Biomimetic Membrane Arrays on Cast Hydrogel Supports

    DEFF Research Database (Denmark)

    Roerdink-Lander, Monique; Ibragimova, Sania; Rein Hansen, Christian

    2011-01-01

    Lipid bilayers are intrinsically fragile and require mechanical support in technical applications based on biomimetic membranes. Tethering the lipid bilayer membranes to solid substrates, either directly through covalent or ionic substrate−lipid links or indirectly on substrate-supported cushions......, provides mechanical support but at the cost of small molecule transport through the membrane−support sandwich. To stabilize biomimetic membranes while allowing transport through a membrane−support sandwich, we have investigated the feasibility of using an ethylene tetrafluoroethylene (ETFE...

  7. Hydrogels for in situ encapsulation of biomimetic membrane arrays

    DEFF Research Database (Denmark)

    Ibragimova, Sania; Jensen, Karin Bagger Stibius; Szewczykowski, Piotr Przemyslaw

    2012-01-01

    Hydrogels are hydrophilic, porous polymer networks that can absorb up to thousands of times their own weight in water. They have many potential applications, one of which is the encapsulation of freestanding black lipid membranes (BLMs) for novel separation technologies or biosensor applications....... membranes retained their integrity and functionality after encapsulation with hydrogel. Our results show that hydrogel encapsulation is a potential means to provide stability for biomimetic devices based on functional proteins reconstituted in biomimetic membrane arrays....

  8. Large-Aperture Membrane Active Phased-Array Antennas

    Science.gov (United States)

    Karasik, Boris; McGrath, William; Leduc, Henry

    2009-01-01

    Large-aperture phased-array microwave antennas supported by membranes are being developed for use in spaceborne interferometric synthetic aperture radar systems. There may also be terrestrial uses for such antennas supported on stationary membranes, large balloons, and blimps. These antennas are expected to have areal mass densities of about 2 kg/sq m, satisfying a need for lightweight alternatives to conventional rigid phased-array antennas, which have typical areal mass densities between 8 and 15 kg/sq m. The differences in areal mass densities translate to substantial differences in total mass in contemplated applications involving aperture areas as large as 400 sq m. A membrane phased-array antenna includes patch antenna elements in a repeating pattern. All previously reported membrane antennas were passive antennas; this is the first active membrane antenna that includes transmitting/receiving (T/R) electronic circuits as integral parts. Other integral parts of the antenna include a network of radio-frequency (RF) feed lines (more specifically, a corporate feed network) and of bias and control lines, all in the form of flexible copper strip conductors on flexible polymeric membranes. Each unit cell of a prototype antenna (see Figure 1) contains a patch antenna element and a compact T/R module that is compatible with flexible membrane circuitry. There are two membrane layers separated by a 12.7-mm air gap. Each membrane layer is made from a commercially available flexible circuit material that, as supplied, comprises a 127-micron-thick polyimide dielectric layer clad on both sides with 17.5-micron-thick copper layers. The copper layers are patterned into RF, bias, and control conductors. The T/R module is located on the back side of the ground plane and is RF-coupled to the patch element via a slot. The T/R module is a hybrid multilayer module assembled and packaged independently and attached to the membrane array. At the time of reporting the information for

  9. Biomimetic triblock copolymer membrane arrays: a stable template for functional membrane proteins

    DEFF Research Database (Denmark)

    Gonzalez-Perez, A.; Jensen, Karin Bagger Stibius; Vissing, Thomas

    2009-01-01

    It is demonstrated that biomimetic stable triblock copolymer membrane arrays can be prepared using a scaffold containing 64 apertures of 300 μm diameter each. The membranes were made from a stock solution of block copolymers with decane as a solvent using a new deposition method. By using decane...

  10. Membrane-Assisted Growth of DNA Origami Nanostructure Arrays

    Science.gov (United States)

    2015-01-01

    Biological membranes fulfill many important tasks within living organisms. In addition to separating cellular volumes, membranes confine the space available to membrane-associated proteins to two dimensions (2D), which greatly increases their probability to interact with each other and assemble into multiprotein complexes. We here employed two DNA origami structures functionalized with cholesterol moieties as membrane anchors—a three-layered rectangular block and a Y-shaped DNA structure—to mimic membrane-assisted assembly into hierarchical superstructures on supported lipid bilayers and small unilamellar vesicles. As designed, the DNA constructs adhered to the lipid bilayers mediated by the cholesterol anchors and diffused freely in 2D with diffusion coefficients depending on their size and number of cholesterol modifications. Different sets of multimerization oligonucleotides added to bilayer-bound origami block structures induced the growth of either linear polymers or two-dimensional lattices on the membrane. Y-shaped DNA origami structures associated into triskelion homotrimers and further assembled into weakly ordered arrays of hexagons and pentagons, which resembled the geometry of clathrin-coated pits. Our results demonstrate the potential to realize artificial self-assembling systems that mimic the hierarchical formation of polyhedral lattices on cytoplasmic membranes. PMID:25734977

  11. Membrane-assisted growth of DNA origami nanostructure arrays.

    Science.gov (United States)

    Kocabey, Samet; Kempter, Susanne; List, Jonathan; Xing, Yongzheng; Bae, Wooli; Schiffels, Daniel; Shih, William M; Simmel, Friedrich C; Liedl, Tim

    2015-01-01

    Biological membranes fulfill many important tasks within living organisms. In addition to separating cellular volumes, membranes confine the space available to membrane-associated proteins to two dimensions (2D), which greatly increases their probability to interact with each other and assemble into multiprotein complexes. We here employed two DNA origami structures functionalized with cholesterol moieties as membrane anchors--a three-layered rectangular block and a Y-shaped DNA structure--to mimic membrane-assisted assembly into hierarchical superstructures on supported lipid bilayers and small unilamellar vesicles. As designed, the DNA constructs adhered to the lipid bilayers mediated by the cholesterol anchors and diffused freely in 2D with diffusion coefficients depending on their size and number of cholesterol modifications. Different sets of multimerization oligonucleotides added to bilayer-bound origami block structures induced the growth of either linear polymers or two-dimensional lattices on the membrane. Y-shaped DNA origami structures associated into triskelion homotrimers and further assembled into weakly ordered arrays of hexagons and pentagons, which resembled the geometry of clathrin-coated pits. Our results demonstrate the potential to realize artificial self-assembling systems that mimic the hierarchical formation of polyhedral lattices on cytoplasmic membranes.

  12. Microtube array membrane bioreactor promotes neuronal differentiation and orientation.

    Science.gov (United States)

    Morelli, Sabrina; Piscioneri, Antonella; Salerno, Simona; Chen, Chien-Chung; Chew, Chee Ho; Giorno, Lidietta; Drioli, Enrico; De Bartolo, Loredana

    2017-05-17

    An important challenge in neuronal tissue engineering is to create innovative tools capable of promoting cellular response in terms of neuronal differentiation and neurite orientation that may be used as investigational platforms for studying neurobiological events and neurodegenerative disorders. A novel membrane bioreactor was created to provide a 3D well-controlled microenvironment for neuronal outgrowth. The bioreactor consisted of poly-L-lactic acid highly aligned microtube array (PLLA-MTA) membranes assembled in parallel within a chamber that establish an intraluminal and an extraluminal compartment whose communication occurs through the pores of the MTA membrane walls. The bioreactor configuration provided a wide surface area for cell adhesion in a small volume, and offered a peculiar arrangement that directed neuronal orientation. The combination of an appropriate membrane porosity, pore interconnectivity and very thin walls ensured optimal indirect perfusion to cell compartment, and enhanced the mass transfer of metabolites and catabolites protecting neurons from shear stress. The PLLA-MTA membrane bioreactor promoted the growth and differentiation of SH-SY5Y cells toward a neuronal phenotype, and guided neurite alignment giving rise to a 3D neuronal tissue-like construct. It provides an innovative platform to study neurobiological phenomena in vitro and by guiding neuronal orientation for repair and/or regeneration.

  13. Ultra-high Performance Liquid Chromatography with Photodiode Array and Chemiluminescence Detection for the Determination of Polyphenolic Antioxidants in Erigeron acris L. Extracts.

    Science.gov (United States)

    Malejko, Julita; Nalewajko-Sieliwoniuk, Edyta; Szabuńko, Julia; Nazaruk, Jolanta

    2016-09-01

    The quality of herbs is directly related to the presence of polyphenolic antioxidants. This is the first report on the quantification of individual polyphenolic constituents of Erigeron acris L. To develop a new method using ultra-high performance liquid chromatography with photodiode array and chemiluminescence (UHPLC-PDA-CL) detection for the separation and determination of polyphenols in Erigeron acris extracts. The methanolic extracts from leaves and inflorescences of Erigeron acris were prepared by ultrasound assisted extraction. The chromatographic separation was performed on C18 column packed with 1.7-μm particles. The post-column CL detection was based on the enhancing effect of polyphenols on the CL generated in manganese(IV)-hexametaphosphate-formaldehyde system. The UHPLC method allowed to separate polyphenols in a short running time (13 min), which was three times shorter compared with traditional HPLC. The CL detection was characterised by 6-48 times higher sensitivity and up to three times lower detection limits compared to PDA detection. Qualitative and quantitative differences were observed in polyphenolic composition of Erigeron acris extracts. The main components of leaves were scutellarin and chlorogenic acid, whereas in inflorescences quercetin 3-O-glucoside was predominant. Coupling of UHPLC with CL detection has been developed for the first time. This advanced chromatographic technique coupled with sensitive CL detection is a powerful approach for the investigation of polyphenolic profiles in natural products. The shorter analysis time and diminished waste generation makes the UHPLC method more environmentally friendly and more cost-effective in comparison with conventional HPLC. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Chemiluminescence by polymorphonuclear leukocytes adhering to surfaces.

    OpenAIRE

    Yanai, M.; Quie, P. G.

    1981-01-01

    Stimulation of the plasma membranes of granulocytes results in an oxidative metabolic response. This response can be measured by measuring the reduction of oxidizable substrates, such as Nitro Blue Tetrazolium, as well as by measuring the energy released as light (chemiluminescence). While investigating the oxidative response of human granulocytes, we observed a marked variation in the chemiluminescence response when leukocytes were suspended in a balanced salt solution without gelatin or any...

  15. A novel array of chemiluminescence sensors for sensitive, rapid and high-throughput detection of explosive triacetone triperoxide at the scene.

    Science.gov (United States)

    Li, Xiaohua; Zhang, Zhujun; Tao, Liang

    2013-09-15

    Triacetone triperoxide (TATP) is relatively easy to make and has been used in various terrorist acts. Early but easy detection of TATP is highly desired. We designed a new type sensor array for H2O2. The unique CL sensor array was based on CeO2 nanoparticles' membranes, which have an excellent catalytic effect on the luminol-H2O2 CL reaction in alkaline medium. It exhibits a linear range for the detection of H2O2 from 1.0×10(-8) to 5.0×10(-5)M (R(2)=0.9991) with a 1s response time. The detection limit is 1.0×10(-9)M. Notably, the present approach allows the design of CL sensor array assays in a more simple, time-saving, long-lifetime, high-throughput, and economical approach when compared with conventional CL sensor. It is conceptually different from conventional CL sensor assays. The novel sensor array has been successfully applied for the detection of TATP at the scene. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. HKUST-1 Membranes Anchored on Porous Substrate by Hetero MIL-110 Nanorod Array Seeds.

    Science.gov (United States)

    Mao, Yiyin; Cao, Wei; Li, Junwei; Sun, Luwei; Peng, Xinsheng

    2013-09-02

    Great anchors and seeds: Hetero-seeding growth processes and anchored nanorod arrays were successfully utilized in the synthesis of HKUST-1 membranes. These arrays were firmly anchored on porous substrates by using a MIL-110 nanorod array as both the anchor and seed. The resulting HKUST-1 membranes demonstrated good separation factors for binary gases exceeding the Knudson selectivity. Copyright © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Assessing the efficacy of vesicle fusion with planar membrane arrays using a mitochondrial porin as reporter

    DEFF Research Database (Denmark)

    Pszon-Bartosz, Kamila Justyna; Hansen, Jesper S.; Stibius, Karin B.

    2011-01-01

    establish a protein incorporation efficacy assay using the major non-specific porin of Fusobacterium nucleatum (FomA) as reporter. We use electrical conductance measurements and fluorescence microscopy to characterize proteoliposome fusion with an array of planar membranes. We show that protein...... in a bilayer array with a total membrane area of 2mm2 within 20min. This novel assay for quantifying protein delivery into lipid bilayers may be a useful tool in developing biomimetic membrane applications....

  18. Ceramic oxygen transport membrane array reactor and reforming method

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Sean M.; Christie, Gervase Maxwell; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.

    2016-11-08

    The invention relates to a commercially viable modular ceramic oxygen transport membrane reforming reactor configured using repeating assemblies of oxygen transport membrane tubes and catalytic reforming reactors.

  19. Ceramic oxygen transport membrane array reactor and reforming method

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Sean M.; Christie, Gervase Maxwell; Rosen, Lee J.; Robinson, Charles; Wilson, Jamie R.; Gonzalez, Javier E.; Doraswami, Uttam R.

    2016-09-27

    A commercially viable modular ceramic oxygen transport membrane reforming reactor for producing a synthesis gas that improves the thermal coupling of reactively-driven oxygen transport membrane tubes and catalyst reforming tubes required to efficiently and effectively produce synthesis gas.

  20. Array of planar membrane modules for producing hydrogen

    Science.gov (United States)

    Vencill, Thomas R [Albuquerque, NM; Chellappa, Anand S [Albuquerque, NM; Rathod, Shailendra B [Hillsboro, OR

    2012-05-08

    A shared or common environment membrane reactor containing a plurality of planar membrane modules with top and bottom thin foil membranes supported by both an intermediary porous support plate and a central base which has both solid extended members and hollow regions or a hollow region whereby the two sides of the base are in fluid communication. The membrane reactor operates at elevate temperatures for generating hydrogen from hydrogen rich feed fuels.

  1. Super-resolution imaging of aquaporin-4 orthogonal arrays of particles in cell membranes

    National Research Council Canada - National Science Library

    Rossi, Andrea; Moritz, Tobias J; Ratelade, Julien; Verkman, A S

    2012-01-01

    Aquaporin-4 (AQP4) is a water channel expressed in astrocytes, skeletal muscle and epithelial cells that forms supramolecular aggregates in plasma membranes called orthogonal arrays of particles (OAPs...

  2. Freestanding membrane composed of micro-ring array with ultrahigh sidewall aspect ratio for application in lightweight cathode arrays

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lanlan [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Liu, Hongzhong, E-mail: hzliu@mail.xjtu.edu.cn [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Jiang, Weitao, E-mail: wtjiang@mail.xjtu.edu.cn [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Gao, Wei [Key Laboratory of Mechanics on Western Disasters and Environment, Lanzhou University, Lanzhou 730000 (China); Chen, Bangdao [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Li, Xin [Department of Microelectronics, Xi’an Jiaotong University, Xi’an 710049 (China); Ding, Yucheng [State Key Laboratory for Manufacturing Systems Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); An, Ningli [Department of Packaging Engineering, Xi’an University of Technology, Xi’an 710048 (China)

    2014-12-15

    Graphical abstract: A freestanding multilayer ultrathin nano-membrane (FUN-membrane) with a micro-ring array (MRA), in which the dimension of each micro-ring is 3 μm in diameter, 2 μm in height and sub-100 nm in sidewall thickness is successfully fabricated, as shown in the SEM image of figure (a). Due to the MRA with ultrahigh aspect ratio of dielectric-metal sidewall, the FUN-membrane can be transferred to either rigid or flexible substrate to be used as the cathode for lightweight display panel, as shown in the schematic of figure (b). - Highlights: • Exploring a new fabrication method for the freestanding ultrathin nano-membrane (FUN-membrane). • FUN-membrane is composed of micro-ring array with ultrahigh aspect ratio of the insulator-metal sidewall. • The sharp metal edge of each micro-ring is preferred to be served as the micro-emitter. - Abstract: A freestanding multilayer ultrathin nano-membrane (FUN-membrane) with a micro-ring array (MRA) is successfully fabricated through the controllable film deposition. Each micro-ring of FUN-membrane is 3 μm in diameter, 2 μm in height and sub-100 nm in sidewall thickness, demonstrating an ultrahigh sidewall aspect ratio of 20:1. In our strategy, a silica layer (200 nm in thickness), a chromium transition layer (5 nm-thick) and a gold layer (40 nm-thick), were in sequence deposited on patterned photoresist. After removal of the photoresist by lift-off process, a FUN-membrane with MRA was peeled off from the substrate, where the gold layer acted as a protecting layer to prevent the MRA from fracture. The FUN-membrane was then transferred to a flexible polycarbonate (PC) sheet coated with indium tin oxide (ITO) layer, which was then used as a flexible and lightweight cathode. Remarkably, the field emission effect of the fabricated FUN-membrane cathode performs a high field-enhancement factor of 1.2 × 10{sup 4} and a low turn-on voltage of 2 V/μm, indicating the advantages of the sharp metal edge of MRA. Due

  3. Ceramic oxygen transport membrane array reactor and reforming method

    Science.gov (United States)

    Kelly, Sean M.; Christie, Gervase Maxwell; Robinson, Charles; Wilson, Jamie R; Gonzalez, Javier E.; Doraswami, Uttam R.

    2017-10-03

    The invention relates to a commercially viable modular ceramic oxygen transport membrane system for utilizing heat generated in reactively-driven oxygen transport membrane tubes to generate steam, heat process fluid and/or provide energy to carry out endothermic chemical reactions. The system provides for improved thermal coupling of oxygen transport membrane tubes to steam generation tubes or process heater tubes or reactor tubes for efficient and effective radiant heat transfer.

  4. CHEMILUMINESCENCE ON OXIDE SURFACE

    OpenAIRE

    L. I. IVANKIV; O. V. DZYUPYN; Balitskii, O. A.

    2008-01-01

    This paper describes the oxygen adsorption properties on magnesium oxide surface. The results are compared with theoretical adsorption kinetics. Temperature and time dependences of adsorption mechanisms and chemiluminescence are discussed.

  5. Multichannel Discriminative Detection of Explosive Vapors with an Array of Nanofibrous Membranes Loaded with Quantum Dots

    Science.gov (United States)

    Wu, Zhaofeng; Duan, Haiming; Li, Zhijun; Guo, Jixi; Zhong, Furu; Cao, Yali; Jia, Dianzeng

    2017-01-01

    The multichannel fluorescent sensor array based on nanofibrous membranes loaded with ZnS quantum dots (QDs) was created and demonstrated for the discriminative detection of explosives. The synergistic effect of the high surface-to-volume ratio of QDs, the good permeability of nanofibrous membranes and the differential response introduced by surface ligands was played by constructing the sensing array using nanofibrous membranes loaded with ZnS QDs featuring several surface ligands. Interestingly, although the fluorescence quenching of the nanofibrous membranes is not linearly related to the exposure time, the fingerprint of each explosive at different times is very similar in shape, and the fingerprints of the three explosives show different shapes. Three saturated vapors of nitroaromatic explosives could be reliably detected and discriminated by the array at room temperature. This work is the first step toward devising a monitoring system for explosives in the field of public security and defense. It could, for example, be coupled with the technology of image recognition and large data analysis for a rapid diagnostic test of explosives. This work further highlights the power of differential, multichannel arrays for the rapid and discriminative detection of a wide range of chemicals. PMID:29156627

  6. Multichannel Discriminative Detection of Explosive Vapors with an Array of Nanofibrous Membranes Loaded with Quantum Dots

    Directory of Open Access Journals (Sweden)

    Zhaofeng Wu

    2017-11-01

    Full Text Available The multichannel fluorescent sensor array based on nanofibrous membranes loaded with ZnS quantum dots (QDs was created and demonstrated for the discriminative detection of explosives. The synergistic effect of the high surface-to-volume ratio of QDs, the good permeability of nanofibrous membranes and the differential response introduced by surface ligands was played by constructing the sensing array using nanofibrous membranes loaded with ZnS QDs featuring several surface ligands. Interestingly, although the fluorescence quenching of the nanofibrous membranes is not linearly related to the exposure time, the fingerprint of each explosive at different times is very similar in shape, and the fingerprints of the three explosives show different shapes. Three saturated vapors of nitroaromatic explosives could be reliably detected and discriminated by the array at room temperature. This work is the first step toward devising a monitoring system for explosives in the field of public security and defense. It could, for example, be coupled with the technology of image recognition and large data analysis for a rapid diagnostic test of explosives. This work further highlights the power of differential, multichannel arrays for the rapid and discriminative detection of a wide range of chemicals.

  7. Analysis of Protein Interactions with Immobilized Peptide Arrays Synthesized on Membrane Supports

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Ronald Frank and Stefan Dübel This protocol was adapted from “Analysis of Protein Interactions with Immobilized Peptide Arrays Synthesized on Membrane Supports,” contributed by Ronald Frank and Stefan Dübel, Chapter 31, in [*Protein-Protein Interactions*, ](http://www.cshlpress.com/link/protpro2p.htm)2nd edition (eds. Golemis and Adams). Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY, USA, 2005. ### INTRODUCTION The following protocol describes the synt...

  8. Piezoelectric performance of continuous beam and narrow supported beam arrays for artificial basilar membranes

    Science.gov (United States)

    Song, Won Joon; Jang, Jongmoon; Kim, Sangwon; Choi, Hongsoo

    2014-09-01

    We report an experimental assessment of the electrical performance of two piezoelectric beam arrays for artificial basilar membranes (ABMs): a continuous beam array (CBA) and a narrow-supports beam array (NSBA). Both arrays consist of piezoelectric beams of sequentially varying lengths that mimic the frequency selectivity of mammalian cochleae. The narrow supports of the NSBA resulted in lateral deformation of the beams, whereas the CBA beams were flat. The displacement and piezoelectric output of each beam were measured at the resonance frequency of each beam using a scanning laser-Doppler vibrometer (SLDV). Both ABM prototypes showed mechanical frequency selectivity that depended on the beam length. The CBA generated a piezoelectric output in the range 6.6-23.2 μV and exhibited electrical frequency separability, whereas the NSBA failed to generate sufficient electrical potential due to the lateral deformation of the piezoelectric beams. The CBA was found to be more effective as an ABM, with potential for use in cochlear implants.

  9. Protein Array-Based Detection of Proteins in Kidney Tissues from Patients with Membranous Nephropathy

    Directory of Open Access Journals (Sweden)

    Shuqiang Wang

    2017-01-01

    Full Text Available Membranous nephropathy (MN is an autoimmune inflammatory disease in which proteins related with plenty of biological processes play an important role. However, the role of these proteins in the pathogenesis of MN is still unclear. This study aimed to screen differential proteins in kidney tissue samples from MN patients by using protein arrays and determine the pathways involved in the pathogenesis of MN. This study first tested a quantitative protein array (QAH-INF-3 and two semiquantitative protein arrays (L-493 and L-507 with normal renal tissue and identified L-493 as the most appropriate assay to compare protein levels between MN tissues and normal control tissues. The L-493 array identified 66 differentially expressed proteins (DEPs that may be associated with MN. The gene oncology (GO and protein-protein interaction (PPI analyses revealed several processes potentially involved in MN, including extracellular matrix disassembly and organization, cell adhesion, cell-cell signaling, cellular protein metabolic process, and immune response (P<0.05. We suggest that these different pathways work together via protein signaling and result in the pathogenesis and progression of MN.

  10. Multilayered membranes with tuned well arrays to be used as regenerative patches.

    Science.gov (United States)

    Martins, Nádia I; Sousa, Maria P; Custódio, Catarina A; Pinto, Vânia C; Sousa, Paulo J; Minas, Graça; Cleymand, Franck; Mano, João F

    2017-07-15

    Membranes have been explored as patches in tissue repair and regeneration, most of them presenting a flat geometry or a patterned texture at the nano/micrometer scale. Herein, a new concept of a flexible membrane featuring well arrays forming pore-like environments to accommodate cell culture is proposed. The processing of such membranes using polysaccharides is based on the production of multilayers using the layer-by-layer methodology over a patterned PDMS substrate. The detached multilayered membrane exhibits a layer of open pores at one side and a total thickness of 38±2.2µm. The photolithography technology used to produce the molds allows obtaining wells on the final membranes with a tuned shape and micro-scale precision. The influence of post-processing procedures over chitosan/alginate films with 100 double layers, including crosslinking with genipin or fibronectin immobilization, on the adhesion and proliferation of human osteoblast-like cells is also investigated. The results suggest that the presence of patterned wells affects positively cell adhesion, morphology and proliferation. In particular, it is seen that cells colonized preferentially the well regions. The geometrical features with micro to sub-millimeter patterned wells, together with the nano-scale organization of the polymeric components along the thickness of the film will allow to engineer highly versatile multilayered membranes exhibiting a pore-like microstructure in just one of the sides, that could be adaptable in the regeneration of multiple tissues. Flexible multilayered membranes containing multiple micro-reservoirs are found as potential regenerative patches. Layer-by-layer (LbL) methodology over a featured PDMS substrate is used to produce patterned membranes, composed only by natural-based polymers, that can be easily detached from the PDMS substrate. The combination of nano-scale control of the polymeric organization along the thickness of the chitosan/alginate (CHT

  11. Nanochannel arrays as supports for proton exchange membranes in microfluidic fuel cells

    Science.gov (United States)

    Wadsworth, Chandelle J.; Yanagisawa, Naoki; Dutta, Debashis

    In this article, we report the use of nanochannel arrays as supports for proton exchange membranes in microfluidic fuel cells. The proposed design has been demonstrated by fabricating a sodium silicate based sol-gel structure within such an array bridging two microchannels containing the fuel (HCOOH) and the oxidant (KMnO 4) streams. A voltage was generated in this system by bringing two platinum electrodes in contact with these solutions and then connecting them through an external circuitry. With this current design, we have been able to generate an open circuit potential of 1.31 V and a maximum current of 31.2 μA at 25 °C.

  12. Quantification of chemical mixture interactions modulating dermal absorption using a multiple membrane fiber array.

    Science.gov (United States)

    Baynes, Ronald E; Xia, Xin Rui; Imran, Mudassar; Riviere, Jim E

    2008-03-01

    Dermal exposures to chemical mixtures can potentially increase or decrease systemic bioavailability of toxicants in the mixture. Changes in dermal permeability can be attributed to changes in physicochemical interactions between the mixture, the skin, and the solute of interest. These physicochemical interactions can be described as changes in system coefficients associated with molecular descriptors described by Abraham's linear solvation energy relationship (LSER). This study evaluated the effects of chemical mixtures containing either a solvent (ethanol) or a surfactant (sodium lauryl sulfate, SLS) on solute permeability and partitioning by quantifying changes in system coefficients in skin and a three-membrane-coated fiber (MCF) system, respectively. Regression analysis demonstrated that changes in system coefficients in skin were strongly correlated ( R2 = 0.89-0.98) to changes in system coefficients in the three-membrane MCF array with mixtures containing either 1% SLS or 50% ethanol. The PDMS fiber appeared to play a significant role (R2 = 0.84-0.85) in the MCF array in predicting changes in solute permeability, while the WAX fiber appeared to contribute less (R2 = 0.59-0.77) to the array than the other two fibers. On the basis of changes in system coefficients that are part of a LSER, these experiments were able to link physicochemical interactions in the MCF with those interactions in skin when either system is exposed to 1% SLS or 50% ethanol. These experiments further demonstrated the utility of a MCF array to adequately predict changes in dermal permeability when skin is exposed to mixtures containing either a surfactant or a solvent and provide some insight into the nature of the physiochemical interactions that modulate dermal absorptions.

  13. Selective growth and piezoelectric properties of highly ordered arrays of vertical ZnO nanowires on ultrathin alumina membranes

    Science.gov (United States)

    Wen, Liaoyong; Shao, Zhengzheng; Fang, Yaoguo; Wong, Kin Mun; Lei, Yong; Bian, Lifeng; Wilde, Gerhard

    2010-08-01

    A well controlled and cost effective method of fabricating highly ordered arrays of vertical zinc oxide (ZnO) nanowires or nanopores is demonstrated where an ultrathin alumina membrane (UTAM) itself is utilized as a substrate for the selective growth of the ordered arrays. A thin film of gold was thermally evaporated on the UTAM followed by the growth of highly regular ZnO nanowires using chemical vapor deposition (CVD). Alternatively, highly ordered ZnO nanopores arrays were also grown by CVD on the bare UTAM. Additionally, piezoelectric currents were generated from the ZnO nanowires during the conductive atomic force microscopy probe tip scan across the array.

  14. Simulations for membrane-based HEB mixers in array configuration for SHAHIRA

    Science.gov (United States)

    Baubert, Jean; Salez, Morvan; Merkel, Harald F.; Pons, Patrick; Delorme, Yan; Lecomte, Benoit

    2004-10-01

    We present in this paper the front-end design and the results of RF simulations, carried out with Microwave Studio (CST) and HFSS for SHAHIRA (Submillimeter Heterodyne Array for High-speed Radio Astronomy), a 4x4 heterodyne array at 2.5 THz and 4.7 THz. One can then observe 16 spatial positions at 2 frequencies. The design has been chosen to be quasi-optic, because of its simplicity, novelty and multi-pixels applicability. Pixels are made of Niobium Nitride HEB mixers with double-slot antennas, processed on 1 μm thick stress-less Si3N4/SiO2 membrane. The use of the membrane shows numerous advantages: for instance the use of the mixers at higher RF frequencies, a better power coupling efficiency or a solution for avoiding dielectric modes, losses and reflections. This work is supported by ESA and is a collaboration between LERMA, CHALMERS and LAAS. The Camera is expected to find applications, for SOFIA or CIDRE.

  15. Mechanical frequency selectivity of an artificial basilar membrane using a beam array with narrow supports

    Science.gov (United States)

    Kim, Sangwon; Song, Won Joon; Jang, Jongmoon; Jang, Jeong Hun; Choi, Hongsoo

    2013-09-01

    The study presented in this paper assessed the frequency selectivity of an artificial basilar membrane (ABM) constructed using a piezoelectric beam array with narrow supports. Three ABM samples were constructed. Each ABM contained 16 beams with various lengths in a one-dimensional array. To experimentally assess the frequency selectivity of the ABM, mechanical vibration induced either by an electrical or an acoustic stimulus was measured with a scanning laser-Doppler vibrometer. The electro-mechanical and acousto-mechanical transfer functions were defined for the same purpose. The tonotopy of each beam array was visualized by post-processing the experimental results. Finite element analyses were conducted to numerically compute the resonance frequencies, identify the associated vibrational modes, and evaluate the harmonic responses of the beams. The influence of the residual stresses existing in the beams was reflected in the geometric models by introducing three different levels of arc-shaped lateral deformations in the beams. The harmonic analyses revealed that each beam of the ABM samples presented independent band-pass characteristics. The experiments and simulations commonly showed a frequency selectivity of the fabricated ABMs in the range of 2-20 kHz. Therefore, the device is suitable for development of a totally implantable artificial cochlea, implementing a mechanical frequency analyzer. This work is part of research to develop a prototype of a totally implantable artificial cochlea.

  16. Fabrication of Core-Shell Nanotube Array for Artificial Photosynthesis Featuring an Ultrathin Composite Separation Membrane.

    Science.gov (United States)

    Edri, Eran; Aloni, Shaul; Frei, Heinz

    2018-01-23

    Macroscale arrays of cobalt oxide-silica core-shell nanotubes with high aspect ratio and ultrathin walls of less than 20 nm have been fabricated. The silica shells feature embedded oligo-para(phenylenevinylene) molecules for charge transport across the insulating silica layer, which is tightly controlled by their electronic properties. The assembly is based on the use of a sacrificial Si nanorod array template combined with atomic layer deposition, covalent anchoring of organic wire molecules, and dry cryo-etching. High-resolution TEM imaging of samples prepared by microtome affords structural details of single core-shell nanotubes. The integrity of silica-embedded organic wire molecules exposed to atomic layer deposition, thermal treatment, and harsh etching procedures is demonstrated by grazing angle ATR FT-IR, FT-Raman, and XPS spectroscopy. The inorganic oxide-based core-shell nanotubes with ultrathin gas-impermeable, proton-conducting silica shells functionalized by molecular wires enable complete nanoscale photosynthetic units for CO2 reduction by H2O under membrane separation. Arrays of massive numbers of such core-shell nanotube units afford a design that extends the separation of the incompatible H2O oxidation and CO2 reduction catalysis environments across the continuum of length scales from nanometers to centimeters.

  17. Miniaturizable Ion-Selective Arrays Based on Highly Stable Polymer Membranes for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Mònica Mir

    2014-07-01

    Full Text Available Poly(vinylchloride (PVC is the most common polymer matrix used in the fabrication of ion-selective electrodes (ISEs. However, the surfaces of PVC-based sensors have been reported to show membrane instability. In an attempt to overcome this limitation, here we developed two alternative methods for the preparation of highly stable and robust ion-selective sensors. These platforms are based on the selective electropolymerization of poly(3,4-ethylenedioxythiophene (PEDOT, where the sulfur atoms contained in the polymer covalently interact with the gold electrode, also permitting controlled selective attachment on a miniaturized electrode in an array format. This platform sensor was improved with the crosslinking of the membrane compounds with poly(ethyleneglycol diglycidyl ether (PEG, thus also increasing the biocompatibility of the sensor. The resulting ISE membranes showed faster signal stabilization of the sensor response compared with that of the PVC matrix and also better reproducibility and stability, thus making these platforms highly suitable candidates for the manufacture of robust implantable sensors.

  18. Fabrication and characterization of TiO2 nanotube arrays on Ti membrane enlarged by anodic oxidation

    Directory of Open Access Journals (Sweden)

    Kim Jong-Oh

    2015-09-01

    Full Text Available TiO2 nanotube arrays have attracted a great deal of attention as photocatalytic and photoelectrode materials due to their large surface area, low cost and easy fabrication. Highly ordered TiO2 nanotube arrays for the photoelectrodes in dye-sensitized solar cells have been fabricated from Ti foil. However, the TiO2 nanotube arrays from Ti foil were not effective for the photocatalytic materials, because it had only one plane for the photocatalytic reaction. We have fabricated the TiO2 nanotube arrays from macroporous Ti metal membrane by anodic oxidation and tried to scale it up. Various factors were controlled to obtain the optimal microstructure of the TiO2 nanotube arrays on the surface of macroporous Ti metallic membrane. Microstructure and phase were studied by SEM and XRD, respectively. Temperature was a very important factor in anodic oxidation of large surface area. 10 μm thick TiO2 nanotube arrays on Ti metallic membrane having a large surface area were fabricated and some factors for scaling-up were discussed.

  19. Fabrication of In Vitro Cancer Microtissue Array on Fibroblast-Layered Nanofibrous Membrane by Inkjet Printing

    Directory of Open Access Journals (Sweden)

    Tae-Min Park

    2017-11-01

    Full Text Available In general, a drug candidate is evaluated using 2D-cultured cancer cells followed by an animal model. Despite successful preclinical testing, however, most drugs that enter human clinical trials fail. The high failure rates are mainly caused by incompatibility between the responses of the current models and humans. Here, we fabricated a cancer microtissue array in a multi-well format that exhibits heterogeneous and batch-to-batch structure by continuous deposition of collagen-suspended Hela cells on a fibroblast-layered nanofibrous membrane via inkjet printing. Expression of both Matrix Metalloproteinase 2 (MMP2 and Matrix Metalloproteinase 9 (MMP9 was higher in cancer microtissues than in fibroblast-free microtissues. The fabricated microtissues were treated with an anticancer drug, and high drug resistance to doxorubicin occurred in cancer microtissues but not in fibroblast-free microtissues. These results introduce an inkjet printing fabrication method for cancer microtissue arrays, which can be used for various applications such as early drug screening and gradual 3D cancer studies.

  20. Fabrication of In Vitro Cancer Microtissue Array on Fibroblast-Layered Nanofibrous Membrane by Inkjet Printing.

    Science.gov (United States)

    Park, Tae-Min; Kang, Donggu; Jang, Ilho; Yun, Won-Soo; Shim, Jin-Hyung; Jeong, Young Hun; Kwak, Jong-Young; Yoon, Sik; Jin, Songwan

    2017-11-07

    In general, a drug candidate is evaluated using 2D-cultured cancer cells followed by an animal model. Despite successful preclinical testing, however, most drugs that enter human clinical trials fail. The high failure rates are mainly caused by incompatibility between the responses of the current models and humans. Here, we fabricated a cancer microtissue array in a multi-well format that exhibits heterogeneous and batch-to-batch structure by continuous deposition of collagen-suspended Hela cells on a fibroblast-layered nanofibrous membrane via inkjet printing. Expression of both Matrix Metalloproteinase 2 (MMP2) and Matrix Metalloproteinase 9 (MMP9) was higher in cancer microtissues than in fibroblast-free microtissues. The fabricated microtissues were treated with an anticancer drug, and high drug resistance to doxorubicin occurred in cancer microtissues but not in fibroblast-free microtissues. These results introduce an inkjet printing fabrication method for cancer microtissue arrays, which can be used for various applications such as early drug screening and gradual 3D cancer studies.

  1. An Investigation of Chemiluminescent Reactions.

    Science.gov (United States)

    1984-06-01

    rubrenesulfonate, 0.01 g; sodium perborate tetrahydrate, 0.23 g, and 2.5mi water It is important to note that all chemiluminescence intensity curves...chemiluminescence of rubrenesulfonate was found to be enhanced in the presence of sodium decylsulfate (SDeS), no enhancement was observed for its...aq), H20 and NaCl (aq). The " methylene chloride was separated, dried with sodium sulfate, and .4 - .’.-.. -"","".. % 7 concentrated, yielding 6.2

  2. On-Demand Formation of Supported Lipid Membrane Arrays by Trehalose-Assisted Vesicle Delivery for SPR Imaging.

    Science.gov (United States)

    Hinman, Samuel S; Ruiz, Charles J; Drakakaki, Georgia; Wilkop, Thomas E; Cheng, Quan

    2015-08-12

    The fabrication of large-scale, solid-supported lipid bilayer (SLB) arrays has traditionally been an arduous and complex task, primarily due to the need to maintain SLBs within an aqueous environment. In this work, we demonstrate the use of trehalose vitrified phospholipid vesicles that facilitate on-demand generation of microarrays, allowing each element a unique composition, for the label-free and high-throughput analysis of biomolecular interactions by SPR imaging (SPRi). Small, unilamellar vesicles (SUVs) are suspended in trehalose, deposited in a spatially defined manner, with the trehalose vitrifying on either hydrophilic or hydrophobic SPR substrates. SLBs are subsequently spontaneously formed on-demand simply by in situ hydration of the array in the SPR instrument flow cell. The resulting SLBs exhibit high lateral mobility, characteristic of fluidic cellular lipid membranes, and preserve the biological function of embedded cell membrane receptors, as indicated by SPR affinity measurements. Independent fluorescence and SPR imaging studies show that the individual SLBs stay localized at the area of deposition, without any encapsulating matrix, confining coral, or boundaries. The introduced methodology allows individually addressable SLB arrays to be analyzed with excellent label-free sensitivity in a real-time, high-throughput manner. Various protein-ganglioside interactions have been selected as a model system to illustrate discrimination of strong and weak binding responses in SPRi sensorgrams. This methodology has been applied toward generating hybrid bilayer membranes on hydrophobic SPR substrates, demonstrating its versatility toward a range of surfaces and membrane geometries. The stability of the fabricated arrays, over medium to long storage periods, was evaluated and found to be good. The highly efficient and easily scalable nature of the method has the potential to be applied to a variety of label-free sensing platforms requiring lipid membranes for

  3. Two Dimensional Array of Piezoresistive Nanomechanical Membrane-Type Surface Stress Sensor (MSS with Improved Sensitivity

    Directory of Open Access Journals (Sweden)

    Nico F. de Rooij

    2012-11-01

    Full Text Available We present a new generation of piezoresistive nanomechanical Membrane-type Surface stress Sensor (MSS chips, which consist of a two dimensional array of MSS on a single chip. The implementation of several optimization techniques in the design and microfabrication improved the piezoresistive sensitivity by 3~4 times compared to the first generation MSS chip, resulting in a sensitivity about ~100 times better than a standard cantilever-type sensor and a few times better than optical read-out methods in terms of experimental signal-to-noise ratio. Since the integrated piezoresistive read-out of the MSS can meet practical requirements, such as compactness and not requiring bulky and expensive peripheral devices, the MSS is a promising transducer for nanomechanical sensing in the rapidly growing application fields in medicine, biology, security, and the environment. Specifically, its system compactness due to the integrated piezoresistive sensing makes the MSS concept attractive for the instruments used in mobile applications. In addition, the MSS can operate in opaque liquids, such as blood, where optical read-out techniques cannot be applied.

  4. Fluidic communication between multiple vertically segregated microfluidic channels connected by nanocapillary array membranes.

    Science.gov (United States)

    Gong, Maojun; Flachsbart, Bruce R; Shannon, Mark A; Bohn, Paul W; Sweedler, Jonathan V

    2008-03-01

    Hybrid microfluidic/nanofluidic devices offer unique capabilities for manipulating and analyzing minute volumes of expensive or hard-to-obtain samples. Here, multilayer poly-(methyl methacrylate) microchips, with multiple spatially isolated microfluidic channels interconnected by nanocapillary array membranes (NCAMs), are fabricated using an adhesive contact printing process. The NCAMs, positioned between the microfluidic channel layers, add functionality to the inter-microchannel fluid transfer unit operation. They do so because the transport of specific analytes through the NCAM can be controlled by adjusting the ionic strength, the polarity of the applied bias, the surface charge density, and the pore size. A simplified, floating injection technique for NCAM-coupled nanofluidic devices is described and compared with conventional biased injection. In the floating injection approach, a voltage is applied across the injection channel and the slight electric field extension at the cross-section is used to transfer analytes through the nanopores to the separation channel. Floating injection excels in plug reproducibility, separation resolution, and operation simplicity, although it decreases assay throughput relative to biased injection. Floating injection can avoid the uneven distribution of analytes in the microfluidic channel that sometimes results from biased injection because of the volume mismatch between NCAM nanopore transport capacity and the supply of fluid. Moreover, the pressure-driven flow caused by the mismatch of the EOFs in the microfluidic channels connected by an NCAM must be considered when using NCAMs with pore diameters below 50 nm.

  5. Super-resolution imaging of aquaporin-4 orthogonal arrays of particles in cell membranes.

    Science.gov (United States)

    Rossi, Andrea; Moritz, Tobias J; Ratelade, Julien; Verkman, A S

    2012-09-15

    Aquaporin-4 (AQP4) is a water channel expressed in astrocytes, skeletal muscle and epithelial cells that forms supramolecular aggregates in plasma membranes called orthogonal arrays of particles (OAPs). AQP4 is expressed as a short isoform (M23) that forms large OAPs, and a long isoform (M1) that does not form OAPs by itself but can mingle with M23 to form relatively small OAPs. AQP4 OAPs were imaged with ~20 nm spatial precision by photoactivation localization microscopy (PALM) in cells expressing chimeras of M1- or M23-AQP4 with photoactivatable fluorescent proteins. Native AQP4 was imaged by direct stochastic optical reconstruction microscopy (dSTORM) using a primary anti-AQP4 antibody and fluorescent secondary antibodies. We found that OAP area increased from 1878±747 to 3647±958 nm(2) with decreasing M1:M23 ratio from 1:1 to 1:3, and became elongated. Two-color dSTORM indicated that M1 and M23 co-assemble in OAPs with a M1-enriched periphery surrounding a M23-enriched core. Native AQP4 in astrocytes formed OAPs with an area of 2142±829 nm(2), which increased to 5137±1119 nm(2) with 2-bromopalmitate. PALM of AQP4 OAPs in live cells showed slow diffusion (average ~10(-12) cm(2)/s) and reorganization. OAP area was not altered by anti-AQP4 IgG autoantibodies (NMO-IgG) that cause the neurological disease neuromyelitis optica. Super-resolution imaging allowed elucidation of novel nanoscale structural and dynamic features of OAPs.

  6. Chemiluminescence methods (present and future

    Directory of Open Access Journals (Sweden)

    Navas, M. J.

    2002-03-01

    Full Text Available This article provides a general review of chemiluminescent methods in some of their recent applications in drug analysis, sea water analysis or antioxidant activity of natural and synthetic products (including olive oil. Practical considerations are not included in the review since the main interest is to state, through the aforementioned applications, that chemiluminescence has been, is, and will be a versatile tool for Analytical Chemistry in future years.Este artículo da una visión general de los métodos de quimiluminiscencia en algunas de las aplicaciones más recientes en análisis de drogas, análisis del agua marina o la actividad antioxidante de productos naturales y de síntesis (incluyendo el aceite de oliva. Las consideraciones prácticas no están incluidas ya que el principal interés es establecer, a través de las aplicaciones mencionadas, que la quimiluminiscencia ha sido, es y será en los próximos años una herramienta versátil de la Química Analítica.

  7. Development of Chemiluminescent Lateral Flow Assay for the Detection of Nucleic Acids

    Directory of Open Access Journals (Sweden)

    Sam R. Nugen

    2012-01-01

    Full Text Available Rapid, sensitive detection methods are of utmost importance for the identification of pathogens related to health and safety. Herein we report the development of a nucleic acid sequence-based lateral flow assay which achieves a low limit of detection using chemiluminescence. On-membrane enzymatic signal amplification is used to reduce the limit of detection to the sub-femtomol level. To demonstrate this assay, we detected synthetic nucleic acid sequences representative of Trypanosoma mRNA, the causative agent for African sleeping sickness, with relevance in human and animal health in sub-Saharan Africa. The intensity of the chemiluminescent signal was evaluated by using a charge-coupled device as well as a microtiter plate reader. We demonstrated that our lateral flow chemiluminescent assay has a very low limit of detection and is easy to use. The limit of detection was determined to be 0.5 fmols of nucleic acid target.

  8. Development of Chemiluminescent Lateral Flow Assay for the Detection of Nucleic Acids

    Science.gov (United States)

    Wang, Yuhong; Fill, Catherine; Nugen, Sam R.

    2012-01-01

    Rapid, sensitive detection methods are of utmost importance for the identification of pathogens related to health and safety. Herein we report the development of a nucleic acid sequence-based lateral flow assay which achieves a low limit of detection using chemiluminescence. On-membrane enzymatic signal amplification is used to reduce the limit of detection to the sub-femtomol level. To demonstrate this assay, we detected synthetic nucleic acid sequences representative of Trypanosoma mRNA, the causative agent for African sleeping sickness, with relevance in human and animal health in sub-Saharan Africa. The intensity of the chemiluminescent signal was evaluated by using a charge-coupled device as well as a microtiter plate reader. We demonstrated that our lateral flow chemiluminescent assay has a very low limit of detection and is easy to use. The limit of detection was determined to be 0.5 fmols of nucleic acid target. PMID:25585630

  9. Electrostatically Driven Assembly of Charged Amphiphiles Forming Crystallized Membranes, Vesicles and Nanofiber Arrays

    Science.gov (United States)

    Leung, Cheuk Yui Curtis

    Charged amphiphilic molecules can self-assemble into a large variety of objects including membranes, vesicles and fibers. These micro to nano-scale structures have been drawing increasing attention due to their broad applications, especially in biotechnology and biomedicine. In this dissertation, three self-assembled systems were investigated: +3/-1 self-assembled catanionic membranes, +2/-1 self-assembled catanionic membranes and +1 self-assembled nanofibers. Transmission electron microscopy (TEM) combined with synchrotron small and wide angle x-ray scattering (SAXS and WAXS) were used to characterize the coassembled structures from the mesoscopic to nanometer scale. We designed a system of +3 and -1 ionic amphiphiles that coassemble into crystalline ionic bilayer vesicles with large variety of geometries that resemble polyhedral cellular crystalline shells and archaea wall envelopes. The degree of ionization of the amphiphiles and their intermolecular electrostatic interactions can be controlled by varying pH. The molecular packing of these membranes showed a hexagonal to rectangular-C to hexagonal phase transition with increasing pH, resulting in significant changes to the membrane morphology. A similar mixture of +2 and -1 ionic amphiphiles was also investigated. In addition to varying pH, which controls the headgroup attractions, we also adjust the tail length of the amphiphiles to control the van der Waals interactions between the tails. A 2D phase diagram was developed to show how pH and tail length can be used to control the intermolecular packing within the membranes. Another system of self-assembled nanofiber network formed by positively charged amphiphiles was also studied. These highly charged fibers repel each other and are packed in hexagonal lattice with lattice constant at least eight times of the fiber diameter. The d-spacing and the crystal structure can be controlled by varying the solution concentration and temperature.

  10. Opening a Gateway for Chemiluminescence Cell Imaging: Distinctive Methodology for Design of Bright Chemiluminescent Dioxetane Probes.

    Science.gov (United States)

    Green, Ori; Eilon, Tal; Hananya, Nir; Gutkin, Sara; Bauer, Christoph R; Shabat, Doron

    2017-04-26

    Chemiluminescence probes are considered to be among the most sensitive diagnostic tools that provide high signal-to-noise ratio for various applications such as DNA detection and immunoassays. We have developed a new molecular methodology to design and foresee light-emission properties of turn-ON chemiluminescence dioxetane probes suitable for use under physiological conditions. The methodology is based on incorporation of a substituent on the benzoate species obtained during the chemiexcitation pathway of Schaap's adamantylidene-dioxetane probe. The substituent effect was initially evaluated on the fluorescence emission generated by the benzoate species and then on the chemiluminescence of the dioxetane luminophores. A striking substituent effect on the chemiluminescence efficiency of the probes was obtained when acrylate and acrylonitrile electron-withdrawing groups were installed. The chemiluminescence quantum yield of the best probe was more than 3 orders of magnitude higher than that of a standard, commercially available adamantylidene-dioxetane probe. These are the most powerful chemiluminescence dioxetane probes synthesized to date that are suitable for use under aqueous conditions. One of our probes was capable of providing high-quality chemiluminescence cell images based on endogenous activity of β-galactosidase. This is the first demonstration of cell imaging achieved by a non-luciferin small-molecule probe with direct chemiluminescence mode of emission. We anticipate that the strategy presented here will lead to development of efficient chemiluminescence probes for various applications in the field of sensing and imaging.

  11. Membrane Material-Based Rigid Solar Array Design and Thermal Simulation for Stratospheric Airships

    Directory of Open Access Journals (Sweden)

    Kangwen Sun

    2014-01-01

    Full Text Available In order to improve effective utilization of rigid solar array used in stratospheric airships here, the flexible connection design and light laminated design were introduced to rigid solar array. Based on the analysis of the design scheme, firstly, the equivalent coefficient of thermal conductivity was calculated by the theoretical formula. Subsequently, the temperature variation characteristics of the solar cell module were accurately modeled and simulated by using Computational Fluid Dynamics (CFD software. Compared to the results of test samples, the solar cell module described here guaranteed effective output as well as good heat insulating ability, effectively improving the feasibility of the stratospheric airship design. In addition, the simulation model can effectively simulate the temperature variation characteristics of the solar cell, which, therefore, provides technical support for the engineering application.

  12. A Facile and Effective Chemiluminescence Demonstration Experiment

    Science.gov (United States)

    Mohan, Arthur G.; Turro, Nicholas J.

    1974-01-01

    Describes a chemiluminescence system which can be used to demonstrate the effects of certain factors which affect the rate of reaction (temperature, concentration, catalysis, solvent, etc.), and to perform experiments relevant to the mechanism of the system. (SLH)

  13. A hierarchically assembled mesoporous ZnO hemisphere array and hollow microspheres for photocatalytic membrane water filtration.

    Science.gov (United States)

    Pan, Jia Hong; Zhang, Xiwang; Du, Alan J; Bai, Hongwei; Ng, Jiawei; Sun, Darren

    2012-05-28

    A mesoporous ZnO hemisphere array has been prepared via a topotactic transition of Zn(4)(OH)(6)CO(3)·H(2)O (ZCHH) by chemical bath deposition. Each hemisphere is comprised of a radially oriented nanoflake shell grown on the hemispherical interior. Reaction time-dependent SEM analysis shows that the morphological formation of ZCHH involves a deposition-growth-secondary growth-redeposition procedure. Upon calcination, ZCHH readily decomposes to nanocrystalline wurtzite-phase ZnO without significant change in morphology, and the release of CO(2) and H(2)O from ZCHH creates an additional mesoporous structure in both hemispherical interior and nanoflake shell. A similar process but without using a substrate has been developed for synthesis of mesoporous ZnO hollow microspheres in powder form. Both the elaborated superstructured photocatalysts consisting of mesoporous nanoflakes have been demonstrated to exhibit excellent performances in the photocatalytic membrane filtration.

  14. A microelectromechanical system artificial basilar membrane based on a piezoelectric cantilever array and its characterization using an animal model.

    Science.gov (United States)

    Jang, Jongmoon; Lee, JangWoo; Woo, Seongyong; Sly, David J; Campbell, Luke J; Cho, Jin-Ho; O'Leary, Stephen J; Park, Min-Hyun; Han, Sungmin; Choi, Ji-Wong; Jang, Jeong Hun; Choi, Hongsoo

    2015-07-31

    We proposed a piezoelectric artificial basilar membrane (ABM) composed of a microelectromechanical system cantilever array. The ABM mimics the tonotopy of the cochlea: frequency selectivity and mechanoelectric transduction. The fabricated ABM exhibits a clear tonotopy in an audible frequency range (2.92-12.6 kHz). Also, an animal model was used to verify the characteristics of the ABM as a front end for potential cochlear implant applications. For this, a signal processor was used to convert the piezoelectric output from the ABM to an electrical stimulus for auditory neurons. The electrical stimulus for auditory neurons was delivered through an implanted intra-cochlear electrode array. The amplitude of the electrical stimulus was modulated in the range of 0.15 to 3.5 V with incoming sound pressure levels (SPL) of 70.1 to 94.8 dB SPL. The electrical stimulus was used to elicit an electrically evoked auditory brainstem response (EABR) from deafened guinea pigs. EABRs were successfully measured and their magnitude increased upon application of acoustic stimuli from 75 to 95 dB SPL. The frequency selectivity of the ABM was estimated by measuring the magnitude of EABRs while applying sound pressure at the resonance and off-resonance frequencies of the corresponding cantilever of the selected channel. In this study, we demonstrated a novel piezoelectric ABM and verified its characteristics by measuring EABRs.

  15. A microelectromechanical system artificial basilar membrane based on a piezoelectric cantilever array and its characterization using an animal model

    Science.gov (United States)

    Jang, Jongmoon; Lee, Jangwoo; Woo, Seongyong; Sly, David J.; Campbell, Luke J.; Cho, Jin-Ho; O'Leary, Stephen J.; Park, Min-Hyun; Han, Sungmin; Choi, Ji-Wong; Hun Jang, Jeong; Choi, Hongsoo

    2015-07-01

    We proposed a piezoelectric artificial basilar membrane (ABM) composed of a microelectromechanical system cantilever array. The ABM mimics the tonotopy of the cochlea: frequency selectivity and mechanoelectric transduction. The fabricated ABM exhibits a clear tonotopy in an audible frequency range (2.92-12.6 kHz). Also, an animal model was used to verify the characteristics of the ABM as a front end for potential cochlear implant applications. For this, a signal processor was used to convert the piezoelectric output from the ABM to an electrical stimulus for auditory neurons. The electrical stimulus for auditory neurons was delivered through an implanted intra-cochlear electrode array. The amplitude of the electrical stimulus was modulated in the range of 0.15 to 3.5 V with incoming sound pressure levels (SPL) of 70.1 to 94.8 dB SPL. The electrical stimulus was used to elicit an electrically evoked auditory brainstem response (EABR) from deafened guinea pigs. EABRs were successfully measured and their magnitude increased upon application of acoustic stimuli from 75 to 95 dB SPL. The frequency selectivity of the ABM was estimated by measuring the magnitude of EABRs while applying sound pressure at the resonance and off-resonance frequencies of the corresponding cantilever of the selected channel. In this study, we demonstrated a novel piezoelectric ABM and verified its characteristics by measuring EABRs.

  16. Ferromagnetic resonance investigation in permalloy magnetic antidot arrays on alumina nanoporous membranes

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Suárez, R.L., E-mail: rrodriguez@fis.puc.cl [Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860 Casilla 306, Santiago (Chile); Palma, J.L.; Burgos, E.O. [Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Michea, S. [Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860 Casilla 306, Santiago (Chile); Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Escrig, J.; Denardin, J.C. [Departamento de Física, Universidad de Santiago de Chile (USACH), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Aliaga, C. [Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avda. Ecuador 3493, 917-0124 Santiago (Chile); Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago (Chile)

    2014-01-15

    The magnetic properties of Ni{sub 80}Fe{sub 20} antidot arrays with hole diameters of 18 and 70 nm fabricated by a template-assisted method were investigated using the ferromagnetic resonance technique. Tuning the antidot arrays by changing the hole diameter enables control on the angular dependence of the ferromagnetic resonance field. The scanning electron microscope images reveal a quite regular hexagonal arrangement of the pores, however the angular dependence of the resonance field do not exhibit the six-fold symmetry expected for this symmetry. Micromagnetic simulations performed on a perfect hexagonal lattice, when compared with those made on our real system taken from the scanning microscope images, reveal that the presence of defects in the antidot lattice affects the ferromagnetic resonance field symmetry. - Highlights: • We use the FMR technique to investigate the magnetic properties of Py antidots. • We studied the effect of pore diameter on FMR angular measurement. • FMR field does not exhibit the six-fold symmetry. • For all angular positions there are two resonance modes always present. • Micromagnetic simulations agree with the experimental results with defects.

  17. Membraner

    DEFF Research Database (Denmark)

    Bach, Finn

    2009-01-01

    Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner......Notatet giver en kort introduktion til den statiske virkemåde af membraner og membrankonstruktioner...

  18. Solar fuel production in a novel polymeric electrolyte membrane photoelectrochemical (PEM-PEC) cell with a web of titania nanotube arrays as photoanode and gaseous reactants

    NARCIS (Netherlands)

    Stoll, T.; Zafeiropoulos, G.; Tsampas, M. N.

    2016-01-01

    A novel photoelectrochemical (PEC) cell design is proposed and investigated for H-2 production with gaseous reactants. The core of the cell is a membrane electrode assembly (MEA) that consists of a TiO2 nanotube arrays photoanode, a Pt/C cathode, a Pt/C reference electrode and a proton conducting

  19. Native vs photoinduced chemiluminescence in dimethoate determination

    Energy Technology Data Exchange (ETDEWEB)

    Catala-Icardo, M., E-mail: mocaic@qim.upv.es [Instituto de investigacion para la Gestion Integrada de Zonas Costeras (IGIC), Universidad Politecnica de Valencia, C/Paranimf n Degree-Sign 1, 46730 Grao de Gandia, Valencia (Spain); Lopez-Paz, J.L.; Choves-Baron, C.; Pena-Badena, A. [Instituto de investigacion para la Gestion Integrada de Zonas Costeras (IGIC), Universidad Politecnica de Valencia, C/Paranimf n Degree-Sign 1, 46730 Grao de Gandia, Valencia (Spain)

    2012-01-13

    Highlights: Black-Right-Pointing-Pointer Comparison between native and photoinduced chemiluminescence of dimethoate. Black-Right-Pointing-Pointer Hexadecylpyridinium enhanced greatly the chemiluminescence. Black-Right-Pointing-Pointer Solid phase extraction allowed the successful determination of dimethoate in water. - Abstract: The determination of dimethoate using either its native chemiluminescent (CL) properties or its photoinduced chemiluminescence obtained by irradiation with a 15 W low-pressure mercury lamp was studied. Thereby, two flow injection systems (FIA) with and without irradiation were exhaustively optimized and their analytical characteristics studied. Better sensitivity and selectivity was found in absence of irradiation, due to the enhancing effect of hexadecylpyridinium chloride (HPC), which acted as a sensitizer. In the developed FIA-CL system, the alkaline hydrolysis of dimethoate with NaOH was performed on-line in presence of HPC. The oxidation of the product of hydrolysis with Ce(IV) in hydrochloric medium induced chemiluminescence. The method provided a limit of detection of only 0.05 ng mL{sup -1} without any pre-treatment. However, the combination with solid phase extraction allowed the removal of some potential interferents as well as the preconcentration of the pesticide. Finally, the developed method was successfully applied to natural waters with recoveries between 95 and 108%.

  20. The influence of dioxygen on luminol chemiluminescence.

    Science.gov (United States)

    Baj, Stefan; Krawczyk, Tomasz; Staszewska, Karina

    2009-01-01

    Assays of peroxy compounds are commonly performed after chromatographic separation of analysed mixtures. In high-performance liquid chromatography (HPLC), solvent reservoirs are sparged by helium or inline vacuum-degassed in order to control the compressibility of the solvents for efficient pumping. In this study, we investigated the influence of degassing the reaction solution on the light output of the hemin-catalyzed luminol oxidation by various oxidants. We found that, when t-butyl hydroperoxide, hydrogen peroxide, n-butyl hydroperoxide, iodosobenzene and iodobenzene diacetate were used as oxidants, the luminol chemiluminescence was lowered by 50-70% compared with an equilibrated and degassed solution. The opposite effect was observed when dibenzoyl peroxide and 3-chloroperoxybenzoic acid were used as oxidants, as the chemiluminescence increased by approximately 20-30%. The reduced chemiluminescence was explained based on the known role of dioxygen in luminol chemiluminescence. The enhancement of chemiluminescence was rationalized by suggesting an alternative mechanism of luminol oxidation valid for peroxyacids and diacyl peroxides in which the reaction of a peroxyacid anion with the diazaquinone led to light emission with a higher quantum yield than the usual path, which is suppressed by the removal of dioxygen from the reaction solution.

  1. Development of Chemiluminescent Lateral Flow Assay for the Detection of Nucleic Acids

    OpenAIRE

    Sam R. Nugen; Catherine Fill; Yuhong Wang

    2012-01-01

    Rapid, sensitive detection methods are of utmost importance for the identification of pathogens related to health and safety. Herein we report the development of a nucleic acid sequence-based lateral flow assay which achieves a low limit of detection using chemiluminescence. On-membrane enzymatic signal amplification is used to reduce the limit of detection to the sub-femtomol level. To demonstrate this assay, we detected synthetic nucleic acid sequences representative of Trypanosoma mRNA, th...

  2. Opening a Gateway for Chemiluminescence Cell Imaging: Distinctive Methodology for Design of Bright Chemiluminescent Dioxetane Probes

    OpenAIRE

    Green, Ori; Eilon, Tal; Hananya, Nir; Gutkin, Sara; Bauer, Christoph R.; Shabat, Doron

    2017-01-01

    Chemiluminescence probes are considered to be among the most sensitive diagnostic tools that provide high signal-to-noise ratio for various applications such as DNA detection and immunoassays. We have developed a new molecular methodology to design and foresee light-emission properties of turn-ON chemiluminescence dioxetane probes suitable for use under physiological conditions. The methodology is based on incorporation of a substituent on the benzoate species obtained during the chemiexcitat...

  3. Fabrication and optical properties of TiO sub 2 nanowire arrays made by sol-gel electrophoresis deposition into anodic alumina membranes

    CERN Document Server

    Lin, Y; Yuan, X Y; Xie, T; Zhang, L D

    2003-01-01

    Ordered TiO sub 2 nanowire arrays have been successfully fabricated into the nanochannels of a porous anodic alumina membrane by sol-gel electrophoretic deposition. After annealing at 500 deg. C, the TiO sub 2 nanowire arrays and the individual nanowires were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and x-ray diffraction (XRD). SEM and TEM images show that these nanowires are dense and continuous with a uniform diameter throughout their entire length. XRD and SAED analysis together indicate that these TiO sub 2 nanowires crystallize in the anatase polycrystalline structure. The optical absorption band edge of TiO sub 2 nanowire arrays exhibits a blue shift with respect of that of the bulk TiO sub 2 owing to the quantum size effect.

  4. Membranes

    OpenAIRE

    Junbo Hou; Min Yang

    2012-01-01

    Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separa...

  5. Ray tracing of chemiluminescence in an unconfined non-premixed turbulent jet flame using large-eddy simulation

    Science.gov (United States)

    Ertem, C. K.; Janicka, J.; Dreizler, A.

    2012-06-01

    Optical diagnostic techniques, such as chemiluminescence imaging, are commonly used to study turbulent flames. Inherent to turbulent flames is the spatio-temporal variation of the volumetric distribution of temperature and chemical composition. In consequence, the index of refraction varies accordingly and causes distortion of any optical ray intersecting the turbulent flame. This distortion is well known as beam steering. Beam steering may degrade imaging quality by reducing the overall spatial resolution. Its impact of course depends on the actual specifications of the imaging system itself. In this study a methodology is proposed to tackle this issue numerically and is exemplified for chemiluminescence imaging in a well-known turbulent hydrogen-fueled jet flame. Large-eddy simulation (LES) of this unconfined non-premixed flame is used to simulate instantaneous volumetric distributions of the flow and scalar fields including the local index of refraction. This simulation additionally predicts local concentrations of electronically excited chemiluminescent active species. At locations with significantly high concentrations of luminescent species, optical rays are initiated in the direction of the array detector used for recording single chemiluminescence images. Assuming the validity of geometrical optics, these rays are tracked along their pathways. Their direction of propagation changes according to the local instantaneous distribution of the index of refraction. After leaving the computational domain of the ray tracing code which is fed by the LES, each ray is processed by the commercial code ZEMAX® and imaged onto an array detector. Measured and numerically simulated ensemble-averaged chemiluminescence images are compared to each other. Overall, a satisfying agreement is observed. The primary aim of this paper is the exposition of this method where numerical and experimental results are not any more compared in the flame but where this comparison is shifted

  6. Multiplex tumor marker detection with new chemiluminescent immunoassay based on silica colloidal crystal beads.

    Science.gov (United States)

    Pei, Xiaoping; Chen, Baoan; Li, Li; Gao, Feng; Jiang, Zhi

    2010-01-01

    A new multiplex chemiluminescent immunoassay (CLIA) based on silica colloidal crystal beads (SCCBs) was developed for tumor marker detection. As the code is the characteristic reflection peak originating from the stop-band of colloid crystal, they avoid photobleaching, the potential interference of encoding fluorescence with analyte-detection fluorescence and chemical instability. Meanwhile our SCCBs suspension array improved the luminescence analysis efficiency by using chemiluminescent detection of enzyme labels. By forming a sandwich immunocomplex on SCCBs, the proposed suspension array was used for simultaneous multiplex detection of tumor markers in one test tube. The results showed that the linear range was 0.5-100ng ml(-1) and 1.0-120ng ml(-1) for carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) with a detection limit of 0.12ng ml(-1) and 0.16ng ml(-1) at 3sigma. The proposed array showed the storage stability and the accuracy for sample detection were acceptable, and the results were in acceptable agreement with the reference electrochemiluminescence method. This technique provided an automated, simple, sensitive and low-cost approach for multianalyte immunoassay.

  7. Simultaneous detection of multiple mRNA markers CK19, CEA, c-Met, Her2/neu and hMAM with membrane array, an innovative technique with a great potential for breast cancer diagnosis.

    Science.gov (United States)

    Chen, Chung-Chi; Hou, Ming-Feng; Wang, Jaw-Yuan; Chang, Tsai-Wang; Lai, Dan-Yu; Chen, Yi-Fang; Hung, Sung-Yu; Lin, Shiu-Ru

    2006-08-28

    The objective of this study was mainly to develop and evaluate a membrane array-based method simultaneously detecting the expression levels of a multiple mRNA marker panel in the peripheral blood for used in complementary breast cancer diagnosis. The mRNA markers employed included cytokeratin 19 (CK-19), carcinoembryonic antigen (CEA), c-Met, Her2/neu, and mammaglobin (hMAM). The specimens of peripheral blood were collected from 80 healthy women and 102 female patients with breast cancer. The expression levels of molecular markers were evaluated by real-time Q-PCR and membrane array. Data obtained from real-time Q-PCR and membrane array were subjected to linear regression analysis, revealing that there was a high degree of correlation between the results of these two methods (r=0.979, Pmembrane array assay with a combined panel of five mRNA markers was demonstrated to achieve sensitivity of 80.6%, and specificity of 83.8% for breast cancer detection, much higher than those of analysis of single marker. In addition, we demonstrated that the membrane array method could detect circulating cancer cells at a density as low as five cancer cells per 1 ml of blood. The analysis of correlation between the outcome of membrane array and clinicopathological characteristics indicated that overexpression of the multiple marker panel was significantly correlated with tumor size (P=0.030) and TNM stage (0.009). In conclusion, the detection of circulating cancer cells by means of membrane array simultaneously monitoring five mRNA markers could significantly enhance the sensitivity and specificity for cancer cell detection.

  8. Near-Infrared Intraoperative Chemiluminescence Imaging

    KAUST Repository

    Büchel, Gabriel E.

    2016-08-03

    Intraoperative imaging technologies recently entered the operating room, and their implementation is revolutionizing how physicians plan, monitor, and perform surgical interventions. In this work, we present a novel surgical imaging reporter system: intraoperative chemiluminescence imaging (ICI). To this end, we have leveraged the ability of a chemiluminescent metal complex to generate near-infrared light upon exposure to an aqueous solution of Ce4+ in the presence of reducing tissue or blood components. An optical camera spatially resolves the resulting photon flux. We describe the construction and application of a prototype imaging setup, which achieves a detection limit as low as 6.9pmolcm-2 of the transition-metal-based ICI agent. As a proof of concept, we use ICI for the invivo detection of our transition metal tracer following both systemic and subdermal injections. The very high signal-to-noise ratios make ICI an interesting candidate for the development of new intraoperative imaging technologies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Are dioxetanes chemiluminescent intermediates in lipoperoxidation?

    Science.gov (United States)

    Di Mascio, P; Catalani, L H; Bechara, E J

    1992-01-01

    Ultraweak chemiluminescence arising from lipoperoxidation has been attributed by several authors to the radiative deactivation of singlet oxygen and triplet carbonyl products. The latter emitters have been suggested to come from annihilation of RO. and ROO. radicals as well as from the thermolysis of dioxetane intermediates formed by (2 + 2) cycloaddition of 1O2 to polyunsaturated fatty acids. This article questions possible dioxetane intermediacy in lipoperoxidation, as the literature clearly states that addition of 1O2 to alpha-hydrogen-containing alyphatic olefins yields only the corresponding allylic hydroperoxides. These compounds may undergo dark thermal or Lewis acid-assisted decomposition to the same product obtained from dioxetane cleavage. Here, reexamining the chemiluminescence properties of dioxygenated tetramethylethylene and linoleic acid and comparing them with those of tetraethyldioxetane, a hindered dioxetane, we corroborate the literature information that only steric hindrance leads to dioxetane formation upon singlet oxygen addition to electron-poor olefins, albeit in very low yields. Proton nuclear magnetic resonance (1H-NMR) analysis, quenching by dioxygen and energy transfer studies to 9,10-dibromoanthracene, as well as gas chromatography (GC) analysis of triphenylphosphine-treated and untreated photo- and chemically dioxygenated olefins support our final conclusion that dioxetane formation during lipoperoxidation can be safely excluded on the basis of the data presently available.

  10. Polymeric Electrolyte Membrane Photoelectrochemical (PEM-PEC Cell with a Web of Titania Nanotube Arrays as Photoanode and Gaseous Reactants

    Directory of Open Access Journals (Sweden)

    Tsampas M.N.

    2017-01-01

    Photoanodes of titania nanotube arrays, TNTAs, were developed, for the first time, on a Ti-web of microfiber substrates, by electrochemical anodization. The performance of TNTAs/Ti-web photoanodes were evaluated in both gaseous and liquid reactants. Due to the presence of reliable reference electrode in gas phase direct comparison of the results was possible. Gas phase operation with He or Air as carrier gases and only 2.5% of water content exhibits very promising photoefficiency in comparison with conventional PEC cells.

  11. Biological water quality monitoring using chemiluminescent and bioluminescent techniques

    Science.gov (United States)

    Thomas, R. R.

    1978-01-01

    Automated chemiluminescence and bioluminescence sensors were developed for the continuous monitoring of microbial levels in water supplies. The optimal chemical procedures were determined for the chemiluminescence system to achieve maximum sensitivity. By using hydrogen peroxide, reaction rate differentiation, ethylene diamine tetraacetic acid (EDTA), and carbon monoxide pretreatments, factors which cause interference were eliminated and specificity of the reaction for living and dead bacteria was greatly increased. By employing existing technology with some modifications, a sensitive and specific bioluminescent system was developed.

  12. Vertically aligned carbon-coated titanium dioxide nanorod arrays on carbon paper with low platinum for proton exchange membrane fuel cells

    Science.gov (United States)

    Jiang, Shangfeng; Yi, Baolian; Zhang, Changkun; Liu, Sa; Yu, Hongmei; Shao, Zhigang

    2015-02-01

    Carbon-coated titanium dioxide (TiO2-C) has received much attention as a catalyst support in proton exchange membrane fuel cells. In this study, TiO2 nanorod arrays (NRs) are hydrothermally grown on carbon paper and converted into TiO2-C NRs by heat treatment at 900 °C under methane atmosphere. Then, platinum nanoparticles are sputtered onto the TiO2 NRs by physical vapor deposition to produce Pt-TiO2-C. The as-prepared Pt-TiO2-C exhibits high stability during accelerated durability tests. As compared with the commercial gas diffusion electrode (GDE, 34.4% decrease), a minor reduction in the electrochemically active surface area of the Pt-TiO2-C electrode after 1500 cycles (10.6% decrease) is observed. When the as-prepared electrode with ultra-low platinum content (Pt loading: 28.67 μg cm-2) is employed as the cathode of a single cell, the electrode generates power that is 4.84 × that of the commercial GDE (Pt loading: 400 μg cm-2). An electrode that generates power of 11.9 kW gPt-1 (as the cathode) is proposed. The fabricated Pt-TiO2-C electrode can be used in proton exchange membrane fuel cells.

  13. Piezoelectric transducer array microspeaker

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of a piezoelectric micro-speaker. The speaker is an array of micro-machined piezoelectric membranes, fabricated on silicon wafer using advanced micro-machining techniques. Each array contains 2n piezoelectric transducer membranes, where “n” is the bit number. Every element of the array has a circular shape structure. The membrane is made out four layers: 300nm of platinum for the bottom electrode, 250nm or lead zirconate titanate (PZT), a top electrode of 300nm and a structural layer of 50

  14. Base-induced Oxygenation and Chemiluminescence of 3,6-Disubstituted Pyridazines : A Model for Luminol Chemiluminescence

    OpenAIRE

    Suzuki, Nobutaka; Ueyama, Takeshi; Kato, Mamoru; 鈴木, 喜隆; 上山, 武士; 加藤, 守

    1984-01-01

    Monocyclic 3,6-disubstituted pyridazines were oxidized by molecular oxygen under the basic conditions in dimethyl sulfoxide at room temperature to give the corresponding maleic acids and/or its derivatives with chemiluminescent light emission.

  15. Combination of multiple mRNA markers (PTTG1, Survivin, UbcH10 and TK1) in the diagnosis of Taiwanese patients with breast cancer by membrane array.

    Science.gov (United States)

    Chen, Chung-Chi; Chang, Tsai-Wang; Chen, Fang-Ming; Hou, Ming-Feng; Hung, Sung-Yu; Chong, Inn-Wen; Lee, Su-Chen; Zhou, Tian-Hong; Lin, Shiu-Ru

    2006-01-01

    Early detection is a prerequisite to the effective reduction of morbidity and mortality from breast cancer. The present study intended to employ a high-throughput membrane array to detect a panel of mRNA markers expressed by circulating tumor cells (CTCs) in the peripheral blood of female patients with breast cancer. Peripheral blood was sampled from 92 breast cancer patients and 100 normal persons. CTCs were detected by using a membrane array technique. The markers used included the pituitary tumor transforming gene 1, survivin, UbcH10 and thymidine kinase 1. The results showed that the membrane array could positively detect 5 cancer cells per 1 ml of peripheral blood in breast cancer cell dilution experiments. For the panel of 4 mRNA markers, sensitivity and specificity were elevated up to 86 and 88%, respectively. Furthermore, it was found that the patients' clinicopathological characteristics tumor size (p = 0.006), histologic grade (p = 0.012), lymph node metastasis (p = 0.001) and TNM stage (p = 0.006) significantly correlated with the positive detection rate of the multimarker panel. These findings demonstrated that our multimarker membrane array method could detect CTCs in the circulation of breast cancer patients with considerably high sensitivity and specificity. Copyright (c) 2006 S. Karger AG, Basel.

  16. Using a large area CMOS APS for direct chemiluminescence detection in Western blotting electrophoresis

    Science.gov (United States)

    Esposito, Michela; Newcombe, Jane; Anaxagoras, Thalis; Allinson, Nigel M.; Wells, Kevin

    2012-03-01

    Western blotting electrophoretic sequencing is an analytical technique widely used in Functional Proteomics to detect, recognize and quantify specific labelled proteins in biological samples. A commonly used label for western blotting is Enhanced ChemiLuminescence (ECL) reagents based on fluorescent light emission of Luminol at 425nm. Film emulsion is the conventional detection medium, but is characterized by non-linear response and limited dynamic range. Several western blotting digital imaging systems have being developed, mainly based on the use of cooled Charge Coupled Devices (CCDs) and single avalanche diodes that address these issues. Even so these systems present key drawbacks, such as a low frame rate and require operation at low temperature. Direct optical detection using Complementary Metal Oxide Semiconductor (CMOS) Active Pixel Sensors (APS)could represent a suitable digital alternative for this application. In this paper the authors demonstrate the viability of direct chemiluminescent light detection in western blotting electrophoresis using a CMOS APS at room temperature. Furthermore, in recent years, improvements in fabrication techniques have made available reliable processes for very large imagers, which can be now scaled up to wafer size, allowing direct contact imaging of full size western blotting samples. We propose using a novel wafer scale APS (12.8 cm×13.2 cm), with an array architecture using two different pixel geometries that can deliver an inherently low noise and high dynamic range image at the same time representing a dramatic improvement with respect to the current western blotting imaging systems.

  17. Abnormal Magnetic Field Effects on Electrogenerated Chemiluminescence

    Science.gov (United States)

    Pan, Haiping; Shen, Yan; Wang, Hongfeng; He, Lei; Hu, Bin

    2015-03-01

    We report abnormal magnetic field effects on electrogenerated chemiluminescence (MFEECL) based on triplet emission from the Ru(bpy)3Cl2-TPrA electrochemical system: the appearance of MFEECL after magnetic field ceases. In early studies the normal MFEECL have been observed from electrochemical systems during the application of magnetic field. Here, the abnormal MFEECL suggest that the activated charge-transfer [Ru(bpy)33+ … TPrA•] complexes may become magnetized in magnetic field and experience a long magnetic relaxation after removing magnetic field. Our analysis indicates that the magnetic relaxation can gradually increase the density of charge-transfer complexes within reaction region due to decayed magnetic interactions, leading to a positive component in the abnormal MFEECL. On the other hand, the magnetic relaxation facilitates an inverse conversion from triplets to singlets within charge-transfer complexes. The inverse triplet --> singlet conversion reduces the density of triplet light-emitting states through charge-transfer complexes and gives rise to a negative component in the abnormal MFEECL. The combination of positive and negative components can essentially lead to a non-monotonic profile in the abnormal MFEECL after ceasing magnetic field. Nevertheless, our experimental studies may reveal un-usual magnetic behaviors with long magnetic relaxation from the activated charge-transfer [Ru(bpy)33+ … TPrA•] complexes in solution at room temperature.

  18. Photoinduced chemiluminescence determination of carbamate pesticides.

    Science.gov (United States)

    Catalá-Icardo, M; Meseguer-Lloret, S; Torres-Cartas, S

    2016-05-11

    A liquid chromatography method with post-column photoinduced chemiluminescence (PICL) detection is proposed for the simultaneous determination of eight carbamate pesticides, namely aldicarb, butocarboxim, ethiofencarb, methomyl, methiocarb, thiodicarb, thiofanox and thiophanate-methyl. After chromatographic separation, quinine (sensitizer) was incorporated and the flow passed through an UV lamp (67 s of irradiation time) to obtain the photoproducts, which reacted with acidic Ce(iv) and provided a CL emission. The PICL method showed great selectivity for carbamate pesticides containing sulphur in their chemical structure. A solid-phase extraction process increased sensitivity (LODs ranging from 0.06 to 0.27 ng mL(-1)) and allowed the carbamate pesticides in surface and ground water samples to be determined, with recoveries in the range 87-110% (except for thiophanate-methyl, whose recoveries were between 60 and 75%). The intra- and inter-day precision was evaluated, with RSD ranging from 1.1 to 7.5% and from 2.6 to 12.3%, respectively. A discussion about the PICL mechanism is also included.

  19. Lab-on-paper-based devices using chemiluminescence and electrogenerated chemiluminescence detection.

    Science.gov (United States)

    Ge, Lei; Yu, Jinghua; Ge, Shenguang; Yan, Mei

    2014-09-01

    As an analytical support, paper, being low cost, highly abundant, of high porosity, disposable or biodegradable, and easy to use, store, transport, and print, has excellent chemical compatibility with many applications. Since the first microfluidic paper-based analytical device (μ-PAD or lab-on-paper) was proposed, the paper-based assay has never attracted as much attention as it does now. There has recently been rapidly increasing interest in using sensitive luminescence methods, for example chemiluminescence (CL) and electrogenerated chemiluminescence (ECL), as the detection strategy for lab-on-paper devices. Because of their intrinsic characteristics, CL and ECL provide outstanding performance while retaining the simplicity, low cost, multifunctionality, versatility, flexibility, and disposability of μ-PADs. The objective of this review is to cover the development of lab-on-paper-based devices using CL and ECL detection, including fabrication of paper devices, construction of sensing interfaces, signal amplification strategies, external instruments used, and applications. We believe that lab-on-paper devices with CL and ECL detection methods will meet the diverse requirements of point-of-care diagnosis.

  20. Developments and Applications of Electrogenerated Chemiluminescence Sensors Based on Micro- and Nanomaterials

    Directory of Open Access Journals (Sweden)

    David T. Pierce

    2008-09-01

    Full Text Available A variety of recent developments and applications of electrogenerated chemiluminescence (ECL for sensors are described. While tris(2,2′-bipyridyl-ruthenium(II and luminol have dominated and continue to pervade the field of ECL-based sensors, recent work has focused on use of these lumophores with micro- and nanomaterials. It has also extended to inherently luminescent nanomaterials, such as quantum dots. Sensor configurations including microelectrode arrays and microfluidics are reviewed and, with the recent trend toward increased use of nanomaterials, special attention has been given to sensors which include thin films, nanoparticles and nanotubes. Applications of ECL labels and examples of label-free sensing that incorporate nanomaterials are also discussed.

  1. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  2. Field-flow fractionation of cells with chemiluminescence detection.

    Science.gov (United States)

    Melucci, Dora; Roda, Barbara; Zattoni, Andrea; Casolari, Sonia; Reschiglian, Pierluigi; Roda, Aldo

    2004-11-12

    Field-flow fractionation is a separation technique characterized by a retention mechanism which makes it suitable for sorting cells over a short analysis time, with low sample carry-over and preserving cell viability. Thanks to its high sensitivity, chemiluminescence detection is suitable for the quantification of just a few cells expressing chemiluminescence or bioluminescence. In this work, different formats for coupling gravitational field-flow fractionation and chemiluminescence detection are explored to achieve ultra-sensitive cell detection in the framework of cell sorting. The study is carried out using human red blood cells as model sample. The best performance is obtained with the on-line coupling format, performed in post-column flow-injection mode. Red cells are isolated from diluted whole human blood in just a few minutes and detected using the liquid phase chemiluminescent reaction of luminol catalysed by the red blood cell heme. The limit of detection is a few hundred injected cells. This is lower than the limit of detection usually achieved by means of conventional colorimetric/turbidimetric methods, and it corresponds to a red blood cell concentration in the injected sample of five orders of magnitude lower than in whole blood.

  3. Detection of antiphospholipid antibodies by automated chemiluminescence assay.

    Science.gov (United States)

    Capozzi, Antonella; Lococo, Emanuela; Grasso, Maria; Longo, Agostina; Garofalo, Tina; Misasi, Roberta; Sorice, Maurizio

    2012-05-31

    The laboratory diagnosis of antiphospholipid antibody syndrome (APS) requires the demonstration of antiphospholipid antibodies (aPL) by lupus anticoagulant (LAC) measured through coagulation assays, anticardiolipin IgG or IgM antibodies (aCL) and/or anti-β2-glycoprotein I IgG or IgM antibodies (anti-β2-GPI), usually detected by ELISA. In this study we tested aCL by a new automated system using the chemiluminescence principle. Our results showed that, while almost all the sera from APS patients, positive for IgG aCL and anti-β2-GPI by ELISA, were also positive for IgG aCl by chemiluminescence, only 30.13% of patients without clinical manifestations of APS, but positive for aCL and persistently negative for anti-β2-GPI (by ELISA) and LA, confirmed the positive test by chemiluminescence. This difference was highly significant (paCL and anti-β2-GPI IgG (ELISA). Thus, the new technology of automated chemiluminescence assay for measuring aPL may represent an useful tool to identify "true" APS patients. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Chemi-luminescent technique using low dose effect characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmenko, A.I.; Porokhnyak, L.A. [A.V. palladin Institute of Biochemistry, Ukrainian National Academy of Sciences, Kiev (Ukraine)

    1997-03-01

    Some Ukrainian and Belarusian territories are polluted by radioactive elements as Chernobyl AES accident consequence in 1986. Radioactive substances enter to animals and human organism with the food and lead to internal irradiation. The purpose of this work is he changes characteristic for an organism under internal irradiation low dose estimated by means of chemi-luminescent (Chl) techniques. (authors)

  5. Chemiluminescent reductive acridinium triggering (CRAT) - mechanism and applications

    NARCIS (Netherlands)

    Kooter, I.M.; Jedynska, A.D.; Zomer, B.; Collé, L.; Pasterkamp, G.; Bloemen, H.

    2011-01-01

    Acridinium esters traditionally are triggered using basic hydrogen peroxide. By serendipity, we have found that acridinium esters can also be triggered with emission of chemiluminescence by reductive triggering, e.g., by zinc metal or reduced forms of ferric and cupric salts. Furthermore, organic

  6. Inherently chemiluminescent compounds as new labels in clinical analysis.

    NARCIS (Netherlands)

    Hummelen, Jan Cornelis

    1985-01-01

    This thesis describes the synthesis, the properties, and the use of organic componds which emit light upon heating to ± 200˚C, without the need for a chemical additive. These chemiluminescent compounds belong to the class of relatively very stable 1,2-dioxetanes. 1,2 -Dioxetanes are cyclic peroxides

  7. Layered-nanomaterial-amplified chemiluminescence systems and their analytical applications.

    Science.gov (United States)

    Zhong, Jinpan; Yuan, Zhiqin; Lu, Chao

    2016-12-01

    Layered nanomaterial has become a popular hierarchical material for amplifying chemiluminescence (CL) in recent years, mainly because of its ease of preparation and modification, large specific surface area, and high catalytic activity. In this review, we mainly discuss layered-nanomaterial-amplified CL systems based on graphene and its derivatives, layered double hydroxides, and clay. Detection mechanisms and strategies of layered-nanomaterial-amplified CL systems are provided to show the basic concepts for designing sensitive and selective sensing systems. Strategies for expanding the applications of layered-nanomaterial-amplified CL systems by combination with surfactants, quantum dots, organic dyes, and nanoparticles are introduced for the analysis of various analytes in real samples. The challenges and future trends of layered-nanomaterial-amplified CL systems are discussed at the end of the review. Graphical Abstract Schematic illustration of layered nanomaterial amplified chemiluminescence.

  8. Detection of gamma irradiated pepper and papain by chemiluminescence

    Science.gov (United States)

    Sattar, Abdus; Delincée, H.; Diehl, J. F.

    Chemiluminescence (CL) measurements of black pepper and of papain using luminol and lucigenin reactions were studied. Effects of grinding, irradiation (5-20 kGy) and particle size (750-140 μm) on CL of pepper, and of irradiation (10-30 kGy) on CL of papain, were investigated. All the tested treatments affected the luminescence response in both the luminol and lucigenin reactions; however, the pattern of changes in each case, was inconsistent. Optimum pepper size for maximum luminescence was 560 μm, and optimum irradiation doses were >15 kGy for pepper and >20 kGy for papain. Chemiluminescence may possibly be used as an indicator or irradiation treatment for pepper and papain at a dose of 10 kGy or higher, but further research is needed to establish the reliability of this method.

  9. Chemiluminescence. Principles and applications in biology and medicine

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, A.K.

    1988-01-01

    Chemiluminescence, the emission of light caused by a chemical reaction, is a phenomenon used for many applications and of wide biological importance. It occurs in bacteria and insects (including glow-worms and fireflies), in many of the animals in the deep sea and even in human cells. The last 25 years have witnessed fast progress in the elucidation of the reactions and mechanisms underlying bioluminescence and light production by synthetic systems. Together with the development of highly sensitive light detectors, this has made available new biomedical methods and has given rise to new concepts concerning the biology and pathology of the cell. The book describes the occurrence, chemistry and measurement of chemiluminescence. It deals with the biological function and evolutionary significance, and looks at the many biomedical applications. The author describes the uses of chemiluminescence to measure enzymes, substrates and metabolites, to detect the changes of calcium concentration in living cells, to determine oxygen radicals or to replace the radioactive labels in immunoassays. Future applications in research and clinical laboratories are also discussed.

  10. Electrochemistry, Spectroscopy and Electrogenerated Chemiluminescence of Perylene, Terrylene, and Quaterrylene Diimides in Aprotic Solution

    NARCIS (Netherlands)

    Lee, Sang Kwon; Zu, Yanbing; Herrmann, Andreas; Geerts, Yves; Müllen, Kläus; Bard, Allen J.

    1999-01-01

    The electrochemistry, UV-vis spectrophotometry, photoluminescence, and electrogenerated chemiluminescence (ECL) of perylenedicarboxylic imide, perylenetetracarboxylic diimide (PDI), terrylenetetracarboxylic diimide (TDI), and quaterrylenecarboxylic diimide (QDI) were investigated. All compounds

  11. A simple and compact smartphone accessory for quantitative chemiluminescence-based lateral flow immunoassay for salivary cortisol detection.

    Science.gov (United States)

    Zangheri, Martina; Cevenini, Luca; Anfossi, Laura; Baggiani, Claudio; Simoni, Patrizia; Di Nardo, Fabio; Roda, Aldo

    2015-02-15

    We have developed a simple and accurate biosensor based on a chemiluminescent (CL)-lateral flow immunoassay (LFIA) method integrated in a smartphone to quantitatively detect salivary cortisol. The biosensor is based on a direct competitive immunoassay using peroxidase-cortisol conjugate, detected by adding the chemiluminescent substrate luminol/enhancer/hydrogen peroxide. The smartphone camera is used as light detector, for image acquisition and data handling via a specific application. We 3D-printed simple accessories to adapt the smartphone. The system comprises a cartridge, which houses the LFIA strip, and a smartphone adaptor with a plano-convex lens and a cartridge-insertion slot. This provides a mini-darkbox and aligned optical interface between the camera and the LFIA membrane for acquiring CL signals. The method is simple and fast, with a detection limit of 0.3 ng/mL. It provides quantitative analysis in the range of 0.3-60 ng/mL, which is adequate for detecting salivary cortisol in the clinically accepted range. It could thus find application in the growing area of home-self-diagnostic device technology for clinical biomarker monitoring, overcoming the current difficulties in achieving sensitive and quantitative information with conventional systems taking the advantage of smartphone connectivity and the enhanced performance of the included camera. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Characteristic of peroxyoxalate-chemiluminescence intensity in the presence of Chlorpheniramine maleate and its analytical application

    Energy Technology Data Exchange (ETDEWEB)

    Samadi-Maybodi, Abdolraouf, E-mail: samadi@umz.ac.ir [Analytical Division, Faculty of Chemistry, University of Mazandaran, Babolsar 4741695447 (Iran, Islamic Republic of); Akhoondi, Reza [Analytical Division, Faculty of Chemistry, University of Mazandaran, Babolsar 4741695447 (Iran, Islamic Republic of)

    2011-08-15

    It has been shown that Chlorpheniramine maleate (CPM) increases chemiluminescence intensity of bis-(2,4,6-trichlorophenyl)oxalate (TCPO) with hydrogen peroxide in the presence of biphenylquinoxaline as a fluorophore. In this work, the effect of CPM on the intensity of chemiluminescence (CL) in the system of (TCPO-sodium salicylate-fluorophore-hydrogen peroxide) was investigated. The fall and rise rates constants were also studied. A pooled-intermediate model was used for determining the kinetics parameters of CL with and without CPM. Results indicated that addition of CMP to this system increases the fall rate constant and decreases the rise rate constant. Results also specified that there is a linear relationship between CPA concentration and chemiluminescence intensity in the range 0.66-21.5 {mu}g/ml. Detection limit 0.18 {mu}g/ml and the relative standard deviation (RSD) <7% was obtained. This work is introduced as a new method for the determination of CMP. - Highlights: > The present study convincingly shows the enhancement of chemiluminescence intensity of peroxyoxalte chemiluminescence system (TCPO- H{sub 2}O{sub 2}- sodium salicylate- fluorescer) in the presence of chlorpheniramine maleate. > Results also introduced a reliable method for determination of chlorpheniramine using peroxyoxalte chemiluminescence system. > A pooled-intermediate model was used for determination the kinetics parameters of chemiluminescence with and without chlorpheniramine maleate. > Results also specified that there is a linear relationship between chlorpheniramine maleate concentration and chemiluminescence intensity.

  13. A 3-Step Chemiluminescence Method for Chemical Oxygen Demand Measurement.

    Science.gov (United States)

    Hue, Do Thi Kim; Hashimoto, Shohei; Nishikawa, Haruka; Maeda, Yasuaki; Takenaka, Norimichi

    2017-01-01

    Direct chemiluminescence emission from the reaction of acidic permanganate and organic compounds was employed for determining the chemical oxygen demand (COD) in water (1-step CL COD). Due to the diversity of organic pollutants in water, there are no standards for COD measurements, and many compounds do not show any chemiluminescence signal in the 1-step CL COD method. As a result, this method shows a low correlation with the conventional CODMn method. In this study, a new 3-step CL COD method was developed to overcome these drawbacks. The basic principle of the 3-step CL COD method is based on the principle of "back titration" in the CODMn method: (i) the sample is treated with permanganate under heating, (ii) the excess permanganate is treated with pyrogallol, and (iii) the excess pyrogallol is measured by the chemiluminescence reaction with permanganate. The reagent concentration, sample volume, and heating temperature were optimized, and the 3-step CL COD method successfully obtained the signal from some samples that cannot be detected by 1-step CL COD method. The calibration graph is linear in the range of 0 - 12.86 mg/L with a detection limit of 0.082 mg/L. This method is continuous, sensitive and low cost compared with the conventional method, and is applicable for on-site monitoring. The effect of the chloride ion was investigated, and showed an insignificant effect after two-times dilution of high-salinity samples. The correlation with the CODMn method for various organic compounds showed a good coefficient of determination, R2 = 0.9773 (n = 16).

  14. CO2^{*} chemiluminescence study at low and elevated pressures

    Science.gov (United States)

    Kopp, M.; Brower, M.; Mathieu, O.; Petersen, E.; Güthe, F.

    2012-06-01

    Chemiluminescence experiments have been performed to assess the state of current CO2^{*} kinetics modeling. The difficulty with modeling CO2^{*} lies in its broad emission spectrum, making it a challenge to isolate it from background emission of species such as CH∗ and CH2O∗. Experiments were performed in a mixture of 0.0005H2+0.01N2O+0.03CO+0.9595Ar in an attempt to isolate CO2^{*} emission. Temperatures ranged from 1654 K to 2221 K at two average pressures, 1.4 and 10.4 atm. The unique time histories of the various chemiluminescence species in the unconventional mixture employed at these conditions allow for easy identification of the CO2^{*} concentration. Two different wavelengths to capture CO2^{*} were used; one optical filter was centered at 415 nm and the other at 458 nm. The use of these two different wavelengths was done to verify that broadband CO2^{*} was in fact being captured, and not emission from other species such as CH∗ and CH2O∗. As a baseline for time history and peak magnitude comparison, OH∗ emission was captured at 307 nm simultaneously with the two CO2^{*} filters. The results from the two CO2^{*} filters were consistent with each other, implying that indeed the same species (i.e., CO2^{*}) was being measured at both wavelengths. A first-generation kinetics model for CO2^{*} and CH2O∗ was developed, since no comprehensively validated one exists to date. CH2O∗ and CH∗ were ruled out as being present in the experiments at any measurable level, based on calculations and comparisons with the data. Agreement with the CO2^{*} model was only fair, which necessitates future improvements for a better understanding of CO2^{*} chemiluminescence as well as the kinetics of the ground state species.

  15. Assessment of nitric oxide signals by triiodide chemiluminescence.

    Science.gov (United States)

    Hausladen, Alfred; Rafikov, Ruslan; Angelo, Michael; Singel, David J; Nudler, Evgeny; Stamler, Jonathan S

    2007-02-13

    Nitric oxide (NO) bioactivity is mainly conveyed through reactions with iron and thiols, furnishing iron nitrosyls and S-nitrosothiols with wide-ranging stabilities and reactivities. Triiodide chemiluminescence methodology has been popularized as uniquely capable of quantifying these species together with NO byproducts, such as nitrite and nitrosamines. Studies with triiodide, however, have challenged basic ideas of NO biochemistry. The assay, which involves addition of multiple reagents whose chemistry is not fully understood, thus requires extensive validation: Few protein standards have in fact been characterized; NO mass balance in biological mixtures has not been verified; and recovery of species that span the range of NO-group reactivities has not been assessed. Here we report on the performance of the triiodide assay vs. photolysis chemiluminescence in side-by-side assays of multiple nitrosylated standards of varied reactivities and in assays of endogenous Fe- and S-nitrosylated hemoglobin. Although the photolysis method consistently gives quantitative recoveries, the yields by triiodide are variable and generally low (approaching zero with some standards and endogenous samples). Moreover, in triiodide, added chemical reagents, changes in sample pH, and altered ionic composition result in decreased recoveries and misidentification of NO species. We further show that triiodide, rather than directly and exclusively producing NO, also produces the highly potent nitrosating agent, nitrosyliodide. Overall, we find that the triiodide assay is strongly influenced by sample composition and reactivity and does not reliably identify, quantify, or differentiate NO species in complex biological mixtures.

  16. A study of interferences in ozone UV and chemiluminescence monitors

    Energy Technology Data Exchange (ETDEWEB)

    Hudgens, E.E.; Kleindienst, T.E. [ManTech Environmental Technology, Inc., Research Triangle Park, NC (United States); McElroy, F.F. [Environmental Protection Agency, Research Triangle Park, NC (United States). Atmospheric Research and Exposure Assessment Laboratory; Ollison, W.M. [American Petroleum Inst., Washington, DC (United States)

    1994-12-31

    A study was conducted to examine interferences and other measurement anomalies in chemiluminescence and ultraviolet ozone monitors. Previous results had show that there was a positive deviation in the chemiluminescence monitors and no direct interference with ultraviolet monitors due to the presence of water at non-condensing concentrations. The present study continues this effort, examining both potential positive and negative effects of moisture and other interferences on these monitors. Aromatic compounds and their oxidation products could potentially show a positive interference with ultraviolet monitors, and test measurements were made with aromatics such as toluene, benzaldehyde, and nitrotoluene to determine their possible retention in the ozone scrubber and their absorption in the cell as a function of the humidity. A detailed examination of the scrubbers used in ultraviolet ozone monitors has also been undertaken. Ozone scrubbers that have shown anomalous behavior in the field have been studied in various reduced-efficacy modes under controlled laboratory conditions. Longer term tests of unused scrubbers for possible ozone breakthrough under exposure to various simulated field conditions were initiated.

  17. Selective Detection of Neurotransmitters by Fluorescence and Chemiluminescence Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ziqiang Wang; Edward S. Yeung

    2001-08-06

    In recent years, luminescence imaging has been widely employed in neurochemical analysis. It has a number of advantages for the study of neuronal and other biological cells: (1) a particular molecular species or cellular constituent can be selectively visualized in the presence of a large excess of other species in a heterogeneous environment; (2) low concentration detection limits can be achieved because of the inherent sensitivity associated with fluorescence and chemiluminescence; (3) low excitation intensities can be used so that long-term observation can be realized while the viability of the specimen is preserved; and (4) excellent spatial resolution can be obtained with the light microscope so subcellular compartments can be identified. With good sensitivity, temporal and spatial resolution, the flux of ions and molecules and the distribution and dynamics of intracellular species can be measured in real time with specific luminescence probes, substrates, or with native fluorescence. A noninvasive detection scheme based on glutamate dehydrogenase (GDH) enzymatic assay combined with microscopy was developed to measure the glutamate release in cultured cells from the central nervous system (CNS). The enzyme reaction is very specific and sensitive. The detection limit with CCD imaging is down to {micro}M levels of glutamate with reasonable response time. They also found that chemiluminescence associated with the ATP-dependent reaction between luciferase and luciferin can be used to image ATP at levels down to 10 nM in the millisecond time scale. Similar imaging experiments should be feasible in a broad spectrum of biological systems.

  18. Chemiluminescence assay for the detection of biological warfare agents

    Energy Technology Data Exchange (ETDEWEB)

    Langry, K; Horn, J

    1999-11-05

    A chemiluminescent homogeneous immunoassay and a hand-size multiassay reader are described that could be used for detecting biological materials. The special feature of the assay is that it employs two different antibodies that each bind to a unique epitope on the same antigen. Each group of epitope-specific antibodies has linked to it an enzyme of a proximal-enzyme pair. One enzyme of the pair utilizes a substrate in high concentration to produce a second substrate required by the second enzyme. This new substrate enables the second enzyme to function. The reaction of the second enzyme is configured to produce light. This chemiluminescence is detected with a charge-coupled device (CCD) camera. The proximal pair enzymes must be in close proximity to one another to allow the second enzyme to react with the product of the first enzyme. This only occurs when the enzyme-linked antibodies are attached to the antigen, whether antigen is a single protein with multiple epitopes or the surface of a cell with a variety of different antigens. As a result of their juxtaposition, the enzymes produce light only in the presence of the biological material. A brief description is given as to how this assay could be utilized in a personal bio-agent detector system.

  19. New method for monitoring nitric oxide in vivo using microdialysis sampling and chemiluminescence reaction

    Science.gov (United States)

    Yao, Dachun; Evmiridis, Nick P.; Zhou, Yikai; Xu, Shunqing; Zhou, Huarong

    2001-09-01

    A new method employing a combination of micro dialysis sampling and chemiluminescence reaction was developed to monitor nitric oxide (NO) in vivo. A special probe was designed with an interference-free membrane to achieve a very high selectivity for NO. High sensitivity was achieved by optimizing the working system and improving the NO sampling time. This system was used in vivo to monitor blood and brain tissue in rats and rabbits. We have established that this system is sensitive enough to detect variations in NO production in difference physiological state. The system can detect NO in the linear range of 5nM-1(mu) M, with a detection limit of 1nM, and real NO concentrations in our experimental animals were found to be in the range of 1-5 nM or even less. Finally, the effects of body temperature, NO donors, Viagra, NO activators, NO cofactors, NO interference were investigated carefully in different physiological situations.

  20. Tumor detection with sonodynamic chemiluminescence from ATX-70 and FCLA under ultrasonic excitation

    Science.gov (United States)

    He, Yonghong; Xing, Da; Yao, Yong; Yan, Guihong; Ueda, Ken-ichi

    2002-06-01

    A new tumor detection method by use of sonodynamic chemiluminescence was proposed in our previous work. In this paper, we further improved the diagnosis sensitivity by use of Gallium-porphyrin analogue ATX-70, one of the most active sonosensitizer found. In vitro experiments, sono-chemiluminescence of ATX-70 + FCLA system is about two times stronger than that of HpD + FCLA system. The sono-chemiluminescence was inhibited by 1O2 scavenger, but was not affected by other free radical scavenger. The mechanism of sonosensitizing was discussed. In vivo experiments, a more clearly tumor diagnostic image was obtained.

  1. Storable near-infrared chemiluminescent probes for in vivo optical imaging

    Science.gov (United States)

    Smith, Bradley D.

    2011-03-01

    A new class of chemiluminescent and fluorescent dyes and dye-doped nanoparticles can be stored at zero degrees and then made to emit near-infrared light by warming to body temperature (no chemical or electrical stimulus is needed). In vivo chemiluminescence imaging permits identification of target sites that are five times deeper than planar fluorescence imaging. A new imaging paradigm employs the dual modality probes first in high contrast chemiluminescence mode to locate relatively deep anatomical locations in vivo and subsequently in fluorescent mode to identify the microscopic targets within thin histopathology sections taken from the same specimen.

  2. [Neutrophil chemiluminescence using the Luminometer-1251 device and the Lumograf program].

    Science.gov (United States)

    Borunov, E V; Shchepetkin, I A; Cherdyntsev, E S; Cherdyntseva, N V

    1993-01-01

    Luminometer-1251 device in complex with the IBM-PC type computer was used to record the neutrophilic chemiluminescence response. Luminol-dependent chemiluminescent response of human neutrophils treated with phorbol-12-myristate-13-acetate in concentrations from 0.5 to 100 nM was examined over a 5 h incubation period. The results were computer-processed using an authors' program Lumograf. The suggested method may be used to record and process the data of long-coursing processes of chemiluminescence in a large series of samples.

  3. 3D-printed and CNC milled flow-cells for chemiluminescence detection.

    Science.gov (United States)

    Spilstead, Kara B; Learey, Jessica J; Doeven, Egan H; Barbante, Gregory J; Mohr, Stephan; Barnett, Neil W; Terry, Jessica M; Hall, Robynne M; Francis, Paul S

    2014-08-01

    Herein we explore modern fabrication techniques for the development of chemiluminescence detection flow-cells with features not attainable using the traditional coiled tubing approach. This includes the first 3D-printed chemiluminescence flow-cells, and a milled flow-cell designed to split the analyte stream into two separate detection zones within the same polymer chip. The flow-cells are compared to conventional detection systems using flow injection analysis (FIA) and high performance liquid chromatography (HPLC), with the fast chemiluminescence reactions of an acidic potassium permanganate reagent with morphine and a series of adrenergic phenolic amines. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Chemiluminescence enzyme immunoassay for the determination of sulfamethoxydiazine

    Science.gov (United States)

    Wu, Yongjun; Yu, Songcheng; Yu, Fei; Yan, Nali; Qu, Lingbo; Zhang, Hongquan

    2011-10-01

    Sulfamethoxydiazine (SMD), which is often used for animal disease treatment, is harmful to human health. No SMD residue should be detected in food in some countries, such as USA and Japan. Therefore, it is significant to develop a high-throughput, high-sensitivity and accurate method for the determination of the content of SMD in food. In this paper, chemiluminescence enzyme immunoassay (CLEIA) was developed for quantification of SMD. For this method, the limit of detection was 3.2 pg/ml, the linear range was from 10 to 2000 pg/ml, the within-day and inter-day precision were below 13% and below 18%, respectively, and the recovery was from 85% to 105%. Milk and egg were selected as samples to be examined with this method, and the result indicated that this CLEIA method was suitable for screening and quality control of food.

  5. Measurement of soil/dust arsenic by gas phase chemiluminescence.

    Science.gov (United States)

    Sawalha, Maather F; Sengupta, Mrinal K; Ohira, Shin-Ichi; Idowu, Ademola D; Gill, Thomas E; Rojo, Lila; Barnes, Melanie; Dasgupta, Purnendu K

    2008-10-19

    A gas phase chemiluminescence (GPCL)-based method for trace measurement of arsenic has been recently described for the measurement of arsenic in water. The principle is based on the reduction of inorganic As to AsH(3) at a controlled pH (the choice of pH governs whether only As(III) or all inorganic As is converted) and the reaction of AsH(3) with O(3) to produce chemiluminescence (Idowu et al., Anal. Chem. 78 (2006) 7088-7097). The same general principle has also been used in postcolumn reaction detection of As, where As species are separated chromatographically, then converted into inorganic As by passing through a UV photochemical reactor followed by AsH(3) generation and CL reaction with ozone (Idowu and Dasgupta, Anal. Chem. 79 (2007) 9197-9204). In the present paper we describe the measurement of As in different soil and dust samples by serial extraction with water, citric acid, sulfuric acid and nitric acid. We also compare parallel measurements for total As by induction coupled plasma mass spectrometry (ICP-MS). As(V) was the only species found in our samples. Because of chloride interference of isobaric ArCl(+) ICP-MS analyses could only be carried out by standard addition; these results were highly correlated with direct GPCL and LC-GPCL results (r(2)=0.9935 and 1.0000, respectively). The limit of detection (LOD) in the extracts was 0.36 microg/L by direct GPCL compared to 0.1 microg/L by ICP-MS. In sulfuric acid-based extracts, the LC-GPCL method provided LODs inferior to those previously observed for water-based standards and were 2.6, 1.3, 6.7, and 6.4 microg/L for As(III), As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA), respectively.

  6. Screening for antibodies against Treponema pallidum with chemiluminescent microparticle immunoassay: analysis of discordant serology results and clinical characterization.

    Science.gov (United States)

    Li, Zhiyan; Feng, Zhenru; Liu, Ping; Yan, Cunling

    2016-09-01

    Traditionally, testing for syphilis has consisted of initial screening with a non-treponemal test, then retesting reactive specimens with a treponemal test. Recent availability of a chemiluminescent microparticle immunoassay for detecting antibodies against Treponema pallidum has led several laboratories in China to adopt chemiluminescent microparticle immunoassay for screening of syphilis, with subsequent testing of reactive serum samples with non-treponemal tests. We evaluated the utility of chemiluminescent microparticle immunoassay for routine screening of syphilis. Antibodies against Treponema pallidum were screened in 20,550 serum samples using chemiluminescent microparticle immunoassay. Chemiluminescent microparticle immunoassay-positive samples were reflexively tested with rapid plasma reagin tests and Treponema pallidum particle agglutination assays. Dot-immunoblot assays were used to confirm results of chemiluminescent microparticle immunoassay-positive and Treponema pallidum particle agglutination-negative serum samples. Overall, 267 samples (1.3%) were chemiluminescent microparticle immunoassay-positive, and 185 (69.3%) of those chemiluminescent microparticle immunoassay-positive serum samples were also Treponema pallidum particle agglutination-positive. Samples' signal to cut-off ratio for chemiluminescent microparticle immunoassay correlated with diagnostic reliability, as greater samples' signal to cut-off ratio corresponded with greater concordance between chemiluminescent microparticle immunoassay and Treponema pallidum particle agglutination results. Dot-immunoblot testing of 82 chemiluminescent microparticle immunoassay-positive and Treponema pallidum particle agglutination-negative serum samples showed that 16 samples (19.5%) were Dot-immunoblot-positive, 28 (34.2%) were indeterminate and 38 (46.3%) were negative. Because there is a certain percentage of false-positive results using chemiluminescent microparticle immunoassay for routine

  7. Real time imaging of live cell ATP leaking or release events by chemiluminescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yun [Iowa State Univ., Ames, IA (United States)

    2008-12-18

    The purpose of this research was to expand the chemiluminescence microscopy applications in live bacterial/mammalian cell imaging and to improve the detection sensitivity for ATP leaking or release events. We first demonstrated that chemiluminescence (CL) imaging can be used to interrogate single bacterial cells. While using a luminometer allows detecting ATP from cell lysate extracted from at least 10 bacterial cells, all previous cell CL detection never reached this sensitivity of single bacteria level. We approached this goal with a different strategy from before: instead of breaking bacterial cell membrane and trying to capture the transiently diluted ATP with the firefly luciferase CL assay, we introduced the firefly luciferase enzyme into bacteria using the modern genetic techniques and placed the CL reaction substrate D-luciferin outside the cells. By damaging the cell membrane with various antibacterial drugs including antibiotics such as Penicillins and bacteriophages, the D-luciferin molecules diffused inside the cell and initiated the reaction that produces CL light. As firefly luciferases are large protein molecules which are retained within the cells before the total rupture and intracellular ATP concentration is high at the millmolar level, the CL reaction of firefly luciferase, ATP and D-luciferin can be kept for a relatively long time within the cells acting as a reaction container to generate enough photons for detection by the extremely sensitive intensified charge coupled device (ICCD) camera. The result was inspiring as various single bacterium lysis and leakage events were monitored with 10-s temporal resolution movies. We also found a new way of enhancing diffusion D-luciferin into cells by dehydrating the bacteria. Then we started with this novel single bacterial CL imaging technique, and applied it for quantifying gene expression levels from individual bacterial cells. Previous published result in single cell gene expression quantification

  8. Flow-injection chemiluminescence determination of tryptophan through its peroxidation and epoxidation by peroxynitrous acid.

    Science.gov (United States)

    Liang, Yao-Dong; Song, Jun-Feng

    2005-06-01

    A flow-injection chemiluminescence method for the determination of tryptophan was proposed, which was based on an intense chemiluminescence of tryptophan in hydrogen peroxide-nitrite-sulfuric acid medium. The chemiluminescence reaction was attributed to peroxidation and epoxidation of tryptophan by peroxynitrous acid, and subsequent decomposition of the formed dioxetane. The chemiluminescence intensity was linear with tryptophan in the range of 6.0 x 10(-7) to 3.0 x 10(-5)mol l(-1) and the limit of detection (S/N=3) was 1.8 x 10(-7)mol l(-1). The proposed method was applied to the analysis of tryptophan in pharmaceutical preparations and human serum.

  9. Surface plasmon coupled chemiluminescence during adsorption of oxygen on magnesium surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, Ulrich [Interdisciplinary Center for the Analytics on the Nanoscale (ICAN) and Center for Nanointegration Duisburg-Essen (CENIDE), Carl-Benz-Str. 199, 47057 Duisburg (Germany); Nienhaus, Hermann, E-mail: hermann.nienhaus@uni-due.de [Faculty of Physics, University of Duisburg-Essen and Center for Nanointegration Duisburg-Essen (CENIDE), Lotharstr. 1, 47048 Duisburg (Germany)

    2015-12-28

    The dissociative adsorption of oxygen molecules on magnesium surfaces represents a non-adiabatic reaction exhibiting exoelectron emission, chemicurrent generation, and weak chemiluminescence. Using thin film Mg/Ag/p-Si(111) Schottky diodes with 1 nm Mg on a 10-60 nm thick Ag layer as 2π-photodetectors, the chemiluminescence is internally detected with a much larger efficiency than external methods. The chemically induced photoyield shows a maximum for a Ag film thickness of 45 nm. The enhancement is explained by surface plasmon coupled chemiluminescence, i.e., surface plasmon polaritons are effectively excited in the Ag layer by the oxidation reaction and decay radiatively leading to the observed photocurrent. Model calculations of the maximum absorption in attenuated total reflection geometry support the interpretation. The study demonstrates the extreme sensitivity and the practical usage of internal detection schemes for investigating surface chemiluminescence.

  10. Inhibition of human monocyte chemotaxis and chemiluminescence by Pseudomonas aeruginosa elastase

    DEFF Research Database (Denmark)

    Kharazmi, A; Nielsen, H

    1991-01-01

    The in vitro effect of Pseudomonas aeruginosa elastase on human monocyte function was examined. Mononuclear cells isolated from the peripheral blood of healthy individuals were incubated with various concentrations of elastase, and the chemotactic activity and chemiluminescence response of these ...

  11. Chemiluminescence determination of surfactant Triton X-100 in environmental water with luminol-hydrogen peroxide system

    National Research Council Canada - National Science Library

    Liu, Xiaoyu; Li, Aifang; Zhou, Baohui; Qiu, Chaokun; Ren, Hongmin

    2009-01-01

    ... studied.The novel chemiluminescence method for the determination of non-ionic surfactant Triton X-100 was based on the phenomenon that Triton X-100 greatly enhanced the CL signal of the luminol-H2O2 system...

  12. A highly selective chemiluminescent probe for the detection of chromium(VI).

    Science.gov (United States)

    Jin, Yan; Sun, Yonghua; Li, Chongying; Yang, Chao

    2017-11-07

    In present work, rhodamine B hydrazide and rhodamine 6G hydrazide were synthesized and the chemiluminescence performance has been investigated. Based on the chemiluminescence of rhodamine 6G hydrazide‑chromium(VI), a selective and sensitive method for the direct detection of chromium(VI) was developed. The chemiluminescence intensity was linearly related to the concentration of chromium(VI) in the range of 2.60×10(-8)-8.00×10(-6)mol/L with a correlation coefficient of r=0.998 and a detection limit of 1.4×10(-8)mol/L (S/N=3). The results indicated rhodamine 6G hydrazide was an excellent chemiluminescent probe for chromium(VI) without reduction of chromium(VI) to chromium(III). A possible mechanism of CL emission was also suggested. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Chemiluminescence response of human neutrophils to He-Ne laser irradiation (in vivo and in vitro)

    OpenAIRE

    Schepetkin, I.; Udut, V.; Karpov, A.

    1994-01-01

    He-Ne laser irradiation (0.01-6 J/cm3) of the blood and neutrophile suspension in vitrowas shown to modulate reactive oxygen species (ROS) production in healthy donors. Intravascular laser irradiation of the blood (5 mW, 30 minutes, daily) of the patients with chronic gastric ulcer during first 5 days resulted in increasing stimul-induced ROS production in patients with the low initial chemiluminescence response and its decreasing in patients with the high initial chemiluminescence response.

  14. Acridinium Ester-Functionalized Carbon Nanomaterials: General Synthesis Strategy and Outstanding Chemiluminescence.

    Science.gov (United States)

    Han, Zhili; Li, Fang; Shu, Jiangnan; Gao, Lingfeng; Liu, Xiaoying; Cui, Hua

    2016-07-13

    In this work, three different kinds of acridinium ester (AE)-functionalized carbon nanomaterials, including AE-functionalized carbon nanoparticles (AE-CNPs), AE-functionalized graphene oxide (AE-GO), and AE-functionalized multiwalled carbon nanotubes (AE-MCNTs), were synthesized for the first time via a simple, general, and noncovalent strategy. AE molecules were assembled on the surface of carbon nanomaterials by electrostatic interaction, π-π stacking interaction, and amide bond. The synthesized AE-CNPs, AE-GO, and AE-MCNTs with 5.0 × 10(-8) mol·L(-1) of synthetic AE concentration, which was very low compared with other chemiluminescence (CL) reagents such as luminol, N-(aminobutyl)-N-(ethylisoluminol), and lucigenin at the concentration of 3.3 × 10(-4) to 5.0 × 10(-6) mol·L(-1) used for the synthesis of CL-functionalized nanomaterials, exhibited outstanding CL activity and good stability. It was found that carbon nanomaterials as nanosized platforms could efficiently immobilize AE molecules and facilitate the formation of OH(•) and O2(•-), leading to strong light emission. Moreover, the CL intensity of AE-GO was the highest, which was about 8.7 and 3.7 times higher than that of AE-CNPs and AE-MCNTs, respectively. This mainly resulted from a difference in the amount of adsorbed AE molecules on the surface of different carbon nanomaterials. Additionally, the prepared AE-CNPs demonstrated excitation-dependent fluorescence property and good fluorescence stability against photobleaching. On the basis of the excellent CL and special fluorescence properties of AE-CNPs, a dual-mode array strategy has been proposed for the first time and seven kinds of transition-metal ions could be successfully discriminated.

  15. Chemiluminescence generation and detection in a capillary-driven microfluidic chip

    Science.gov (United States)

    Ramon, Charlotte; Temiz, Yuksel; Delamarche, Emmanuel

    2017-02-01

    The use of microfluidic technology represents a strong opportunity for providing sensitive, low-cost and rapid diagnosis at the point-of-care and such a technology might therefore support better, faster and more efficient diagnosis and treatment of patients at home and in healthcare settings both in developed and developing countries. In this work, we consider luminescence-based assays as an alternative to well-established fluorescence-based systems because luminescence does not require a light source or expensive optical components and is therefore a promising detection method for point-of-care applications. Here, we show a proof-of-concept of chemiluminescence (CL) generation and detection in a capillary-driven microfluidic chip for potential immunoassay applications. We employed a commercial acridan-based reaction, which is catalyzed by horseradish peroxidase (HRP). We investigated CL generation under flow conditions using a simplified immunoassay model where HRP is used instead of the complete sandwich immunocomplex. First, CL signals were generated in a capillary microfluidic chip by immobilizing HRP on a polydimethylsiloxane (PDMS) sealing layer using stencil deposition and flowing CL substrate through the hydrophilic channels. CL signals were detected using a compact (only 5×5×2.5 cm3) and custom-designed scanner, which was assembled for less than $30 and comprised a 128×1 photodiode array, a mini stepper motor, an Arduino microcontroller, and a 3D-printed housing. In addition, microfluidic chips having specific 30-μm-deep structures were fabricated and used to immobilize ensembles of 4.50 μm beads functionalized with HRP so as to generate high CL signals from capillary-driven chips.

  16. Chemiluminescence assay for quinones based on generation of reactive oxygen species through the redox cycle of quinone.

    Science.gov (United States)

    Kishikawa, Naoya; Ohkubo, Nobuhiro; Ohyama, Kaname; Nakashima, Kenichiro; Kuroda, Naotaka

    2009-02-01

    A sensitive and selective chemiluminescence assay for the determination of quinones was developed. The method was based on generation of reactive oxygen species through the redox reaction between quinone and dithiothreitol as reductant, and then the generated reactive oxygen was detected by luminol chemiluminescence. The chemiluminescence was intense, long-lived, and proportional to quinone concentration. It is concluded that superoxide anion was involved in the proposed chemiluminescence reaction because the chemiluminescence intensity was decreased only in the presence of superoxide dismutase. Among the tested quinones, the chemiluminescence was observed from 9,10-phenanthrenequinone, 1,2-naphthoquinone, and 1,4-naphthoquinone, whereas it was not observed from 9,10-anthraquinone and 1,4-benzoquinone. The chemiluminescence property was greatly different according to the structure of quinones. The chemiluminescence was also observed for biologically important quinones such as ubiquinone. Therefore, a simple and rapid assay for ubiquinone in pharmaceutical preparation was developed based on the proposed chemiluminescence reaction. The detection limit (blank + 3SD) of ubiquinone was 0.05 microM (9 ng/assay) with an analysis time of 30 s per sample. The developed assay allowed the direct determination of ubiquinone in pharmaceutical preparation without any purification procedure.

  17. Novel chemiluminescent Western blot blocking and antibody incubation solution for enhanced antibody-antigen interaction and increased specificity.

    Science.gov (United States)

    Schwartz, Kimberly; Bochkariov, Dmitry

    2017-10-01

    Western blotting is a ubiquitous tool used in protein and molecular biology research, providing information about the presence, size, relative abundance, and state of a protein in a mixture. First, the proteins in a sample are separated by size using SDS-PAGE then transferred onto a membrane for detection with a set of primary and secondary antibodies. High-quality Western data requires high signal-to-noise ratios, which depend upon reduction of nonspecific antibody interactions. Blocking is a critical step in the Western blot method as it prevents the antibodies from binding nonspecifically to the membrane and irrelevant proteins. A solution of nonfat dry milk (NFDM) in physiological buffer is commonly used for this purpose, but does not perform well with every type of antibody and is not optimal for low-abundance proteins. We present a novel blocking solution for chemiluminescent Western blots, AdvanBlock™-chemi, which outperforms NFDM in experiments with 20 unique antibodies by increasing signal-to-noise ratios and minimizing nonspecific binding. This solution enhances protein detection by Western blot and provides consistent results for detection of low abundant and modified proteins. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Water Membrane Evaporator

    Science.gov (United States)

    Ungar, Eugene K.; Almlie, Jay C.

    2010-01-01

    A water membrane evaporator (WME) has been conceived and tested as an alternative to the contamination-sensitive and corrosion-prone evaporators currently used for dissipating heat from space vehicles. The WME consists mainly of the following components: An outer stainless-steel screen that provides structural support for the components mentioned next; Inside and in contact with the stainless-steel screen, a hydrophobic membrane that is permeable to water vapor; Inside and in contact with the hydrophobic membrane, a hydrophilic membrane that transports the liquid feedwater to the inner surface of the hydrophobic membrane; Inside and in contact with the hydrophilic membrane, an annular array of tubes through which flows the spacecraft coolant carrying the heat to be dissipated; and An inner exclusion tube that limits the volume of feedwater in the WME. In operation, a pressurized feedwater reservoir is connected to the volume between the exclusion tube and the coolant tubes. Feedwater fills the volume, saturates the hydrophilic membrane, and is retained by the hydrophobic membrane. The outside of the WME is exposed to space vacuum. Heat from the spacecraft coolant is conducted through the tube walls and the water-saturated hydrophilic membrane to the liquid/vapor interface at the hydrophobic membrane, causing water to evaporate to space. Makeup water flows into the hydrophilic membrane through gaps between the coolant tubes.

  19. Evaluation of a new chemiluminescence immunoassay for diagnosis of syphilis

    Directory of Open Access Journals (Sweden)

    Mo Xiaohui

    2010-02-01

    Full Text Available Abstract Objective To assess the sensitivity, specificity, and feasibility of a new chemiluminescence immunoassay (CLIA in the diagnosis of syphilis. Methods At first, a retrospective study was conducted, using 135 documented cases of syphilis and 30 potentially interfering samples and 80 normal sera. A prospective study was also performed by testing 2, 071 unselected samples for routine screening for syphilis. CLIA was compared with a nontreponemal test (TRUST and a treponemal test (TPPA. Results There was an agreement of 100% between CLIA and TPPA in the respective study. The percentage of agreement among the 245 sera tested was 100.0%. Compared with TPPA, the specificity of CLIA was 99.9% (1817/1819, the sensitivity of CLIA was 100.0% (244/244 in the prospective study. CLIA showed 99.5% agreement with TPPA by testing 2, 071 unselected samples. And CLIA seemed to be more sensitive than TPPA in detecting the samples of primary syphilis. Conclusions CLIA is easy to perform and the indicator results are objective and unequivocal. It may be suitable for large-scale screening as a treponemal test substituted for TPPA.

  20. Mechanism of alcohol-enhanced lucigenin chemiluminescence in alkaline solution.

    Science.gov (United States)

    Chi, Quan; Chen, Wanying; He, Zhike

    2015-11-01

    The chemiluminescence (CL) of lucigenin (Luc(2+)) can be enhanced by different alcohols in alkaline solution. The effect of different fatty alcohols on the CL of lucigenin was related to the carbon chain length and the number of hydroxyl groups. Glycerol provides the greatest enhancement. UV/Vis absorption spectra and fluorescence spectra showed that N-methylacridone (NMA) was produced in the CL reaction in the presence of different alcohols. The peak of the CL spectrum was located at 470 nm in all cases, indicating that the luminophore was always the excited-state NMA. The quenching of lucigenin CL by superoxide dismutase (SOD) and the electron spin resonance (ESR) results with the spin trap of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) demonstrated that superoxide anions (O2 (•-)) were generated from dissolved oxygen in the CL reaction and that glycerol and dihydroxyacetone (DHA) can promote O2 (•-) production by the reduction of dissolved oxygen in alkaline solution. It was assumed that the enhancement provided by different alcohols was related to the solvent effect and reducing capacity. Glycerol and DHA can also reduce Luc(2+) into lucigenin cation radicals (Luc(•+) ), which react with O2 (•-) to produce CL, and glycerol can slowly transform into DHA, which is oxidized quickly in alkaline solution. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Influence of temperature changes on ambient air NOx chemiluminescence measurements.

    Science.gov (United States)

    Miñarro, Marta Doval; Ferradás, Enrique González; Martínez, Francisco J Marzal

    2012-09-01

    Users of automatic air pollution monitors are largely unaware of how certain parameters, like temperature, can affect readings. The present work examines the influence of temperature changes on chemiluminescence NO(x) measurements made with a Thermo Scientific 42i analyzer, a model widely used in air monitoring networks and air pollution studies. These changes are grouped into two categories according to European Standard EN 14211: (1) changes in the air surrounding the analyzers and (2) changes in the sampled air. First, the sensitivity tests described in Standard EN 14211 were performed to determine whether the analyzer performance was adapted to the requirements of the standard. The analyzer met the performance criteria of both tests; however, some differences were detected in readings with temperature changes even though the temperature compensator was on. Sample temperature changes were studied more deeply as they were the most critical (they cannot be controlled and differences of several tens of degrees can be present in a single day). Significant differences in readings were obtained when changing sample temperature; however, maximum deviations were around 3% for temperature ranges of 15°C. If other possible uncertainty contributions are controlled and temperature variations with respect to the calibration temperature are not higher than 15°C, the effect of temperature changes could be acceptable and no data correction should have to be applied.

  2. Sensitive determination of triacetone triperoxide explosives using electrogenerated chemiluminescence.

    Science.gov (United States)

    Parajuli, Suman; Miao, Wujian

    2013-08-20

    Sensitive and selective detection and quantification of high explosive triacetone triperoxide (TATP) with electrogenerated chemiluminescence (ECL) at a glassy carbon electrode in water-acetonitrile solvent mixture were reported. In the presence of ruthenium(II) tris(bipyridine), TATP or hydrogen peroxide derived from TATP via UV irradiation or acid treatment produced ECL emissions upon cathodic potential scanning. Interference from hydrogen peroxide on TATP detection was eliminated by pretreatment of the analyte with catalase enzyme. Selective detection of TATP from hexamethylene triperoxide diamine (HMTD, another common peroxide-based explosive) was realized by comparing ECL responses obtained from the anodic and the cathodic potential scanning; TATP produced ECL upon cathodic potential scanning only, whereas HMTD produced ECL upon both cathodic and anodic potential scanning. The hydroxyl radical formed after the electrochemical reduction of TATP was believed to be the key intermediate for ECL production, and its stability was strongly dependent on the solution composition, which was verified with electron paramagnetic resonance spectroscopy. A detection limit of 2.5 μM TATP was obtained from direct electrochemical reduction of the explosive or hydrogen peroxide derived from TATP in 70/30% (v/v) water-acetonitrile solutions, which was ~400 times lower than that reported previously based on liquid chromatography separation and Fourier transform infrared detection.

  3. Chemiluminescence microarrays in analytical chemistry: a critical review.

    Science.gov (United States)

    Seidel, Michael; Niessner, Reinhard

    2014-09-01

    Multi-analyte immunoassays on microarrays and on multiplex DNA microarrays have been described for quantitative analysis of small organic molecules (e.g., antibiotics, drugs of abuse, small molecule toxins), proteins (e.g., antibodies or protein toxins), and microorganisms, viruses, and eukaryotic cells. In analytical chemistry, multi-analyte detection by use of analytical microarrays has become an innovative research topic because of the possibility of generating several sets of quantitative data for different analyte classes in a short time. Chemiluminescence (CL) microarrays are powerful tools for rapid multiplex analysis of complex matrices. A wide range of applications for CL microarrays is described in the literature dealing with analytical microarrays. The motivation for this review is to summarize the current state of CL-based analytical microarrays. Combining analysis of different compound classes on CL microarrays reduces analysis time, cost of reagents, and use of laboratory space. Applications are discussed, with examples from food safety, water safety, environmental monitoring, diagnostics, forensics, toxicology, and biosecurity. The potential and limitations of research on multiplex analysis by use of CL microarrays are discussed in this review.

  4. Strongly Chemiluminescent Acridinium Esters under Neutral Conditions: Synthesis, Properties, Determination, and Theoretical Study.

    Science.gov (United States)

    Nakazono, Manabu; Oshikawa, Yuji; Nakamura, Mizuho; Kubota, Hidehiro; Nanbu, Shinkoh

    2017-03-03

    Various novel acridinium ester derivatives having phenyl and biphenyl moieties were synthesized, and their optimal chemiluminescence conditions were investigated. Several strongly chemiluminescent acridinium esters under neutral conditions were found, and then these derivatives were used to detect hydrogen peroxide and glucose. Acridinium esters having strong electron-withdrawing groups such as cyano, methoxycarbonyl, and nitro at the 4-position of the phenyl moiety in phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt showed strong chemiluminescence intensities. The chemiluminescence intensity of 3,4-dicyanophenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt was approximately 100 times stronger than that of phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7. The linear calibration ranges of hydrogen peroxide and glucose were 0.05-10 mM and 10-2000 μM using 3,4-(dimethoxycarbonyl)phenyl 10-methyl-10λ4-acridine-9-carboxylate trifluoromethanesulfonate salt at pH 7 and pH 7.5, respectively. The proposed chemiluminescence reaction mechanism of acridinium ester via a dioxetanone structure was evaluated via quantum chemical calculation on density functional theory. The proposed mechanism was composed of the nucleophilic addition reaction of hydroperoxide anion, dioxetanone ring formation, and nonadiabatic transition due to spin-orbit coupling around the transition state (TS) to the triplet state (T1) following the decomposition pathway. The TS which appeared in the thermal decomposition would be a rate-determining step for all three processes.

  5. Harmful Gas Recognition Exploiting a CTL Sensor Array

    Directory of Open Access Journals (Sweden)

    Yao Zheng

    2013-10-01

    Full Text Available In this paper, a novel cataluminescence (CTL-based sensor array consisting of nine types of catalytic materials is developed for the recognition of several harmful gases, namely carbon monoxide, acetone, chloroform and toluene. First, the experimental setup is constructed by using sensing nanomaterials, a heating plate, a pneumatic pump, a gas flow meter, a digital temperature device, a camera and a BPCL Ultra Weak Chemiluminescence Analyzer. Then, unique CTL patterns for the four types of harmful gas are obtained from the sensor array. The harmful gases are successful recognized by the PCA method. The optimal conditions are also investigated. Finally, experimental results show high sensitivity, long-term stability and good linearity of the sensor array, which combined with simplicity, make our system a promising application in this field.

  6. Storable, thermally activated, near-infrared chemiluminescent dyes and dye-stained microparticles for optical imaging

    Science.gov (United States)

    Baumes, Jeffrey M.; Gassensmith, Jeremiah J.; Giblin, Jay; Lee, Jung-Jae; White, Alexander G.; Culligan, William J.; Leevy, W. Matthew; Kuno, Masaru; Smith, Bradley D.

    2010-12-01

    Imaging techniques are a vital part of clinical diagnostics, biomedical research and nanotechnology. Optical molecular imaging makes use of relatively harmless, low-energy light and technically straightforward instrumentation. Self-illuminating, chemiluminescent systems are particularly attractive because they have inherently high signal contrast due to the lack of background emission. Currently, chemiluminescence imaging involves short-lived molecular species that are not stored but are instead generated in situ, and they typically emit visible light, which does not penetrate far through heterogeneous biological media. Here, we describe a new paradigm for optical molecular imaging using squaraine rotaxane endoperoxides, interlocked fluorescent and chemiluminescent dye molecules that have a squaraine chromophore encapsulated inside a macrocycle endoperoxide. Squaraine rotaxane endoperoxides can be stored indefinitely at temperatures below -20 °C, but upon warming to body temperature they undergo a unimolecular chemical reaction and emit near-infrared light that can pass through a living mouse.

  7. A kinetic study of the enhancement of solution chemiluminescence of glyoxylic acid oxidation by manganese species.

    Science.gov (United States)

    Otamonga, Jean-Paul; Abdel-Mageed, Amal; Agater, Irena B; Jewsbury, Roger A

    2015-08-01

    In order to study the mechanism of the enhancement of solution chemiluminescence, the kinetics of the decay of the oxidant and the chemiluminescence emission were followed for oxidations by permanganate, manganese dioxide sol and Mn(3+) (aq) of glyoxylic acid, using stopped-flow spectrophotometry. Results are reported for the glyoxylic acid oxidized under pseudo first-order conditions and in an acidic medium at 25 °C. For permanganate under these conditions, the decay is sigmoidal, consistent with autocatalysis, and for manganese dioxide sol and Mn(3+) it is pseudo first order. The effects of the presence of aqueous formaldehyde and Mn(2+) were observed and a fit to a simple mechanism is discussed. It is concluded that chemiluminescent enhancement in these systems is best explained by reaction kinetics. Copyright © 2014 John Wiley & Sons, Ltd.

  8. Chemiluminescence of benzo(a)pyrene-7,8-diol

    Energy Technology Data Exchange (ETDEWEB)

    Seliger, H.H.; Thompson, A.; Hamman, J.P.; Posner, G.H.

    1982-01-01

    The chemiluminescence (CL) of benzo(a)pyrene-7,8-diol (BP-7,8-diol) originally observed in liver microsomal extracts has been produced in greater than 10/sup 4/ higher yield by reaction with sodium hypochlorite and hydrogen peroxide (NaOCl - H/sub 2/O/sub 2/). The kinetics and the substrate concentration dependence for the NaOCl/H/sub 2/O/sub 2/ initiated CL are the same as those for Rose Bengal photosensitization of CL. In this latter singlet oxygen generating system the CL is quenched by ..beta..-carotene at a diffusion controlled rate of 1.2 x 10/sup 10/ M/sup -1/ s/sup -1/. The chemically-initiated CL emission spectrum of BP-7,8-diol appears to be the same as that of the microsomal CL. The long lifetime of the CL (tau = 240s), the production of CL by /sup 1/O/sub 2/ and the effects of electron donors upon the effective rate constant for decay of CL are consistent with the formation of a dioxetane intermediate. The linear dependence of CL upon substrate concentration indicates that the emission is from a monomer excited state rather than from an exciplex as suggested previously. Under the same chemical conditions the relative light yields from benzo(a)pyrene, its 12 monohydroxy derivatives and its other dihydro-diol derivatives range from 10/sup -2/ to 10/sup -5/ of the CL from BP-7,8-diol. The specificity of the chemically-initiated CL of BP-7,8-diol may provide a sensitive assay for this metabolite. 6 figures.

  9. Clinical utility of automated chemiluminescent antiphospholipid antibody assay.

    Science.gov (United States)

    Iwaniec, Teresa; Kaczor, Marcin P; Celińska-Löwenhoff, Magdalena; Polański, Stanisław; Musiał, Jacek

    2015-11-01

    The threshold for clinically relevant levels of antiphospholipid (aPL) antibodies for the diagnosis of antiphospholipid syndrome (APS) remains a matter of debate. As new technologies for antibody detection are introduced, their performance characteristics must be clearly understood and compared to traditional assays. To assess the analytical performance and clinical utility of fully automated anticardiolipin (aCL) and anti-β2 glycoprotein I (aβ2GPI) chemiluminescent immunoassays (CIA) in comparison to the traditional ELISA tests. Samples from 220 autoimmune patients were studied (primary APS - 74; secondary APS - 47, systemic lupus erythematosus (SLE) without APS - 99). All samples were tested for IgG and IgM aCL and β2GPI antibodies using both CIA and ELISA, and for lupus anticoagulant (LAC). Good qualitative agreement and quantitative correlation were found between methods in regard to individual antibodies and their categories (profiles). All assays showed good clinical performance in APS, and strong correlation with APS-related clinical symptoms. Importance of determining individual laboratory 99 percentile values for a healthy population as normal cut-off values was shown. Additionally, based on a clinical approach, this study has established the low/medium threshold for QUANTA Flash aCL IgG and IgM assays. This study showed good clinical performance and strong correlation of the new automated CIA aPL assays with APS clinical symptoms. It also enabled us to determine the corresponding low/medium antibody threshold for the aCL antibody methods with different unit types. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Enzymatic elongation of microsatellite oligomers for use in direct-label chemiluminescent hybridizations.

    Science.gov (United States)

    Longmire, J L; Ratliff, R L

    1994-12-01

    Short, synthetic oligonucleotide sequences representing microsatellites and other short tandem repeats can be elongated (concatamerized) using a simple method in which complementary strands are annealed, phosphorylated, primer extended and ligated. When used in direct-label chemiluminescent hybridizations, the elongated microsatellite sequences provide an approximately 30-fold increase in signal strength compared with microsatellite oligomers that have not been concatamerized. Concatamerization of simple repeat oligomers further enables the use of relatively short oligonucleotide sequences in direct-label chemiluminescent hybridization experiments, thereby reducing the overall need for radioisotopes in certain commonly performed laboratory procedures such as DNA fingerprinting and selection of clones containing microsatellite sequences.

  11. Flow-injection chemiluminescence determination of chloroquine using peroxynitrous acid as oxidant.

    Science.gov (United States)

    Liang, Yao-Dong; Song, Jun-Feng; Yang, Xiao-Feng; Guo, Wei

    2004-03-10

    A new flow-injection chemiluminescence (CL) method for determination of chloroquine is proposed based on a stronger chemiluminescence of chloroquine in hydrogen peroxide-nitrite-sulfuric acid medium. The proposed method allows the measurement of chloroquine over the range of 3.0x10(-7) to 1.0x10(-5)moll(-1). The detection limit is 8.6x10(-8)moll(-1), and the relative standard deviation for 1.0x10(-6)moll(-1) chloroquine (n=11) is 1.6%. The CL mechanism is also discussed.

  12. Microfabricated Renewable Beads-Trapping/Releasing Flow Cell for Rapid Antigen-Antibody Reaction in Chemiluminescent Immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Zhifeng; Shao, Guocheng; Wang, Jun; Lu, Donglai; Wang, Wanjun; Lin, Yuehe

    2011-04-01

    A filter pillar-array microstructure was coupled with a pneumatic micro-valve to fabricate a reusable miniaturized beads-trapping/releasing flow cell, in which trapping and releasing beads can be conveniently realized by switching the micro-valve. This miniaturized device was suitable to construct automatic fluidic system for “renewable surface analysis”. The renewable surface strategy based on pneumatic micro-valve enabled capture of beads in beads chamber prior to each assay, and release of the used beads after the assay. Chemiluminescent competitive immunoassay of 3,5,6-trichloropyridinol (TCP) was performed as a model to demonstrate the application potential of this reusable miniaturized flow cell. The whole fluidic assay process including beads trapping, immuno-binding, beads washing, beads releasing and signal collection could be completed in 10 min. Immunoassay of TCP using this miniaturized device showed a linear range of 0.20-70 ng/mL with a limit of detection of 0.080 ng/mL. The device had been successfully used for detection of TCP spiked in rat serum with average recovery of 97%. This investigation provides a rapid, sensitive, reusable, low-cost and automatic miniaturized device for solid-phase biochemical analysis for various purposes.

  13. Development of immune-affinity 96 spots monolith array for multiple mycotoxins detection in food samples.

    Science.gov (United States)

    Li, Li; Xia, Li-Ru; Zhao, Yong-Fu; Wang, He-Ye

    2016-09-01

    In this paper, a novel highly sensitive chemiluminescence immune-affinity 96 spots monolith array was developed to detect deoxynivalenol (DON), zearalenone (ZEN), T-2 toxin (T-2), and fumonisin B1 (FB1) in corn samples. Firstly, the monolith array was prepared through on suit UV-initiated copolymerization using polyethylene glycol diacrylate (PEGDA) as cross-linker, glycidyl methacrylate (GMA) as functional monomer and polyethylene glycol 200 (PEG 200) as the porogen. Subsequently, the four mycotoxins immune-affinity monolith array was prepared by immobilization of DON, ZEN, T-2, and FB1 antibody. The mole ratio of PEGDA/GMA, UV exposure time, and the volume ratio of PEG 200/PEGDA were optimized to improve the performances of the immune-affinity monolith array. For the mycotoxins immune-affinity monolith array based on chemiluminescence detection, the limit of detection was 0.0036ng/mL (DON), 0.0048ng/mL (ZEN), 0.0039ng/mL (T-2), and 0.0017ng/mL (FB1), respectively. The linear response in the range of 0.01-0.1ng/mL (R(2)=0.98). The results showed that the proposed four mycotoxins immune-affinity monolith array was a stable, accurate, and highly sensitive method to determine levels of DON, ZEN, T-2, and FB1 in real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  15. A comparison of chemiluminescent and radioenzymatic methods for the measurement of acetylcholine released from a rat phrenic nerve-hemidiaphragm preparation.

    Science.gov (United States)

    Ehler, K W; Hoops, E A; Storella, R J; Bierkamper, G G

    1986-11-01

    A chemiluminescent assay coupled to a periodide extraction method is described for the measurement of acetylcholine release from the vascular perfused rat phrenic nerve-hemidiaphragm preparation. A direct comparison of the chemiluminescent assay with an established radioenzymatic assay for acetylcholine demonstrates that the two assays are quantitatively equivalent and yield similar limits of sensitivity of approximately 2 pmol, and that the periodide extraction/chemiluminescent assay method is more consistent than the tetraphenylboron extraction/radioenzymatic assay method. Additionally, cholinergic drug interference with the chemiluminescent assay is minimal. The absence of radioactivity and the reduced cost of the chemiluminescent assay make it an attractive alternative to the radioenzymatic assay.

  16. [Luminol-enhanced chemiluminescence of rabbit polymorphonuclear leukocytes: the nature of oxidants that directly induce luminol oxidation].

    Science.gov (United States)

    Roshchupkin, D I; Belakina, N S; Murina, M A

    2006-01-01

    The present work deals with the reaction pathways, including the formation of hydroxyl radicals and chloroamines, which lead to luminol chemiluminescence caused by hypochlorite generation in a suspension of stimulated rabbit polymorphnonuclear leukocyte. Luminol-enhanced (0.02 mM) chemiluminescence of leukocytes stimulated by phorbol 12-myristate 13-acetate does not change in the presence of dimethyl sulfoxide at moderate concentrations (0.02-2.6 mM) at which it must show the specific ability to scavenge hydroxyl radicals. It suggests that no generation of hydroxyl radical with the participation of hypochlorite and superoxide anion takes place after the stimulation of polymorphnonuclear leukocytes. A high dimethyl sulfoxide concentrations (260 mM) a significant fall in chemiluminescence intensity, due to direct interaction of the scavenger with hypochlorite, is observed. Chemiluminescence intensity rose if luminol was added to a leukocyte suspension preliminary stimulated for 10 min. The effect results from the accumulation of hydrogen peroxide but not chloroamines. Exogenic amino acids and taurin at high concentrations (3-15 mM) weaken the chemiluminescence. The data obtained suggest that chemiluminescence in the system studied results predominantly from the direct initial reaction of hypochlorite with luminol. The chemiluminescence intensity is enhanced by hydrogen peroxide via the oxidation of luminol oxidation products.

  17. Microfluidic paper-based chemiluminescence biosensor for simultaneous determination of glucose and uric acid.

    Science.gov (United States)

    Yu, Jinghua; Ge, Lei; Huang, Jiadong; Wang, Shoumei; Ge, Shenguang

    2011-04-07

    In this study, a novel microfluidic paper-based chemiluminescence analytical device (μPCAD) with a simultaneous, rapid, sensitive and quantitative response for glucose and uric acid was designed. This novel lab-on-paper biosensor is based on oxidase enzyme reactions (glucose oxidase and urate oxidase, respectively) and the chemiluminescence reaction between a rhodanine derivative and generated hydrogen peroxide in an acid medium. The possible chemiluminescence assay principle of this μPCAD is explained. We found that the simultaneous determination of glucose and uric acid could be achieved by differing the distances that the glucose and uric acid samples traveled. This lab-on-paper biosensor could provide reproducible results upon storage at 4 °C for at least 10 weeks. The application test of our μPCAD was then successfully performed with the simultaneous determination of glucose and uric acid in artificial urine. This study shows the successful integration of the μPCAD and the chemiluminescence method will be an easy-to-use, inexpensive, and portable alternative for point-of-care monitoring.

  18. Gold nanorods-enhanced rhodamine B-permanganate chemiluminescence and its analytical application

    Science.gov (United States)

    Hassanzadeh, Javad; Amjadi, Mohammad; Manzoori, Jamshid L.; Sorouraddin, Mohammad Hossein

    2013-04-01

    A novel enhanced chemiluminescence system was developed by applying gold nanorods (Au NRs) as catalysts in rhodamine B-permanganate reaction. Au NRs with three different aspect ratios were synthesized by seed mediated growth method and characterized by UV-Vis spectra and transmission electron microscopy. It was demonstrated that Au NRs have much higher catalytic effect than spherical nanoparticles on rhodamine B-permanganate chemiluminescence reaction. Among various sizes of Au NRs, those with average aspect ratio of 3.0 were found to have the most remarkable catalytic activity. As an analytical application of the new chemiluminescence system, albumin as a model protein was quantified based on its interaction with NRs. Albumin binds to Au NRs active surfaces and inhibits their catalytic action and therefore decreases the intensity of chemiluminescence. This diminution effect is linearly related to the concentration of the human and bovine serum albumin over the ranges of 0.45-90 and 0.75-123 nmol L-1, respectively with the corresponding limits of detection of 0.18 and 0.30 nmol L-1. The method was successfully applied to the determination of albumin in human and bovine serum samples.

  19. Chemiluminescence in the reaction of ozone with 6-methyluracil in aqueous solutions

    Science.gov (United States)

    Zimin, Yu. S.; Khairullina, L. R.; Kutlugil'dina, G. G.; Mustafin, A. G.

    2015-12-01

    Chemiluminescence in the visible part of the spectrum during the oxidation of 6-methyluracil with ozone in aqueous solutions was found. The kinetics of variation of the luminescence intensity was studied in the temperature range 287-333 K, and the activation parameters of the process were determined.

  20. Acidic Potassium Permanganate Chemiluminescence for the Determination of Antioxidant Potential in Three Cultivars of Ocimum basilicum.

    Science.gov (United States)

    Srivastava, Shivani; Adholeya, Alok; Conlan, Xavier A; Cahill, David M

    2016-03-01

    Ocimum basilicum, a member of the family Lamiaceae, is a rich source of polyphenolics that have antioxidant properties. The present study describes the development and application of an online HPLC-coupled acidic potassium permanganate chemiluminescence assay for the qualitative and quantitative assessment of antioxidants in three cultivars of O. basilicum grown under greenhouse conditions. The chemiluminescence based assay was found to be a sensitive and efficient method for assessment of total and individual compound antioxidant potential. Leaves, flowers and roots were found to be rich reserves of the antioxidant compounds which showed intense chemiluminescence signals. The polyphenolics such as rosmarinic, chicoric, caffeic, p-coumaric, m-coumaric and ferulic acids showed antioxidant activity. Further, rosmarinic acid was found to be the major antioxidant component in water-ethanol extracts. The highest levels of rosmarinic acid was found in the leaves and roots of cultivars "holy green" (14.37; 11.52 mM/100 g DW respectively) followed by "red rubin" (10.02; 10.75 mM/100 g DW respectively) and "subja" (6.59; 4.97 mM/100 g DW respectively). The sensitivity, efficiency and ease of use of the chemiluminescence based assay should now be considered for its use as a primary method for the identification and quantification of antioxidants in plant extracts.

  1. Application of chemiluminescence for the detection of peroxy compounds in high-performance liquid chromatography.

    Science.gov (United States)

    Baj, Stefan; Chrobok, Anna; Cieślik, Mariola; Krawczyk, Tomasz

    2003-01-01

    The possibility of applying post-column reaction and chemiluminescence to determine organic peroxy compounds by RP-HPLC was investigated. Conditions of qualitative and quantitative analyses have been established. The applicability of the method has been demonstrated for a series of compounds representative of the most important groups of peroxy-type compounds, that is, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and peroxyacids.

  2. Flame Response to Equivalence Ratio Fluctuations — Relationship between Chemiluminescence and Heat Release

    Directory of Open Access Journals (Sweden)

    Shreekrishna

    2013-12-01

    Full Text Available This paper presents a comparative study of the global responses of heat release and chemiluminescence emissions of a laminar premixed flame excited by oscillations in fuel/air ratio. Chemiluminescence fluctuations are a commonly used marker of heat release oscillations in unsteady flames. While there is strong evidence of a good correlation between these two quantities in situations where the flame is excited by velocity oscillations, the situation is less well understood for cases where the excitation is due to fuel/air ratio oscillations. This is due to the fact that chemiluminescence is not only a function of the heat release rate, but also a strong function of the fuel/air ratio itself. This work attempts to assess this issue by theoretically evaluating linear transfer functions for the global chemiluminescence and heat release responses of the flame. It is shown that they are qualitatively similar in all cases, but that there are quantitative differences between the two that depend upon operating conditions, nominal flame geometry, and which radical species is being measured.

  3. Numerical and Experimental Investigation of Computed Tomography of Chemiluminescence for Hydrogen-Air Premixed Laminar Flames

    Directory of Open Access Journals (Sweden)

    Liang Lv

    2016-01-01

    Full Text Available Computed tomography of chemiluminescence (CTC is a promising technique for combustion diagnostics, providing instantaneous 3D information of flame structures, especially in harsh circumstance. This work focuses on assessing the feasibility of CTC and investigating structures of hydrogen-air premixed laminar flames using CTC. A numerical phantom study was performed to assess the accuracy of the reconstruction algorithm. A well-designed burner was used to generate stable hydrogen-air premixed laminar flames. The OH⁎ chemiluminescence intensity field reconstructed from 37 views using CTC was compared to the OH⁎ chemiluminescence distributions recorded directly by a single ICCD camera from the side view. The flame structures in different flow velocities and equivalence ratios were analyzed using the reconstructions. The results show that the CTC technique can effectively indicate real distributions of the flame chemiluminescence. The height of the flame becomes larger with increasing flow velocities, whereas it decreases with increasing equivalence ratios (no larger than 1. The increasing flow velocities gradually lift the flame reaction zones. A critical cone angle of 4.76 degrees is obtained to avoid blow-off. These results set up a foundation for next studies and the methods can be further developed to reconstruct 3D structures of flames.

  4. Luminol-, isoluminol- and lucigenin-enhanced chemiluminescence of rat blood phagocytes stimulated with different activators

    Czech Academy of Sciences Publication Activity Database

    Pavelková, Martina; Kubala, Lukáš

    2004-01-01

    Roč. 19, č. 1 (2004), s. 37-42 ISSN 1522-7235 R&D Projects: GA ČR GA524/02/0395; GA AV ČR IBS5004009 Institutional research plan: CEZ:AV0Z5004920 Keywords : blood * chemiluminescence * leukocyte Subject RIV: BO - Biophysics Impact factor: 1.297, year: 2004

  5. Soot and chemiluminescence in diesel combustion of bio-derived, oxygenated and reference fuels

    NARCIS (Netherlands)

    Klein-Douwel, R.J.H.; Donkerbroek, A.J.; Vliet, A.P. van; Boot, M.D.; Somers, L.M.T.; Baert, R.S.G.; Dam, N.J.; Meulen, J.J. ter

    2009-01-01

    High-speed imaging, spectroscopy and thermodynamical characterization are applied to an optically accessible, heavy-duty diesel engine in order to compare sooting and chemiluminescence behaviour of bio-derived, oxygenated fuels and various reference fuels. The fuels concerned include the bio-derived

  6. Nitroxyl radicals remarkably enhanced the superoxide anion radical-induced chemiluminescence of Cypridina luciferin analogues.

    Science.gov (United States)

    Takeshita, Keizo; Okazaki, Shoko; Itoda, Akiko

    2013-07-16

    Measuring the superoxide anion radical (superoxide) with high sensitivity is necessary to clarify the mechanisms of diseases for the development of methods for their prophylaxes, diagnoses, and therapies. The chemiluminescence technique using Cypridina luciferin analogues such as MCLA and CLA is currently the most sensitive method available. Using large concentrations of these reagents, however, leads to increases in background levels due to spontaneous luminescence of the reagent, which is a limitation of this method. This study demonstrated that the superoxide-induced chemiluminescence of MCLA or CLA was markedly enhanced by adding a cyclic nitroxyl radical to the reaction medium. When MCLA was measured spectrophotometrically, the nitroxyl radical was shown to increase the reaction rate of superoxide and MCLA without altering their stoichiometry, whereas consumption of the nitroxyl radical was negligible, as determined by electron paramagnetic resonance (EPR) spectroscopy. These observations indicate that the nitroxyl radical catalytically enhanced the reaction between superoxide and MCLA, resulting in an enhancement in superoxide-dependent MCLA chemiluminescence. This method is applicable to biological systems such as superoxide-generation by neutrophils. The inclusion of the cyclic nitroxyl radical in a sample solution contributed to reductions in the concentration of the chemiluminescence reagent, thereby decreasing background levels. The catalytic mechanism was also discussed.

  7. Chemiluminescent DNA probes: a comparison of the acridinium ester and dioxetane detection systems and their use in clinical diagnostic assays.

    Science.gov (United States)

    Nelson, N C; Kacian, D L

    1990-12-17

    Nucleic acid hybridization has the potential to markedly improve the diagnosis of infectious and genetic diseases. Recently, chemiluminescent hybridization assays using acridinium esters and stabilized dioxetanes have been described with sensitivities comparable to those obtained with radioactive labels. Acridinium esters are used as direct labels that are attached to the probe throughout the hybridization reaction. Methods have been developed for labeling DNA probes with acridinium esters at high specific activity and for stabilizing the label under the relatively harsh conditions of hybridization reactions. The label does not affect the kinetics of the hybridization reaction or the stability of the resulting hybrid. The label emits light upon exposure to alkaline peroxide; thus, the assay format can be an extremely simple one. The acridinium ester labels are stable in storage and exhibit extremely rapid light-off kinetics which permit reading large numbers of samples within a brief period as well as limiting the contribution of background signal. A special property of acridinium esters allows chemical destruction of the label when it is present on unhybridized probe, whereas the label is stable to this process when the probe is hybridized. This behavior forms the basis of techniques to minimize assay background signals and allows a homogeneous assay format which does not require physical separation of hybridized and unhybridized probe. The adamantyl-stabilized 1,2-dioxetanes have been used to produce high-sensitivity detection systems for clinical assays. The probe is labeled with enzymes such as alkaline phosphatase or beta-D-galactosidase that hydrolyze the dioxetane derivative to produce a chemiluminescent molecule. As with other enzyme-based labeling systems, the signal increases with time, allowing greater sensitivity to be achieved with longer incubations. The amount of light generated is sufficient to expose sensitive photographic film with extended

  8. Development and characterization of a microfluidic glucose sensing system based on an enzymatic microreactor and chemiluminescence detection

    NARCIS (Netherlands)

    Moon, B. -U; de Vries, M. G.; Westerink, B. H. C.; Verpoorte, E.

    Chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidics-based continuous glucose monitoring system. Amperometric detection allows easy determination of hydrogen peroxide, a product of the glucose oxidase-catalyzed

  9. On use of CO{sub 2} chemiluminescence for combustion metrics in natural gas fired reciprocating engines.

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, S. B.; Bihari, B.; Biruduganti, M.; Sekar, R.; Zigan, J. (Energy Systems); (Cummins Technical Center)

    2011-01-01

    Flame chemiluminescence is widely acknowledged to be an indicator of heat release rate in premixed turbulent flames that are representative of gas turbine combustion. Though heat release rate is an important metric for evaluating combustion strategies in reciprocating engine systems, its correlation with flame chemiluminescence is not well studied. To address this gap an experimental study was carried out in a single-cylinder natural gas fired reciprocating engine that could simulate turbocharged conditions with exhaust gas recirculation. Crank angle resolved spectra (266-795 nm) of flame luminosity were measured for various operational conditions by varying the ignition timing for MBT conditions and by holding the speed at 1800 rpm and Brake Mean effective Pressure (BMEP) at 12 bar. The effect of dilution on CO*{sub 2}chemiluminescence intensities was studied, by varying the global equivalence ratio (0.6-1.0) and by varying the exhaust gas recirculation rate. It was attempted to relate the measured chemiluminescence intensities to thermodynamic metrics of importance to engine research -- in-cylinder bulk gas temperature and heat release rate (HRR) calculated from measured cylinder pressure signals. The peak of the measured CO*{sub 2} chemiluminescence intensities coincided with peak pressures within {+-}2 CAD for all test conditions. For each combustion cycle, the peaks of heat release rate, spectral intensity and temperature occurred in that sequence, well separated temporally. The peak heat release rates preceded the peak chemiluminescent emissions by 3.8-9.5 CAD, whereas the peak temperatures trailed by 5.8-15.6 CAD. Such a temporal separation precludes correlations on a crank-angle resolved basis. However, the peak cycle heat release rates and to a lesser extent the peak cycle temperatures correlated well with the chemiluminescent emission from CO*{sub 2}. Such observations point towards the potential use of flame chemiluminescence to monitor peak bulk gas

  10. Membrane tension and membrane fusion

    OpenAIRE

    Kozlov, Michael M.; Chernomordik, Leonid V.

    2015-01-01

    Diverse cell biological processes that involve shaping and remodeling of cell membranes are regulated by membrane lateral tension. Here we focus on the role of tension in driving membrane fusion. We discuss the physics of membrane tension, forces that can generate the tension in plasma membrane of a cell, and the hypothesis that tension powers expansion of membrane fusion pores in late stages of cell-to-cell and exocytotic fusion. We propose that fusion pore expansion can require unusually la...

  11. ParaSol - A Novel Deployable Approach for Very Large Ultra-lightweight Solar Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High power solar arrays with capabilities of >100kW are needed for projected NASA missions. Photovoltaic arrays using deployable membranes with thin cells have...

  12. Chemiluminescence assay for catechin based on generation of hydrogen peroxide in basic solution

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Hidetoshi; Kanemitsu, Mahina; Tajima, Noriko; Maeda, Masako

    2002-11-20

    We have determined that the catechin group in basic solution efficiently produces hydrogen peroxide; moreover, a highly sensitive analysis methodology was developed to measure catechin employing a peroxalate chemiluminescence detection system. Identification of hydrogen peroxide generated by catechin was determined by ESR as well as peroxalate chemiluminescence using catalase and SOD. As a result, catechin-generated superoxide by electron reduction to dissolved oxygen in basic solution, followed by production of hydrogen peroxide through dismutation reaction. This method could measure several tea catechins, (+)-catechin (CC), (-)-epigallocatechin-3-gallate (EGCg), (-)-epicatechin-3-gallate (ECG) and gallic acid, with measurement range from 10{sup -7} to 10{sup -3} mol/l and sensitivity of 10{sup -8} mol/l. This method was also applied to the determination of total catechin levels in green tea, black tea and roasted green tea.

  13. Insights into the ninhydrin chemiluminescent reaction and its potential for micromolar determination of human serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, M. Rodriguez [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Av. Julian Claveria, 8 33006 Oviedo (Spain); Laino, R. Badia [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Av. Julian Claveria, 8 33006 Oviedo (Spain); Diaz-Garcia, M.E. [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Av. Julian Claveria, 8 33006 Oviedo (Spain)]. E-mail: medg@uniovi.es

    2006-06-15

    The N-terminal region of human serum albumin (HSA) has an inherent affinity for Co(II) ions. On this basis a new continuous flow method for detection of HSA has been developed taking advantage of the strong quenching effect of the albumin in the ninhydrin-H{sub 2}O{sub 2}-Co(II) chemiluminescent system. The analytical potential of the system is compared with other conventional chemiluminescent reagents. The method gives linear responses from the detection limit (0.30 {mu}M HSA) up to 6.8 {mu}M. The repeatability of the method is good (RSD=7%), it is cheap and rapid to apply and does not require the use of insoluble or expensive reagents nor sophisticated equipment.

  14. Detecting free radicals in sunscreens exposed to UVA radiation using chemiluminescence.

    Science.gov (United States)

    Millington, Keith R; Osmond, Megan J; McCall, Maxine J

    2014-04-05

    One of the current concerns with the application of nanoparticles in sunscreens, and in particular nano-TiO2 and ZnO, is their potential to photogenerate free radicals and reactive oxygen species (ROS) when they absorb ultraviolet wavelengths from sunlight. Free radicals and ROS are known to be associated with UV-induced skin damage and oxidative stress, from which sunscreens are expected to offer significant protection. Here we describe a simple method, based on chemiluminescence emission, for detecting free radicals generated in commercial sunscreens alone, and when applied to various substrates, following exposure to UVA (320-400nm) radiation. This photo-induced chemiluminescence (PICL) technique could be used to optimise sunscreen formulations so as to minimise free radical photogeneration during exposure to sunlight. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  15. Artemisinin-Luminol Chemiluminescence for Forensic Bloodstain Detection Using a Smart Phone as a Detector.

    Science.gov (United States)

    Gao, Wenyue; Wang, Chao; Muzyka, Kateryna; Kitte, Shimeles Addisu; Li, Jianping; Zhang, Wei; Xu, Guobao

    2017-06-06

    Forensic luminol chemiluminescence test is one of the most sensitive and popular methods for the determination of latent bloodstains. It mainly uses hydrogen peroxide or sodium perborate as coreactants. The easy decomposition of hydrogen peroxide and sodium perborate in the presence of many ions significantly affects the selectivity. Artemisinin is a natural peroxide that is quite stable in the presence of common ions. In the present study, artemisinin has been exploited for the forensic bloodstain chemiluminescence detection for the first time. Using smart phone as cost-effective portable detector, the visual detection of bloodstains has been achieved with a dilution factor of blood up to 100 000. Moreover, this system shows excellent selectivity against many common species. It can well differentiate bloodstains from other stains, such as coffee, brown sugar, and black tea. Both favorable sensitivity and selectivity makes the present method promising in forensic detection.

  16. Development of a chemiluminescent and bioluminescent system for the detection of bacteria in wastewater effluent

    Science.gov (United States)

    Thomas, R. R.

    1975-01-01

    Automated chemiluminescent and bioluminescent sensors were developed for continuous monitoring of microbial levels in wastewater effluent. Development of the chemiluminescent system included optimization of reagent concentrations as well as two new techniques which will allow for increased sensitivity and specificity. The optimal reagent concentrations are 0.0025 M luminol and 0.0125 M sodium perborate in 0.75N sodium hydroxide before addition of sample. The methods developed to increase specificity include (1) extraction of porphyrins from bacteria collected in a filter using 0.1N NaOH - 50 percent Ethanol, and (2) use of the specific reaction rate characteristics for the different luminol catalysts. Since reaction times are different for each catalyst, the reaction can be made specific for bacteria by measuring only the light emission from the particular reaction time zone specific for bacteria. Developments of the bioluminescent firefly luciferase system were in the area of flow system design.

  17. Chemiluminescence determination of potassium bromate in flour based on flow injection analysis.

    Science.gov (United States)

    Yan, Zhengyu; Zhang, Zhengwei; Yu, Yan; Liu, Zhen; Chen, Jianqiu

    2016-01-01

    A novel and highly sensitive flow-injection chemiluminescence method for the determination of potassium bromate (KBrO3) has been developed. This method is based on the luminescence properties of the KBrO3-Na2SO3-quinine sulfate system in acid medium. Optimized experimental conditions and a possible mechanism were investigated. The relative chemiluminescence intensity responded linearly to the concentration of KBrO3 in the range of 7.054 × 10(-6)-1.008 × 10(-4) mol/L with a detection limit of 2.116 × 10(-6) mol/L. The relative standard deviation (RSD) at 5.0 × 10(-5) mol/L KBrO3 (n = 12) was 2.3%. The proposed method was applied successfully to the determination of KBrO3 in flour. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Chemiluminescence of curcumin and quenching effect of dimethyl sulfoxide on its peroxyoxalate system

    Energy Technology Data Exchange (ETDEWEB)

    Yari, Abdollah, E-mail: a.yari@ymail.co [Lorestan University, Department of Chemistry, Flakalaflak Street, 68178-17133 Khorramabad (Iran, Islamic Republic of); Saidikhah, Marzieh [Lorestan University, Department of Chemistry, Flakalaflak Street, 68178-17133 Khorramabad (Iran, Islamic Republic of)

    2010-04-15

    The chemiluminescence behavior of the reaction between bis(2,4,6-trichlorophenyl)oxalate (TCPO) and hydrogen peroxide, in the presence of curcumin as fluorophore, has been investigated. Experimental factors such as TCPO, sodium salicylate (SS), hydrogen peroxide and curcumin concentration were optimized. The chemiluminescence signal showed a linear decay while dimethyl sulfoxide (DMSO) was added to the peroxyoxalate (PO-CL) system. The reaction resulted in a Stern-Volmer plot with a K{sub q} value of 7.3x10{sup 4}. The evaluated lower and upper detection limits of measurable concentrations of DMSO are 3.50x10{sup -5} and 1.53x10{sup -4} M, respectively. The PO-CL parameters were estimated by computer fitting of the experimental CL intensity to proper models.

  19. Chemiluminescent nanomicelles for imaging hydrogen peroxide and self-therapy in photodynamic therapy.

    Science.gov (United States)

    Chen, Rui; Zhang, Luzhong; Gao, Jian; Wu, Wei; Hu, Yong; Jiang, Xiqun

    2011-01-01

    Hydrogen peroxide is a signal molecule of the tumor, and its overproduction makes a higher concentration in tumor tissue compared to normal tissue. Based on the fact that peroxalates can make chemiluminescence with a high efficiency in the presence of hydrogen peroxide, we developed nanomicelles composed of peroxalate ester oligomers and fluorescent dyes, called peroxalate nanomicelles (POMs), which could image hydrogen peroxide with high sensitivity and stability. The potential application of the POMs in photodynamic therapy (PDT) for cancer was also investigated. It was found that the PDT-drug-loaded POMs were sensitive to hydrogen peroxide, and the PDT drug could be stimulated by the chemiluminescence from the reaction between POMs and hydrogen peroxide, which carried on a self-therapy of the tumor without the additional laser light resource.

  20. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  1. Microwave Power for Smart Membrane Actuators

    Science.gov (United States)

    Choi, Sang H.; Song, Kyo D.; Golembiewski, Walter T.; Chu, Sang-Hyon; King, Glen C.

    2002-01-01

    The concept of microwave-driven smart membrane actuators is envisioned as the best option to alleviate the complexity associated with hard-wired control circuitry. A large, ultra-light space structure, such as solar sails and Gossamer spacecrafts, requires a distribution of power into individual membrane actuators to control them in an effective way. A patch rectenna array with a high voltage output was developed to drive smart membrane actuators. Networked patch rectenna array receives and converts microwave power into a DC power for an array of smart actuators. To use microwave power effectively, the concept of a power allocation and distribution (PAD) circuit is developed and tested for networking a rectenna/actuator patch array. For the future development, the PAD circuit could be imbedded into a single embodiment of rectenna and actuator array with the thin-film microcircuit embodiment. Preliminary design and fabrication of PAD circuitry that consists of a sixteen nodal elements were made for laboratory testing.

  2. Integrated luminometer for the determination of trace metals in seawater using fluorescence, phosphorescence and chemiluminescence detection

    OpenAIRE

    Worsfold, P. J.; E. P. Achterberg; A. R. Bowie; Cannizzaro, V.; Charles, S.; Costa, J.M.; Dubois, F.; Pereiro, R.; San Vicente, B.; Sanz-Medel, A.; Vandeloise, R.; Donckt, E. Vander; Wollast, P; Yunus, S

    2002-01-01

    The paper describes an integrated luminometer able to perform fluorescence (FL), room temperature phosphorescence (RTP) and chemiluminescence (CL) measurements on seawater samples. The technical details of the instrumentation are presented together with flow injection (FI) manifolds for the determination of cadmium and zinc (by FL), lead (RTP) and cobalt (CL). The analytical figures of merit are given for each manifold and results are presented for the determination of the four trace metals i...

  3. Temperature measurements by oh lif and chemiluminescence kinetic modeling for ethanol flames

    OpenAIRE

    Marques,Carla S. T.; Leila R. dos Santos; Sbampato,Maria E.; Barreta, Luiz G.; Alberto M. dos Santos

    2009-01-01

    OH LIF-thermometry was applied to premixed ethanol flames at atmospheric pressure in a burner for three flame conditions. Flame temperatures were simulated from energy equation with PREMIX code of CHEMKIN software package for comparison. A kinetic modeling based on a model validated through chemiluminescence measurements and on a set of reactions for nitrogen chemistry was evaluated. Marinov's mechanism was also tested. Sensitivity analysis was performed for fuel-rich flame condition with ...

  4. Measurement and simulation of rotationally-resolved chemiluminescence spectra in flames

    Science.gov (United States)

    Brockhinke, A.; Krüger, J.; Heusing, M.; Letzgus, M.

    2012-06-01

    In recent years, there has been renewed interest in chemiluminescence, since it has been shown that these emissions can be used to determine flame parameters such as stoichiometry and heat release under some conditions. Even though the origin of these emissions has been known for a long time, little attention has been paid to the detailed analysis of the spectral structure. In this contribution, we present rotationally-resolved spectra of all important chemiluminescent emissions OH A-X, CH B-X, CH A-X, and C2 d-a in CH4/air flames. A numerical model based on the LASKIN ν 2 code has been developed that allows, for the first time, to accurately predict the shape of the measured spectra for all of these transitions. Reabsorption of chemiluminescence within the emitting flame is shown to be a major factor, affecting both intensity and structure of OH∗ spectra. Even in lab-scale flames, it might change the intensity of individual lines by a factor of 5. The shape of chemiluminescence spectra depends on several processes including initial state distribution and rotational and vibrational energy transfer (which, in turn, depend on the collisional environment and the temperature). It is shown that chemical reactions form OH∗ in highly excited states and that the number of collisions is not sufficient to equilibrate the initial distribution. Therefore, high apparent temperatures are necessary to describe the shape of the measured spectra. In contrast, CH∗ is formed with less excess energy and the spectral shape is very close to thermal. The rotational structure of C2^{*} is close to thermal equilibrium as well. Vibrational temperatures are, however, significantly higher than the flame temperature. Implications and perspectives for flame measurements are discussed.

  5. Chemiluminescent Nanomicelles for Imaging Hydrogen Peroxide and Self-Therapy in Photodynamic Therapy

    OpenAIRE

    Rui Chen; Luzhong Zhang; Jian Gao; Wei Wu; Yong Hu; Xiqun Jiang

    2011-01-01

    Hydrogen peroxide is a signal molecule of the tumor, and its overproduction makes a higher concentration in tumor tissue compared to normal tissue. Based on the fact that peroxalates can make chemiluminescence with a high efficiency in the presence of hydrogen peroxide, we developed nanomicelles composed of peroxalate ester oligomers and fluorescent dyes, called peroxalate nanomicelles (POMs), which could image hydrogen peroxide with high sensitivity and stability. The potential application o...

  6. Robot Printing of Reverse Dot Blot Arrays for Human Mutation Detection

    National Research Council Canada - National Science Library

    Lappin, Stephen; Cahlik, Jeff; Gold, Bert

    2001-01-01

    ..., from disposable barrier pipette tips and then to touch the drops on preactivated membranes. Printed arrays consist of alternating rows of oligonucleotides containing normal and mutant sequences...

  7. Screening test for rapid food safety evaluation by menadione-catalysed chemiluminescent assay.

    Science.gov (United States)

    Yamashoji, Shiro; Yoshikawa, Naoko; Kirihara, Masayuki; Tsuneyoshi, Toshihiro

    2013-06-15

    The chemiluminescent assay of menadione-catalysed H2O2 production by living mammalian cells was proposed to be useful for rapid food safety evaluation. The tested foods were extracted with water, ethanol and dimethylsulfoxide, and each extract was incubated with NIH3T3, Neuro-2a and HepG2 cells for 4h. Menadione-catalysed H2O2 production by living mammalian cells exposed to each extract was determined by the chemiluminescent assay requiring only 10 min, and the viability of the cells was estimated as percentage based on H2O2 production by intact cells. In this study the cytotoxicity of food was rated in order of inhibitory effect on H2O2 production by intact cells. The well known natural toxins such as Fusarium mycotoxin, tomato toxin tomatine, potato toxin solanine and marine toxins terodotoxin and brevetoxin could be detected by the above chemiluminescent assay. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Chemiluminescent imaging of transpired ethanol from the palm for evaluation of alcohol metabolism.

    Science.gov (United States)

    Arakawa, Takahiro; Kita, Kazutaka; Wang, Xin; Miyajima, Kumiko; Toma, Koji; Mitsubayashi, Kohji

    2015-05-15

    A 2-dimensional imaging system was constructed and applied in measurements of gaseous ethanol emissions from the human palm. This imaging system measures gaseous ethanol concentrations as intensities of chemiluminescence by luminol reaction induced by alcohol oxidase and luminol-hydrogen peroxide-horseradish peroxidase system. Conversions of ethanol distributions and concentrations to 2-dimensional chemiluminescence were conducted on an enzyme-immobilized mesh substrate in a dark box, which contained a luminol solution. In order to visualize ethanol emissions from human palm skin, we developed highly sensitive and selective imaging system for transpired gaseous ethanol at sub ppm-levels. Thus, a mixture of a high-purity luminol solution of luminol sodium salt HG solution instead of standard luminol solution and an enhancer of eosin Y solution was adapted to refine the chemiluminescent intensity of the imaging system, and improved the detection limit to 3 ppm gaseous ethanol. The highly sensitive imaging allows us to successfully visualize the emissions dynamics of transdermal gaseous ethanol. The intensity of each site on the palm shows the reflection of ethanol concentrations distributions corresponding to the amount of alcohol metabolized upon consumption. This imaging system is significant and useful for the assessment of ethanol measurement of the palmar skin. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Chemiluminescence characterisation of the reaction system Tb(III)-amino acid-peroxynitrous acid

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, M. [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan (Poland); Lis, S. [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan (Poland)], E-mail: blis@amu.edu.pl

    2008-02-28

    Chemiluminescence of the reaction system tryptophan-hydrogen peroxide-nitrite-Tb(III)-H{sub 2}SO{sub 4} was used for the determination of tryptophan. The chemiluminescence intensity observed in the system tryptophan-hydrogen peroxide-nitrite-sulfuric acid, in the presence of Tb(III) ions was five times higher than that in a solution without Tb(III) ions. The chemiluminescence spectrum obtained for the system tryptophan-hydrogen peroxide-nitrite-sulfuric acid solution showed one band, with {lambda}{sub max} {approx} 520 nm, whereas in the presence of Tb(III) ions two bands with {lambda}{sub max} {approx} 520 nm and 550 nm were observed. The peak centered at {approx}550 nm, corresponding to the {sup 5}D{sub 4} {yields} {sup 7}F{sub 5} transition, which is typical for the Tb(III) ion. A linear dependence was found for the CL intensity versus the tryptophan concentration, in the range of 1.2 x 10{sup -7} to 1 x 10{sup -4} mol/l. Terbium(III) ions play the role of sensitizer in the reaction mixture tryptophan-hydrogen peroxide-nitrite-sulfuric acid.

  10. Chemiluminescence of a cyclometallated iridium(III) complex and its application in the detection of cysteine.

    Science.gov (United States)

    Dong, Yong Ping; Shi, Ming Juan; Tong, Bi Hai; Zhang, Qian Feng

    2012-01-01

    Chemiluminescence (CL) of a cyclometallated iridium (III) complex {tris[1-(2,6-dimethylphenoxy)-4-(4-chlorophenyl)phthalazine]iridium(III)} in the presence of potassium permanganate and oxalic acid is reported for the first time. Cysteine exhibits sufficient enhancing effect on the CL generated from the cyclometallated iridium(III) complex, which make it possible for the sensitive detection of cysteine using a flow-injection-chemiluminescence (FI-CL) method. The optimum conditions for the chemiluminescence emission were investigated. Under the optimal condition, the linear range for the determination of cysteine was 1.0 × 10(-9) -5.0 × 10(-6)  mol/L with a detection limit of 6.9 × 10(-10)  mol/L. A relative standard deviation of 1.6% was obtained for eight replicate determinations. The mechanisms of CL are proposed and the emitting species was identified as the metal-to-ligand charge-transfer (MLCT) excited states of the iridium complex. Copyright © 2011 John Wiley & Sons, Ltd.

  11. The effect of storage on whole blood chemiluminescence measurement of equine neutrophils.

    Science.gov (United States)

    Krumrych, Wiesław; Skórzewski, Radosław; Malinowski, Edward

    2013-01-01

    The aim of this study was to determine the effect of duration and temperature of sample storage on whole blood chemiluminescence measurement results. Venous blood from 18 clinically healthy Polish half-bred horses aged 4 to 11 years were used in the study. Luminol dependent chemiluminescence (CL) was used to measure neutrophil oxygen metabolism in whole blood. Blood samples were examined for spontaneous CL and stimulated by a surface receptor stimulus as well as extra-receptor stimulus. The assay was performed in two parallel experimental sets with samples stored at 4 and 22 °C, respectively. Whole blood CL was estimated at 2, 6, 24, 48, 72, 96 and 120 h after collection. The study demonstrated that temperature and duration of sample storage are factors that determine the quality of CL measurements of whole blood in horses. The study concluded that samples should be stored at 4 °C and the assay should be performed as early as possible. It was also shown that the viability period of horse blood for CL assays is relatively long. Material stored at room temperature for 24 h and even up to 48 h at 4 °C did not show any significant decrease in spontaneous or stimulated chemiluminescence. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Reagentless chemiluminescence-based fiber optic sensors for regenerative life support in space

    Science.gov (United States)

    Atwater, James E.; Akse, James R.; DeHart, Jeffrey; Wheeler, Richard R., Jr.

    1995-04-01

    The initial feasibility demonstration of a reagentless chemiluminescence based fiber optic sensor technology for use in advanced regenerative life support applications in space and planetary outposts is described. The primary constraints for extraterrestrial deployment of any technology are compatibility with microgravity and hypogravity environments; minimal size, weight, and power consumption; and minimal use of expendables due to the great expense and difficulty inherent to resupply logistics. In the current research, we report the integration of solid state flow through modules for the production of aqueous phase reagents into an integrated system for the detection of important analytes by chemiluminescence, with fiber optic light transmission. By minimizing the need for resupply expendables, the use of solid phase modules makes complex chemical detection schemes practical. For the proof of concept, hydrogen peroxide and glucose were chosen as analytes. The reaction is catalyzed by glucose oxidase, an immobilized enzyme. The aqueous phase chemistry required for sensor operation is implemented using solid phase modules which adjust the pH of the influent stream, catalyze the oxidation of analyte, and provide the controlled addition of the luminophore to the flowing aqueous stream. Precise control of the pH has proven essential for the long-term sustained release of the luminophore. Electrocatalysis is achieved using a controlled potential across gold mesh and gold foil electrodes which undergo periodic polarity reversals. The development and initial characterization of performance of the reagentless fiber optic chemiluminescence sensors are presented in this paper.

  13. A streptavidin functionalized graphene oxide/Au nanoparticles composite for the construction of sensitive chemiluminescent immunosensor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhanjun, E-mail: zjyang@yzu.edu.cn [Key Laboratory of Environmental Material and Environmental Engineering of Jiangsu Province, College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Luo, Shufen; Li, Juan; Shen, Juan; Yu, Suhua; Hu, Xiaoya [Key Laboratory of Environmental Material and Environmental Engineering of Jiangsu Province, College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002 (China); Dionysiou, Dionysios D. [Environmental Engineering and Science Program, School of Energy Environmental, Biological and Medical Engineering, University of Cincinnati, Cincinnati, OH 45221-0012 (United States)

    2014-08-11

    Highlights: • A novel streptavidin/GO/AuNPs composite is prepared for immobilizing antibody. • A highly sensitive chemiluminescent immunosensor is constructed for tumor marker. • The immunoassay system shows extremely low detection limit down to picogram level. • This work provides a promising approach for ultrasensitive biosensing applications. - Abstract: In this work, a novel streptavidin functionalized graphene oxide/Au nanoparticles (streptavidin/GO/AuNPs) composite is prepared and for the first time used to construct sensitive chemiluminescent immunosensor for the detection of tumor marker. The streptavidin/GO/AuNPs composite and the immunosensor are characterized using scanning electron microscopy, static water contact angle measurement and electrochemical impedance spectroscopy. The biofunctionalized composite has large reactive surface area and excellent biocompatibility, thus the capture antibody can be efficiently immobilized on its surface based on the highly selective recognition of streptavidin to biotinylated antibody. Using α-fetoprotein (AFP) as a model, the proposed chemiluminescent immunosensor shows a wide linear range from 0.001 to 0.1 ng mL{sup −1} with an extremely low detection limit down to 0.61 pg mL{sup −1}. The resulting AFP immunosensor shows high detection sensitivity, fast assay speed, acceptable detection and fabrication reproducibility, good specificity and stability. The assay results of serum samples with the proposed method are in an acceptable agreement with the reference values. This work provides a promising biofunctionalized nanostructure for sensitive biosensing applications.

  14. Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

    KAUST Repository

    Izadi Najafabadi, Mohammad

    2017-11-06

    A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

  15. Introducing novel amorphous carbon nanoparticles as energy acceptors into a chemiluminescence resonance energy transfer immunoassay system.

    Science.gov (United States)

    Wang, Zhenxing; Gao, Hongfei; Fu, Zhifeng

    2013-11-21

    A novel chemiluminescence resonance energy transfer (CRET) system for competitive immunoassay of biomolecules was developed by using novel amorphous carbon nanoparticles (CNPs) prepared from candle soot as energy acceptors. The CNPs were firstly prepared to bind with the antigen (Ag) for obtaining the nanocomposite CNP-Ag, and this obtained CNP-Ag was then reacted with the horseradish peroxidase-labeled antibody (HRP-Ab) to assemble the CRET system. The luminol catalyzed by HRP serving as the energy donor for CNPs triggered the CRET phenomenon between luminol and CNPs, which led to the chemiluminescence signal decrease. Due to the competitive immunoreaction of the target antigen and the CNP-Ag, a part of the CNP-Ag was replaced from the HRP-Ab, and then resulted in a weaker interaction between luminol and CNPs. Thus the competitive immunoreaction led to a higher chemiluminescence emission. This CNP-based CRET system was successfully applied to detect the human IgG as a model analyte, and a linear range of 10-200 ng mL(-1) and a detection limit of 1.9 ng mL(-1) (S/N = 3) were obtained. The results for real sample analysis demonstrated its application potential in some important areas such as clinical diagnosis.

  16. Evaluation of the oxidative activity of some free base porphyrins by a chemiluminescence method

    Directory of Open Access Journals (Sweden)

    MARIANA VOICESCU

    2010-03-01

    Full Text Available Due to their spectral characteristics, phototoxicity and high affinity for tumour tissues, porphyrins and their derivatives are widely used in modern medicine as contrast agents for cancer diagnostics and as sensitizers in photodynamic therapy, where they kill tumours via enhancement of tumour oxidative stress. The aim of this work was to simulate in vitro the effects caused by oxidation of two free base porphyrins, 5,10,15,20-tetraphenylporphyrin (TPP and 5,10,15,20‑tetra(4‑methoxyphenylporphyrin (TMOPP. The kinetic study was monitored using spectral techniques and chemiluminescence. The effect of both porphyrins on an oxidation process was evidenced using the chemilumi-nescent system, luminal–hydrogen peroxide, in a phosphate buffer at pH 7. It was found that at low concentration, TPP exerts the anti-oxidative effect in the employed chemiluminescent system, while at higher concentrations; its effect is pro-oxidative. TMOPP exerts a pro-oxidant effect, which was more pronounced than TPP. The results are discussed with respect to oxidative stress.

  17. FEATURES NEUTROPHIL CHEMILUMINESCENCE OF PERIPHERAL BLOOD IN ONCOUROLOGICAL PATIENTS IN THE DISEASE DYNAMICS

    Directory of Open Access Journals (Sweden)

    L. M. Kurtasova

    2016-01-01

    Full Text Available Study Objectives – the study of indicators and luminol- lucigenin-dependent chemiluminescence of peripheral blood neutrophils in patients with renal cell carcinoma and bladder cancer prior to the surgery and 10 days after surgery. Held for observation of renal cell carcinoma and bladder cancer patients prior to the (n = 60 and 10 days after surgery (n = 46, aged 45-55 years. The control group consisted of 56 healthy blood donors. Luminol- and lucigenin-dependent chemiluminescence of blood neutrophils estimated De Sole et al. (1983.In patients with renal cell carcinoma and bladder cancer in blood neutrophils showed a change of the system of production of reactive oxygen species in the course of the disease. The observed changes depend on the localization of the tumor process. In patients with renal cell carcinoma changes mainly affect the primary production of reactive oxygen species in patients with bladder cancer early stages of oxidative metabolism and secondary reactive oxygen species. Restoring compensatory metabolic capacity of blood neutrophils in the postoperative period will occur in patients with bladder cancer.The findings clarify the features of the chemiluminescence response of peripheral blood neutrophils from oncourological patients that should probably be used in the development of immune rehabilitation programs in this category of patients in the postoperative period.

  18. Effects of pteridines on luminol-dependent chemiluminescence induced by chloramine-T.

    Science.gov (United States)

    Reibnegger, G; Fuchs, D; Murr, C; Dierich, M P; Pfleiderer, W; Wachter, H

    1995-03-01

    Pteridines are ubiquitous in living organisms, but little is known about their biological functions. Different pteridines were tested for their ability to modulate luminol-dependent chemiluminescence induced by chloramine-T at pH = 7.5 and at a concentration of 100 microM for each pteridine. We observed striking differences between the compounds; whereas reduced pteridine species were generally potent scavengers, aromatic pteridines were weak to strong enhancers of the chemiluminescence. Taking into account the detailed chemical structure of the molecules, by multiple linear regression analysis a simple index was constructed that allows prediction of the effects of the different pteridines with high accuracy (linear correlation coefficient between predicted and observed values r = 0.89). The effects of different pteridines on free radical-induced chemiluminescence might bear biological significance since, for example, certain pteridines take part in enzymic reactions involving free-radical intermediates, or are related to the activation of macrophages in close relationship with the oxidative burst.

  19. Interdigitated microelectrode array-coupled bipolar semiconductor photodiode array (IMEA-PDA) microchip for on-chip electrochemiluminescence detection.

    Science.gov (United States)

    Pal, Sukdeb; Kim, Min Jung; Tak, Yu Kyung; Kwon, Ho Taik; Song, Joon Myong

    2009-10-01

    This paper reports the design, fabrication and testing of a microchip wherein interdigitated microelectrode arrays (IMEA) were integrated with bipolar semiconductor photodiode array (PDA) chip to fabricate a highly compact embodiment for on-chip handling of solutions and electrochemiluminescence (ECL) detection. A 12 x 12 micro array of photodiodes, each coupled with an interdigitated microelectrode array (IMEA), an array of current amplifiers, and a photodiode element-addressing circuit were integrated into a single 2 x 2 cm² IC chip. Each photodiode had dimensions of 300 x 300 μm² and the photodiode-to-photodiode distance was 100 μm. The chip was successfully applied to the on-chip quantification of electro-chemiluminescing probe-labeled single stranded oligonucleotides. The minimum detectable limit at signal/noise ≥ 3 was found to be 5 x 10⁻¹⁴ moles of oligonucleotides with a sample volume as low as 5 microl (i.e., 10 fmole/μl). The attractive features of the developed IMEA-PDA microchip are that a plurality of samples can be analyzed simultaneously using a chip and that for a given sample the data can be averaged from values obtained from multiple, individually addressed pixels. These in turn bring in speed and statistical confidence in analysis. The IMEA-PDA microchip system has the potential to be used as a versatile and highly compact chemical analysis tool for chemical sensing and metrology applications.

  20. Layer-by-layer cell membrane assembly

    Science.gov (United States)

    Matosevic, Sandro; Paegel, Brian M.

    2013-11-01

    Eukaryotic subcellular membrane systems, such as the nuclear envelope or endoplasmic reticulum, present a rich array of architecturally and compositionally complex supramolecular targets that are as yet inaccessible. Here we describe layer-by-layer phospholipid membrane assembly on microfluidic droplets, a route to structures with defined compositional asymmetry and lamellarity. Starting with phospholipid-stabilized water-in-oil droplets trapped in a static droplet array, lipid monolayer deposition proceeds as oil/water-phase boundaries pass over the droplets. Unilamellar vesicles assembled layer-by-layer support functional insertion both of purified and of in situ expressed membrane proteins. Synthesis and chemical probing of asymmetric unilamellar and double-bilayer vesicles demonstrate the programmability of both membrane lamellarity and lipid-leaflet composition during assembly. The immobilized vesicle arrays are a pragmatic experimental platform for biophysical studies of membranes and their associated proteins, particularly complexes that assemble and function in multilamellar contexts in vivo.

  1. Phased arrays '85

    Science.gov (United States)

    Stiglitz, M. R.

    1985-11-01

    The conference Phased Arrays '85 was held in Bedford, MA, on October 15-18, 1985. It is pointed out that the 15 years between the 1970 and 1985 conferences dedicated to phased array antennas have seen many technological advances. Attention is given to the principle of operation, monolithic phased arrays, active arrays of monopole elements, scan compensated active element patterns, microstrip arrays, time delay technologies for phased array systems, ferrite materials for mm-wave phase shifters, phase-only optimization of phased array excitation by B-quadratic programming, a nearly frequency-independent sidelobe suppression technique for phased arrays, and active impedance effects in low sidelobe and ultrawideband phased arrays.

  2. Preparation and characterization of haematite nanowire arrays

    CERN Document Server

    Xue, D S; Liu, Q F; Zhang, L Y

    2003-01-01

    Arrays of alpha-Fe sub 2 O sub 3 nanowires embedded in anodic alumina membranes were obtained after heat-treating beta-FeOOH nanowire arrays fabricated by electrochemical deposition. Haematite polycrystalline nanowires with maximum length of about 7 mu m and average diameter of about 120 nm were characterized by means of x-ray diffraction and transmission electron microscopy. The Morin temperature below 80 K and Neel temperature of about 350 K for the alpha-Fe sub 2 O sub 3 nanowire arrays, far lower than those of bulk material, were measured by Moessbauer spectroscopy and using a Magnetic Property Measurement System.

  3. Piezoelectric array elements for sound reconstruction with a digital input

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-10-13

    Various examples are provided for digital sound reconstruction using piezoelectric array elements. In one example, a digital loudspeaker includes a fixed frame and an array of transducers disposed on the fixed frame. Individual transducers of the array of transducers can include a flexible membrane disposed on a piezoelectric actuation element positioned over a corresponding opening that extends through the fixed frame. In another example, a method includes forming a flexible membrane structure on a substrate and backetching the substrate opposite the flexible membrane structure. The flexible membrane structure can be formed by disposing a first electrode layer on a substrate, disposing a piezoelectric layer on the first electrode layer and disposing a second electrode layer on the piezoelectric layer. A flexible membrane layer (e.g., polyimide) can be disposed on the second electrode layer.

  4. Coupling in reflector arrays

    DEFF Research Database (Denmark)

    Appel-Hansen, Jørgen

    1968-01-01

    In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present communic......In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present...

  5. Deployable Wide-Aperture Array Antennas

    Science.gov (United States)

    Fink, Patrick W.; Dobbins, Justin A.; Lin, Greg Y.; Chu, Andrew; Scully, Robert C.

    2005-01-01

    Inexpensive, lightweight array antennas on flexible substrates are under development to satisfy a need for large-aperture antennas that can be stored compactly during transport and deployed to full size in the field. Conceived for use aboard spacecraft, antennas of this type also have potential terrestrial uses . most likely, as means to extend the ranges of cellular telephones in rural settings. Several simple deployment mechanisms are envisioned. One example is shown in the figure, where the deployment mechanism, a springlike material contained in a sleeve around the perimeter of a flexible membrane, is based on a common automobile window shade. The array can be formed of antenna elements that are printed on small sections of semi-flexible laminates, or preferably, elements that are constructed of conducting fabric. Likewise, a distribution network connecting the elements can be created from conventional technologies such as lightweight, flexible coaxial cable and a surface mount power divider, or preferably, from elements formed from conductive fabrics. Conventional technologies may be stitched onto a supporting flexible membrane or contained within pockets that are stitched onto a flexible membrane. Components created from conductive fabrics may be attached by stitching conductive strips to a nonconductive membrane, embroidering conductive threads into a nonconductive membrane, or weaving predetermined patterns directly into the membrane. The deployable antenna may comprise multiple types of antenna elements. For example, thin profile antenna elements above a ground plane, both attached to the supporting flexible membrane, can be used to create a unidirectional boresight radiation pattern. Or, antenna elements without a ground plane, such as bow-tie dipoles, can be attached to the membrane to create a bidirectional array such as that shown in the figure. For either type of antenna element, the dual configuration, i.e., elements formed of slots in a conductive

  6. Membrane Biophysics

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  7. A new method for immunoassays using field-flow fractionation with on-line, continuous chemiluminescence detection.

    Science.gov (United States)

    Melucci, D; Guardigli, M; Roda, B; Zattoni, A; Reschiglian, P; Roda, A

    2003-06-13

    Chemiluminescence detection has already been combined with different separation techniques such as HPLC and capillary electrophoresis. In this work, it was applied to gravitational field-flow fractionation, a low-cost, flow-assisted separation technique for micronsized particles suited to further on-line detection of the separated analytes. Horseradish peroxidase was used as model sample, either free in solution or immobilized onto micronsized, polystyrene beads. The chemiluminescent substrates were added directly into the mobile phase, and the continuous, steady-state chemiluminescence generated during elution was detected on-line by either a flow-through luminometer or a CCD camera. Ultra-low detection limits, two orders of magnitude lower than those achievable with spectrophotometric detection, were found. The possibility to fully separate and quantitate free and bead-immobilized enzymes is reported, as a step towards the development of multianalyte, ultra-sensitive, micronsized beads-based flow-assisted immunoassays.

  8. Chemiluminescence determination of ferulic acid by flow-injection analysis using cerium(IV) sensitized by rhodamine 6G.

    Science.gov (United States)

    Wang, Ju Peng; Li, Nian Bing; Luo, Hong Qun

    2008-11-01

    A simple, sensitive and rapid flow-injection chemiluminescence method has been developed for the determination of ferulic acid based on the chemiluminescence reaction of ferulic acid with rhodamine 6G and ceric sulfate in sulphuric acid medium. Strong chemiluminescence signal was observed when ferulic acid was injected into the acidic ceric sulfate solution in a flow-cell. The present method allowed the determination of ferulic acid in the concentration range of 8.0 x 10(-6) to 1.0 x 10(-4) mol l(-1) and the detection limit for ferulic acid was 8.7 x 10(-9) mol l(-1). The relative standard deviation was 2.4% for 10 replicate analyses of 1.0 x 10(-5) mol l(-1) ferulic acid. The proposed method was applied to the determination of ferulic acid in Taita Beauty Essence samples with satisfactory results.

  9. MIL-53(Fe) MOF-mediated catalytic chemiluminescence for sensitive detection of glucose.

    Science.gov (United States)

    Yi, Xueling; Dong, Wenfei; Zhang, Xiaodan; Xie, Jianxin; Huang, Yuming

    2016-12-01

    Various analytical applications of metal-organic frameworks (MOFs) have been rapidly developed in the past few years. However, the employment of MOFs as catalysts in chemiluminescence (CL) analysis is rare. Here, for the first time, we found that MIL-53(Fe) MOFs could significantly enhance the CL of luminol in the presence of H2O2 in an alkaline medium. The CL intensity in the luminol-H2O2-MIL-53(Fe) system was about 20 times higher than that in the luminol-H2O2 system. Moreover, the XRD pattern of MIL-53(Fe) after CL reaction was almost the same as that of the original MIL-53(Fe), confirming the catalytic role of MIL-53(Fe) in the luminol-H2O2-MIL-53(Fe) system. The possible mechanism behind the enhancing phenomenon was discussed based on the results from the CL spectra, FL probe experiments, and active oxygen species measurements. By coupling with the glucose oxidase-based catalytic oxidation reaction, a sensitive and selective CL method was developed for the detection of glucose. There is a linear relationship between the logarithm of CL intensity and the logarithm of glucose concentration in the range from 0.1 to 10 μM, and a detection limit of 0.05 μM (S/N = 3) is obtained. The proposed method has been applied to the determination of glucose in human serum samples with satisfactory results. Graphical abstract MIL-53(Fe) MOFs are found to greatly enhance the chemiluminescence emission of the luminol-H2O2 system, and this finding resulted in a new chemiluminescence method for biosensing of glucose when coupled with the glucose oxidase.

  10. Evaluation of nitrogen dioxide chemiluminescence monitors in a polluted urban environment

    Directory of Open Access Journals (Sweden)

    M. J. Molina

    2007-05-01

    Full Text Available Data from a recent field campaign in Mexico City are used to evaluate the performance of the EPA Federal Reference Method for monitoring the ambient concentrations of NO2. Measurements of NO2 from standard chemiluminescence monitors equipped with molybdenum oxide converters are compared with those from Tunable Infrared Laser Differential Absorption Spectroscopy (TILDAS and Differential Optical Absorption Spectroscopy (DOAS instruments. A significant interference in the chemiluminescence measurement is shown to account for up to 50% of ambient NO2 concentration during afternoon hours. As expected, this interference correlates well with non-NOx reactive nitrogen species (NOz as well as with ambient O3 concentrations, indicating a photochemical source for the interfering species. A combination of ambient gas phase nitric acid and alkyl and multifunctional alkyl nitrates is deduced to be the primary cause of the interference. Observations at four locations at varying proximities to emission sources indicate that the percentage contribution of HNO3 to the interference decreases with time as the air parcel ages. Alkyl and multifunctional alkyl nitrate concentrations are calculated to reach concentrations as high as several ppb inside the city, on par with the highest values previously observed in other urban locations. Averaged over the MCMA-2003 field campaign, the chemiluminescence monitor interference resulted in an average measured NO2 concentration up to 22% greater than that from co-located spectroscopic measurements. Thus, this interference has the potential to initiate regulatory action in areas that are close to non-attainment and may mislead atmospheric photochemical models used to assess control strategies for photochemical oxidants.

  11. Automated determinations of selenium in thermal power plant wastewater by sequential hydride generation and chemiluminescence detection.

    Science.gov (United States)

    Ezoe, Kentaro; Ohyama, Seiichi; Hashem, Md Abul; Ohira, Shin-Ichi; Toda, Kei

    2016-02-01

    After the Fukushima disaster, power generation from nuclear power plants in Japan was completely stopped and old coal-based power plants were re-commissioned to compensate for the decrease in power generation capacity. Although coal is a relatively inexpensive fuel for power generation, it contains high levels (mgkg(-1)) of selenium, which could contaminate the wastewater from thermal power plants. In this work, an automated selenium monitoring system was developed based on sequential hydride generation and chemiluminescence detection. This method could be applied to control of wastewater contamination. In this method, selenium is vaporized as H2Se, which reacts with ozone to produce chemiluminescence. However, interference from arsenic is of concern because the ozone-induced chemiluminescence intensity of H2Se is much lower than that of AsH3. This problem was successfully addressed by vaporizing arsenic and selenium individually in a sequential procedure using a syringe pump equipped with an eight-port selection valve and hot and cold reactors. Oxidative decomposition of organoselenium compounds and pre-reduction of the selenium were performed in the hot reactor, and vapor generation of arsenic and selenium were performed separately in the cold reactor. Sample transfers between the reactors were carried out by a pneumatic air operation by switching with three-way solenoid valves. The detection limit for selenium was 0.008 mg L(-1) and calibration curve was linear up to 1.0 mg L(-1), which provided suitable performance for controlling selenium in wastewater to around the allowable limit (0.1 mg L(-1)). This system consumes few chemicals and is stable for more than a month without any maintenance. Wastewater samples from thermal power plants were collected, and data obtained by the proposed method were compared with those from batchwise water treatment followed by hydride generation-atomic fluorescence spectrometry. Copyright © 2015 Elsevier B.V. All rights

  12. Negative interference by rheumatoid factor in alpha-fetoprotein chemiluminescent microparticle immunoassay.

    Science.gov (United States)

    Wang, Hui; Bi, Xiaohui; Xu, Lei; Li, Yirong

    2017-01-01

    Background Rheumatoid factor causes positive interference in multiple immunoassays. Recently, negative interference has also been found in immunoassays in the presence of rheumatoid factor. The chemiluminescent microparticle immunoassay is widely used to determine serum alpha-fetoprotein. However, it is not clear whether the presence of rheumatoid factor in the serum causes interference in the chemiluminescent microparticle immunoassay of alpha-fetoprotein. Methods Serum alpha-fetoprotein was determined using the ARCHITECT alpha-fetoprotein assay. The estimation of alpha-fetoprotein recovery was carried out in samples prepared by diluting high-concentration alpha-fetoprotein serum with rheumatoid factor-positive or rheumatoid factor-negative serum. Paramagnetic microparticles coated with hepatitis B surface antigen-anti-HBs complexes were used to remove rheumatoid factor from the serum. Results The average recovery of alpha-fetoprotein was 88.4% and 93.8% in the rheumatoid factor-positive and rheumatoid factor-negative serum samples, respectively. The recovery of alpha-fetoprotein was significantly lower in the rheumatoid factor-positive serum samples than in the rheumatoid factor-negative serum samples. In two of five rheumatoid factor-positive samples, a large difference was found (9.8%) between the average alpha-fetoprotein recoveries in the serially diluted and initial recoveries. Fourteen rheumatoid factor-positive serum samples were pretreated with hepatitis B surface antigen-anti-HBs complex-coated paramagnetic microparticles. The alpha-fetoprotein concentrations measured in the pretreated samples increased significantly. Conclusions It was concluded that the alpha-fetoprotein chemiluminescent microparticle immunoassay is susceptible to interference by rheumatoid factor, leading to significantly lower results. Eliminating the incidence of negative interference from rheumatoid factor should be an important goal for immunoassay providers. In the meantime

  13. Fabrication of micro-Ni arrays by electroless and electrochemical ...

    Indian Academy of Sciences (India)

    Nickel micro-arrays were fabricated by electroless and electrochemical deposition in an etched porous aluminum membrane. The aluminum membrane with metal characteristic could be fabricated from high-purity aluminium by electrochemical method. The aluminum reduced Ni2+ into Ni and the formed Ni nuclei served as ...

  14. Clinical Performance Evaluation of Four Automated Chemiluminescence Immunoassays for Hepatitis C Virus Antibody Detection▿

    OpenAIRE

    Kim, Sinyoung; Kim, Jeong-Ho; Yoon, Seoyoung; Park, Youn-Hee; Kim, Hyon-Suk

    2008-01-01

    Various automated chemiluminescence immunoassay (CLIA) analyzers for the detection of antibodies to hepatitis C virus (HCV) are now commercially available in clinical laboratories and are replacing conventional enzyme immunoassays. We investigated the performance of four anti-HCV CLIAs (the Architect Anti-HCV assay on the Architect i2000 system, the Vitros Anti-HCV assay on the Vitros ECiQ Immunodiagnostic System, the Access HCV Ab PLUS assay on the UniCel DxI 800 analyzer, and the newly deve...

  15. Temperature measurements by oh lif and chemiluminescence kinetic modeling for ethanol flames

    Directory of Open Access Journals (Sweden)

    Carla S. T. Marques

    2009-01-01

    Full Text Available OH LIF-thermometry was applied to premixed ethanol flames at atmospheric pressure in a burner for three flame conditions. Flame temperatures were simulated from energy equation with PREMIX code of CHEMKIN software package for comparison. A kinetic modeling based on a model validated through chemiluminescence measurements and on a set of reactions for nitrogen chemistry was evaluated. Marinov's mechanism was also tested. Sensitivity analysis was performed for fuel-rich flame condition with Φ = 1.34. Simulated temperatures from both reaction mechanisms evaluated were higher than experimental values. However, the proposed kinetic modeling resulted in temperature profiles qualitatively very close to the experimental.

  16. Chemiluminescence of phthalhydrazide derivatives in organized media: Interactions with surfactants and cyclodextrins

    Energy Technology Data Exchange (ETDEWEB)

    Maeztu, Raquel [Departamento de Quimica y Edafologia, Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona (Spain); Gonzalez-Gaitano, Gustavo, E-mail: gaitano@unav.e [Departamento de Quimica y Edafologia, Facultad de Ciencias, Universidad de Navarra, 31080 Pamplona (Spain); Tardajos, Gloria [Departamento de Quimica-Fisica I, Facultad de CC. Quimicas, Universidad Complutense, 28040 Madrid (Spain); Stilbs, Peter [Division of Physical Chemistry and Industrial NMR Centre, Department of Chemistry, Royal Institute of Technology, SE-10044, Stockholm (Sweden)

    2011-04-15

    The chemiluminescent oxidation of some phthalhydrazide derivatives, luminol (LUM), isoluminol (ISOL), N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and N-(6-aminohexyl)-N-ethylisoluminol (AHEI), has been carried out in micellar media and in the presence of natural cyclodextrins (CDs), using Co(II) as catalyst and H{sub 2}O{sub 2} as oxidant. The cationic cetyltrimethylammonium bromide (CTAB) and, in a lesser extent, the anionic sodium dodecyl sulfate (SDS) produce quenching in the chemiluminescence (CL) of all the luminophores at concentrations above the cmc, whereas slight enhancements are attained with the non-ionic pentaethylene glycol monododecyl ether (C{sub 12}E{sub 5}). On the contrary, the incorporation of the CDs to the reaction produces a remarkable intensification of the CL. Binding of the luminophores to the macrocycles and the micelles has been studied by Pulsed-Gradient-Spin-Echo-NMR (PGSE-NMR) and fluorescence anisotropy. The cationic CTAB decreases the emission mainly due to charge compensation as a result of the association of the luminophores and the luminescent intermediates to the micelles. The presence of the alkyl substituents of ABEI and AHEI provides an additional hydrophobic contribution to the binding process. SDS quenches this reaction as the micelles retain Co(II) on their anionic layer. The protection and stabilization of these luminophores or their luminescent intermediates provided by the cavities of the CDs make this family of cyclic oligosaccharides much more suitable agents than the surfactants for enhancing the CL in aqueous media for this specific reaction. - Research highlights: Natural cyclodextrins act as boosters of the chemiluminescence of luminol and its derivatives. Cyclodextrins can be successfully employed for improving the possibilities of those applications that make use of the CL of luminol and its derivatives as a detection or quantification method. Ionic and non-ionic surfactants do not either enhance or even quench the

  17. Measurement of fecal sulfide using gas chromatography and a sulfur chemiluminescence detector.

    Science.gov (United States)

    Fume, J K; Springfield, J; Koenig, T; Suarez, F; Levitt, M D

    2001-04-15

    We describe a simple technique to measure sulfide in fecal homogenates (or any other liquid milieu), which involves acidification followed by the G.C. measurement of H2S in a gas space equilibrated with a small quantity of homogenate. An internal standard of Zn35S added to the homogenate permits correction for incomplete recovery of H2S in the gas space. The use of a sulfur chemiluminescence detector, which specifically and sensitively responds to sulfur-containing compounds, greatly facilitates this measurement.

  18. Luminol-dependent chemiluminescence of hemocytes derived from marine and estuarine molluscs.

    Science.gov (United States)

    Kumazawa, N H; Morimoto, N; Okamoto, Y

    1993-04-01

    Hemocytes of two marine molluscs, Nerita albicilla (gastropod) and Mytilus edulis (bivalve), were stimulated in vitro with zymosan and live cells of Vibrio parahaemolyticus and Escherichia coli as determined by luminol-dependent chemiluminescence (CL). The CL response was enhanced in the presence of the respective molluscan plasma. Hemocytes of an estuarine gastropod, Clithon retropictus, showed low CL response to zymosan and V. parahaemolyticus, which was slightly enhanced in the presence of C. retropictus plasma. Hemocytes of an estuarine bivalve, Corbicula japonica, showed no CL response. CL response of hemocytes might be a useful tool to analyze defense mechanisms of estaurine molluscs.

  19. Four-port gas separation membrane module assembly

    Science.gov (United States)

    Wynn, Nicholas P.; Fulton, Donald A.; Lokhandwala, Kaaeid A.; Kaschemekat, Jurgen

    2010-07-20

    A gas-separation membrane assembly, and a gas-separation process using the assembly. The assembly incorporates multiple gas-separation membranes in an array within a single vessel or housing, and is equipped with two permeate ports, enabling permeate gas to be withdrawn from both ends of the membrane module permeate pipes.

  20. Thermal chemiluminescence from γ-irradiated polytetrafluoroethylene and its emission mechanism: Investigation by multichannel Fourier-transform luminescence spectroscopy

    Science.gov (United States)

    Noguchi, Tsuyoshi; Yamada, Emi; Akai, Nobuyuki; Ishii, Hiroshi; Satoh, Chikahiro; Hironiwa, Takayuki; Millington, Keith R.; Nakata, Munetaka

    2014-10-01

    Thermal chemiluminescence spectra of polytetrafluoroethylene powder irradiated by γ rays in air at room temperature were measured with a multichannel Fourier-transform chemiluminescence spectrometer. The luminescence appeared immediately after heating the irradiated samples at 160, 180 and 200 °C in dry air and in N2 and then disappeared within a few minutes, whereas virgin samples showed no luminescence. The lifetime of luminescence decreased as the heating temperature increased, but the total amount of luminescence at each temperature was nearly constant. From this observation an emission mechanism was derived with the aid of ESR and IR spectroscopy.

  1. Integrated infrared array technology

    Science.gov (United States)

    Goebel, J. H.; Mccreight, C. R.

    1987-01-01

    An overview of integrated infrared (IR) array technology is presented. Although the array pixel formats are smaller, and the readout noise of IR arrays is larger than the corresponding values achieved with optical charge-coupled-device silicon technology, substantial progress is being made in IR technology. Both existing IR arrays and those being developed are described. Examples of astronomical images are given which illustrate the potential of integrated IR arrays for scientific investigations.

  2. An electrically active microneedle array for electroporation

    Science.gov (United States)

    Choi, Seong-O; Kim, Yeu Chun; Park, Jung-Hwan; Hutcheson, Joshua; Gill, Harvinder S.; Yoon, Yong-Kyu; Prausnitz, Mark R.; Allen, Mark G.

    2010-01-01

    We have designed and fabricated a microneedle array with electrical functionality with the final goal of electroporating skin’s epidermal cells to increase their transfection by DNA vaccines. The microneedle array was made of polymethylmethacrylate (PMMA) by micromolding technology from a master PDMS mold, followed by metal deposition, patterning using laser ablation, and electrodeposition. This microneedle array possessed sufficient mechanical strength to penetrate human skin in vivo and was also able to electroporate both red blood cells and human prostate cancer cells as an in vitro model to demonstrate cell membrane permeabilization. A model to predict the effective volume for electroporation with respect to applied voltages was constructed from finite element simulation. This study demonstrates the mechanical and electrical functionalities of the first MEMS-fabricated microneedle array for electroporation, designed for DNA vaccine delivery. PMID:20012696

  3. Multicomponent membranes

    Science.gov (United States)

    Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

    1988-01-01

    A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

  4. A Novel Technique for Generating and Observing Chemiluminescence in a Biological Setting

    KAUST Repository

    Büchel, Gabriel E.

    2017-03-10

    Intraoperative imaging techniques have the potential to make surgical interventions safer and more effective; for these reasons, such techniques are quickly moving into the operating room. Here, we present a new approach that utilizes a technique not yet explored for intraoperative imaging: chemiluminescent imaging. This method employs a ruthenium-based chemiluminescent reporter along with a custom-built nebulizing system to produce ex vivo or in vivo images with high signal-to-noise ratios. The ruthenium-based reporter produces light following exposure to an aqueous oxidizing solution and re-reduction within the surrounding tissue. This method has allowed us to detect reporter concentrations as low as 6.9 pmol/cm(2). In this work, we present a visual guide to our proof-of-concept in vivo studies involving subdermal and intravenous injections in mice. The results suggest that this technology is a promising candidate for further preclinical research and might ultimately become a useful tool in the operating room.

  5. Evaluation of Antibacterial Enrofloxacin in Eggs by Matrix Solid Phase Dispersion-Flow Injection Chemiluminescence

    Directory of Open Access Journals (Sweden)

    Xiaocui Duan

    2014-01-01

    Full Text Available The study based on the chemiluminescence (CL reaction of potassium ferricyanide and luminol in sodium hydroxide medium, enrofloxacin (ENRO could dramatically enhance CL intensities and incorporated with matrix solid-phase dispersion (MSPD technique (Florisil used as dispersant, dichloromethane eluted the target compounds. A simple flow injection chemiluminescence (FL-CL method with MSPD technique for determination of ENRO in eggs was described. Under optimal conditions, the CL intensities were linearly related to ENRO concentration ranging from 4.0×10-8 g.L−1 to 5.0×10-5 g.L−1, with a correlation coefficient of 0.9989 and detection limit of 5.0×10-9 g.L−1. The relative standard deviation was 3.6% at an ENRO concentration of 2.0×10-6 g.L−1. Our testing technique can help ensure food safety, and thus, protect public health.

  6. Luminol Chemiluminescence Catalyzed by Silver Nanoparticles for the Sensitive Determination of Penicillamine

    Directory of Open Access Journals (Sweden)

    Fakhr Eldin O. Suliman

    2018-01-01

    Full Text Available A sequential injection method for the determination of penicillamine (PA was developed based on quenching the chemiluminescence generated by oxidation of luminol by hydrogen peroxide in presence of silver nanoparticles (AgNPs. The chemiluminescence (CL of the reaction was found to greatly enhance in presence of AgNPs due to the increased catalyst surface area. The method was sensitive and found suitable for analysis of penicillamine in pharmaceutical preparations. Linear calibration curve is obtained in the range 0.2-1.0 mg mL-1 with a relative standard deviation less than 2%. A recovery percent of 102.3 ±0.2 was obtained with the tablets matrix indicating reasonable selectivity of the method for PA in tablets. The mechanism of quenching of the CL reaction was investigated by UV-Visible spectroscopy and transmission electron microscopy as well as by theoretical calculations using DFT-B3LYP method. The covalent attachment of PA to the AgNPs triggers aggregation of the particles thereby diminishing the surface significantly. The method was applied for the assay of PA in pharmaceutical preparations.

  7. Detection of ochratoxin A (OTA) in coffee using chemiluminescence resonance energy transfer (CRET) aptasensor.

    Science.gov (United States)

    Jo, Eun-Jung; Mun, Hyoyoung; Kim, Su-Ji; Shim, Won-Bo; Kim, Min-Gon

    2016-03-01

    We report a chemiluminescence resonance energy transfer (CRET) aptasensor for the detection of ochratoxin A (OTA) in roasted coffee beans. The aptamer sequences used in this study are 5'-DNAzyme-Linker-OTA aptamer-3'-dabcyl. Dabcyl at the end of the OTA aptamer region plays as a quencher in CRET aptasensor. When hemin and OTA are added, the dabcyl-labeled OTA aptamer approaches to the G-quadruplex-hemin complex by formation of the G-quadruplex-OTA complex. The G-quadruplex-hemin complexes possess horseradish peroxidase (HRP)-like activity, and therefore, the HRP-mimicking DNAzyme (HRPzyme) catalyzes peroxidation in the presence of luminol and H2O2. Resonance energy transfer between luminol (donor) and dabcyl (acceptor) enables quenching of chemiluminescence signals. The signal decreases with increasing the concentration of OTA within the range of 0.1-100ngmL(-1) (limit of detection 0.22ngmL(-1)), and the level of recovery of the respective 1ngmL(-1) and 10ngmL(-1) spiked coffee samples was 71.5% and 93.3%. These results demonstrated the potential of the proposed method for OTA analysis in diverse foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Flow injection chemiluminescent determination of clenbuterol using GoldMag particles as carrier.

    Science.gov (United States)

    Li, Zhefei; Jian, Liru; Wang, Huirong; Cui, Yali

    2007-01-01

    A novel flow injection chemiluminescent (CL) enzyme immunoassay for clenbuterol analysis based on GoldMag particles is described. GoldMag is a new type of super-paramagnetic Fe3O4/Au composite particle used as a carrier in a flow injection CL system. Clenbuterol conjugated with ovalbumin (OVA) was immobilized onto GoldMag particles and the particles fixed in a micro-channel by an external electromagnetic field. The clenbuterol test sample and clenbuterol polyclonal antibody (Ab) were injected into the channel and incubated with GoldMag particles. Clenbuterol, immobilized on the magnetic particle surfaces, competes for polyclonal antibodies with clenbuterol in the test sample. The free Ab or Ab combined with the clenbuterol sample was washed away and the magnetic particles conjugated with Ag-Ab left in the micro-channel. Horseradish peroxidase (HRP)-labelled goat anti-rabbit immunoglobulin G (IgG) was added and reacted with clenbuterol polyclonal antibodies; excess goat anti-rabbit-HRP was then washed off. When chemiluminescent reagents were injected into the channel, emitted light from the magnetic particle surface was measured and recorded using a photomultiplier-based apparatus. The linear range of this novel method was 0.01-0.1 ng g(-1) and recovery of clenbuterol was 85-105% with a RSD of 3.2% (n = 11).

  9. Sonodynamic diagnosis of cancer with sonosensitization of ATX-70 mediated by chemiluminescence probe

    Science.gov (United States)

    Li, Xiaoyuan; Xing, Da

    2005-01-01

    In order to develop a novel diagnostic technique, as an adjunct modality to SDT, that uses the gallium-porphyrin derivative ATX-70 as a sonosensitiser mediated by a chemiluminescent probe to produce sonochemiluminescence (SCL) for imaging and localization of cancer within tissue in vivo. The fluoresceinyl Cyprodina luminescent analogue (FCLA) was used as an optical reporter for singlet oxygen generated from the sonosensitisation reaction of ATX-70 in the model solutions and in the in vivo nude mice bearing mammary cancer. The sonosensitized chemiluminescence from the reaction of FCLA with 1O2 was detected by a highly sensitive light-detector. The effect of FCLA with different doses on cell viability was also assessed with MTT assay. The results showed with the FCLA as the reporter, there is clear evidence that the aqueous solution of ATX-70 exposed to ultrasound forms 1O2 in the system. In the in vivo experiments, the tumor-bearing mice are imaged with a great contrast during sonosensitization of ATX-70 mixed with FCLA as the SCL probe. No significant cytotoxity was detected at the different FCLA doses. The results indicated that a novel cancer imaging method, named as the sonodynamic diagnosis (SDD), can be established by the sonodynamic action with the assistance of SCL probe. Therefore, this technique could have potential applications in the clinical diagnosis of cancer diseases at an early stage, and can be used to assess the treatment efficacy during the sonodynamic therapy of cancers.

  10. Peroxynitrous-acid-induced chemiluminescence detection of nitrite based on Microfluidic chip.

    Science.gov (United States)

    Wu, Jing; Wang, Xiong; Lin, Yitong; Zheng, Yongzan; Lin, Jin-Ming

    2016-07-01

    A chemiluminescent method for nitrite detection was developed on microfluidic chip. Carbon dots-NaNO2(-) acidified H2O2 system was adopted. Chemiluminescence (CL) spectrum of this system was detected. The radiative recombination of hole-injected and electron-injected carbon dots explained their CL property. Spiral microchannels were designed on the microfluidic chip to allow enough reaction time for the carbon dots-NaNO2-acidified H2O2 system. Carbon dots and NaNO2 were premixed in the branch microchannel, then, the mixture reacted with acidified H2O2 in spiral microchannels. Concentrations of H2SO4 and H2O2, dilution ratio of carbon dots in H2O and flow rate were optimized to obtain the best CL signals. The approach presented satisfactory linear relationship between NaNO2 concentration and CL intensity. The tolerance of metal ions in determination of 1×10(-5)M nitrite was analyzed. The nitrites in water and beverage samples were successfully analyzed on the microfluidic chip with good repeatability. The data were well accordance with the results obtained from GB 5009.33(-) 2010. This microfluidic CL detection method is believed to be a simple, automatic and agent-save approach for inorganic ion analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Flow-injection chemiluminescence determination of diazepam by oxidation with N-bromosuccinimide.

    Science.gov (United States)

    Han, Suqin; Jia, Shize; Guo, Liang

    2013-01-01

    A rapid and sensitive flow-injection chemiluminescence (FI-CL) method is described for the determination of diazepam based on its reaction with N-bromosuccinimide (NBS) in alkaline medium in the presence of dichlorofluorescein (DCF) as an effective energy-transfer agent. Under optimum conditions, the proposed method allowed the measurement of diazepam over the range of 2.0 × 10(-6) to 2.0 × 10(-4) mol/L with a detection limit of 5.0 × 10(-7) mol/L. The relative standard deviation for 11 parallel measurements of 2.0 × 10(-5) mol/L diazepam was 2.1%. The method was applied satisfactorily for the determination of diazepam in pharmaceutical preparations, and the results agree well with those obtained by spectrophotometry. The use of the proposed system for the determination of diazepam in urine and plasma samples was also tested. The possible mechanism of the chemiluminescence reaction is discussed briefly. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Reactive oxygen species in human semen: validation and qualification of a chemiluminescence assay.

    Science.gov (United States)

    Vessey, Wayne; Perez-Miranda, Ana; Macfarquhar, Rachel; Agarwal, Ashok; Homa, Sheryl

    2014-12-01

    To standardize and validate an assay for reactive oxygen species (ROS) in human semen. ROS levels assayed in blanks, negative and positive control samples (30% H2O2), and human semen, with the use of a luminol-based chemiluminescence assay measured in a single tube luminometer. Andrology laboratory. Semen samples from 19 men attending for routine semen analysis. None. ROS levels reported in relative light units (RLU) per second, adjusted for sperm concentration. The ROS assay equipment performed according to expectations, generating a chemiluminescence signal for positive control samples and semen samples that decayed rapidly and was captured within 10 minutes. Blanks and negative control samples gave negligible readings. There was no significant intra- or interassay variation. Interference from extraneous factors was negligible. The assay distinguished changes in ROS over a wide range of concentrations and provided consistent results between reagent batches. Working reagents remained stable for 3 months. Acceptable levels for negative and positive control samples were established to set criteria for the test passing or failing on any given day. The assay was sensitive to ambient temperature >25°C. ROS declined significantly with time after ejaculation. Mechanical agitation doubled ROS production in semen. These results validate the ROS assay and demonstrate that it is a highly reliable and accurate diagnostic test. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  13. l-Tyrosine Contained in Dietary Supplement by Chemiluminescence Reaction of an Iron-Phthalocyanine Complex

    Directory of Open Access Journals (Sweden)

    Takao Ohtomo

    2012-01-01

    Full Text Available The chemiluminescence (CL signal immediately appeared when a hydrogen peroxide solution was injected into an iron-phthalocyanine tetrasulfonic acid (Fe-PTS aqueous solution. Moreover, the CL intensity of Fe-PTS decreased by adding L-tyrosine. Based on these results, the determination of trace amounts of L-tyrosine was developed using the quenching-chemiluminescence. The calibration curve of L-tyrosine was obtained in the concentration range of 2.0×10−7 M to 2.0×10−5 M. Moreover, the relative standard deviation (RSD was 1.63 % (=5 for 2.0×10−6 M L-tyrosine, and its detection limits (3σ were 1.81×10−7 M. The spike and recovery experiments for L-tyrosine were performed using a soft drink. Furthermore, the determination of L-tyrosine was applied to supplements containing various kinds of amino acids. Each satisfactory relative recovery was obtained at 98 to 102%.

  14. Establishment of a Simple and Convenient Method for Folic Acid Enzyme Chemiluminescence Immunoassay

    Science.gov (United States)

    Liu, Ting; Zeng, Ling; Yu, Zhengwei; Yang, Yanfei; Qu, Yunhuan

    2018-01-01

    The enzyme chemiluminescence new immunoassay for folic acid (FA) was established by competition model. Add FA samples to a microtiter plate precoated with the goat anti-mouse IgG firstly, then add enzyme abled FA and FA monoclonal antibody (McAb). The values of CLIA were measured to reflect the quantity of FA. The limit of detection(LOD) of assay is 0.37ng/mL. The assay shows good correlation during 1∼30 ng/mL with correlation coefficient 0.9976. The intra- and inter-assay coefficients of variation are 4.8 % ∼ 7.3 % and 6.1 % ∼ 12.2 %, respectively. The recovery of folic acid in serum is 90.4 %∼113.2 %. Compared with determine value clinically in chemiluminescence immunoassay kit from Roche company, the correlative equation is y = 0.9689x + 0.0228, and correlation coefficient is 0.9780. Various components and kit overall show good stabilities. This method is simple and convenient, and has low LOD value. The method has overcome the shortcomings of the present references. It is easy to apply and has broad clinical application prospect. It lays an experimental foundation for the preparation of Mc Ab against folic acid and the development of domestic kit.

  15. Chemiluminescence of graphene quantum dots and its application to the determination of uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Amjadi, Mohammad, E-mail: amjadi@tabrizu.ac.ir; Manzoori, Jamshid L.; Hallaj, Tooba

    2014-09-15

    We report on the chemiluminescence (CL) of graphene quantum dots (GQDs) induced by direct chemical oxidation. GQDs were prepared by a simple carbonization method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and Raman spectroscopy. It was found that Ce(IV) could oxidize GQDs to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra. It was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. In order to show the analytical application potential of GQDs-Ce(IV) CL system, it was applied to the determination of uric acid. Under the optimized conditions, the proposed CL system exhibited excellent analytical performance for determination of uric acid in the range of 1.0×10{sup −6} M–5.0×10{sup −4} M with a limit of detection of 5.0×10{sup −7} M. The method was applied to the determination of uric acid in human plasma and urine samples, with satisfactory results. - Highlights: • Chemiluminescence of graphene quantum dots by direct oxidation was studied. • Intense CL is produced by reaction of graphene quantum dots with Ce(IV). • The new CL system was applied to determination of uric acid in plasma and urine.

  16. Microplate-reader method for the rapid analysis of copper in natural waters with chemiluminescence detection

    Directory of Open Access Journals (Sweden)

    Axel eDurand

    2013-01-01

    Full Text Available We have developed a method for the determination of copper in natural waters at nanomolar levels. The use of a microplate-reader minimises sample processing time (~ 25 sec per sample, reagent consumption (~ 120 μL per sample and sample volume (~ 700 μL. Copper is detected by chemiluminescence. This technique is based on the formation of a complex between copper and 1,10-phenanthroline and the subsequent emission of light during the oxidation of the complex by hydrogen peroxide. Samples are acidified to pH 1.7 and then introduced directly into a 24-well plate. Reagents are added during data acquisition via two reagent injectors. When trace metal clean protocols are employed, the reproducibility is generally less then 7% on blanks and the detection limit is 0.7 nM for seawater and 0.4 nM for freshwater. More than 100 samples per hour can be analyzed with this technique, which is simple, robust, and amenable to at-sea analysis. Seawater samples from Storm Bay in Tasmania illustrate the utility of the method for environmental science. Indeed other trace metals for which optical detection methods exist (e.g. chemiluminescence, fluorescence and absorbance could be adapted to the microplate-reader.

  17. The importance of chain length for the polyphosphate enhancement of acidic potassium permanganate chemiluminescence.

    Science.gov (United States)

    Holland, Brendan J; Adcock, Jacqui L; Nesterenko, Pavel N; Peristyy, Anton; Stevenson, Paul G; Barnett, Neil W; Conlan, Xavier A; Francis, Paul S

    2014-09-09

    Sodium polyphosphate is commonly used to enhance chemiluminescence reactions with acidic potassium permanganate through a dual enhancement mechanism, but commercially available polyphosphates vary greatly in composition. We have examined the influence of polyphosphate composition and concentration on both the dual enhancement mechanism of chemiluminescence intensity and the stability of the reagent under analytically useful conditions. The average chain length (n) provides a convenient characterisation, but materials with similar values can exhibit markedly different distributions of phosphate oligomers. There is a minimum polyphosphate chain length (∼6) required for a large enhancement of the emission intensity, but no further advantage was obtained using polyphosphate materials with much longer average chain lengths. Providing there is a sufficient average chain length, the optimum concentration of polyphosphate is dependent on the analyte and in some cases, may be lower than the quantities previously used in routine detection. However, the concentration of polyphosphate should not be lowered in permanganate reagents that have been partially reduced to form high concentrations of the key manganese(III) co-reactant, as this intermediate needs to be stabilised to prevent formation of insoluble manganese(IV). Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Streptavidin-functionalized capillary immune microreactor for highly efficient chemiluminescent immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Yang Zhanjun [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); College of Chemistry and Engineering, Yangzhou University, 88 South University Avenue, Yangzhou 225002 (China); Zong Chen [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Ju Huangxian, E-mail: hxju@nju.edu.cn [State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093 (China); Yan Feng, E-mail: yanfeng2007@sohu.com [Jiangsu Institute of Cancer Prevention and Cure, Nanjing 210009 (China)

    2011-11-07

    Highlights: {yields} A novel capillary immune microreactor was proposed for highly efficient flow-through chemiluminescent immunoassay. {yields} The microreactor was prepared by functionalizing capillary inner wall with streptavidin for capture of biotinylated antibody. {yields} The proposed immunoassay method showed wide dynamic range, good reproducibility, stability and practicality. {yields} The microreactor was low-cost and disposable, and possessed several advantages over the conventional immunoreactors. - Abstract: A streptavidin functionalized capillary immune microreactor was designed for highly efficient flow-through chemiluminescent (CL) immunoassay. The functionalized capillary could be used as both a support for highly efficient immobilization of antibody and a flow cell for flow-through immunoassay. The functionalized inner wall and the capture process were characterized using scanning electron microscopy. Compared to conventional packed tube or thin-layer cell immunoreactor, the proposed microreactor showed remarkable properties such as lower cost, simpler fabrication, better practicality and wider dynamic range for fast CL immunoassay with good reproducibility and stability. Using {alpha}-fetoprotein as model analyte, the highly efficient CL flow-through immunoassay system showed a linear range of 3 orders of magnitude from 0.5 to 200 ng mL{sup -1} and a low detection limit of 0.1 ng mL{sup -1}. The capillary immune microreactor could make up the shortcoming of conventional CL immunoreactors and provided a promising alternative for highly efficient flow-injection immunoassay.

  19. Improvement on simultaneous determination of chromium species in aqueous solution by ion chromatography and chemiluminescence detection

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Liao, Y.P.; Jons, O.

    1997-01-01

    A sensitive method for the simultaneous determination of chromium(III) and chromium(VI) was chromatography and chemiluminescence detection. Two Dionex ion-exchange guard columns in series, CG5 and AG7, were used to separate chromium(III) from chromium(VI). Chromium(VI) was reduced by potassium...... sulphite, whereupon both species were detected by use of the luminol-hydrogen peroxide chemiluminescence system. Parameters affecting retention times and resolution of the separator columns, such as eluent pH, eluent composition, reductant pH and concentration, and flow rates were optimized. Furthermore...... was 1.4% for chromium(III) and 2.5% for chromium(VI), respectively. The accuracy of the chromium(III) determination was determined by analysis of the NIST standard reference material 1643c, Trace elements in water with the result 19.1 +/- 1.0 mu g Cr(III) l(-1) (certified value 19.0 +/- 0.6 mu g Cr...

  20. Quantification of sorbic acid using the molecularly imprinted chemiluminescence method with rhodanine derivative.

    Science.gov (United States)

    Yu, Jinghua; Zhang, Congcong; Ge, Lei; Dai, Ping; Ge, Shenguang

    2009-11-01

    A novel molecular imprinting-chemiluminescence (MI-CL) method for the determination of sorbic acid (SA) was established, taking the molecularly imprinted polymer (MIP) as recognition material and a novel rhodanine derivative as chemiluminescence reagent. The MIP was prepared by a self-assembly technique with SA as template molecule, methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker. It was found that 3-o-methoxyphenyl-5-(2'-sulfono phenylazo) rhodanine (2MORASP) significantly enhanced the luminescence intensity of the SA-potassium permanganate-hydrochloride acid system. The method was proved to be selective and sensitive. Under the optimized experimental conditions, the system exhibits an excellent linear relationship over the range of 3.0 x 10(-7)-6.0 x 10(-4) g mL(-1). The detection limit of the proposed method was 2.2 x 10(-8) g mL(-1). This method was successfully applied to the determination of SA in milk and fruit juice samples.

  1. Cochlear implant insertion forces in microdissected human cochlea to evaluate a prototype array.

    Science.gov (United States)

    Nguyen, Yann; Miroir, Mathieu; Kazmitcheff, Guillaume; Sutter, Jasmine; Bensidhoum, Morad; Ferrary, Evelyne; Sterkers, Olivier; Bozorg Grayeli, Alexis

    2012-01-01

    Cochlear implant array insertion forces are potentially related to cochlear trauma. We compared these forces between a standard (Digisonic SP; Neurelec, Vallauris, France) and an array prototype (Neurelec) with a smaller diameter. The arrays were inserted by a mechatronic tool in 23 dissected human cochlea specimens exposing the basilar membrane. The array progression under the basilar membrane was filmed together with dynamic force measurements. Insertion force profiles and depth of insertion were compared. The recordings showed lower insertion forces beyond 270° of insertion and deeper insertions with the thin prototype array. This will potentially allow larger cochlear coverage with less trauma. Copyright © 2012 S. Karger AG, Basel.

  2. Application of multi-step excitation schemes for detection of actinides and lanthanides in solutions by luminescence/chemiluminescence laser spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Izosimov, I. [Joint Institute for Nuclear Research, Joliot Curie 6, Dubna 141980 (Russian Federation)

    2016-07-01

    The use of laser radiation with tunable wavelength allows the selective excitation of actinide/lanthanide species with subsequent registration of luminescence/chemiluminescence for their detection. This work is devoted to applications of the time-resolved laser-induced luminescence spectroscopy and time-resolved laser-induced chemiluminescence spectroscopy for the detection of lanthanides and actinides. Results of the experiments on U, Eu, and Sm detection by TRLIF (Time Resolved Laser Induced Fluorescence) method in blood plasma and urine are presented. Data on luminol chemiluminescence in solutions containing Sm(III), U(IV), and Pu(IV) are analyzed. It is shown that appropriate selectivity of lanthanide/actinide detection can be reached when chemiluminescence is initiated by transitions within 4f- or 5f-electron shell of lanthanide/actinide ions corresponding to the visible spectral range. In this case chemiluminescence of chemiluminogen (luminol) arises when the ion of f element is excited by multi-quantum absorption of visible light. The multi-photon scheme of chemiluminescence excitation makes chemiluminescence not only a highly sensitive but also a highly selective tool for the detection of lanthanide/actinide species in solutions. (author)

  3. Enhancement of peroxyoxalate chemiluminescence by copper (II) in flow-injection analysis: optimization by factorial design analysis.

    NARCIS (Netherlands)

    Steijger, O.M.; den Nieuwenboer, H.C.M.; Lingeman, H.; Brinkman, U.A.T.; Holthuis, J.J.M.; Smilde, A.K.

    1996-01-01

    A flow injection analysis (FIA) system with peroxyoxalate chemiluminescence (CL) detection was optimized by factorial design analysis in the absence and presence of Cu(II) ions. The carrier stream was a mixture of acetonitrile and an aqueous imidazole solution of pH 7.0. The effect of the metal ions

  4. Comparison of chemiluminescence and toluidine blue in the diagnosis of dysplasia in leukoplakia: a cross-sectional study.

    Science.gov (United States)

    Chaudhry, Astha; Manjunath, Muniraju; Ashwatappa, Deepak; Krishna, Sowmya; Krishna, Annaji Gopal

    2016-05-01

    The early diagnosis and treatment of oral cancer at a potentially-malignant stage would reduce morbidity and improve the survival rates and quality of life of patients. Leukoplakia is the most common potentially-malignant disorder. Clinical examination alone cannot differentiate between dysplastic and non-dysplastic leukoplakia. Chemiluminescence and toluidine blue are adjuncts to conventional examination for the early detection of dysplasia. The present study was conducted to compare the efficacies of chemiluminescence and toluidine blue for the diagnosis of dysplasia in leukoplakia. One hundred patients with leukoplakia were subjected to conventional oral examination, chemiluminescent examination with ViziLite and toluidine blue test, followed by histopathological confirmation of dysplasia. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of chemiluminescence was 84.84%, 41.17%, 73.68%, 58.33%, and 70%, respectively. For toluidine blue it was 42.4%, 88.23%, 87.50%, 44.11%, and 58% respectively. Both the techniques have adjunctive utility in the diagnosis of dysplasia in leukoplakia, but toluidine blue was more effective in identifying the more severe grades of dysplasia, and thus it effectively discriminated high-risk from low-risk lesions. © 2014 Wiley Publishing Asia Pty Ltd.

  5. Enhanced sensitivity of Cypridina luciferin analog (CLA) chemiluminescence for the detection of O2- with non ionic detergents

    NARCIS (Netherlands)

    Osman, A.M.; Laane, C.; Hilhorst, R.

    2000-01-01

    Superoxide anion-triggered chemiluminescence of Cypridina luciferin analogue (CLA), 2-methyl-6-phenyl-3,7-dohydroimidazo[1,2-]pyrazin-3-one, is enhanced by non-ionic detergents such as Tween 20, Triton X-100 and Tween 80. At the concentration of 0.6øv/v) the largest increase (2.7-fold) of CLA light

  6. Simultaneous determination of chromium(III) and chromium(VI) in aqueous solutions by ion chromatography and chemiluminescence detection

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jøns, O; Nielsen, B

    1992-01-01

    A method for the simultaneous determination of chromium(iii) and chromium(vi) in a flow system based on chemiluminescence was developed. A Dionex cation-exchange guard column was used to separate chromium(iii) from chromium(vi), and chromium(vi) was reduced by potassium sulfite, whereupon both...

  7. Egg-Citing! Isolation of Protoporphyrin IX from Brown Eggshells and Its Detection by Optical Spectroscopy and Chemiluminescence

    Science.gov (United States)

    Dean, Michelle L.; Miller, Tyson A.; Bruckner, Christian

    2011-01-01

    A simple and cost-effective laboratory experiment is described that extracts protoporphyrin IX from brown eggshells. The porphyrin is characterized by UV-vis and fluorescence spectroscopy. A chemiluminescence reaction (peroxyoxalate ester fragmentation) is performed that emits light in the UV region. When the porphyrin extract is added as a fluor…

  8. Investigation of RuBPS-Ce(IV) chemiluminescence reaction and its application in determination of two diuretics

    Energy Technology Data Exchange (ETDEWEB)

    Xi Juan [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Ji Xinghu [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Zhang Shaohong [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Xiang Fan Vocational and Technical College, Xiangfan 441021 (China); Ai Xinping [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); He Zhike [College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)]. E-mail: zhkhe@whu.edu.cn

    2005-06-13

    The chemiluminescence mechanism of tris-(4,7-diphenyl-1,10-phenanthrolinedisulfonic acid)ruthenium(II) (RuBPS)-Ce(IV) system and the effects of two diuretics, hydrochlorothiazide and furosemide, on its chemiluminescence intensity were investigated in detail. It was found that each of the two diuretics could enhance the chemiluminescence emission intensity of RuBPS-Ce(IV) system, based on which, they were sensitively detected by chemiluminescence analysis, respectively. Under the optimum experimental conditions, the linear range and detection limit of hydrochlorothiazide were 2.5 x 10{sup -3} to 6.0 x 10{sup -1} {mu}g ml{sup -1} and 1.0 x 10{sup -3} {mu}g ml{sup -1}, respectively; those of furosemide were 1.0 x 10{sup -2} to 4.0 {mu}g ml{sup -1} and 8.8 x 10{sup -3} {mu}g ml{sup -1}, respectively. The proposed method has been applied to analyze the pharmaceuticals with satisfied results.

  9. High-density assembly of chemiluminescence functionalized gold nanodots on multiwalled carbon nanotubes and their application as biosensing platforms.

    Science.gov (United States)

    Zhang, Hongli; Cui, Hua

    2014-03-07

    A one-step strategy was developed for high-density assembly of N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functionalized gold nanodots onto the sidewalls of chitosan-grafted multiwalled carbon nanotubes (cs-MWCNTs) via the reduction of HAuCl4 with ABEI in the presence of cs-MWCNTs, resulting in novel hybrid nanomaterials with excellent chemiluminescence and electrochemiluminescence properties.

  10. A simple microfluidic chlorine gas sensor based on gas-liquid chemiluminescence of luminol-chlorine system.

    Science.gov (United States)

    Gao, Zhao-Xin; Li, Hai-Fang; Liu, Jiangjiang; Lin, Jin-Ming

    2008-08-01

    In this work, a microfluidic chlorine gas sensor based on gas-liquid interface absorption and chemiluminescence detection was described. The liquid chemiluminescence reagent-alkaline luminol solution can be stably sandwiched between two convex halves of a microchannel by surface tension. When chlorine gas was introduced into the micro device, it was dissolved into the interfacial luminol solution and transferred to ClO(-), and simultaneously luminol was excited and chemiluminescence emitted. The emitted chemiluminescence light was perpendicularly detected by a photomultiplier tube on a certain detection region. The remarkable advantage of the detection system is that both adsorption and detection were carried out at the gas-liquid interface, which avoids the appearance of bubbles. The whole analytical cycle including filling CL reagent, sample injection, CL detection and emptying the device was as short as 30 s. The linear concentration range of chlorine gas detection with direct introduction of sample method is from 0.5 to 478 ppm. The detection limit of this method is 0.2 ppm for standard chlorine gas and the relative standard deviation of five determinations of 3.19 ppm spiked chlorine sample was 5.2%.

  11. Membrane processes

    Science.gov (United States)

    Staszak, Katarzyna

    2017-11-01

    The membrane processes have played important role in the industrial separation process. These technologies can be found in all industrial areas such as food, beverages, metallurgy, pulp and paper, textile, pharmaceutical, automotive, biotechnology and chemical industry, as well as in water treatment for domestic and industrial application. Although these processes are known since twentieth century, there are still many studies that focus on the testing of new membranes' materials and determining of conditions for optimal selectivity, i. e. the optimum transmembrane pressure (TMP) or permeate flux to minimize fouling. Moreover the researchers proposed some calculation methods to predict the membrane processes properties. In this article, the laboratory scale experiments of membrane separation techniques, as well their validation by calculation methods are presented. Because membrane is the "heart" of the process, experimental and computational methods for its characterization are also described.

  12. Axiom turkey genotyping array

    Science.gov (United States)

    The Axiom®Turkey Genotyping Array interrogates 643,845 probesets on the array, covering 643,845 SNPs. The array development was led by Dr. Julie Long of the USDA-ARS Beltsville Agricultural Research Center under a public-private partnership with Hendrix Genetics, Aviagen, and Affymetrix. The Turk...

  13. Clocked combustor can array

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won-Wook; McMahan, Kevin Weston; Srinivasan, Shiva Kumar

    2017-01-17

    The present application provides a clocked combustor can array for coherence reduction in a gas turbine engine. The clocked combustor can array may include a number of combustor cans positioned in a circumferential array. A first set of the combustor cans may have a first orientation and a second set of the combustor cans may have a second orientation.

  14. Primordial membranes

    DEFF Research Database (Denmark)

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during...... the various evolutionary stages that led from inanimate to living matter. It is also likely that primitive membranes played a similar role in protocell 'physiology'. The composition of such ancestral membranes has been proposed as mixtures of single hydrocarbon chain amphiphiles, which are simpler versions...

  15. Thermophotovoltaic Array Optimization

    Energy Technology Data Exchange (ETDEWEB)

    SBurger; E Brown; K Rahner; L Danielson; J Openlander; J Vell; D Siganporia

    2004-07-29

    A systematic approach to thermophotovoltaic (TPV) array design and fabrication was used to optimize the performance of a 192-cell TPV array. The systematic approach began with cell selection criteria that ranked cells and then matched cell characteristics to maximize power output. Following cell selection, optimization continued with an array packaging design and fabrication techniques that introduced negligible electrical interconnect resistance and minimal parasitic losses while maintaining original cell electrical performance. This paper describes the cell selection and packaging aspects of array optimization as applied to fabrication of a 192-cell array.

  16. Sequential Injection Determination of D-Glucose by Chemiluminescence Using an Open Tubular Immobilised Enzyme Reactor

    DEFF Research Database (Denmark)

    Liu, Xuezhu; Hansen, Elo Harald

    1996-01-01

    A sequential injection analysis system is described that incorporates a nylon tubular reactor containing immobilised glucose oxidase, allowing determination of D-glucose by means of subsequent luminol chemiluminescence detection of the hydrogen peroxide generated in the enzymatic reaction....... The operating parameters were optimised by fractional factorial screening and response surface modelling. The linear range of D-glucose determination was 30-600 mu M, With a detection limit of 15 mu M using a photodiode detector. The sampling frequency was 54 h(-1). Lower LOD (0.5 mu M D-glucose) could...... be reached by using a PMT as the detector. Fermentation broth samples were determined and good recoveries were obtained....

  17. Chemiluminescence determination of trimetazidine via inducing the aggregation of gold nanoparticles

    Science.gov (United States)

    Li, Jiao; Quan, Jie; Du, Jianxiu; Liu, Mei

    2013-10-01

    A simple, rapid and sensitive chemiluminescence (CL) method combined with flow injection analysis was developed for the determination of trimetazidine. Trimetazidine was found to significantly increase the CL signal arising from N-bromosuccinimide-luminol reaction in the presence of gold nanoparticles. The enhanced CL intensity was proportional to trimetazidine concentration in the range of 0.01-5.0 μg/mL, with a limit of detection (3sb) of 6.7 ng/mL. The relative standard deviation was 2.8% for 11 repetitive measurements of 0.1 μg/mL trimetazidine solution. The practicality of the method was evaluated by determining trimetazidine in pharmaceutical formulations and in spiked human serum samples. Moreover, the possible CL reaction mechanism was also discussed.

  18. Nitrite sensing based on the carbon dots-enhanced chemiluminescence from peroxynitrous acid and carbonate.

    Science.gov (United States)

    Lin, Zhen; Dou, Xiangnan; Li, Haifang; Ma, Yuan; Lin, Jin-Ming

    2015-01-01

    In this work, chemiluminescence (CL) from peroxynitrous acid (ONOOH)-carbonate system greatly amplified by carbon dots was observed. The CL mechanism of the ONOOH-carbonate-carbon dots system has been investigated and the results reveal that the carbon dots could serve as the energy acceptor, which gives us new insight into the optical properties of the new emerging carbon nanomaterial. There is a good linear relationship between the CL signal and the concentration of the nitrite using for ONOOH formation, which provides us a nitrite sensing method with sensitivity as high as 5.0×10(-9) M (S/N=3). The method has been successfully applied to the determination of nitrite in tap water with the recovery of 98%. The standard deviations are within 2.5%. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Development of an Electrogenerated Chemiluminescence Biosensor using Carboxylic acid-functionalized MWCNT and Au Nanoparticles

    Science.gov (United States)

    Piao, Ming-Hua; Yang, Dae-Soo; Yoon, Kuk-Ro; Lee, Seung-Ho; Choi, Seong-Ho

    2009-01-01

    A COOH-F-MWCNT-Nafion-Ru(bpy)32+-Au-ADH electrogenerated chemiluminescence (ECL) electrode using COOH-functionalized MWCNT (COOH-F-MWCNT) and Au nanoparticles synthesized by the radiation method was fabricated for ethanol sensing. A higher sensing efficiency for ethanol for the ECL biosensor prepared by PAAc-g-MWCNT was measured compared to that of the ECL biosensor prepared by PMAc-g-MWCNT, and purified MWCNT. Experimental parameters affecting ethanol detection were also examined in terms of pH and the content of PAAc-g-MWCNT in Nafion. Little interference of other compounds was observed for the assay of ethanol. Results suggest this ECL biosensor could be applied for ethanol detection in real samples. PMID:22573979

  20. Investigation on the chemiluminescence reaction of the phenylhydrazine-luminol-peroxide system.

    Science.gov (United States)

    Chandel, A L S; Khan, S A; Kher, R S; Tiwari, Ashish

    2012-01-01

    We studied the chemiluminescence (CL) oxidation of phenyl hydrazine-luminol with various organic and inorganic peroxides. Maximum CL intensity for this system was obtained for t-butylhydroperoxide. The enhancement in CL depended strongly on pH and was greatest at pH 12.5. The solvent drastically enhanced the CL intensity. DMSO was found to increase the CL intensity many-fold as compared to acetonitrile and water. The effect of temperature on CL intensity has also been studied. The CL spectra revealed a broad peak at 425 nm, which suggests excited 3-aminophthalate ion as the luminophor. A mechanism to explain the reactions is suggested. Copyright © 2012 John Wiley & Sons, Ltd.

  1. High-Speed OH* Chemiluminescence Imaging of Shock Tube End-Wall

    Science.gov (United States)

    Troutman, V. A.; Miller, V. A.; Strand, C. S.; Tulgestke, A. M.; Campbell, M. F.; Davidson, D. F.; Hanson, R. K.

    2015-11-01

    We have developed a high-speed OH* chemiluminesence imaging diagnostic and a transparent end-wall for the Stanford Aerosol Shock Tube to better understand the structure and homogeneity of the combustion event behind a reflected shock wave. We use an intensified high repetition rate imaging system to acquire images of OH* chemiluminescence (near 308 nm) at 10-33 kHz from n-heptane combustion. Case studies are presented to illustrate the power of this novel imaging diagnostic: first, we infer the temperature homogeneity of the ignition event; then we image the effect of surface imperfections in the wall of the shock tube; lastly, we visualize the effect of particulates in the shock tube and verify the importance of shock tube cleaning routines.

  2. Droplet-based micro-flow chemiluminescence system for in vivo glucose determination by microdialysis sampling.

    Science.gov (United States)

    Liu, Wei; Zhang, Zhujun; Liu, Haisheng

    2005-04-01

    A micro-flow chemiluminescence (CL) system in vivo for glucose determination by the on-line microdialysis sampling is described in this paper. The micro-flow CL system uses discrete sample droplets, which formed at the tip of the capillary with the sampling volume of 4.5 microl. The sol-gel method is introduced to co-immobilize horseradish peroxidase (HRP) and glucose oxidase (GOD) on the inside surface of the micro-flow cell which was fabricated in polymethyl methacrylate (PMMA). The CL detection involved enzymatic oxidation of glucose to D-gluconic acid and H2O2, then H2O2 oxidizing luminol to produce CL in presence of HRP. The microdialysis probe was utilized for sampling in the rabbit blood; the sample throughput was 20 h(-1). The glucose level in blood of the rabbit was on-line monitored with good results.

  3. Chemiluminescence determination of tetracyclines using Fenton system in the presence europium(III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, Malgorzata [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60 - 780 Poznan (Poland); Lis, Stefan, E-mail: blis@amu.edu.pl [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60 - 780 Poznan (Poland)

    2009-04-20

    A new simple chemiluminescent method for the determination of chlortetracycline (Chlor-TC), oxytetracycline (Oxy-TC) and doxycycline (Doxy-TC) is described. This method is based on the europium(III) emission as a result of the energy transfer process from the excited product of the tetracyclines oxidation to the uncomplexed Eu(III). Under the optimum conditions, calibration graphs were obtained for 4 x 10{sup -7} to 2 x 10{sup -5} mol L{sup -1} of Chlor-TC; 2 x 10{sup -7} to 2 x 10{sup -5} mol L{sup -1} of Oxy-TC and 1 x 10{sup -7} to 3 x 10{sup -5} mol L{sup -1} of Doxy-TC. The method was successfully applied to the determination of these drugs in pharmaceutical and veterinary formulation and honey.

  4. TSH Comparison Between Chemiluminescence (Architect) and Electrochemiluminescence (Cobas) Immunoassays: An Indian Population Perspective.

    Science.gov (United States)

    Sarkar, Rajarshi

    2014-04-01

    Although 3rd generation TSH assays are the most widely used immunoassays, credible comparison studies, specially involving Indian sub-populations are practically non-existent. To compare the TSH measurements between chemiluminescence (Architect) and electrochemiluminescence (Cobas) inmmunoassays in an urban ambulatory Indian population. 1,615 subjects were selected randomly from the usual laboratory workflow, their TSH measured in Architect and Cobas and the paired data thus generated were statistically analysed. TSH values of Cobas were observed to be higher than the Architect values by 28.7 %, with a significant proportional difference between the two, but majority of the Cobas values (above 90 %) were within the limits of agreement with Architect values. In situations where both the instruments are in use simultaneously, a standardization of the methods is imperative, in larger interest of the patient populace.

  5. A novel chemiluminescence system with diperiodatonickelate (IV) for the determination of adrenaline

    Science.gov (United States)

    Yang, Chunyan; Chen, Fubin; Chang, Ziqiang; Sun, Yonghua; Zhang, Zhujun

    2014-03-01

    A novel chemiluminescence (CL) system with diperiodatonickelate (IV) (DPN) was developed for the determination of adrenaline for the first time. The possible CL emission mechanism was briefly discussed by comparing the fluorescence emission spectra with CL spectra. Under the optimum conditions, the relative CL intensity was linear over the concentration of AD ranging from 1.0 × 10-7 to 1.0 × 10-5 g mL-1 with a detection limit of 4.0 × 10-8 g mL-1 (3σ). And the relative standard deviation was 3.7% for 2.0 × 10-6 g mL-1 AD (n = 11). The developed method has been successfully applied to the determination of AD in pharmaceutical preparations.

  6. A review of electrogenerated chemiluminescent biosensors for assays in biological matrices.

    Science.gov (United States)

    Gross, Erin M; Maddipati, Sai Sujana; Snyder, Sarah M

    2016-10-01

    Electrogenerated chemiluminescence (ECL) is the production of light via electron transfer reactions between electrochemically produced reagents. ECL-based biosensors use specific biological interactions to recognize an analyte and produce a luminescent signal. Biosensors fabricated with novel biorecognition species have increased the number of analytes detected. Some of these analytes include peptides, cells, enzymes and nucleic acids. ECL biosensors are selective, simple, sensitive and have low detection limits. Traditional methods use ruthenium complexes or luminol to generate ECL. Nanomaterials can be incorporated into ECL biosensors to improve efficiency, but also represent a new class of ECL emitters. This article reviews the application of ruthenium complex, luminol and nanomaterial-based ECL biosensors to making measurements in biological matrices over the past 4 years.

  7. Determination of oxidative deterioration of milk powder and reconstituted milk by measurement of chemiluminescence.

    Science.gov (United States)

    Timms, R E; Roupas, P; Rogers, W P

    1982-11-01

    A scintillation counter was used to measure chemiluminescence (CL) from milk powder and reconstituted milk. Only a small amount of CL, just above the background level, was observed from powders, but reconstituted milks emitted easily measurable CL. CL from milk was stimulated by exposure to light and found to decline gradually but non-exponentially after the exposure ceased. CL was at a maximum immediately after the milk was reconstituted from milk powder. Without light exposure, CL then declined gradually but non-exponentially over several hours to reach a constant value related to the level of oxidation of the powder. When determined under standard conditions 60 min after reconstitution, CL of milk reconstituted from stored milk powders correlated well with peroxide values and oxidized flavour as assessed by a taste panel.

  8. Chemiluminescence determination of gemifloxacin based on diperiodatoargentate (III)-sulphuric acid reaction in a micellar medium.

    Science.gov (United States)

    Zhao, Fang; Zhao, Wen-hui; Xiong, Wei

    2013-01-01

    A novel flow-injection chemiluminescence (FI-CL) analysis method for the determination of gemifloxacin in the presence of cetyltrimethylammonium bromide (CTAB) surfactant micelles is described. Strong CL signal was generated during the reaction of gemifloxacin with diperiodatoargentate (III) in a sulfuric acid medium sensitized by CTAB. Under optimum experimental conditions, the CL intensity was linearly related to the concentration of gemifloxacin from 1.0 × 10(-9) to 3.0 × 10(-7) g/mL and the detection limit was 7.3 × 10(-10) g/mL (3σ). The relative standard deviation (RSD) was 1.7 % for a 3.0 × 10(-8) g/mL gemifloxacin solution (11 repeated measurements). The proposed method was successfully applied to the determination of gemifloxacin in pharmaceutical preparations and biological fluids. The possible mechanism of the CL reaction is also discussed briefly. Copyright © 2012 John Wiley & Sons, Ltd.

  9. Determination of Picogram Levels of Diacerein in a Pharmaceutical Formulation by Flow-Injection Chemiluminescence

    Directory of Open Access Journals (Sweden)

    Gao Suya

    2017-01-01

    Full Text Available A simple, sensitive and inexpensive method for determination of diacerein by flow-injection chemiluminescence was proposed, based on the quenching effect of diacerein on the luminol-protein (bovine serum albumin, BSA reaction. It was found that the decrement of CL intensity was linearly proportional to the logarithm of diacerein concentration ranging from 5.0 to 7.0×103 pg·mL-1 (r = 0.9968, with the limit of detection (LOD of 1.0 pg·mL-1 (3σ. The proposed procedure was successfully applied to the determination of diacerein in pharmaceutical formulation, human saliva, and serum samples without interference from its potential impurities, with the recoveries ranging from 96.4% to 104.0% and the relative standard deviations (RSDs less than 4.0% (n=6.

  10. Stimulus-response mesoporous silica nanoparticle-based chemiluminescence biosensor for cocaine determination.

    Science.gov (United States)

    Chen, Zhonghui; Tan, Yue; Xu, Kefeng; Zhang, Lan; Qiu, Bin; Guo, Longhua; Lin, Zhenyu; Chen, Guonan

    2016-01-15

    Mesoporous silica nanoparticles (MSN) based controlled release system had been coupled with diverse detection technologies to establish biosensors for different targets. Chemiluminescence (CL) system of luminol/H2O2 owns the characters of simplicity, low cost and high sensitivity, but the targets of which are mostly focused on some oxidants or which can participate in a chemical reaction that yields a product with a role in the CL reaction. In this study, chemiluminescent detection technique had been coupled with mesoporous silica-based controlled released system for the first time to develop a sensitive biosensor for the target which does not cause effect to the CL system itself. Cocaine had been chosen a model target, the MSN support was firstly loaded with glucose, then the positively charged MSN interacted with negatively charged oligonucleotides (the aptamer cocaine) to close the mesopores of MSN. At the present of target, cocaine binds with its aptamer with high affinity; the flexible linear aptamer structured will become stems structured through currently well-defined non-Waston-Crick interactions and causes the releasing of entrapped glucose into the solution. With the assistant of glucose oxidase (GOx), the released glucose can react with the dissolved oxgen to produce gluconic acid and H2O2, the latter can enhance the CL of luminol in the NaOH solution. The enhanced CL intensity has a relationship with the cocaine concentration in the range of 5.0-60μM with the detection limit of 1.43μM. The proposed method had been successfully applied to detect cocaine in serum samples with high selectivity. The same strategy can be applied to develop biosensors for different targets. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Chemiluminescence study of active oxygen species produced by TiO2 photocatalytic reaction.

    Science.gov (United States)

    Wu, Xing-Zheng; Lingyue, Min; Akiyama, Keiko

    2005-01-01

    Two chemiluminescence approaches have been used for study of active oxygen species produced by the TiO2 photocatalytic reaction. One is based on flow injection analysis (FIA)-luminol chemiluminescence (CL); another is a time-resolved CL method. In the FIA-CL experiment, an UV-illuminated TiO2 suspension and water were passed into a mixing cell by two separate flow lines. Luminol solution was injected into the water flow line at different times. The injected luminol reacted with active oxygen species generated by the TiO2 photocatalytic reaction in a mixing coil and produced CL. It was found that the maximum CL was detected at the first injection of luminol. CL intensity decreased with time of injection. When the luminol was injected after 5 min, the CL intensity was almost unchanged. Addition of scavengers of active oxygen species indicated that the CL produced early in the 5 min was caused by O2- and H2O2, while CL after 5 min was only from H2O2. In the time-resolved CL, the third harmonic wavelength of Nd:YAG laser (355 nm) was used as a UV light source, and CL was detected by a PMT and recorded in a millisecond time scale using a digital oscilloscope. It was found that CL induced by the photocatalytic reaction increased with concentration of the TiO2 suspension. Scavengers of active oxygen species of *OH, O2- and H2O2 were added to study the involvement of the active oxygen species.

  12. Reference values of parathyroid hormone and vitamin D Hormone by chemiluminescent automated assay

    Directory of Open Access Journals (Sweden)

    Beatriz Martiarena

    2015-05-01

    Full Text Available ABSTRACT Objective. Provide reference data for parathyroid hormone 1-84 (PTH 1-84 and 25OH Vitamin D (25OH D using a new technique. Materials and methods. The hormones were evaluated, in serum, using a third generation automated chemiluminescent method for PTH in a group of 60 adult dogs, clinically healthy, grouped according to age in years in GA: 1 to 5, GB: 6 to 10 and GC:>10. Results. Data expressed as average ± DS were for PTH (pg/ml: 9.3±2.3; 12±6.3; 12.2±3.7; and for 25OH D (ng/ml: 84.2±27.8; 68.2±16.0; 63.6±23.1, respectively. The PTH value was significantly greater (p<0.05 in groups B and C in comparison with A, but no significant differences were observed between GB and GC. The 25OH D concentration was significantly less in GB (p<0.05 and in GC (p<0.01 in comparison with GA, showing no differences between GB and GC. A negative correlation between 25OH D and PTH was found (r= -0.28; p=0.015. Conclusions. Data contributed by this study provide reference values for PTH 1-84 and 25OH D, evaluated using a third generation automated chemiluminescent method for PTH in local dogs. The results will facilitate monitoring diseases that alter the metabolism of calcium and phosphorus in dogs.

  13. High-speed OH* chemiluminescence imaging of ignition through a shock tube end-wall

    Science.gov (United States)

    Troutman, V. A.; Strand, C. L.; Campbell, M. F.; Tulgestke, A. M.; Miller, V. A.; Davidson, D. F.; Hanson, R. K.

    2016-03-01

    A high-speed OH* chemiluminescence imaging diagnostic was developed to image the structure and homogeneity of combustion events behind reflected shock waves in the Stanford Constrained Reaction Volume Shock Tube. An intensified high-repetition-rate imaging system was used to acquire images of OH* chemiluminescence (near 308 nm) through a fused quartz shock tube end-wall window at 10-33 kHz during the combustion of n-heptane (21 % O2/Ar, φ = 0.5). In general, the imaging technique enabled observation of the main ignition event in the core of the shock tube that corresponded to typical markers of ignition (e.g., pressure rise), as well as localized ignition near the wall that preceded the main core ignition event for some conditions. Case studies were performed to illustrate the utility of this novel imaging diagnostic. First, by comparing localized wall ignition events to the core ignition event, the temperature homogeneity of the post-reflected shock gas near the end-wall was estimated to be within 0.5 % for the test condition presented (T=1159 hbox {K}, P=0.25 hbox {MPa}). Second, the effect of a recession in the shock tube wall, created by an observation window, on the combustion event was visualized. Localized ignition was observed near the window, but this disturbance did not propagate to the core of the shock tube before the main ignition event. Third, the effect of shock tube cleanliness was investigated by conducting tests in which the shock tube was not cleaned for multiple consecutive runs. For tests after no cleaning was performed, ignition events were concentrated in the lower half of the shock tube. In contrast, when the shock tube was cleaned, the ignition event was distributed around the entire circumference of the shock tube; validating the cleaning procedure.

  14. Chemiluminescence-based multivariate sensing of local equivalence ratios in premixed atmospheric methane-air flames

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Markandey M.; Krishnan, Sundar R.; Srinivasan, Kalyan K.; Yueh, Fang-Yu; Singh, Jagdish P.

    2011-09-07

    Chemiluminescence emissions from OH*, CH*, C2, and CO2 formed within the reaction zone of premixed flames depend upon the fuel-air equivalence ratio in the burning mixture. In the present paper, a new partial least square regression (PLS-R) based multivariate sensing methodology is investigated and compared with an OH*/CH* intensity ratio-based calibration model for sensing equivalence ratio in atmospheric methane-air premixed flames. Five replications of spectral data at nine different equivalence ratios ranging from 0.73 to 1.48 were used in the calibration of both models. During model development, the PLS-R model was initially validated with the calibration data set using the leave-one-out cross validation technique. Since the PLS-R model used the entire raw spectral intensities, it did not need the nonlinear background subtraction of CO2 emission that is required for typical OH*/CH* intensity ratio calibrations. An unbiased spectral data set (not used in the PLS-R model development), for 28 different equivalence ratio conditions ranging from 0.71 to 1.67, was used to predict equivalence ratios using the PLS-R and the intensity ratio calibration models. It was found that the equivalence ratios predicted with the PLS-R based multivariate calibration model matched the experimentally measured equivalence ratios within 7%; whereas, the OH*/CH* intensity ratio calibration grossly underpredicted equivalence ratios in comparison to measured equivalence ratios, especially under rich conditions ( > 1.2). The practical implications of the chemiluminescence-based multivariate equivalence ratio sensing methodology are also discussed.

  15. Flow injection chemiluminescence determination of loxoprofen and naproxen with the acidic permanganate-sulfite system

    Directory of Open Access Journals (Sweden)

    Li-Juan Wang

    2011-02-01

    Full Text Available A novel flow injection chemiluminescence (CL method for the determination of loxoprofen and naproxen was proposed based on the CL system of KMnO4, and Na2SO3 in acid media. The CL intensity of KMnO4-Na2SO3 was greatly enhaneed in the presence of loxoprofen and naproxen. The mechanism of the CL reaction was studied by the kinetic proecss and UV-vis absorption and the conditions were optimized. Under optimized conditions, the CL intensity was linear with loxoprofen and naproxen concentration in the range of 7.0 × 10−8 – 1.0 × 10−5 g/mL and 2.0 × 10−7 – 4.0 × 10−6 g/mL with the detection limit of 2.0 × 10−8 g/mL and 3.0 × 10−8 g/mL (S/N = 3, respectively. Thc relative standard deviations were 2.39% and 1.37% for 5.0 × 10−7 g/mL naproxen and 5.0 × 10−7 g/mL loxoprofen (n = 10, respectively. The proposed method was satisfactorily applied to thc determination of loxoprofen and naproxen in pharmaceutical preparations. Keywords: chemiluminescence, KMnO4, loxoprofen, naproxen

  16. Highly luminescent S,N co-doped carbon quantum dots-sensitized chemiluminescence on luminol-H2 O2 system for the determination of ranitidine.

    Science.gov (United States)

    Chen, Jianqiu; Shu, Juan; Chen, Jiao; Cao, Zhiran; Xiao, An; Yan, Zhengyu

    2017-05-01

    S,N co-doped carbon quantum dots (N,S-CQDs) with super high quantum yield (79%) were prepared by the hydrothermal method and characterized by transmission electron microscopy, photoluminescence, UV-Vis spectroscopy and Fourier transformed infrared spectroscopy. N,S-CQDs can enhance the chemiluminescence intensity of a luminol-H2 O2 system. The possible mechanism of the luminol-H2 O2 -(N,S-CQDs) was illustrated by using chemiluminescence, photoluminescence and ultraviolet analysis. Ranitidine can quench the chemiluminescence intensity of a luminol-H2 O2 -N,S-CQDs system. So, a novel flow-injection chemiluminescence method was designed to determine ranitidine within a linear range of 0.5-50 μg ml(-1) and a detection limit of 0.12 μg ml(-1) . The method shows promising application prospects. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Design and fabrication of novel photodetector arrays

    Science.gov (United States)

    Li, Mary J.; Allen, Christine A.; Aslam, Shahid; Chen, Tina C.; Finkbeiner, Fred M.; Gordon, Scott A.; Kuhn, Jonathan L.; Mott, David B.; Stahle, Carl M.; Stahle, Caroline K.; Tralshawala, Nilesh; Wang, Liqin L.

    1999-10-01

    We are developing novel photodetector arrays based on superconducting transition-edge sensor (TES) and pop-up detector (PUD) technologies. The TES has the potential for a new generation of high sensitivity photodetectors from the IR to the x-ray. This is directly due to the sharpness of the resistance change with temperature at the superconducting transition. The TESs are deposited on the PUD arrays and serve as the sensing elements. The PUDs are close-packed, folded membrane arrays that provide the TES substrate and the thermal isolation required by the bolometers and microcalorimeters. This paper presents the processing-related characterization result of preliminary TES and PUD designs. The gaol of this work is to fabricate a new generation of x-ray calorimeters and IR bolometers for space flight projects.

  18. Superconducting Bolometer Array Architectures

    Science.gov (United States)

    Benford, Dominic J.; Chervenak, James A.; Irwin, Kent D.; Moseley, S. H., Jr.; Shafer, Richard A.; Staguhn, Johannes G.; Wollack, Ed

    2003-02-01

    The next generation of far-infrared and submillimeter instruments require large arrays of detectors containing thousands of elements. These arrays will necessarily be multiplexed, and superconducting bolometer arrays are the most promising present prospect for these detectors. We discuss our current research into superconducting bolometer array technologies, which has recently resulted in the first multiplexed detections of submillimeter light and the first multiplexed astronomical observations. Prototype arrays containing 512 pixels are in production using the Pop-Up Detector (PUD) architecture, which can be extended easily to 1000 pixel arrays. Planar arrays of close-packed bolometers are being developed for the GBT and for future space missions. For certain applications, such as a slewed far-infrared sky survey, feedhorn-coupling of a large sparsely-filled array of bolometers is desirable, and is being developed using photolithographic feedhorn arrays. Individual detectors have achieved a Noise Equivalent Power (NEP) of ~10-17 W/√Hz at 300mK, but several orders of magnitude improvement are required and can be reached with existing technology. The testing of such ultralow-background detectors will prove difficult, as this requires optical loading of below 1fW. Antenna-coupled bolometer designs have advantages for large format array designs at low powers due to their mode selectivity. We also present a design and preliminary results for an enhanced-dynamic-range transition edge sensor suitable for broadband ultralow-background detectors.

  19. Electronic Switch Arrays for Managing Microbattery Arrays

    Science.gov (United States)

    Mojarradi, Mohammad; Alahmad, Mahmoud; Sukumar, Vinesh; Zghoul, Fadi; Buck, Kevin; Hess, Herbert; Li, Harry; Cox, David

    2008-01-01

    Integrated circuits have been invented for managing the charging and discharging of such advanced miniature energy-storage devices as planar arrays of microscopic energy-storage elements [typically, microscopic electrochemical cells (microbatteries) or microcapacitors]. The architecture of these circuits enables implementation of the following energy-management options: dynamic configuration of the elements of an array into a series or parallel combination of banks (subarrarys), each array comprising a series of parallel combination of elements; direct addressing of individual banks for charging/or discharging; and, disconnection of defective elements and corresponding reconfiguration of the rest of the array to utilize the remaining functional elements to obtain the desited voltage and current performance. An integrated circuit according to the invention consists partly of a planar array of field-effect transistors that function as switches for routing electric power among the energy-storage elements, the power source, and the load. To connect the energy-storage elements to the power source for charging, a specific subset of switches is closed; to connect the energy-storage elements to the load for discharging, a different specific set of switches is closed. Also included in the integrated circuit is circuitry for monitoring and controlling charging and discharging. The control and monitoring circuitry, the switching transistors, and interconnecting metal lines are laid out on the integrated-circuit chip in a pattern that registers with the array of energy-storage elements. There is a design option to either (1) fabricate the energy-storage elements in the corresponding locations on, and as an integral part of, this integrated circuit; or (2) following a flip-chip approach, fabricate the array of energy-storage elements on a separate integrated-circuit chip and then align and bond the two chips together.

  20. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  1. Novel membrane technology for food and water monitoring

    Science.gov (United States)

    Senecal, Kris J.; Soares, Jason W.; Mello, Charlene M.; Pivarnik, Philip; Senecal, Andre

    2004-03-01

    The need exists to improve sensitivity of detection of toxic pollutants and pathogenic microorganisms, ensuring food and water safety. Developing methods that would increase antibody binding surface area and/or improve the sampling process by specifically concentrating the analyte of interest from the diluted extracted food sample would increase the chances of finding and detecting food pathogens and their toxins. Our approach to improve sensitivity was to generate high surface nanofibrous membranes with covalently attached molecular recognition elements (MREs, e.g. antibodies and peptides) for the selective capture of target analytes through the use of electrospinning. Electrospinning is a process by which high static voltages are used to produce an interconnected membrane-like web of small fibers with diameters ranging from 50-1000 nanometers. These nanofibrous membranes can have surface areas approximately one to two orders of magnitude higher than those found in continuous films. The association of MREs with electrospun fibers presents the opportunity for developing both biosensor detection platforms with increased surface area and membrane concentrators. It is expected that the available surface area demonstrated by this technique will provide increased sensitivity, capture efficiency and fast response time in sensing applications. Antibodies and peptide-based receptors were selectively immobilized onto these nanoporous membranes for bioaffinity capture. Initial results involving fluorescent and chemiluminescent imaging for quantifying attachment and activity in association with the electrospinning process will be discussed.

  2. Dynamically Reconfigurable Microphone Arrays

    Science.gov (United States)

    2011-05-01

    Static + 2 Wireless Using only a standard computer sound card, a robot is limited to binaural inputs. Even when using wireless microphones, the audio...Abstract—Robotic sound localization has traditionally been restricted to either on-robot microphone arrays or embedded microphones in aware...a microphone array has a significant impact on the mathematics of sound source localization. Arrays, for instance, are commonly designed to

  3. Development of an Automation Technique for the Establishment of Functional Lipid Bilayer Arrays

    DEFF Research Database (Denmark)

    Hansen, Jesper Søndergaard; Perry, Mark; Vogel, Jörg

    2009-01-01

    In the present work, a technique for establishing multiple black lipid membranes (BLMs) in arrays of micro structured ethylene tetrafluoroethylene (ETFE) films, and supported by a micro porous material was developed. Rectangular 8 x 8 arrays with apertures having diameters of 301 +/- 5 mu m were...... fabricated in ETFE Teflon film by laser ablation using a carbon dioxide laser. Multiple lipid membranes could be formed across the micro structured 8 x 8 array ETFE partitions. Success rates for the establishment of cellulose-supported BLMs across the multiple aperture arrays were above 95%. However...

  4. Rectenna array measurement results

    Science.gov (United States)

    Dickinson, R. M.

    1980-01-01

    The measured performance characteristics of a rectenna array are reviewed and compared to the performance of a single element. It is shown that the performance may be extrapolated from the individual element to that of the collection of elements. Techniques for current and voltage combining were demonstrated. The array performance as a function of various operating parameters is characterized and techniques for overvoltage protection and automatic fault clearing in the array demonstrated. A method for detecting failed elements also exists. Instrumentation for deriving performance effectiveness is described. Measured harmonic radiation patterns and fundamental frequency scattered patterns for a low level illumination rectenna array are presented.

  5. Integrated Avalanche Photodiode arrays

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, Eric S.

    2017-04-18

    The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

  6. Integrated avalanche photodiode arrays

    Science.gov (United States)

    Harmon, Eric S.

    2015-07-07

    The present disclosure includes devices for detecting photons, including avalanche photon detectors, arrays of such detectors, and circuits including such arrays. In some aspects, the detectors and arrays include a virtual beveled edge mesa structure surrounded by resistive material damaged by ion implantation and having side wall profiles that taper inwardly towards the top of the mesa structures, or towards the direction from which the ion implantation occurred. Other aspects are directed to masking and multiple implantation and/or annealing steps. Furthermore, methods for fabricating and using such devices, circuits and arrays are disclosed.

  7. Long-range magnetostatic interactions in arrays of nanowires

    CERN Document Server

    Raposo, V; González, J M; Vázquez, M

    2000-01-01

    Experimental measurements and micromagnetic simulations of the hysteresis loops of arrays of cobalt nanowires are compared here. Arrays of cobalt nanowires (200 nm in diameter) were electrodeposited into the pores of alumina membranes (thickness 60 mu m). Their hysteresis loops along the axial direction of nanowires were measured using vibrating sample magnetometry. Micromagnetic simulations were performed considering dipolar interaction between nanowires leading to similar hysteresis loops as those obtained experimentally.

  8. Chemiluminescence analysis for HBV-DNA hybridization detection with magnetic nanoparticles based DNA extraction from positive whole blood samples.

    Science.gov (United States)

    He, Nongyue; Wang, Fang; Ma, Chao; Li, Chuanyan; Zeng, Xin; Deng, Yan; Zhang, Liming; Li, Zhiyang

    2013-02-01

    Molecular detection of HBV has a significant impact on prognosis and therapy of the disease. In this paper, a sensitive nucleic acid detection method of HBV was established taking advantage of magnetic nanoparticles (MNPs), chemiluminescence (CL) and polymerase chain reaction (PCR). HBV-DNA was extracted from hepatitis B positive human blood samples using MNPs adsorption method and biotin was labeled on the DNA segment after base insertion of bintin-dUTP in PCR. The biotinylated DNA segment was captured by amino probe immobilized on carboxyl MNPs and was detected by the chemiluminescence system of alkaline phosphatase catalyzing 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy) phenyl-1, 2-dioxetane. Different concentrations of HBV-DNA were detected under the optimized experiment conditions and the relevant CL intensity were obtained, which provided a novel research or clinic diagnosis method for the quantification detection of HBV-DNA.

  9. Thermal chemiluminescence from γ-irradiated polytetrafluoroethylene and its emission mechanism: Kinetic analysis and bond dissociation energy of fluoroperoxide group

    Science.gov (United States)

    Yamada, Emi; Noguchi, Tsuyoshi; Akai, Nobuyuki; Ishii, Hiroshi; Satoh, Chikahiro; Hironiwa, Takayuki; Millington, Keith R.; Nakata, Munetaka

    2014-11-01

    Temperature dependence of the time evolution of chemiluminescence intensity from γ-irradiated polytetrafluoroethylene was examined by heating isothermally in the range of 150 and 200 °C. Kinetic analysis was carried out to estimate the rate constants, from which the dissociation energy of the Osbnd O bond in the fluoroperoxide group was determined to be 97 ± 4 kJ mol-1, being consistent with the corresponding value for small fluorocarbon model systems obtained by quantum chemical calculations. This strongly supports the emission mechanism [sbnd CF(OOF)sbnd CF2sbnd → sbnd COsbnd CF2sbnd + OF2 + hν] proposed in our previous paper to explain chemiluminescence from the γ-irradiated polytetrafluoroethylene.

  10. Rapid determination of Papaver somniferum alkaloids in process streams using monolithic column high-performance liquid chromatography with chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Costin, Jason W. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Lewis, Simon W. [Department of Applied Chemistry, Curtin University of Technology, Perth, WA 6845 (Australia); Purcell, Stuart D. [GlaxoSmithKline, Port Fairy, Victoria 3284 (Australia); Waddell, Lucy R. [GlaxoSmithKline, Port Fairy, Victoria 3284 (Australia); Francis, Paul S. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia); Barnett, Neil W. [School of Life and Environmental Sciences, Deakin University, Geelong, Victoria 3217 (Australia)]. E-mail: barnie@deakin.edu.au

    2007-07-30

    We have combined high-performance liquid chromatography (HPLC) separations using a monolithic column with acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection in a rapid and highly sensitive method to monitor the process of extracting opiate alkaloids from Papaver somniferum. Due to the high flow rates allowed with the monolithic column and the inherent selectivity of the chemiluminescence reactions, the four predominant alkaloids - morphine, codeine, oripavine and thebaine - were determined in less than 2 min. The results obtained with numerous process samples compared favourable with those of the standard HPLC methodology. Limits of detection were 1 x 10{sup -10} M, 5 x 10{sup -10} M, 5 x 10{sup -10} M and 1 x 10{sup -9} M, for morphine, codeine, oripavine and thebaine, respectively.

  11. Enhanced sensitivity of Cypridina luciferin analogue (CLA) chemiluminescence for the detection of *O2(-) with non-ionic detergents.

    Science.gov (United States)

    Osman, A M; Laane, C; Hilhorst, R

    2001-01-01

    Superoxide anion-triggered chemiluminescence of Cypridina luciferin analogue (CLA), 2-methyl-6-phenyl-3,7-dohydroimidazo[1,2-alpha]pyrazin-3-one, is enhanced by non-ionic detergents such as Tween 20, Triton X-100 and Tween 80. At the concentration of 0.6% (v/v) the largest increase (2.7-fold) of CLA light intensity was obtained with Tween 20, followed by Tween 80 and Triton X-100. Using this detergent-amplified CLA chemiluminescence, the detection limits of xanthine and xanthine oxidase were examined at pH 7.4 and reinvestigated at pH 5.5. At pH 5.5, concentrations of xanthine and xanthine oxidase as low as 5 nmol/L and 3.85 x 10(-7) U/mL, respectively, could be accurately determined, whereas, under the experimental conditions used, at pH 7.4 the lowest concentrations of xanthine and xanthine oxidase detectable were 10 nmol/L and 3.85 x 10(-6) U/mL. The lowest detectable values of xanthine and xanthine oxidase obtained at pH 5.5 are about 400 and 10 times lower than those previously reported. The detection limit of xanthine (5 nmol/L) by this chemiluminescent-based method is about 200 and 20 times more sensitive than the determination of xanthine by enzymatic means or by HPLC with detection limits of 1 micromol/L and 0.1 micromol/L, respectively. Our data suggest that this chemiluminescent probe can detect concentrations of superoxide anion below the nanomolar range. Copyright 2001 John Wiley & Sons, Ltd.

  12. Delayed fluorescence spectra of intact leaves photoexcited by sunlight measured with a multichannel Fourier-transform chemiluminescence spectrometer

    Science.gov (United States)

    Akita, Saeka; Yano, Ayako; Ishii, Hiroshi; Satoh, Chikahiro; Akai, Nobuyuki; Nakata, Munetaka

    2013-06-01

    Delayed fluorescence spectra of intact leaves of Green pak choi (Brassica rapa var. chinensis) were measured with a multichannel Fourier-transform chemiluminescence spectrometer, which we developed recently. The intact samples, photoexcited by sunlight without artificial light sources, showed delayed fluorescence around 740 nm with a lifetime of ˜6 s. The observed spectra were deconvoluted into two Gaussian bands: the delayed fluorescence from photosystem II and photosystem I complexes. Their relative intensities depended on the chlorophyll concentration, but their wavelengths were unchanged.

  13. Measurements of OH* and CH* Chemiluminescence in Premixed Flames in a Constant Volume Combustion Bomb under Autoignition Conditions

    OpenAIRE

    TINAUT FLUIXA, FRANCISCO VICENTE; Reyes, M.; Giménez, B.; Pastor Soriano, José Vicente

    2011-01-01

    The objectives of this paper are as follows: (1) To study parametrically OH* and CH* chemiluminescence trace evolution as a function of the initial pressure, temperature, and equivalence ratio of premixed flames of n-heptane, under autoignition conditions, in a constant volume combustion bomb. The signals of the electronically excited states of OH* (306 nm) and CH* (430 nm) have been detected through band-pass filters with two photomultiplier tubes placed in an optical access of the combustio...

  14. Multicommuted flow system for the determination of glucose in animal blood serum exploiting enzymatic reaction and chemiluminescence detection

    OpenAIRE

    Pires,Cherrine K.; Martelli,Patrícia B.; Reis, Boaventura F.; Lima, José L. F. C.; Saraiva, Maria Lúcia M. F. S.

    2003-01-01

    An automatic flow procedure based on multicommutation dedicated for the determination of glucose in animal blood serum using glucose oxidase with chemiluminescence detection is described. The flow manifold consisted of a set of three-way solenoid valves assembled to implement multicommutation. A microcomputer furnished with an electronic interface and software written in Quick BASIC 4.5 controlled the manifold and performed data acquisition. Glucose oxidase was immobilized on porous silica be...

  15. Study on Enhancement Principle and Stabilization for the Luminol-H2O2-HRP Chemiluminescence System.

    Directory of Open Access Journals (Sweden)

    Lihua Yang

    Full Text Available A luminol-H2O2-HRP chemiluminescence system with high relative luminescent intensity (RLU and long stabilization time was investigated. First, the comparative study on the enhancement effect of ten compounds as enhancers to the luminol-H2O2-HRP chemiluminescence system was carried out, and the results showed that 4-(imidazol-1-ylphenol (4-IMP, 4-iodophenol (4-IOP, 4-bromophenol (4-BOP and 4-hydroxy-4'-iodobiphenyl (HIOP had the best performance. Based on the experiment, the four enhancers were dissolved in acetone, acetonitrile, methanol, and dimethylformamide (DMF with various concentrations, the results indicated that 4-IMP, 4-IOP, 4-BOP and HIOP dissolved in DMF with the concentrations of 0.2%, 3.2%, 1.6% and 3.2% could get the highest RLU values. Subsequently, the influences of pH, ionic strength, HRP, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol on the stabilization of the luminol-H2O2-HRP chemiluminescence system were studied, and we found that pH value, ionic strength, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol have little influence on luminescent stabilization, while HRP has a great influence. In different ranges of HRP concentration, different enhancers should be selected. When the concentration is within the range of 0~6 ng/mL, 4-IMP should be selected. When the concentration of HRP ranges from 6 to 25 ng/mL, 4-IOP was the best choice. And when the concentration is within the range of 25~80 ng/mL, HIOP should be selected as the enhancer. Finally, the three well-performing chemiluminescent enhanced solutions (CESs have been further optimized according to the three enhancers (4-IMP, 4-IOP and HIOP in their utilized HRP concentration ranges.

  16. An Evaluation of the Eclox Chemiluminescence Test, Hach Pesticide/Nerve Agent Test Strips, and Agri-Screen Test Tickets

    Science.gov (United States)

    2010-06-30

    Chemiluminescence Test utilizes horseradish peroxidase to catalyze luminol in the presence of both an oxidant ( sodium perborate ) and enhancer (luminol and para...2 ESB system, ethylene glycol and oxamyl were removed from the chemical test list and sodium azide was added, for a total of 18 test chemicals... sodium arsenite) 0.02 4.5 Azide ( sodium azide) d 0.12 47 Copper (sulfate) 0.14 103 Cyanide ( sodium ) 2 14 Ethylene glycol 2.5 3157 Fenamiphos

  17. Effects of Non-Equilibrium Plasmas on Low-Pressure, Premixed Flames. Part 1: CH* Chemiluminescence, Temperature, and OH

    Science.gov (United States)

    2018-01-16

    with Low-Temperature Plasma: Kinetic Mechanism and Experimental Verification, High Energy Chemistry 2009 43(3), 213 9. Ombrello, T., Won, S.H., Ju, Y... chemistry . Qualitative imaging of CH* chemiluminescence indicates that during plasma discharge, the luminous flame zone is shifted upstream towards...lower-temperature kinetics including O atom, H atom and OH formation kinetics and temperature rise due to the presence of the low-temperature, non

  18. Detection and dosimetry of gamma ray emitted from thallium-201 and technetium-99m based on chemiluminescence technique

    Energy Technology Data Exchange (ETDEWEB)

    Shourian, Mostafa [Laboratory of Microanalysis, Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Tavakoli, Hassan, E-mail: tavakoli@ibb.ut.ac.i [Faculty of Medicine, Department of Physiology and Biophysics, Faculty of Medicine, Baqiyatollah University of Medical Sciences, P.O. Box 19395-6558, Tehran (Iran, Islamic Republic of); Ghourchian, Hedayatollah, E-mail: hadi@ibb.ut.ac.i [Laboratory of Microanalysis, Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Rafiee-Pour, Hossain-Ali [Laboratory of Microanalysis, Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of)

    2010-09-15

    This report describes the detection and dosimetry of gamma ray emitted from Thallium-201 ({sup 201}Tl) and Technetium-99m ({sup 99m}Tc) based on chemiluminescence technique. H{sub 2}O{sub 2} produced by two gamma emitter radioisotopes of {sup 201}Tl and {sup 99m}Tc were quantitatively measured by chemiluminescence method. Upon producing H{sub 2}O{sub 2} in a luminol alkaline solution, in the presence of diperiodatocuprate, as catalyst a chemical reaction was accrued and consequently the emitted light was measured. The determined H{sub 2}O{sub 2} concentration was correlated with the gamma ray detection and dosimetry. The sensitivity of chemiluminescence technique for {sup 201}Tl and {sup 99m}Tc dosimetry was determined to be 0.20 and 0.08 MBq/l (Mega Becquerel per liter) respectively (R.S.D. = %5, N = 3). The plotted calibration curves showed detection limits of 3.24 and 1.76 MBq/l for {sup 201}Tl and {sup 99m}Tc, respectively.

  19. A multiplex chemiluminescent biosensor for type B-fumonisins and aflatoxin B1 quantitative detection in maize flour.

    Science.gov (United States)

    Zangheri, Martina; Di Nardo, Fabio; Anfossi, Laura; Giovannoli, Cristina; Baggiani, Claudio; Roda, Aldo; Mirasoli, Mara

    2015-01-07

    A multiplex chemiluminescent biosensor for simple, rapid and ultrasensitive on-site quantification of aflatoxin B1 and type B-fumonisins in maize samples has been developed. The biosensor integrates a multiplex indirect competitive lateral flow immunoassay (LFIA) based on enzyme-catalyzed chemiluminescence detection and a highly sensitive portable charge-coupled device (CCD) camera, employed in a lensless "contact" imaging configuration. The developed assay requires a simple extraction of the analytes from maize flour samples followed by their detection with a 30 min assay time. The use of chemiluminescence detection allowed accurate and objective analytes quantification, enabling simultaneous detection of type B-fumonisins and aflatoxin B1 down to 6 μg kg(-1) and 1.5 μg kg(-1), respectively, thus fulfilling the standards imposed by the legislation of European Union. Maize flour samples spiked with both analytes were subjected to multiplex analysis obtaining recoveries ranging from 80 to 115% and the coefficient of variation below 20%. Finally, analysis of naturally contaminated maize samples resulted in a good agreement between CL-LFIA and a validated confirmatory HPLC-UV and commercial ELISA kit, obtaining recoveries in the range 88-120%. The proposed CL-LFIA protocol is rapid, inexpensive, easy-to-use, and fit for the purpose of rapid screening of mycotoxins in maize flour.

  20. Inhibition of chemiluminescence and chemotactic activity of phagocytes in vitro by the extracts of selected medicinal plants.

    Science.gov (United States)

    Jantan, Ibrahim; Harun, Nurul Hikmah; Septama, Abdi Wira; Murad, Shahnaz; Mesaik, M A

    2011-04-01

    The methanol extracts of 20 selected medicinal plants were investigated for their effects on the respiratory burst of human whole blood, isolated human polymorphonuclear leukocytes (PMNs) and isolated mice macrophages using a luminol/lucigenin-based chemiluminescence assay. We also tested the effect of the extracts on chemotactic migration of PMNs using the Boyden chamber technique. The extracts of Curcuma domestica L., Phyllanthus amarus Schum & Thonn and C. xanthorrhiza Roxb. were the samples producing the strongest oxidative burst of PMNs with luminol-based chemiluminescence, with IC(50) values ranging from 0.5 to 0.7 μg/ml. For macrophage cells, the extracts which showed strong suppressive activity for luminol-based chemiluminescence were C. xanthorrhiza and Garcinia mangostana L. Among the extracts studied, C. mangga Valton & Vazsjip, Piper nigrum L. and Labisia pumila var. alata showed strong inhibitory activity on lucigenin-amplified oxidative burst of PMNs, with IC(50) values ranging from 0.9 to 1.5 μg/ml. The extracts of Zingiber officinale Rosc., Alpinia galangal (L.) Willd and Averrhoa bilimbi Linn showed strong inhibition on the chemotaxic migration of cells, with IC(50) values comparable to that of ibuprofen (1.5 μg/ml). The results suggest that some of these plants were able to modulate the innate immune response of phagocytes at different steps, emphasizing their potential as a source of new immunomodulatory agents.

  1. Evaluation of chemiluminescence method for the analysis of plasma homocysteine and comparison with HPLC method in children samples

    Directory of Open Access Journals (Sweden)

    Thais Moura Gascón

    2010-06-01

    Full Text Available Objective: To compare the results for homocysteine concentration using chemiluminescence and HPLC methods in samples from school-age children. In addition, to determine the reference values for patients of this age group and assess the real prognostic value of homocysteine in healthy children. Methods: A prospective observational study was undertaken to determine plasma levels of homocysteine using two different assays, HPLC and chemiluminescence, in 185 samples from school-age children living in Santo Andre, with no chronic or inflammatory diseases, and absence of pubertal development. Results: The results were presented in percentiles and reference values were determined within this age group (7-9 years old. Homocysteine concentration ranged from 2.0 to 9.9 μmol/l (r = 0.821 and p < 0.001. Conclusions: It was verified that chemiluminescence is comparable to HPLC when both techniques are used to detect homocysteine in school-age children. There is an important correlation between both methods, which allows investigation of this amino acid as a risk factor for heart diseases.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-04-29

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

  3. Microspot-based ELISA in microfluidics: chemiluminescence and colorimetry detection using integrated thin-film hydrogenated amorphous silicon photodiodes.

    Science.gov (United States)

    Novo, Pedro; Prazeres, Duarte Miguel França; Chu, Virginia; Conde, João Pedro

    2011-12-07

    Microfluidic technology has the potential to decrease the time of analysis and the quantity of sample and reactants required in immunoassays, together with the potential of achieving high sensitivity, multiplexing, and portability. A lab-on-a-chip system was developed and optimized using optical and fluorescence microscopy. Primary antibodies are adsorbed onto the walls of a PDMS-based microchannel via microspotting. This probe antibody is then recognised using secondary FITC or HRP labelled antibodies responsible for providing fluorescence or chemiluminescent and colorimetric signals, respectively. The system incorporated a micron-sized thin-film hydrogenated amorphous silicon photodiode microfabricated on a glass substrate. The primary antibody spots in the PDMS-based microfluidic were precisely aligned with the photodiodes for the direct detection of the antibody-antigen molecular recognition reactions using chemiluminescence and colorimetry. The immunoassay takes ~30 min from assay to the integrated detection. The conditions for probe antibody microspotting and for the flow-through ELISA analysis in the microfluidic format with integrated detection were defined using antibody solutions with concentrations in the nM-μM range. Sequential colorimetric or chemiluminescence detection of specific antibody-antigen molecular recognition was quantitatively detected using the photodiode. Primary antibody surface densities down to 0.182 pmol cm(-2) were detected. Multiplex detection using different microspotted primary antibodies was demonstrated.

  4. Robotic membranes

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette

    2008-01-01

    , Vivisection and Strange Metabolisms, were developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts in Copenhagen as a means of engaging intangible digital data with tactile physical material. As robotic membranes, they are a dual examination...

  5. Coded SQUID arrays

    NARCIS (Netherlands)

    Podt, M.; Weenink, J.; Weenink, J.; Flokstra, Jakob; Rogalla, Horst

    2001-01-01

    We report on a superconducting quantum interference device (SQUID) system to read out large arrays of cryogenic detectors. In order to reduce the number of SQUIDs required for an array of these detectors, we used code-division multiplexing. This simplifies the electronics because of a significantly

  6. Microfabricated ion trap array

    Science.gov (United States)

    Blain, Matthew G [Albuquerque, NM; Fleming, James G [Albuquerque, NM

    2006-12-26

    A microfabricated ion trap array, comprising a plurality of ion traps having an inner radius of order one micron, can be fabricated using surface micromachining techniques and materials known to the integrated circuits manufacturing and microelectromechanical systems industries. Micromachining methods enable batch fabrication, reduced manufacturing costs, dimensional and positional precision, and monolithic integration of massive arrays of ion traps with microscale ion generation and detection devices. Massive arraying enables the microscale ion traps to retain the resolution, sensitivity, and mass range advantages necessary for high chemical selectivity. The reduced electrode voltage enables integration of the microfabricated ion trap array with on-chip circuit-based rf operation and detection electronics (i.e., cell phone electronics). Therefore, the full performance advantages of the microfabricated ion trap array can be realized in truly field portable, handheld microanalysis systems.

  7. Erythrocyte Membrane Failure by Electromechanical Stress

    Directory of Open Access Journals (Sweden)

    E Du

    2018-01-01

    Full Text Available We envision that electrodeformation of biological cells through dielectrophoresis as a new technique to elucidate the mechanistic details underlying membrane failure by electrical and mechanical stresses. Here we demonstrate the full control of cellular uniaxial deformation and tensile recovery in biological cells via amplitude-modified electric field at radio frequency by an interdigitated electrode array in microfluidics. Transient creep and cyclic experiments were performed on individually tracked human erythrocytes. Observations of the viscoelastic-to-viscoplastic deformation behavior and the localized plastic deformations in erythrocyte membranes suggest that electromechanical stress results in irreversible membrane failure. Examples of membrane failure can be separated into different groups according to the loading scenarios: mechanical stiffening, physical damage, morphological transformation from discocyte to echinocyte, and whole cell lysis. These results show that this technique can be potentially utilized to explore membrane failure in erythrocytes affected by other pathophysiological processes.

  8. Gold Magnetic Nanoparticles-based Chemiluminescent Immunoassay for Detection of Chloramphenicol in Milk

    Directory of Open Access Journals (Sweden)

    Wang Linyu

    2017-01-01

    Full Text Available chemiluminescent immunoassays (CLIA based on gold magnetic nanoparticles (Au-MNPs were developed for rapid analysis of chloramphen icol (CAP in milk sample. Anti-CAP antibodies were immobilized on the surfaces of Au-MNPs, luminol (Method I and 2′,6′-DiMethylcarbonylphenyl-10-sulfopropylacridinium-9-carboxylate 4′-NHS Ester, (NSP-DMAE-NHS, Method II were exploited in competitive CLIA for CAP detection in milk using a homemade luminescent measurement system. The sensitivities and limits of detection (LODs of the two methods were obtained according to the inhibition curves. It indicated that NSP-DMAE-NHS as luminescence reagent (reaction II was more sensitive and effective than luminol (reaction I. The LOD of reaction II reached 0.008 ng/ml while it was 4 ng/ml in reaction I. Moreover, the linear range of the inhibition curve of the former was wider than that of the latter. Such results indicated that the proposed CLIA stratery employing NSP-DMAE-NHS was more sensitive than other immunoassay method for CAP detection.

  9. In Situ Real-Time Chemiluminescence Imaging of Reactive Oxygen Species Formation from Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Yunbo Li

    2008-01-01

    Full Text Available We have applied the highly sensitive chemiluminescence (CL imaging technique to investigate the in situ ROS formation in cultured monolayers of rat H9c2 cardiomyocytes. Photon emission was detected via an innovative imaging system after incubation of H9c2 cells in culture with luminol and horseradish peroxidase (HRP, suggesting constitutive formation of ROS by the cardiomyocytes. Addition of benzo(apyrene-1,6-quinone (BPQ to cultured H9c2 cells resulted in a 4-5-fold increase in the formation of ROS, as detected by the CL imaging. Both constitutive and BPQ-stimulated CL responses in cultured H9c2 cells were sustained for up to 1 hour. The CL responses were completely abolished in the presence of superoxide dismutase and catalase, suggesting the primary involvement of superoxide and hydrogen peroxide (H2O2. In contrast to BPQ-mediated redox cycling, blockage of mitochondrial electron transport chain by either antimycin A or rotenone exerted marginal effects on the ROS formation by cultured H9c2 cells. Upregulation of cellular antioxidants for detoxifying both superoxide and H2O2 by 3H-1,2-dithiole-3-thione resulted in marked inhibition of both constitutive and BPQ-augmented ROS formation in cultured H9c2 cells. Taken together, we demonstrate the sensitive detection of ROS by CL imaging in cultured cardiomyocytes.

  10. Chemiluminescence detector based on a single planar transparent digital microfluidic device.

    Science.gov (United States)

    Zeng, Xiangyu; Zhang, Kaidi; Pan, Jian; Chen, Guoping; Liu, Ai-Qun; Fan, Shih-Kang; Zhou, Jia

    2013-07-21

    We report on a compact and portable prototype of chemiluminescence detector based on a single planar single polar transparent electrowetting-on-dielectrics (EWOD) device. The coupling ground model was proposed to build the EWOD device, which could be driven under a single polar voltage. Such a design not only simplified the chip construction and control circuit, but also had the potential for the ball-like droplet to focus the fluorescence and enhance the detection sensitivity. Simulations and experiments both confirmed that the greater the contact angle, the stronger the detected optical signal, and thus the higher the sensitivity. The sensitivity of the prototype detector to H2O2 was 5.45 mV (mmol L(-1))(-1) and the detection limit was 0.01 mmol L(-1) when the contact angle of the EWOD surface was 120°. To further increase the sensitivity and decrease the detection limit, the contact angle of the EWOD device could be increased and the dark current of the photomultiplier decreased. The prototype shows potential applications as highly sensitive, cost effective and portable immuno-detectors, especially as a blood glucose monitor.

  11. High sensitivity chemiluminescence enzyme immunoassay for detecting staphylococcal enterotoxin A in multi-matrices.

    Science.gov (United States)

    Zhang, Chunmei; Liu, Zhijia; Li, Yongming; Li, Qi; Song, Chaojun; Xu, Zhuwei; Zhang, Yun; Zhang, Yusi; Ma, Ying; Sun, Yuanjie; Chen, Lihua; Fang, Liang; Yang, Angang; Yang, Kun; Jin, Boquan

    2013-09-24

    In this study, detection of staphylococcal enterotoxin A (SEA) in multi-matrices using a highly sensitive and specific microplate chemiluminescence enzyme immunoassay (CLEIA) has been established. A pair of monoclonal antibodies (mAbs) was selected from 37 anti-SEA mAbs by pairwise analysis, and the experimental conditions of the CLEIA were optimized. This CLEIA exhibited high performance with a wide dynamic range from 6.4 pg mL(-1) to 1600 pg mL(-1), and the measured low limit of detection (LOD) was 3.2 pg mL(-1). No cross-reactivity was observed when this method was applied to test SEB, SEC1, and SED. It has also been successfully applied for analyzing SEA in a variety of environmental, biological, and clinical matrices, such as sewage, tap water, river water, roast beef, peanut butter, cured ham, 10% nonfat dry milk, milk, orange juice, human urine, and serum. Thus, the highly sensitive and SEA-specific CLEIA should make it attractive for quantifying SEA in public health and diagnosis in near future. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  12. Chemiluminescence lateral flow immunoassay based on Pt nanoparticle with peroxidase activity.

    Science.gov (United States)

    Park, Jong-Min; Jung, Ha-Wook; Chang, Young Wook; Kim, Hyung-Seok; Kang, Min-Jung; Pyun, Jae-Chul

    2015-01-01

    A lateral flow immunoassay (LF-immunoassay) with an enhanced sensitivity and thermostability was developed by using Pt nanoparticles with a peroxidase activity. The Pt nanoparticles were synthesized by citrate reduction method, and the peroxidase activity of Pt nanoparticles was optimized by adjusting reaction conditions. The peroxidase activity was estimated by using Michaelis-Menten kinetics model with TMB as a chromogenic substrate. The kinetics parameters of KM and Vmax were calculated and compared with horseradish peroxidase (HRP). The thermal stability of the Pt nanoparticles was compared with horseradish peroxidase (HRP) according to the storage temperature and long-term storage period. The feasibility of lateral flow immunoassay with a chemiluminescent signal band was demonstrated by the detection of human chorionic gonadotropin (hCG) as a model analyte, and the sensitivity was determined to be improved by as much as 1000-fold compared to the conventional rapid test based on colored gold-colloids. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Peroxynitrous-acid-induced chemiluminescence of fluorescent carbon dots for nitrite sensing.

    Science.gov (United States)

    Lin, Zhen; Xue, Wei; Chen, Hui; Lin, Jin-Ming

    2011-11-01

    In this work, chemiluminescent (CL) property of the carbon dots in the presence of peroxynitrous acid was studied. Peroxynitrous acid is formed by online mixing of nitrite and acidified hydrogen peroxide. The CL intensity was increased linearly with nitrite concentration in the range from 1.0 × 10(-7) M to 1.0 × 10(-5) M, and the detection limit was 5.3 × 10(-8) M (signal-to-noise ratio of S/N = 3). This method has been successfully applied to the determination of nitrites in pond water, river water, and pure milk, with recoveries in the range of 98%-108%. The CL mechanism of the peroxynitrous acid-carbon dots system was investigated using the CL, ultraviolet-visible light (UV-vis), and electron paramagnetic resonance (EPR) spectra. The electron-transfer annihilation of hole-injected and electron-injected carbon dots could mainly account for the CL emission, which sheds new light on the optical properties of the carbon dots.

  14. Carbonate interlayered hydrotalcites-enhanced peroxynitrous acid chemiluminescence for high selectivity sensing of ascorbic acid.

    Science.gov (United States)

    Wang, Zhihua; Teng, Xu; Lu, Chao

    2012-04-21

    In this study, Mg-Al-carbonate layered double hydroxides (denoted as Mg-Al-CO(3) LDHs) were found to catalyze the chemiluminescence (CL) emission from peroxynitrous acid (ONOOH). The enhanced CL signals resulted from the concentration of peroxynitrite (ONOO(-)) onto the LDHs surface by electrostatic attraction, meaning that ONOO(-) can interact with the intercalated carbonate easily and effectively. Moreover, ascorbic acid can react with ONOO(-), or its decomposition products (e.g., ˙OH and ˙NO(2)), resulting in a decrease in the CL intensity from the Mg-Al-CO(3) LDHs-catalyzed ONOOH reaction. Based on these findings, a sensitive, selective and rapid CL method was developed for the determination of ascorbic acid using Mg-Al-CO(3) LDHs-catalyzed ONOOH as a novel CL system. The CL intensity was proportional to the concentration of ascorbic acid in the range from 5.0 to 5000 nM. The detection limit (S/N = 3) was 0.5 nM and the relative standard deviation (RSD) for nine repeated measurements of 0.1 μM ascorbic acid was 2.6%. This method has been successfully applied to determine ascorbic acid in commercial liquid fruit juices with recoveries of 97-107%. This work is not only of importance for a better understanding of the unique properties of LDHs-catalyzed CL but also of great potential for extensive applications in many fields, such as luminescence devices, bioanalysis, and labeling probes.

  15. Evaluation of the total antioxidant capacity by using a multipumping flow system with chemiluminescent detection.

    Science.gov (United States)

    Meneses, Silvia R P; Marques, Karine L; Pires, Cherrine K; Santos, João L M; Fernandes, Eduarda; Lima, José L F C; Zagatto, Elias A G

    2005-10-01

    An automated flow-based procedure for assessment of total antioxidant capacity was developed. It involved a multipumping flow system, a recent approach to flow analysis, and exploited the ability of selected compounds to inhibit the chemiluminescence reactions of luminol or lucigenin with hydrogen peroxide. The system included several discretely actuated solenoid micropumps as the only active components of the flow manifold. This enabled the reproducible insertion and efficient mixing of very low volumes of sample and reagents as well as the transportation of the sample zone toward a flow-through luminometer, where the chemiluminometric response was monitored. With luminol as the chemiluminogenic reagent, linearity of the analytical curves was noted up to 3.2x10(-4), 1.1x10(-3), and 8.8x10(-8) molL-1 for Trolox, ascorbic acid, and resveratrol, respectively. With lucigenin, linear calibration plots up to 2x10(-5) molL-1 of Trolox and 5.7x10(-5)molL-1 of ascorbic acid were obtained. As favorable analytical figures of merit, the measurement precision (RSD typically between 0.2 and 2.0%, n=10), low operational costs, low reagent consumption, sampling rate (160 and 70 h-1), and versatility should be highlighted. The proposed system can be used in distinct analytical circumstances without requiring physical reconfiguration.

  16. A high sensitivity micro format chemiluminescence enzyme inhibition assay for determination of Hg(II).

    Science.gov (United States)

    Deshpande, Kanchanmala; Mishra, Rupesh K; Bhand, Sunil

    2010-01-01

    A highly sensitive and specific enzyme inhibition assay based on alcohol oxidase (AlOx) and horseradish peroxidase (HRP) for determination of mercury Hg(II) in water samples has been presented. This article describes the optimization and miniaturization of an enzymatic assay using a chemiluminescence reaction. The analytical performance and detection limit for determination of Hg(II) was optimized in 96 well plates and further extended to 384 well plates with a 10-fold reduction in assay volume. Inhibition of the enzyme activity by dissolved Hg(II) was found to be linear in the range 5-500 pg·mL(-1) with 3% CV in inter-batch assay. Due to miniaturization of assay in 384 well plates, Hg(II) was measurable as low as 1 pg·mL(-1) within 15 min. About 10-fold more specificity of the developed assay for Hg(II) analysis was confirmed by challenging with interfering divalent metal ions such as cadmium Cd(II) and lead Pb(II). Using the proposed assay we could successfully demonstrate that in a composite mixture of Hg(II), Cd(II) and Pb(II), inhibition by each metal ion is significantly enhanced in the presence of the others. Applicability of the proposed assay for the determination of the Hg(II) in spiked drinking and sea water resulted in recoveries ranging from 100-110.52%.

  17. The practical application of implementing the equimolar response principle of chemiluminescent nitrogen detection in pharmaceutical analysis.

    Science.gov (United States)

    Liang, X; Patel, H; Young, J; Shah, P; Raglione, T

    2008-08-05

    Since nearly 90% of all developmental and marketed drugs contain at least one nitrogen atom, the implementation of chemiluminescent nitrogen detection (CLND) in pharmaceutical analysis is intriguing due to its equimolar response for nitrogen. Although the documented accuracy of CLND when using a surrogate nitrogen-containing standard may be inadequate for purity and potency determinations, it is acceptable for the quantitation of low-level impurities. A comparison of the quantitative results obtained using both CLND and UV detection for a developmental drug and its related impurities is presented. The results indicated that the impurities can be accurately quantified using a surrogate standard, based on the equimolar response principle of CLND, when the concentrations of the surrogate standard and the component of interest are similar. When the impurities are present at much lower levels than the surrogate standard however, the common practice of direct conversion of area percent to weight percent can result in significant errors using CLND, due to the limited linear dynamic range for CLND. To increase quantitation accuracy, the authors propose that a secondary dilution of the surrogate reference standard solution should be used for the quantitation of low-level impurities. The practical application of this approach for impurity quantitation or as a means to determine impurity relative response factors for use with a traditional UV based method is discussed.

  18. Enhancing and inhibiting effects of benzenediols on chemiluminescence of a novel cyclometallated iridium(III) complex.

    Science.gov (United States)

    Dong, Yong Ping; Huang, Li; Tong, Bi Hai; Shi, Ming Juan; Zhang, Wang Bing; Zhang, Qian Feng

    2012-01-01

    A novel chemiluminescence (CL) system, including the cyclometallated iridium(III) complex {tris[1-(2,6-dimethylphenoxy)-4-(4-chlorophenyl)phthalazine]iridium}, potassium permanganate and oxalic acid, is proposed for the determination of benzenediols. This method is based on the fact that hydroquinone and catechol exhibited an inhibiting effect, while resorcinol exhibited an enhancing effect on CL intensity. The optimum conditions for CL emission were investigated. Under optimal conditions, the detection limits of hydroquinone, catechol and resorcinol were 6.4 × 10(-8), 2.7 × 10(-9) and 8.1 × 10(-7)  mol/L, respectively. The method has been successfully applied to the determination of benzenediols in different types of water sample. The luminophors of the CL systems were all identified as the metal-ligand charge-transfer (MLCT) excited state of the iridium complex. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Clinical Performance Evaluation of Four Automated Chemiluminescence Immunoassays for Hepatitis C Virus Antibody Detection▿

    Science.gov (United States)

    Kim, Sinyoung; Kim, Jeong-Ho; Yoon, Seoyoung; Park, Youn-Hee; Kim, Hyon-Suk

    2008-01-01

    Various automated chemiluminescence immunoassay (CLIA) analyzers for the detection of antibodies to hepatitis C virus (HCV) are now commercially available in clinical laboratories and are replacing conventional enzyme immunoassays. We investigated the performance of four anti-HCV CLIAs (the Architect Anti-HCV assay on the Architect i2000 system, the Vitros Anti-HCV assay on the Vitros ECiQ Immunodiagnostic System, the Access HCV Ab PLUS assay on the UniCel DxI 800 analyzer, and the newly developed Elecsys Anti-HCV assay on the Cobas e 411 analyzer). The total percent coefficient of variation values of imprecision were 3.5 to 5.7% with positive control materials and 7.2 to 10.2% with negative control materials. The agreement between the results of the Elecsys, Architect, Vitros, and Access CLIAs ranged from 94.5 to 98.1%. The clinical sensitivity of all CLIAs was 100%. Each CLIA showed excellent reproducibility and clinical sensitivity. The Elecsys, Architect, Vitros, and Access CLIAs showed clinical specificities of 98.2, 98.8, 96.5, and 98.2%. PMID:18945839

  20. Clinical performance evaluation of four automated chemiluminescence immunoassays for hepatitis C virus antibody detection.

    Science.gov (United States)

    Kim, Sinyoung; Kim, Jeong-Ho; Yoon, Seoyoung; Park, Youn-Hee; Kim, Hyon-Suk

    2008-12-01

    Various automated chemiluminescence immunoassay (CLIA) analyzers for the detection of antibodies to hepatitis C virus (HCV) are now commercially available in clinical laboratories and are replacing conventional enzyme immunoassays. We investigated the performance of four anti-HCV CLIAs (the Architect Anti-HCV assay on the Architect i2000 system, the Vitros Anti-HCV assay on the Vitros ECiQ Immunodiagnostic System, the Access HCV Ab PLUS assay on the UniCel DxI 800 analyzer, and the newly developed Elecsys Anti-HCV assay on the Cobas e 411 analyzer). The total percent coefficient of variation values of imprecision were 3.5 to 5.7% with positive control materials and 7.2 to 10.2% with negative control materials. The agreement between the results of the Elecsys, Architect, Vitros, and Access CLIAs ranged from 94.5 to 98.1%. The clinical sensitivity of all CLIAs was 100%. Each CLIA showed excellent reproducibility and clinical sensitivity. The Elecsys, Architect, Vitros, and Access CLIAs showed clinical specificities of 98.2, 98.8, 96.5, and 98.2%.

  1. Investigation of the kinetics of OH∗ and CH∗ chemiluminescence in hydrocarbon oxidation behind reflected shock waves

    Science.gov (United States)

    Bozkurt, M.; Fikri, M.; Schulz, C.

    2012-06-01

    The temporal variation of chemiluminescence emission from OH∗(A2 Σ +) and CH∗(A2 Δ) in reacting Ar-diluted H2/O2/CH4, C2H2/O2 and C2H2/N2O mixtures was studied in a shock tube for a wide temperature range at atmospheric pressures and various equivalence ratios. Time-resolved emission measurements were used to evaluate the relative importance of different reaction pathways. The main formation channel for OH∗ in hydrocarbon combustion was studied with CH4 as benchmark fuel. Three reaction pathways leading to CH∗ were studied with C2H2 as fuel. Based on well-validated ground-state chemistry models from literature, sub-mechanisms for OH∗ and CH∗ were developed. For the main OH∗-forming reaction CH+O2=OH∗+CO, a rate coefficient of k 2=(8.0±2.6)×1010 cm3 mol-1 s-1 was determined. For CH∗ formation, best agreement was achieved when incorporating reactions C2+OH=CH∗+CO ( k 5=2.0×1014 cm3 mol-1 s-1) and C2H+O=CH∗+CO ( k 6=3.6×1012exp(-10.9 kJ mol-1/ RT) cm3 mol-1 s-1) and neglecting the C2H+O2=CH∗+CO2 reaction.

  2. Dog cloning with in vivo matured oocytes obtained using electric chemiluminescence immunoassay-predicted ovulation method.

    Science.gov (United States)

    Lee, Seunghoon; Zhao, Minghui; No, Jingu; Nam, Yoonseok; Im, Gi-Sun; Hur, Tai-Young

    2017-01-01

    Radioactive immunoassay (RIA) is a traditional serum hormone assay method, but the application of the method in reproductive studies is limited by the associated radioactivity. The aim of present study was to evaluate the reliability of RIA and to compare its canine serum progesterone concentration determination accuracy to that of the electric chemiluminescence immunoassay (ECLI). In vivo matured oocytes were utilized for canine somatic cell nuclear transfer (SCNT), and serum progesterone levels were assessed to accurately determine ovulation and oocyte maturation. Canine serum progesterone concentrations during both proestrus and estrus were analyzed by RIA and ECLI to determine the ovulation day. Although both methods detected similar progesterone levels before ovulation, the mean progesterone concentration determined using ECLI was significantly higher than of RIA three days before ovulation. Following ovulation, oocytes were collected by surgery, and a lower percentage of mature oocytes were observed using ECLI (39%) as compared to RIA (67%) if 4-8ng/ml of progesterone were used for determination of ovulation. A high percentage of mature oocytes was observed using ECLI when 6-15 ng/mL of progesterone was used for ovulation determination. To determine whether ECLI could be used for canine cloning, six canines were selected as oocyte donors, and two puppies were obtained after SCNT and embryo transfer. In conclusion, compared to the traditional RIA method, the ECLI method is a safe and reliable method for canine cloning.

  3. Nitrogen doped graphene quantum dots based long-persistent chemiluminescence system for ascorbic acid imaging.

    Science.gov (United States)

    Chen, Hongjun; Wang, Qin; Shen, Qinpeng; Liu, Xin; Li, Wang; Nie, Zhou; Yao, Shouzhuo

    2017-05-15

    High photo-intensity and sluggish flight attenuation are important to highly sensitive chemluminescence imaging. Herein, we present a copper ion catalyzed long-persistent chemiluminescent imaging system of nitrogen-doped graphene quantum dots (NGQDs) for ascorbic acid detection in fruit. NGQDs as luminescent probe are fabricated, emitting out chemluminescence with the direct oxidation by H 2 O 2 . In addition, Cu 2+ ion enlarges over two order magnitudes of NGQDs CL intensity (214 times) due to its catalyzed Fenton-like reaction for H 2 O 2 decomposition, and displaying unique specificity against other metal ions. As a result, the twinkling luminescence of NGQDs is boosted and changes to hold persistent with small decay in the presence of copper ion exhibiting potential for CL imaging. As an imaging model, a visual sensor based on Cu 2+ /NGQDs/H 2 O 2 is developed for AA quantitative monitoring with a limit of detection (LOD) of 0.5μM (S/N=3) and applied in real AA detection in fruit. The CL imaging method demonstrated with high stability and proper sensitivity would provide a convenient and visual tool for AA determination, displaying promising candidates for imaging sensing. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. A fast and precise chemiluminescence ozone detector for eddy flux and airborne application

    Directory of Open Access Journals (Sweden)

    A. Zahn

    2012-02-01

    Full Text Available A commercially available dry chemiluminescence (CI instrument for fast and precise measurement of ozone (O3 is specified. The sensitivity is ~9000 counts s−1 per ppbv of ozone. Its precision is entirely determined by the number of photons reaching the detector (being a photomultiplier, i.e. is quantum-noise limited. The relative precision (ΔO3/O3 in % thus follows Poisson statistics and scales with the square root of the measurement frequency f and with the inverse O3 mixing ratio: ΔO3/O3f0.5 · O3−0.5. At typical O3 mixing ratios between 10 and 100 ppbv (and 1 bar, the precision is 0.3–1.0% at f = 10 Hz. The maximum measurement frequency is 50 Hz. The mechanical and electronic set-up as well as the instrument performance is described. Recommendations on the adequate inlet tube configuration (inlet tube length, sampling flow and on the way of calibration at stationary ground-based platforms and onboard aircraft are given.

  5. Evaluation of the Novel Methotrexate Architect Chemiluminescent Immunoassay: Clinical Impact on Pharmacokinetic Monitoring.

    Science.gov (United States)

    Aumente, Maria D; López-Santamaría, Julia; Donoso-Rengifo, María Concepción; Reyes-Torres, Inmaculada; Montejano Hervás, Pablo

    2017-10-01

    Fluorescence polarization immunoassay (FPIA) has probably been the most widely used technique for the determination of methotrexate (MTX) concentrations in clinical laboratories. After its replacement by a novel architect chemiluminescent microparticle immunoassay (CMIA), it is essential to verify that there are no differences between the methods that can induce an error in leucovorin rescue with dire consequences for the patient. The objective of our study was to compare plasma/serum MTX measurements between CMIA and FPIA (reference method in this study) in the work conditions of a clinical pharmacokinetics unit to determine whether any difference would affect clinical decisions on the management of this drug. FPIA on TDx/FLx and CMIA on Architect ci8200 were simultaneously used to evaluate 127 clinical samples. Within-run (20 repetitions on same day) and between-run (20 repetitions on different days) imprecision was evaluated using 6 control samples provided by the manufacturer and diluting 2 of them by 50% for 0.03 and 0.22 μmol/L, respectively. The Passing-Bablok regression method, Bland-Altman plot, and concordance correlation coefficient (CCC) were used in the statistical analysis. Within-run imprecision was Architect assay to measure MTX concentrations would therefore not affect clinical decisions on MTX management, supporting its employment in routine MTX monitoring.

  6. Determination of dihydralazine based on chemiluminescence resonance energy transfer of hollow carbon nanodots

    Science.gov (United States)

    Han, Suqin; Fan, Zheyan; Chen, Xiaoxia; Wu, Yunfang; Wang, Jianbo

    2017-08-01

    The famous weak chemiluminescence (CL) system of potassium permanganate and sodium bisulfite (KMnO4-HSO3-) was enhanced by the hollow fluorescent carbon nanodots (HCNs). The investigation of mechanism revealed that the enhanced CL was induced by the excited-state HCNs (HCNs*), which could be produced from the electron-transfer annihilation of positively charged HCNs (HCNsrad +) and negatively charged HCNs (HCNsrad -) as well as by CL resonance energy transfer (CRET) from excited SO2 (SO2*)/1O2 to HCNs. The dihydralazine sulfate (DHZS) had a diminishing effect on the CL of HCNs-KMnO4-HSO3- system due to the competitive consumption of rad O2-. Under the optimal conditions, the reduced CL signal with the concentration of DHZS was linear in the range of 1.0 × 10- 7-7.0 × 10- 5 mol/L with a detection limit of 3.0 × 10- 8 mol/L. The relative standard deviation for seven repeated determination of 5.0 × 10- 6 mol/L DHZS was 2.1%. The established method was applied to the determination of DHZS in pharmaceutical preparations, human urine and plasma samples with good precision and accuracy.

  7. Electrogenerated chemiluminescence logic gate operations based on molecule-responsive organic microwires.

    Science.gov (United States)

    Gu, Jianmin; Wu, Jingxiao; Gao, Yahui; Wu, Tianhui; Li, Qing; Li, Aixue; Zheng, Jian-Yao; Wen, Bin; Gao, Faming

    2017-07-27

    Complex logic gate operations using organic microwires as signal transducers based on electrogenerated chemiluminescence (ECL) intensity as the optical readout signal have been developed by taking advantage of the unique ECL reaction between organic semiconductor 9,10-bis(phenylethynyl)anthracene (BPEA) microwires and small molecules. The BPEA microwires, prepared on cleaned-ITO substrate using a simple physical vapor transport (PVT) method, were subsequently used for construction of the ECL sensors. The developed sensor exhibits high ECL efficiency and excellent stability in the presence of co-reactant tripropylamine. Based on the remarkable detection performance of BPEA MWs/TPrA system, the sensors manifested high sensitive ECL response in a wide linear range with low detection limit for the detection of dopamine, proline or methylene blue, which behaves on the basis of molecule-responsive ECL properties based on different ECL reaction mechanisms. Inspired by this, these sensing systems can be utilized to design OR, XOR and INHIBIT logic gates, which would be used for the determination of dopamine, proline and ethylene blue via logic outputs. Importantly, the individual logic gates can be easily brought together through three-input operations to function as integrated logic gates.

  8. Measurement of hydroxyl radical production in ultrasonic aqueous solutions by a novel chemiluminescence method.

    Science.gov (United States)

    Hu, Yufei; Zhang, Zhujun; Yang, Chunyan

    2008-07-01

    Measurement methods for ultrasonic fields are important for reasons of safety. The investigation of an ultrasonic field can be performed by detecting the yield of hydroxyl radicals resulting from ultrasonic cavitations. In this paper, a novel method is introduced for detecting hydroxyl radicals by a chemiluminescence (CL) reaction of luminol-hydrogen peroxide (H2O2)-K5[Cu(HIO6)2](DPC). The yield of hydroxyl radicals is calculated directly by the relative CL intensity according to the corresponding concentration of H2O2. This proposed CL method makes it possible to perform an in-line and real-time assay of hydroxyl radicals in an ultrasonic aqueous solution. With flow injection (FI) technology, this novel CL reaction is sensitive enough to detect ultra trace amounts of H2O2 with a limit of detection (3sigma) of 4.1 x 10(-11) mol L(-1). The influences of ultrasonic output power and ultrasonic treatment time on the yield of hydroxyl radicals by an ultrasound generator were also studied. The results indicate that the amount of hydroxyl radicals increases with the increase of ultrasonic output power (measured by calculating the yield of hydroxyl radicals.

  9. Novel assay of antibacterial components in manuka honey using lucigenin-chemiluminescence-HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, Koji, E-mail: koji180@pharm.showa-u.ac.jp; Haraya, Shiomi; Okubo, Sachie; Arakawa, Hidetoshi

    2017-02-15

    Five components (hydrogen peroxide, methylglyoxal, dihydroxyacetone, fructose and glucose) of New Zealand manuka honey (Leptospermum scoparium) were analyzed using lucigenin chemiluminescence high-performance liquid chromatography (lucigenin-CL-HPLC). We focused on active oxygen species produced from the components in order to easily detect these five components contained in manuka honey. H{sub 2}O{sub 2} and O{sub 2}{sup −} generated from these components were identified by lucigenin-CL and electron spin resonance (ESR), and the bactericidal effect of ROS was confirmed using E. coli. The previously reported assays for Manuka honey components have low specificities and require complicated preprocessing methods. As our results, the detection and identification of these components were possible within 30 min in lucigenin-CL-HPLC system, without any special treatment. It is considered that lucigenin-CL-HPLC is useful for the quality control and the analysis of various honey. - Highlights: • Antibacterial components in manuka honey by HPLC with lucigenin-CL. • Five antibacterial compounds measured via generation of reactive oxygen species. • Simple, sensitive and useful for quality control and analysis of antibacterial honey.

  10. Chemiluminescence response induced by mesenteric ischaemia/reperfusion: effect of antioxidative compounds ex vivo

    Science.gov (United States)

    Nosál'ová, Viera; Sotníková, Ružena; Drábiková, Katarína; Fialová, Silvia; Košťálová, Daniela; Banášová, Silvia; Navarová, Jana

    2010-01-01

    Ischaemia and reperfusion (I/R) play an important role in human pathophysiology as they occur in many clinical conditions and are associated with high morbidity and mortality. Interruption of blood supply rapidly damages metabolically active tissues. Restoration of blood flow after a period of ischaemia may further worsen cell injury due to an increased formation of free radicals. The aim of our work was to assess macroscopically the extent of intestinal pathological changes caused by mesenteric I/R, and to study free radical production by luminol enhanced chemiluminescence (CL) of ileal samples. In further experiments, the antioxidative activity of the drugs tested was evaluated spectrophotometrically by the use of the DPPH radical. We studied the potential protective ex vivo effect of the plant origin compound arbutin as well as of the pyridoindole stobadine and its derivative SMe1EC2. I/R induced pronounced haemorrhagic intestinal injury accompanied by increase of myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAGA) activity. Compared to sham operated (control) rats, there was only a slight increase of CL response after I/R, probably in association with neutrophil increase, indicated by enhanced MPO activity. All compounds significantly reduced the peak values of CL responses of the ileal samples ex vivo, thus reducing the I/R induced increase of free radical production. The antioxidants studied showed a similar inhibitory effect on the CL response influenced by mesenteric I/R. If proved in vivo, these compounds would represent potentially useful therapeutic antioxidants. PMID:21217883

  11. Microplate analytical method for quinones by pulse photo-irradiation and chemiluminescence detection.

    Science.gov (United States)

    Elgawish, Mohamed Saleh; Shimomai, Chikako; Kishikawa, Naoya; Ohyama, Kaname; Nakashima, Kenichiro; Kuroda, Naotaka

    2012-10-21

    Quinones are widely distributed in nature and have various bioactivities. Besides, quinones are also considered as toxicological intermediates which cause severe dangerous effects. Hereby, a sensitive, simple, and rapid method is reported for quinones determination. The proposed method employed time resolved fluorescence (TRF) microplate reader based chemiluminescent (CL) detection for the first time as a novel approach for measurement. Under pulse photo-irradiation, the unique photochemical characteristic of quinones is exploited to liberate reactive oxygen species (ROS) which reacted with photosensitized CL reagent. L-012, luminol analogue, was selected for its high sensitivity. Under our investigation, para-quinones showed high CL response when compared to ortho-quinones. A linear response was obtained for studied quinone concentrations in the range of 0.05-50 μM for 1,4-naphthquinone and of 0.05-150 μM for 2-methyl-1,4-naphthoquinone (menadione) and 9,10-anthraquinone with detection limit (blank + 3SD) of 0.01 μM. The proposed method allowed the rapid determination of large number of samples in very short time (96 sample/125 s). The proposed method was successfully applied for determination of menadione in spiked human serum.

  12. Chemiluminescence of neutrophiles stimulated by opsonized Zymosan in children with bronchial asthma and pneumonia

    Science.gov (United States)

    Lewandowicz-Uszynska, A.; Jankowski, A.

    2004-08-01

    Oxygen metabolism of neutrophils after stimulation with opsonized zymosan was examined using chemiluminescence test (in the presence of the patient serum or pooled serum). Into the study 37 children aged from 2 to 12 years were enrolled (20 girls and 17 boys). 10 healthy volunteers comprised the control group (group III). Two groups of patients were established: group I -- children with bronchial asthma (without infection), group II -- children with pneumonia. The examination in both groups was performed twice -- in acute phase and in remission period. The group I in acute phase comprised 16 children and in remission phase 9 children, group II - 21 children in acute phase and 9 children in remission phase, respectively. The following parameters of CL were estimated average value of so called spontaneous CL, maximal excitation of neutrophils after stimulation by zymogen (CLmax), time of zymosan opsonization. The following results were obtained: increased spontaneous CL and CLmax (at the presence of both sera) in acute phase of bronchial asthma and pneumonia in comparison to the control group. In the period of remission both these parameters were insignificantly decreased. The longest time of zymosan opsonization in acute period of disease was observed in children with pneumonia (18 min.). This time did not change during remission phase. Only slightly longer time of opsonization was observed in the patients from group I (in exacerbation) (15 min) than in the control group (13,1 min). This time was prolonged in the clinical remission (20 min).

  13. The Chemiluminescence and Structure Properties of Normal/Inverse Diffusion Flames

    Directory of Open Access Journals (Sweden)

    Ting Zhang

    2013-01-01

    Full Text Available The flame emission spectrometry was applied to detect the distribution of excited radicals in two types CH4/O2 coflow jet diffusion flames (normal and inverse diffusion flames. Combining the image analysis along with the spectrometry, the chemiluminescence and structure characteristics of these diffusion flames were investigated. The results show that the inverse diffusion flame (IDF with relatively high inlet oxygen velocity is composed of two regions: a bright base and a tower on top of the base, which is quite different from the normal diffusion flame (NDF. The flame is divided into two regions along the flame axis based on maximum OH* position (Region I: initial reaction zone; Region II: further oxidation zone. The degree of the further oxidization taking place in Region II is obvious in accordance with OH* distribution, which is the main difference in reaction zone between fuel-rich condition and fuel-lean condition for NDFs. For IDFs, the change of OH* distribution with increasing equivalence O/C ratio ([O/C]e in Region II is not conspicuous. More OH* and CH* are generated in IDFs, due to the inner high-speed O2 flow promoting the mixing of fuel and oxygen to a certain extent.

  14. Flame Structure and Chemiluminescence Emissions of Inverse Diffusion Flames under Sinusoidally Driven Plasma Discharges

    Directory of Open Access Journals (Sweden)

    Maria Grazia De Giorgi

    2017-03-01

    Full Text Available Reduction of nitric oxides (NOx in aircraft engines and in gas turbines by lean combustion is of great interest in the design of novel combustion systems. However, the stabilization of the flame under lean conditions is a main issue. In this context, the present work investigates the effects of sinusoidal dielectric barrier discharge (DBD on a lean inverse diffusive methane/air flame in a Bunsen-type burner under different actuation conditions. The flame appearance was investigated with fixed methane loading (mass flux, but with varying inner airflow rate. High-speed flame imaging was done by using an intensified (charge-coupled device CCD camera equipped with different optical filters in order to selectively record signals from the chemiluminescent species OH*, CH*, or CO2* to evaluate the flame behavior in presence of plasma actuation. The electrical power consumption was less than 33 W. It was evident that the plasma flame enhancement was significantly influenced by the plasma discharges, particularly at high inner airflow rates. The flame structure changes drastically when the dissipated plasma power increases. The flame area decreases due to the enhancement of mixing and chemical reactions that lead to a more anchored flame on the quartz exit with a reduction of the flame length.

  15. Chemiluminescence of metastable tin with fluorine, chlorine, and nitrogen trifluoride utilizing a beam-gas configuration

    Science.gov (United States)

    Rosano, W. J.; Parson, J. M.

    1986-09-01

    This paper reports the observation of electronic chemiluminescence (CL) from the reaction of metastable Sn with F2, Cl2, and NF3. All three reactions produced CL which was identified as emission from the A 2Σ+-X 2Π system of the tin monohalides and was first order with respect to the scattering gas. All spectra were highly congested suggesting that the product monohalides are produced with a large degree of internal excitation. Attenuation studies of various electronic states of metastable Sn in the beam with H2 show the 1D state to be the major contributor to CL product formation. Absolute CL cross sections were determined for Sn(1D) with F2, Cl2, and NF3 to be 67, >0.07, and 0.006 Å2, respectively, with uncertainties of ˜±60%. The cross section for the F2 reaction is approximately 35 times larger than the corresponding reaction for Sn(3P). The prior model, based on product state densities, predicts an increase of only about 6.5. We propose, in light of recent alignment experiments of Ca p orbitals, that the difference in reactivity of 1D and 3P states is a result of the symmetry of the second p orbital on Sn relative to the F2 molecule. Also, the production of the observed CL states requires a nonadiabatic process. Finally, the CL cross sections for the title reactions were found to increase with increasing collision energy.

  16. Sensor array signal processing

    CERN Document Server

    Naidu, Prabhakar S

    2009-01-01

    Chapter One: An Overview of Wavefields 1.1 Types of Wavefields and the Governing Equations 1.2 Wavefield in open space 1.3 Wavefield in bounded space 1.4 Stochastic wavefield 1.5 Multipath propagation 1.6 Propagation through random medium 1.7 ExercisesChapter Two: Sensor Array Systems 2.1 Uniform linear array (ULA) 2.2 Planar array 2.3 Distributed sensor array 2.4 Broadband sensor array 2.5 Source and sensor arrays 2.6 Multi-component sensor array2.7 ExercisesChapter Three: Frequency Wavenumber Processing 3.1 Digital filters in the w-k domain 3.2 Mapping of 1D into 2D filters 3.3 Multichannel Wiener filters 3.4 Wiener filters for ULA and UCA 3.5 Predictive noise cancellation 3.6 Exercises Chapter Four: Source Localization: Frequency Wavenumber Spectrum4.1 Frequency wavenumber spectrum 4.2 Beamformation 4.3 Capon's w-k spectrum 4.4 Maximum entropy w-k spectrum 4.5 Doppler-Azimuth Processing4.6 ExercisesChapter Five: Source Localization: Subspace Methods 5.1 Subspace methods (Narrowband) 5.2 Subspace methods (B...

  17. A submillimeter VLBI array

    Energy Technology Data Exchange (ETDEWEB)

    Weintroub, Jonathan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA (United States)], E-mail: jweintroub@cfa.harvard.edu

    2008-10-15

    A VLBI array operating at {lambda} 1.3 mm and 0.8 mm is being designed using existing submillimeter telescopes as ad-hoc stations. Initial three station {lambda} = 1.3 mm observations of SgrA* and other AGN have produced remarkable results, which are reported by Doeleman elsewhere in this proceedings. Future observations are planned with an enhanced array which has longer baselines, more stations, and greater sensitivity. At {lambda} = 0.8 mm and on the long baselines, the array will have about a 20 {mu}as angular resolution which equals the diameter of the event horizon of the massive black hole in SgrA*. Candidate single dish facilities include the Arizona Radio Observatory Submillimeter Telescope (SMT) in Arizona, the Caltech Submillimeter Observatory (CSO) and the James Clerk Maxwell telescope (JCMT) in Hawaii, the Large Millimeter Telescope (LMT) in Mexico, ASTE and APEX in Chile, and the IRAM 30 m in Spain; interferometers include the Submillimeter Array (SMA) in Hawaii, the Combined Array for Research in Millimeter-wave Astronomy (CARMA) in California, IRAM PdB Interferometer in France, and the Atacama Large Millimeter Array (ALMA) in Chile. I will discuss the techniques we have developed for phasing interferometric arrays to act as single VLBI station. A strategy for detection of short (10s) time-scale source variability using VLBI closure phase will be described.

  18. Design of Infrasonic Arrays

    National Research Council Canada - National Science Library

    Blandford, Robert

    1997-01-01

    The Infrasound Experts Group of the Geneva Conference on Disarmament Ad Hoc Committee on a Nuclear Test Ban has recommended an infrasound array design consisting of four elements, with three elements...

  19. Protein Functionalized Nanodiamond Arrays

    Directory of Open Access Journals (Sweden)

    Liu YL

    2010-01-01

    Full Text Available Abstract Various nanoscale elements are currently being explored for bio-applications, such as in bio-images, bio-detection, and bio-sensors. Among them, nanodiamonds possess remarkable features such as low bio-cytotoxicity, good optical property in fluorescent and Raman spectra, and good photostability for bio-applications. In this work, we devise techniques to position functionalized nanodiamonds on self-assembled monolayer (SAMs arrays adsorbed on silicon and ITO substrates surface using electron beam lithography techniques. The nanodiamond arrays were functionalized with lysozyme to target a certain biomolecule or protein specifically. The optical properties of the nanodiamond-protein complex arrays were characterized by a high throughput confocal microscope. The synthesized nanodiamond-lysozyme complex arrays were found to still retain their functionality in interacting with E. coli.

  20. Expandable LED array interconnect

    Science.gov (United States)

    Yuan, Thomas Cheng-Hsin; Keller, Bernd

    2011-03-01

    A light emitting device that can function as an array element in an expandable array of such devices. The light emitting device comprises a substrate that has a top surface and a plurality of edges. Input and output terminals are mounted to the top surface of the substrate. Both terminals comprise a plurality of contact pads disposed proximate to the edges of the substrate, allowing for easy access to both terminals from multiple edges of the substrate. A lighting element is mounted to the top surface of the substrate. The lighting element is connected between the input and output terminals. The contact pads provide multiple access points to the terminals which allow for greater flexibility in design when the devices are used as array elements in an expandable array.

  1. The retinal readout array

    Science.gov (United States)

    Litke, Alan; Meister, Markus

    1991-12-01

    We have fabricated and tested a set of electrode arrays for the study of information processing in the retina. Live retinal tissue is placed on top of an array with the output neurons directly above the electrodes. Absorption of light by the photoreceptor cells leads to the generation of electrical pulses in the output neurons. These pulses, in turn, produce voltage signals on the electrodes which are recorded simultaneously by external electronics. Thus, for the first time, the spatial and temporal firing patterns of a large set of retinal nerve cells can be studied. The arrays are fabricated on quartz wafers coated with a transparent conducting layer of indium tin oxide. The electrodes are electroplated with platinum black. Polyimide is used for insulation. The fabrication and properties of these arrays, and illustrative results with retinal tissue, are described.

  2. An Inflatable L-Band Microstrip SAR Array

    Science.gov (United States)

    Huang, J.; Lou, M.; Feria, A.; Kim, Y.

    1998-01-01

    Inflatable structures have been identified as one of the enabling technologies to achieve low mass, high packaging efficiency, and reliable deployment for future NASA spaceborne synthetic aperture radar (SAR) array antennas. A current L-band SAR antenna development, with aperture size of 10 m x 3 m, is required to have the capabilities of dual-linear polarization, 80-MHz bandwidth, electronic beam scanning, and less than 100 kg of mass. An inflatable concept, which employs the inflatable tubular frame structure to support a multilayer, thin membrane, microstrip array radiating aperture, has been identified. It uses a "roll-up" concept, for deploying the thin membranes to form a planar array aperture. To demonstrate this concept, two contracts were independently given to ILC Dover, Inc. and L'Garde Corp. for each to construct a 1/3 size (3.3 m x 1.0 m) functional model with an inflatable structure at L-band frequency. JPL provided both contractors with the antenna RF design and the etched thin membranes. The ILC Dover model has been delivered to JPL and gone through a series of deployment and RF tests. This is believed to be the first inflatable array antenna ever developed. This paper presents the mechanical and electrical constructions of this inflatable array and its test results.

  3. Networked Rectenna Array for Smart Material Actuators

    Science.gov (United States)

    Choi, Sang H.; Golembiewski, Walter T.; Song, Kyo D.

    2000-01-01

    The concept of microwave-driven smart material actuators is envisioned as the best option to alleviate the complexity associated with hard-wired control circuitry. Networked rectenna patch array receives and converts microwave power into a DC power for an array of smart actuators. To use microwave power effectively, the concept of a power allocation and distribution (PAD) circuit is adopted for networking a rectenna/actuator patch array. The PAD circuit is imbedded into a single embodiment of rectenna and actuator array. The thin-film microcircuit embodiment of PAD circuit adds insignificant amount of rigidity to membrane flexibility. Preliminary design and fabrication of PAD circuitry that consists of a few nodal elements were made for laboratory testing. The networked actuators were tested to correlate the network coupling effect, power allocation and distribution, and response time. The features of preliminary design are 16-channel computer control of actuators by a PCI board and the compensator for a power failure or leakage of one or more rectennas.

  4. Imaging beta-galactosidase activity in human tumor xenografts and transgenic mice using a chemiluminescent substrate.

    Directory of Open Access Journals (Sweden)

    Li Liu

    Full Text Available BACKGROUND: Detection of enzyme activity or transgene expression offers potential insight into developmental biology, disease progression, and potentially personalized medicine. Historically, the lacZ gene encoding the enzyme beta-galactosidase has been the most common reporter gene and many chromogenic and fluorogenic substrates are well established, but limited to histology or in vitro assays. We now present a novel approach for in vivo detection of beta-galactosidase using optical imaging to detect light emission following administration of the chemiluminescent 1,2-dioxetane substrate Galacto-Light PlusTM. METHODOLOGY AND PRINCIPAL FINDINGS: B-gal activity was visualized in stably transfected human MCF7-lacZ tumors growing in mice. LacZ tumors were identified versus contralateral wild type tumors as controls, based on two- to tenfold greater light emission following direct intra tumoral or intravenous administration of reporter substrate. The 1,2-dioxetane substrate is commercially available as a kit for microplate-based assays for beta-gal detection, and we have adapted it for in vivo application. Typically, 100 microl substrate mixture was administered intravenously and light emission was detected from the lacZ tumor immediately with gradual decrease over the next 20 mins. Imaging was also undertaken in transgenic ROSA26 mice following subcutaneous or intravenous injection of substrate mixture. CONCLUSION AND SIGNIFICANCE: Light emission was detectable using standard instrumentation designed for more traditional bioluminescent imaging. Use of 1,2-dioxetane substrates to detect enzyme activity offers a new paradigm for non-invasive biochemistry in vivo.

  5. Application of optimized chemiluminescence assay for determination of the antioxidant capacity of herbal extracts.

    Science.gov (United States)

    Pogačnik, Lea; Ulrih, Nataša Poklar

    2012-01-01

    A chemiluminescence (CL) assay for the determination of antioxidant capacity (AOC) has been optimized and applied to analyses of herbal extracts in the present study. The optimal concentrations of reagents (luminol, H2O2, horseradish peroxidase) have been determined, as well as the optimal reaction conditions (wavelength, pH, temperature, sample volume). All of the measurements were performed at the emission maximum of the oxidized form of luminol (425 nm). The optimal concentrations of the reagents were determined as follows: 1.6 mmol/L luminol, 7.5 mmol/L H2O2 and 0.14 U/mL horseradish peroxidase activity in the reaction mixture. Analyses were carried out in phosphate buffer, pH 7.4, at room temperature. With the optimized CL assay, the AOCs of various water and methanol herbal extracts were determined (dog rose hips, plantain leaves and coltsfoot and thyme flowers) and the results were compared to those obtained by other classical methods for the evaluation of antioxidants. Strong correlations (r > 0.9) with the Folin-Ciocalteau assay and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH)(●) assay are confirmed, although there is no correlation between AOC and the concentration of ascorbic acid in the samples analysed. This optimized CL assay is simple, rapid and reliable, and it represents a good alternative to classical methods (Folin-Ciocalteau, DPPH(●)) for the determination of AOC of herbal extracts and other food samples. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Pharmacokinetic of pseudoephedrine in rat serum with luminol-pepsin chemiluminescence system by flow injection analysis.

    Science.gov (United States)

    Luo, Kai; Li, Yajuan; Zheng, Xiaohui; Song, Zhenghua

    2015-02-01

    Pepsin (Pep) accelerated the electron transferring rate of excited 3-aminophathlate and enhanced luminol-dissolved oxygen chemiluminescence (CL) intensity, and the flow injection (FI) luminol-Pep CL system was first developed. It was found that the CL intensity of luminol-Pep reaction could be remarkably inhibited by pseudoephedrine (PE); the decrement of CL intensity was linear to the logarithm of PE concentration in the range of 0.1∼100.0 nmol L(-1) with a detection limit of 0.03 nmol mL(-1) (3σ). At a flow rate of 2.0 mL min(-1), the complete process including washing and sampling was performed within 40 s, offering a sample throughput of 90 h(-1). This proposed method was successfully applied to determining PE in rat serum for 18 h after intragastric administration with the elimination ratio of 42.34 % and recoveries from 90.3 to 110.6 %. The pharmacokinetic results showed that PE could be rapidly absorbed into serum with peak concentration (C max) of 1.45 ± 0.18 g L(-1) at the time (T max) of 1.49 ± 0.02 h; the absorption half-life (0.35 ± 0.04 h), elimination half-life (1.86 ± 0.24 h), the area under curve (109.81 ± 6.03 mg L(-1) h(-1)), mean residence time (3.82 ± 0.27 h), and elimination rate constant (2.26 ± 0.23 L g(-1) h(-1)) in rats vivo were derived, respectively. The possible CL mechanism of luminol-Pep-PE reaction was discussed by FI-CL, fluorescence, and molecular docking (MD) methods.

  7. Rapid determination of vitamin B12 concentration with a chemiluminescence lab on a chip.

    Science.gov (United States)

    Lok, Khoi Seng; Abdul Muttalib, Siti Zubaidah binte; Lee, Peter Peng Foo; Kwok, Yien Chian; Nguyen, Nam-Trung

    2012-07-07

    This paper reports a novel method for the rapid determination of vitamin B(12) concentration in a continuous-flow lab-on-a-chip system. This new method is based on luminol-peroxide chemiluminescence (CL) assays for the detection of cobalt(II) ions in vitamin B(12) molecules. The lab-on-a-chip device consisted of two passive micromixers acting as microreactors and a double spiral microchannel network serving as an optical detection region. This system could operate in two modes. In the first mode, samples are acidified and evaluated directly in the microchip. In the second mode, samples are treated externally by acidification prior to detection in the microchip. In the first mode, the linear range obtained was between 1.00 ng ml(-1) to 10 μg ml(-1), R(2) = 0.996, with a relative standard deviation (RSD) of 1.23 to 2.31% (n = 5) and a limit of detection (lod) of 0.368 pg ml(-1). The minimum sample volume required and the analytical time were 30 μl and 3.6 s, respectively. In the second mode, the linear range obtained was between 0.10 ng ml(-1) to 10 μg ml(-1), R(2) = 0.994, with the RSD of 0.90 to 2.32% (n = 6) and a lod of 0.576 pg ml(-1). The minimum sample and the analytical time required were 50 μl and 6 s, respectively. The lab on a chip working in mode II was successfully used for the determination of vitamin B(12) concentrations in nutritional supplemental tablets and hen egg yolks.

  8. Development of a chemiluminescent ELISA and a colloidal gold-based LFIA for TNT detection.

    Science.gov (United States)

    Girotti, S; Eremin, S; Montoya, A; Moreno, M J; Caputo, P; D'Elia, M; Ripani, L; Romolo, F S; Maiolini, E

    2010-01-01

    To identify the explosive used in a terrorist attack, or to obtain an early sign of environmental pollution it is important to use simple and rapid assays able to detect analytes at low levels, possibly on-site. This is particularly true for TNT (2,4,6-trinitrotoluene), one of the most employed explosives in the 20th century and at the same time, because of its toxicity, a well known pollutant. In this work we describe the development of an indirect competitive ELISA with chemiluminescent detection (CL-ELISA) and of a lateral-flow immunoassay (LFIA) based on colloidal gold nanoparticle labels. A commercially available monoclonal antibody was used and 13 specially synthesized conjugates were tested. We optimized the assay by determining the optimal concentration of monoclonal antibody and conjugates and the influence of various non-specific factors such as: tolerance to organic solvents at different concentrations, the washing and competitive step time, and the cross-reactivity with related compounds. The sensitivity and reproducibility of the CL-ELISA were good (LOD and IC(50) values in the ng mL(-1) range, and CV value about 7%). It has been applied to real samples of various materials involved in a controlled explosion of an "improvised explosive device". Three extraction procedures were tested on these samples, all employing methanol as the solvent. The lateral flow immunoassay (LFIA), developed by using the same immunoreagents, reached a detection limit of 1 microg mL(-1) when tested on the same samples analysed by CL-ELISA.

  9. Serum dosage of CPK-MB in dogs with ST deviation by chemiluminescence

    Directory of Open Access Journals (Sweden)

    André L.F. Santos

    2014-12-01

    Full Text Available Abstract: Although frequently in humans, hypoxic and ischemic heart diseases are poorly documented in dogs, with only few reports of acute myocardial infarction (AMI in this species. Some electrocardiographic findings might suggest myocardium hypoxia/ischemia, like ST segment elevation or depression, but there are no studies showing whether deviations in ST segment are associated to myocardial injury and serum increase of creatine phosphokinase (CPK-MB. In order to investigate possible myocardial cells injury in poor perfusion conditions, 38 dogs were studied, 20 with normal electrocardiogram and 18 with ST segment elevation or depression, recorded in lead II, at a paper speed of 50 mm/sec and N sensibility (1mV=1cm. Serum measurement of creatine phosphokinase isoenzyme MB (CPK-MB in normal dogs (group 1 determined control values (in ng/mL, which were compared to those obtained from dogs with deviation (group 2, which allowed confirmation or not of myocardial injury. CPK-MB mean values obtained from dogs in groups 1 and 2 were 0.540ng/ml (SD±0.890ng/mL and 0.440ng/mL (SD±1.106, respectively. At a significance level of 5%, the relation of CPK-MB with age, mass and total creatine phosphokinase (CPK-T was not significant in groups 1 and 2. CPK-MB showed no difference, at 5% level, between groups 1 and 2. In conclusion, it is possible to use the human chemiluminescent immunometric assay kit in canine species and that hypoxia/ischemia revealed by ST segment deviation does not mean significant myocardium injury.

  10. Sequential injection analysis with chemiluminescence detection for rapid monitoring of commercial Calendula officinalis extractions.

    Science.gov (United States)

    Hughes, Rachel R; Scown, David; Lenehan, Claire E

    2015-01-01

    Plant extracts containing high levels of antioxidants are desirable due to their reported health benefits. Most techniques capable of determining the antioxidant activity of plant extracts are unsuitable for rapid at-line analysis as they require extensive sample preparation and/or long analysis times. Therefore, analytical techniques capable of real-time or pseudo real-time at-line monitoring of plant extractions, and determination of extraction endpoints, would be useful to manufacturers of antioxidant-rich plant extracts. To develop a reliable method for the rapid at-line extraction monitoring of antioxidants in plant extracts. Calendula officinalis extracts were prepared from dried flowers and analysed for antioxidant activity using sequential injection analysis (SIA) with chemiluminescence (CL) detection. The intensity of CL emission from the reaction of acidic potassium permanganate with antioxidants within the extract was used as the analytical signal. The SIA-CL method was applied to monitor the extraction of C. officinalis over the course of a batch extraction to determine the extraction endpoint. Results were compared with those from ultra high performance liquid chromatography (UHPLC). Pseudo real-time, at-line monitoring showed the level of antioxidants in a batch extract of Calendula officinalis plateaued after 100 min of extraction. These results correlated well with those of an offline UHPLC study. SIA-CL was found to be a suitable method for pseudo real-time monitoring of plant extractions and determination of extraction endpoints with respect to antioxidant concentrations. The method was applied at-line in the manufacturing industry. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Sex differences in the significance of isolated reactive treponemal chemiluminescence immunoassay results.

    Science.gov (United States)

    Bopage, Rohan I; Vollmer-Conna, Ute; Shand, Antonia W; Post, Jeffrey John

    2017-10-11

    The significance of sera with isolated reactive treponemal chemiluminescence immunoassay (IRTCIA) results is unclear. Women have this phenotype more commonly than men. Most cohorts examining this phenotype have included predominantly men and have demonstrated evidence of past or subsequently confirmed syphilis infection in a significant proportion of cases. We hypothesised that a proportion of sera with IRTCIA results would be positive on immunoblot testing and that sera from women with IRTCIA would have different results in immunoblot testing than men. IRTCIA sera from a tertiary referral serology laboratory serving multiple clinical sites were analysed with a syphilis line immunoblot assay (LIA) and analysed by sex. Logistic regression was undertaken to assess factors associated with LIA status. Medical record review and descriptive analysis of a separate cohort of women with the IRTCIA phenotype from a single campus was also undertaken. Overall, 19/63 (30.1%) subjects with the IRTCIA phenotype were positive in the LIA, including 13 men and 6 women. Women were significantly less likely to have definitive results (positive or negative) than men (p=0.015). Pregnant women were less likely than non-pregnant women to have a negative LIA result (OR 0.57; p=0.03). Record review of 22 different women with IRTCIA reactivity showed that 2/22 (9.1%) had HIV and previous syphilis infection, 15/22 (68.2%) were pregnant and 3 (13.6%) had autoimmune disease. A significant proportion of sera with IRTCIA results on serological tests are reactive on LIA testing and some may not be false positive results. The interpretation of IRTCIA results should be undertaken in conjunction with an assessment of factors such as sex, pregnancy, a history of syphilis and other STIs and syphilis risk. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  12. Direct and simultaneous determination of Co and Cu on a silicon wafer using a chemiluminescence system.

    Science.gov (United States)

    Sung, Y I; Jang, J W; Lim, H B

    2011-10-07

    In this work, we developed a drop-type chemiluminescence (CL) system with a partial least squares (PLS) calibration in which the coaxial optical fiber sensing head was developed for sampling and detection to determine Cu(2+) and Co(2+) on a silicon wafer directly. The use of time-resolved signal generation and PLS calibration in addition to CL allowed us to determine the metal ions simultaneously and selectively, based on the kinetic difference of Cu and Co ions in the luminol-H(2)O(2) system. Two component mixtures with a set of 15 wafer fragments were orthogonally calibrated. After prediction test, the method was applied to an intentionally contaminated silicon wafer and validated by inductively coupled plasma-mass spectrometer (ICP-MS) measurement with a HF-HNO(3) scanning solution. The average concentrations of Cu(2+) and Co(2+) of 3.45 (±0.95) × 10(13) and 2.30 (±1.18) × 10(11) atoms per cm(2), respectively, were obtained, which were very close to the ICP-MS results of 3.70 × 10(13) for Cu(2+) and 2.46 × 10(11) atoms per cm(2) for Co(2+). In conclusion, this drop mode CL showed almost more than 10 times better reproducibility than the typical batch mode for the profile measurement. Moreover, the adoption of PLS calibration added the function of selectivity for the simultaneous determination to this CL system, in addition to the direct mapping capability for the solid surface analysis.

  13. Characterization of quinone derived protein adducts and their selective identification using redox cycling based chemiluminescence assay.

    Science.gov (United States)

    Elgawish, Mohamed Saleh; Kishikawa, Naoya; Ohyama, Kaname; Kuroda, Naotaka

    2015-07-17

    The cytotoxic mechanism of many quinones has been correlated to covalent modification of cellular proteins. However, the identification of relevant proteins targets is essential but challenging goals. To better understand the quinones cytotoxic mechanism, human serum albumin (HSA) was incubated in vitro with different concentration of menadione (MQ). In this respect, the initial nucleophilic addition of proteins to quinone converts the conjugates to redox-cycling quinoproteins with altered conformation and secondary structure and extended life span than the short lived, free quinones. The conjugation of MQ with nucleophilic sites likewise, free cysteine as well as ɛ-amino group of lysine residue of HSA has been found to be in concentration dependent manner. The conventional methods for modified proteins identification in complex mixtures are complicated and time consuming. Herein, we describe a highly selective, sensitive, simple, and fast strategy for quinoproteins identification. The suggested strategy exploited the unique redox-cycling capability of quinoproteins in presence of a reductant, dithiothreitol (DTT), to generate reactive oxygen species (ROS) that gave sufficient chemiluminescence (CL) when mixed with luminol. The CL approach is highly selective and sensitive to detect the quinoproteins in ten-fold molar excess of native proteins without adduct enrichment. The approach was also coupled with gel filtration chromatography (GFC) and used to identify adducts in complex mixture of proteins in vitro as well as in rat plasma after MQ administration. Albumin was identified as the main protein in human and rat plasma forming adduct with MQ. Overall, the identification of quinoproteins will encourage further studies of toxicological impact of quinones on human health. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Quinones as novel chemiluminescent probes for the sensitive and selective determination of biothiols in biological fluids.

    Science.gov (United States)

    Elgawish, Mohamed Saleh; Kishikawa, Naoya; Kuroda, Naotaka

    2015-12-21

    Altered plasma aminothiol concentrations are thought to be a valuable risk indicator and are interestingly utilized for routine clinical diagnosis and for the monitoring of various metabolic disorders and human diseases, and accordingly there is a need for an accurate and reliable assay capable of simultaneously determining aminothiols including glutathione (GSH), N-acetylcysteine (NAC), homocysteine (Hcys), and cysteine (Cys) in human plasma. Herein, a highly sensitive, selective, and very fast HPLC-chemiluminescence (HPLC-CL) coupled method is reported, exploiting for the first time the strong nucleophilicity and high reactivity of aminothiols toward quinones for a CL assay. The unique redox-cycling capability of quinone and/or Michael addition adducts, thioether-quinone conjugates, was utilized to establish a novel analytical method based on the reaction of adducts with dithiothreitol (DTT) to liberate reactive oxygen species (ROS), which are detected by using a luminol-CL assay. Specimen preparation involved the derivatization of aminothiols with menadione (MQ) for 5 minutes at room temperature. A unique green chemistry synthesis of thioether-quinones in HEPES buffer (pH 8.5) was introduced by using our reaction methodology without needing any hazardous organic solvent or catalyst. The aminothiol-MQ adducts were separated using solid-phase extraction followed by isocratic elution on an ODS column. Linearity was observed in the range of 2.5-500, 5-500, 10-1500, and 20-2000 nM with detection limits (S/N of 3) of 3.8, 4.2, 8, and 16 (fmol per injection) for GSH, NAC, Hcys, and Cys, respectively. The method was successfully applied for the selective determination of aminothiols in human plasma from healthy people and patients with rheumatic arthritis and diabetes mellitus. The obtained results postulated the usefulness of our method for investigating the relationship between aminothiol metabolism and related human disorders.

  15. High-throughput receptor-based assay for the detection of spirolides by chemiluminescence.

    Science.gov (United States)

    Rodríguez, Laura P; Vilariño, Natalia; Molgó, Jordi; Aráoz, Rómulo; Botana, Luis M

    2013-12-01

    The spirolides are marine toxins that belong to a new class of macrocyclic imines produced by dinoflagellates. In this study a previously described solid-phase receptor-based assay for the detection of spirolides was optimized for high-throughput screening and prevalidated. This method is based on the competition between 13-desmethyl spirolide C and biotin-α-bungarotoxin immobilized on a streptavidin-coated surface, for binding to nicotinic acetylcholine receptors. In this inhibition assay the amount of nAChR bound to the well surface is quantified using a specific antibody, followed by a second anti-mouse IgG antibody labeled with horseradish peroxidase (HRP). The assay protocol was optimized for 384-well microplates, which allowed a reduction of the amount of reagents per sample and an increase of the number of samples per plate versus previously published receptor-based assays. The sensitivity of the assay for 13-desmethyl spirolide C ranged from 5 to 150 ng mL(-1). The performance of the assay in scallop extracts was adequate, with an estimated detection limit for 13-desmethyl spirolide C of 50 μg kg(-1) of shellfish meat. The recovery rate of 13-desmethyl spirolide C for spiked samples with this assay was 80% and the inter-assay coefficient of variation was 8%. This 384-well microplate, chemiluminescence method can be used as a high-throughput screening assay to detect 13-desmethyl spirolide C in shellfish meat in order to reduce the number of samples to be processed through bioassays or analytical methods. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Directivity of Antenna Arrays

    Science.gov (United States)

    Bulgakova, A. A.; Gorobets, N. N.; Katrich, V. A.; Lyashchenko, V. A.

    2016-12-01

    Purpose: Theoretical investigation of directive gains of linear and planar antenna arrays depending on the distance between radiators and wavelength. Design/methodology/approach: Computing methods in applied mathematics in MathCad were used to calculate the twofold integrals of the radiation pattern over power throughout the whole space observed, defining the directivity in the most general terms. Patterns of radiators, i. e. elements of antenna arrays, are specified by mathematical models. The calculation accounts for the subintegral fast oscillating function. Findings: Calculations and analysis of a directive gain according to the number of radiators and distances between them in fractions of wavelength are made. It is shown that at the ratio of distance between radiators to wave-length being d/λ =0.5 the directivity of array of isotropic radiators is 1.5N², N - number of radiators. When increasing the d/λ to 0.65÷0.97 the directivity increases according to the law close to the linear one up to the maximum possible value for the specified number of radiators. With the increase of d/λ to the values greater than one, the directivity is significantly reduced (the “blinding” effect of non-phased antenna arrays) and its dependence with the growth of d/λ is decaying and oscillating in character. By that, the transfer function of antenna arrays has some vital difference from the transfer function of continuous antennas. Conclusions: Antenna arrays distort the waveform and spectrum of radiated and received signals as a result of irregular changes of their directivity depending on wavelength. The detected “blinding” effect of non-phased antenna arrays of large electrical dimensions must be taken into account in wideband and superwideband radio-electronics systems, especially in radio astronomy, telecommunications systems and superwideband radar.

  17. Evaluation of a new serological test for syphilis based on chemiluminescence assay in a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Aseem K Tiwari

    2015-01-01

    Full Text Available Context: Syphilis is a transfusion transmissible infections and it is mandatory to do serological test for syphilis (STS on all donor blood samples. STS is usually based on detection of antibodies against the cardiolipin-lecithin antigen or against the Treponema-specific antigen. STS with good sensitivity and specificity helps enhance blood safety and consolidation of STS along with other transfusion transmittable infections such as human immunodeficiency virus, hepatitis-C virus, and hepatitis-B virus helps in reducing the errors and enhances efficiency. Aims: This study was designed to evaluate the performance of newly introduced VITROS ® syphilis Treponema pallidum agglutination (TPA assay based on enhanced chemiluminescence principle for its analytical performance for use as a STS on donor blood samples at a tertiary care health center in National Capital Region, India. Materials and Methods: A total of 108 random blood units collected from the donors (both voluntary and replacement donors and 28 known syphilis sero-reactive samples stored at −20°C, were used to evaluate the performance of VITROS ® syphilis TPA assay based on enhanced chemiluminescence assay on VITROS ® ECiQ immunodiagnostics system along with its analytical performance in terms of its sensitivity, precision, cross-reactivity and interference studies. Results: VITROS ® syphilis TPA showed 100% sensitivity and specificity with precision (20 days study of <10% co-efficient of variation. There was no cross-reactivity with other viral and auto-immune antibodies. No interference was observed from endogenous interfering substances like free hemoglobin or fats. Conclusions: Performance of the VITROS ® syphilis TPA assay meets the requirements for its use as STS in blood bank, thus allowing consolidation with other transfusion transmittable infections screening assay on chemiluminescence platform, which is highly valuable for optimizing workflow and efficiency.

  18. Determination of dissolved Fe(II) in seawater of the western North Pacific with luminol chemiluminescence method

    Science.gov (United States)

    Obata, H.; Mase, A.; Gamo, T.; Nishioka, J.; Takeda, S.

    2010-12-01

    Determination of dissolved Fe(II) in seawater of the western North Pacific with luminol chemiluminescence method Hajime Obata, Akira Mase, Toshitaka Gamo (Atmosphere and Ocean Research Institute, University of Tokyo, Japan), Jun Nishioka (Institute of Low Temperature Science, Hokkaido University, Japan), Shigenobu Takeda (Faculty of Fisheries, Nagasaki University, Japan) Speciation of iron in the ocean is now important topics because the bioavailability of iron depends on its chemical form in seawater. However, marine biogeochemical process of Fe(II) has not been fully investigated. In this study, we determined Fe(II) in seawaters using the luminol chemiluminescence method after acidifying the samples to pH 6(Hansard and Landing, 2009). The same samples collected in the western North Pacific were analyzed by the flow chemiluminescence methods with acidification to pH 6 and without acidification. The results with both methods were almost identical. Time variation of Fe(II) in seawater after acidifying the samples to pH 6 were examined in the western North Pacific and the Bering Sea. Within 10 minutes, variations of Fe(II) were small in the open ocean waters, whereas Fe(II) concentrations increased rapidly in surface waters collected in the Bering Sea. The acidification method is not always applicable for seawater samples, especially in the marginal sea. Surface distributions of Fe(II) in the western subarctic North Pacific were investigated by using a continuous clean sampling system for surface waters. The Fe(II) concentrations ranged from temperatures. The oxidation rates were slower in the Bering Sea than those in the western North Pacific, implying that the oxidation rates were controlled not only by water temperature but also by organic compounds, such as humic substances.

  19. Kinetic Chemiluminescence as a Method for Oxidative Stress Evaluation in Examinations of Patients with Type 2 Diabetes Mellitus.

    Science.gov (United States)

    Proskurnina, E V; Polimova, A M; Sozarukova, M M; Prudnikova, M A; Ametov, A S; Vladimirov, Yu A

    2016-05-01

    We propose a new approach to evaluation of oxidative stress based on kinetic chemiluminescence: measurement of antioxidant and pro-oxidant activities of the plasma. The study included 50 patients with type 2 diabetes mellitus receiving peroral hypoglycemic therapy. In addition to the above parameters, the levels of TBA-reactive products, inflammation markers, clotting parameters, and biochemical values were studied. The new method provides information on oxidative stress in patients with type 2 diabetes mellitus irrespective of the clinical and laboratory values. The use of this method in complex with the clinical, laboratory, and instrumental studies allows comprehensive evaluation of patient's status for the diagnosis and choice of therapy.

  20. Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid-liquid-liquid microextraction.

    Science.gov (United States)

    Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos

    2013-07-25

    On-vial immobilized CdSe quantum dots (QDs) are applied for the first time as chemiluminescent probes for the detection of trace metal ions. Among 17 metal ions tested, inhibition of the chemiluminescence when CdSe QDs are oxidized by H2O2 was observed for Sb, Se and Cu. Liquid-liquid-liquid microextraction was implemented in order to improve the selectivity and sensitivity of the chemiluminescent assay. Factors influencing both the CdSe QDs/H2O2 chemiluminescent system and microextraction process were optimized for ultrasensitive detection of Sb(III) and total Sb. In order to investigate the mechanism by which Sb ions inhibit the chemiluminescence of the CdSe QDs/H2O2 system, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV-vis absorption and fluorescence measurements were performed. The selection of the appropriate CdSe QDs capping ligand was found to be a critical issue. Immobilization of QDs caused the chemiluminescence signal to be enhanced by a factor of 100 as compared to experiments carried out with QDs dispersed in the bulk aqueous phase. Under optimized conditions, the detection limit was 6 ng L(-1) Sb and the repeatability expressed as relative standard deviation (N=7) was about 1.3%. An enrichment factor of 95 was achieved within only 3 min of microextraction. Several water samples including drinking, spring, and river waters were analyzed. The proposed method was validated against CRM NWTM-27.2 fortified lake water, and a recovery study was performed with different types of water samples. Sb recoveries ranged from 94 to 105%. A fast, miniaturized and relatively inexpensive assay for selective and sensitive detection of Sb(III) and total Sb in waters is accomplished. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Intelligent Membranes: Dream or Reality?

    Directory of Open Access Journals (Sweden)

    Annarosa Gugliuzza

    2013-07-01

    Full Text Available Intelligent materials are claimed to overcome current drawbacks associated with the attainment of high standards of life, health, security and defense. Membrane-based sensors represent a category of smart systems capable of providing a large number of benefits to different markets of textiles, biomedicine, environment, chemistry, agriculture, architecture, transport and energy. Intelligent membranes can be characterized by superior sensitivity, broader dynamic range and highly sophisticated mechanisms of autorecovery. These prerogatives are regarded as the result of multi-compartment arrays, where complementary functions can be accommodated and well-integrated. Based on the mechanism of “sense to act”, stimuli-responsive membranes adapt themselves to surrounding environments, producing desired effects such as smart regulation of transport, wetting, transcription, hydrodynamics, separation, and chemical or energy conversion. Hopefully, the design of new smart devices easier to manufacture and assemble can be realized through the integration of sensing membranes with wireless networks, looking at the ambitious challenge to establish long-distance communications. Thus, the transfer of signals to collecting systems could allow continuous and real-time monitoring of data, events and/or processes.

  2. Intelligent Membranes: Dream or Reality?

    Science.gov (United States)

    Gugliuzza, Annarosa

    2013-07-15

    Intelligent materials are claimed to overcome current drawbacks associated with the attainment of high standards of life, health, security and defense. Membrane-based sensors represent a category of smart systems capable of providing a large number of benefits to different markets of textiles, biomedicine, environment, chemistry, agriculture, architecture, transport and energy. Intelligent membranes can be characterized by superior sensitivity, broader dynamic range and highly sophisticated mechanisms of autorecovery. These prerogatives are regarded as the result of multi-compartment arrays, where complementary functions can be accommodated and well-integrated. Based on the mechanism of "sense to act", stimuli-responsive membranes adapt themselves to surrounding environments, producing desired effects such as smart regulation of transport, wetting, transcription, hydrodynamics, separation, and chemical or energy conversion. Hopefully, the design of new smart devices easier to manufacture and assemble can be realized through the integration of sensing membranes with wireless networks, looking at the ambitious challenge to establish long-distance communications. Thus, the transfer of signals to collecting systems could allow continuous and real-time monitoring of data, events and/or processes.

  3. Membrane muscle function in the compliant wings of bats.

    Science.gov (United States)

    Cheney, J A; Konow, N; Middleton, K M; Breuer, K S; Roberts, T J; Giblin, E L; Swartz, S M

    2014-06-01

    Unlike flapping birds and insects, bats possess membrane wings that are more similar to many gliding mammals. The vast majority of the wing is composed of a thin compliant skin membrane stretched between the limbs, hand, and body. Membrane wings are of particular interest because they may offer many advantages to micro air vehicles. One critical feature of membrane wings is that they camber passively in response to aerodynamic load, potentially allowing for simplified wing control. However, for maximum membrane wing performance, tuning of the membrane structure to aerodynamic conditions is necessary. Bats possess an array of muscles, the plagiopatagiales proprii, embedded within the wing membrane that could serve to tune membrane stiffness, or may have alternative functions. We recorded the electromyogram from the plagiopatagiales proprii muscles of Artibeus jamaicensis, the Jamaican fruit bat, in flight at two different speeds and found that these muscles were active during downstroke. For both low- and high-speed flight, muscle activity increased between late upstroke and early downstroke and decreased at late downstroke. Thus, the array of plagiopatagiales may provide a mechanism for bats to increase wing stiffness and thereby reduce passive membrane deformation. These muscles also activate in synchrony, presumably as a means to maximize force generation, because each muscle is small and, by estimation, weak. Small differences in activation timing were observed when comparing low- and high-speed flight, which may indicate that bats modulate membrane stiffness differently depending on flight speed.

  4. Chemiluminescence from the Ca*(/sup 3/P) + SF/sub 6/ reaction: absolute cross section, photon yields, and electronic branching

    Energy Technology Data Exchange (ETDEWEB)

    Verdasco, E.; Rabanos, V.S.; Aoiz, F.J.; Urena, A.G.

    1987-04-09

    A study of the chemiluminescence under single-collision conditions of the reaction of the metastable Ca(4s4p /sup 3/P/sup 0/) of atomic calcium with SF/sup 6/ is presented. Chemiluminescence cross sections and photon yields for production of various CaF (A,B) band systems are also reported. The observed electronic branching ratio sigma/sub A//sigma/sub B/ is 4.77, and a comparison with several statistical model calculations is also discussed.

  5. Efficient Array Design for Sonotherapy

    OpenAIRE

    Stephens, Douglas N.; Kruse, Dustin E.; Ergun, Arif S.; Barnes, Stephen; Ming Lu, X.; Ferrara, Katherine

    2008-01-01

    New linear multi-row, multi-frequency arrays have been designed, constructed and tested as fully operational ultrasound probes to produce confocal imaging and therapeutic acoustic intensities with a standard commercial ultrasound imaging system. The triple-array probes and imaging system produce high quality B-mode images with a center row imaging array at 5.3 MHz, and sufficient acoustic power with dual therapeutic arrays to produce mild hyperthermia at 1.54 MHz. The therapeutic array pair i...

  6. Relativistic membranes

    Science.gov (United States)

    Hoppe, Jens

    2013-01-01

    The classical dynamics of M-dimensional extended objects arising from stationary points of the world volume swept out in space time is discussed from various points of view. A introduction to the Hamiltonian mechanics of bosonic compact M(em)branes is given, emphasing the diversity of the different formulations and gauge choices. For moving hypersurfaces, a graph description—including its nonlinear realization of Lorentz invariance—and hydrodynamic formulations (in light-cone coordinates as well as when choosing the time coordinate of a Lorentz observer as the dependent variable) are presented. A matrix regularization for M = 2 (existing for all topologies) is explained in detail for the 2-sphere, as well as multilinear formulations for M > 2. The recently found dynamical symmetry that exists for all M and related reconstruction algebras are covered, just as some explicit solutions of the level-set equations.

  7. Phased array imaging

    Science.gov (United States)

    1990-09-01

    The problem of recoverable image resolution is investigated for the case where an imaging array is used which array has an optical transfer function that may be described as consisting of islands of nonzero value in a sea of zero values. Can the missing spatial frequency information can be provided--can, in effect, a form of (interpolative) super resolution. The CLEAN algorithm used by radio astronomers suggests that this should be possible. The results developed here indicate that this can be done, with no significant price in terms of signal-to-noise ratio to be paid, and further show that a nonlinear algorithm, like CLEAN, is not required. The results show that the feasibility of doing this depends on the angular size of the object being imaged. We find that its size must be less than the inverse of the largest gap between islands in the array's optical transfer function.

  8. Metachronal waves in cellular automata: Cilia-like manipulation in actuator arrays

    OpenAIRE

    Georgilas, I.; Adamatzky, A.; Barr, D; Dudek, P; Melhuish, C

    2013-01-01

    Paramecium is covered by cilia. It uses the cilia to swim and transport food particles to its mouth. The cilia are synchronised into a collective action by propagating membrane potential and mechan- ical properties of their underlying membrane and the liquid phase en- vironment. The cilia inspired us to design and manufacture a hardware prototype of a massively parallel actuator array, emulated membrane po- tentials via a discrete excitable medium controller and mechanical prop- erties based ...

  9. Metamorphic hemispherical microphone array for three-dimensional acoustics

    Science.gov (United States)

    Biswas, Shantonu; Reiprich, Johannes; Cohrs, Thaden; Stauden, Thomas; Pezoldt, Joerg; Jacobs, Heiko O.

    2017-07-01

    This article describes the realization of a metamorphic stretchable microphone array, which can be inflated by air to morph from a planar to a hemispherical shape. The array undergoes morphological changes to adjust their receive characteristic. To realize this device, a metamorphic printed circuit board technology (m-PCB) is described. The resulting products are millimeter-thin stretchable silicone embedded and electrically interconnected electronic structures with mechanical properties, which resemble a silicone membrane. The microphone array is used to localize a sound source in a 3D space. The results of the planar orientation (resting shape), and the 3D hemispherical orientation after air inflation are compared. The inflated hemispherical microphone array proofs to be better for 3D acoustic localization and/or beam-forming.

  10. Arrays of microscopic organic LEDs for high-resolution optogenetics.

    Science.gov (United States)

    Steude, Anja; Witts, Emily C; Miles, Gareth B; Gather, Malte C

    2016-05-01

    Optogenetics is a paradigm-changing new method to study and manipulate the behavior of cells with light. Following major advances of the used genetic constructs over the last decade, the light sources required for optogenetic control are now receiving increased attention. We report a novel optogenetic illumination platform based on high-density arrays of microscopic organic light-emitting diodes (OLEDs). Because of the small dimensions of each array element (6 × 9 μm(2)) and the use of ultrathin device encapsulation, these arrays enable illumination of cells with unprecedented spatiotemporal resolution. We show that adherent eukaryotic cells readily proliferate on these arrays, and we demonstrate specific light-induced control of the ionic current across the membrane of individual live cells expressing different optogenetic constructs. Our work paves the way for the use of OLEDs for cell-specific optogenetic control in cultured neuronal networks and for acute brain slices, or as implants in vivo.

  11. Photovoltaic array performance model.

    Energy Technology Data Exchange (ETDEWEB)

    Kratochvil, Jay A.; Boyson, William Earl; King, David L.

    2004-08-01

    This document summarizes the equations and applications associated with the photovoltaic array performance model developed at Sandia National Laboratories over the last twelve years. Electrical, thermal, and optical characteristics for photovoltaic modules are included in the model, and the model is designed to use hourly solar resource and meteorological data. The versatility and accuracy of the model has been validated for flat-plate modules (all technologies) and for concentrator modules, as well as for large arrays of modules. Applications include system design and sizing, 'translation' of field performance measurements to standard reporting conditions, system performance optimization, and real-time comparison of measured versus expected system performance.

  12. Solar array welding developement

    Science.gov (United States)

    Elms, R. V., Jr.

    1974-01-01

    The present work describes parallel gap welding as used for joining solar cells to the cell interconnect system. Sample preparation, weldable cell parameter evaluation, bond scheduling, bond strength evaluation, and bonding and thermal shock tests are described. A range of weld schedule parameters - voltage, time, and force - can be identified for various cell/interconnect designs that will provide adequate bond strengths and acceptably small electrical degradation. Automation of solar array welding operations to a significant degree has been achieved in Europe and will be receiving increased attention in the U.S. to reduce solar array fabrication costs.

  13. Separation of tritiated water from water using composite membranes

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.; Nelson, D.

    1996-10-01

    Polymeric composite membranes are being developed to remove tritium from contaminated water at DOE sites. Industrial membrane systems are being developed that have proven to be energy efficient, and membrane technologies such as reverse-osmosis have been well developed for desalination and other industrial/municipal applications. Aromatic polyphosphazene membranes are being investigated because they have excellent radiological, thermal, and chemical stability. The FY 1996 effort is directed toward delineating a potential mechanism, providing a statistical approach to data acquisition, refining a mass balance, and designing a staged array module.

  14. Flow Injection Photosensitized Chemiluminescence of Luminol with Cu(II-Rose Bengal: Mechanistic Approach and Vitamin A and C Determination

    Directory of Open Access Journals (Sweden)

    Muhammad Asgher

    2014-01-01

    Full Text Available Rose Bengal photosensitized flow injection chemiluminescence method is reported using luminol-Cu(II for the determination of vitamins A and C in pharmaceutical formulations. The reaction is based on the enhancement effect of analyte in the production of anion radicals of Rose Bengal (RB•− which rapidly interact with dissolved oxygen and generate superoxide anions radicals (O2•− and hydrogen peroxide (H2O2. Highly reactive hydroxyl radicals (•OH were produced via dismutation of H2O2 by catalyst (Cu2+. The generated superoxide anions radicals and hydroxyl radicals thus oxidize luminol in alkaline medium to generate strong chemiluminescence. The limit of detection (3s of the blank, n=6 of vitamins A and C and RB was found to be 0.008, 0.005, and 0.05 μg mL−1, respectively. The sample throughput of 70 h−1 for vitamins A and C and 30 h−1 for RB was found. Calibration curve was linear in the range of 0.05–15, 0.01–20, and 0.1–50 μg mL−1 for vitamins A and C and RB, respectively, with relative standard deviations (RSDs; n=3 in the range 1.6–3.6%. The method was successfully applied to pharmaceutical formulations and the results obtained were in good agreement with the labeled values.

  15. Characterization of Diesel and Gasoline Compression Ignition Combustion in a Rapid Compression-Expansion Machine using OH* Chemiluminescence Imaging

    Science.gov (United States)

    Krishnan, Sundar Rajan; Srinivasan, Kalyan Kumar; Stegmeir, Matthew

    2015-11-01

    Direct-injection compression ignition combustion of diesel and gasoline were studied in a rapid compression-expansion machine (RCEM) using high-speed OH* chemiluminescence imaging. The RCEM (bore = 84 mm, stroke = 110-250 mm) was used to simulate engine-like operating conditions at the start of fuel injection. The fuels were supplied by a high-pressure fuel cart with an air-over-fuel pressure amplification system capable of providing fuel injection pressures up to 2000 bar. A production diesel fuel injector was modified to provide a single fuel spray for both diesel and gasoline operation. Time-resolved combustion pressure in the RCEM was measured using a Kistler piezoelectric pressure transducer mounted on the cylinder head and the instantaneous piston displacement was measured using an inductive linear displacement sensor (0.05 mm resolution). Time-resolved, line-of-sight OH* chemiluminescence images were obtained using a Phantom V611 CMOS camera (20.9 kHz @ 512 x 512 pixel resolution, ~ 48 μs time resolution) coupled with a short wave pass filter (cut-off ~ 348 nm). The instantaneous OH* distributions, which indicate high temperature flame regions within the combustion chamber, were used to discern the characteristic differences between diesel and gasoline compression ignition combustion. The authors gratefully acknowledge facilities support for the present work from the Energy Institute at Mississippi State University.

  16. Determination of neurotransmitters and their metabolites using one- and two-dimensional liquid chromatography with acidic potassium permanganate chemiluminescence detection.

    Science.gov (United States)

    Holland, Brendan J; Conlan, Xavier A; Stevenson, Paul G; Tye, Susannah; Reker, Ashlie; Barnett, Neil W; Adcock, Jacqui L; Francis, Paul S

    2014-09-01

    High-performance liquid chromatography with chemiluminescence detection based on the reaction with acidic potassium permanganate and formaldehyde was explored for the determination of neurotransmitters and their metabolites. The neurotransmitters norepinephrine and dopamine were quantified in the left and right hemispheres of rat hippocampus, nucleus accumbens and prefrontal cortex, and the metabolites vanillylmandelic acid, 3,4-dihydrophenylacetic acid, 5-hydroxyindole-3-acetic acid and homovanillic acid were identified in human urine. Under optimised chemiluminescence reagent conditions, the limits of detection for these analytes ranged from 2.5 × 10(-8) to 2.5 × 10(-7) M. For the determination of neurotransmitter metabolites in urine, a two-dimensional high-performance liquid chromatography (2D-HPLC) separation operated in heart-cutting mode was developed to overcome the peak capacity limitations of the one-dimensional separation. This approach provided the greater separation power of 2D-HPLC with analysis times comparable to conventional one-dimensional separations.

  17. The Relationship between Nitrogen Dioxide Concentrations in the Atmosphere Measured by the Sodium Arsenite Method and the Chemiluminescence Method

    Directory of Open Access Journals (Sweden)

    Sivapan Choo-in

    2015-01-01

    Full Text Available The relationship between the nitrogen dioxide concentration measured by the Sodium Arsenite method and the Chemiluminescence method, aimed at developing a device for measuring nitrogen dioxide in the atmosphere by means of the Sodium Arsenite method and studying the correlation between the concentration of nitrogen dioxide in the atmosphere which was measured by Sodium Arsenite method and the Chemiluminescense method done by the Pollution Control Department, Thailand. In this research sampling collection of nitrogen dioxide concentration in various conditions by the Sodium Arsenite method was compared with that by the Chemiluminescence method done by the pollution control Department at the Air Quality Measurement Station at the Din Dang district, Bangkok. It was done by one-hour average value totaling of thirty data. The research result found that the sampling collection with the flowing rate of 160 ml/min and the absorption reagent with mixture of 0.2 M sodium hydroxide and 0.015 M sodium arsenite had the highest relationship to the measurement result done by the Pollution Control Department at a statistical significance level of 0.05 with the value of correlation coefficient at 0.658 which had a high relation.

  18. Parabens determination in cosmetic and personal care products exploiting a multi-syringe chromatographic (MSC) system and chemiluminescent detection.

    Science.gov (United States)

    Rodas, Melisa; Portugal, Lindomar A; Avivar, Jessica; Estela, José Manuel; Cerdà, Víctor

    2015-10-01

    Parabens are widely used in dairy products, such as in cosmetics and personal care products. Thus, in this work a multi-syringe chromatographic (MSC) system is proposed for the first time for the determination of four parabens: methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) in cosmetics and personal care products, as a simpler, practical, and low cost alternative to HPLC methods. Separation was achieved using a 5mm-long precolumn of reversed phase C18 and multi-isocratic separation, i.e. using two consecutive mobile phases, 12:88 acetonitrile:water and 28:72 acetonitrile:water. The use of a multi-syringe buret allowed the easy implementation of chemiluminescent (CL) detection after separation. The chemiluminescent detection is based on the reduction of Ce(IV) by p-hydroxybenzoic acid, product of the acid hydrolysis of parabens, to excite rhodamine 6G (Rho 6G) and measure the resulting light emission. Multivariate designs combined with the concepts of multiple response treatments and desirability functions have been employed to simultaneously optimize and evaluate the responses. The optimized method has proved to be sensitive and precise, obtaining limits of detection between 20 and 40 µg L(-1) and RSD <4.9% in all cases. The method was satisfactorily applied to cosmetics and personal care products, obtaining no significant differences at a confidence level of 95% comparing with the HPLC reference method. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A metal (Co)-organic framework-based chemiluminescence system for selective detection of L-cysteine.

    Science.gov (United States)

    Yang, Na; Song, Hongjie; Wan, Xiangyu; Fan, Xiaoqing; Su, Yingying; Lv, Yi

    2015-04-21

    A metal (Co)-Organic Framework (Co-MOF) was first found to catalyze the chemiluminescence (CL) of luminol. On the basis of X-ray photoelectron spectroscopy, powder X-ray diffraction, CL spectral, UV-visible absorption spectral, and electron spin resonance (ESR) spectral studies, as well as the research of the influence of various free radical scavengers, a possible CL mechanism was proposed. The enhanced CL might be attributed to the formation of a peroxide analogous complex between the oxygen-related radicals and the active metal site of the Co-MOF material. The established Co-MOF-luminol CL system was successfully applied to determine L-cysteine (CySH), based on the selective and sensitive enhancing effect of CySH on this CL system. Under the optimized conditions, CySH was selectively detected in the range 0.1-10 μM with a detection limit of 18 nM. This novel CL system obviously gives impetus to the new research field of metal-organic frameworks (MOFs) in chemiluminescence.

  20. Determination of phenolic compounds using high-performance liquid chromatography with Ce{sup 4+}-Tween 20 chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Cui Hua; Zhou Jian; Xu Feng; Lai Chunze; Wan Guohui

    2004-05-31

    A novel method for the simultaneous determination of phenolic compounds such as salicylic acid, resorcinol, phloroglucinol, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, and m-nitrophenol by high-performance liquid chromatography (HPLC) coupled with chemiluminescence (CL) detection was developed. The procedure was based on the chemiluminescent enhancement by phenolic compounds of the cerium(IV)-Tween 20 system in a sulfuric acid medium. The separation was carried out with an isocratic elution or with a gradient elution using a mixture of methanol and 1.5% acetic acid. For six phenolic compounds, the detection limits (3{sigma}) were in the range 1.40-5.02 ng/ml and the relative standard deviations (n=11) for the determination of 0.1 {mu}g/ml compounds were in the range 1.9-2.9%. The CL reaction was well compatible with the mobile phase of HPLC, no baseline drift often occurred in HPLC-CL detection was observed with a gradient elution. The method has been successfully applied to the determination of salicylic acid and resorcinol in Dermatitis Clear Tincture and p-hydroxybenzoic acid in apple juices.

  1. Eco-friendly synthesis of gelatin-capped bimetallic Au-Ag nanoparticles for chemiluminescence detection of anticancer raloxifene hydrochloride.

    Science.gov (United States)

    Alarfaj, Nawal A; El-Tohamy, Maha F

    2016-09-01

    This study described the utility of green analytical chemistry in the synthesis of gelatin-capped silver, gold and bimetallic gold-silver nanoparticles (NPs). The preparation of nanoparticles was based on the reaction of silver nitrate or chlorauric acid with a 1.0 wt% aqueous gelatin solution at 50°C. The gelatin-capped silver, gold and bimetallic NPs were characterized using transmission electron microscopy, UV-vis, X-ray diffraction and Fourier transform infrared spectroscopy, and were used to enhance a sensitive sequential injection chemiluminescence luminol-potassium ferricyanide system for determination of the anticancer drug raloxifene hydrochloride. The developed method is eco-friendly and sensitive for chemiluminescence detection of the selected drug in its bulk powder, pharmaceutical injections and biosamples. After optimizing the conditions, a linear relationship in the range of 1.0 × 10(-9) to 1.0 × 10(-1)  mol/L was obtained with a limit of detection of 5.0 × 10(-10)  mol/L and a limit of quantification of 1.0 × 10(-9)  mol/L. Statistical treatment and method validation were performed based on ICH guidelines. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Luminol functionalized gold nanoparticles as colorimetric and chemiluminescent probes for visual, label free, highly sensitive and selective detection of minocycline

    Science.gov (United States)

    He, Yi; Peng, Rufang

    2014-11-01

    In this work, luminol functionalized gold nanoparticles (LuAuNPs) were used as colorimetric and chemiluminescent probes for visual, label free, sensitive and selective detection of minocycline (MC). The LuAuNPs were prepared by simple one-pot reduction of HAuCl4 with luminol, which exhibited a good chemiluminescence (CL) activity owing to the presence of luminol molecules on their surface and surface plasmon resonance absorption. In the absence of MC, the color of LuAuNPs was wine red and their size was relatively small (˜25 nm), which could react with silver nitrate, producing a strong CL emission. Upon the addition of MC at acidic buffer solutions, the electrostatic interaction between positively charged MC and negatively charged LuAuNPs caused the aggregation of LuAuNPs, generating a purple or blue color. Simultaneously, the aggregated LuAuNPs did not effectively react with silver nitrate, producing a weak CL emission. The signal change was linearly dependent on the logarithm of MC concentration in the range from 30 ng to 1.0 μg for colorimetric detection and from 10 ng to 1.0 μg for CL detection. With colorimetry, a detection limit of 22 ng was achieved, while the detection limit for CL detection modality was 9.7 ng.

  3. Structural features of aquaporin 4 supporting the formation of arrays and junctions in biomembranes.

    Science.gov (United States)

    Höfinger, Siegfried; Yamamoto, Eiji; Hirano, Yoshinori; Zerbetto, Francesco; Narumi, Tetsu; Yasuoka, Kenji; Yasui, Masato

    2012-09-01

    A limited class of aquaporins has been described to form regular arrays and junctions in membranes. The biological significance of these structures, however, remains uncertain. Here we analyze the underlying physical principles with the help of a computational procedure that takes into account protein-protein as well as protein-membrane interactions. Experimentally observed array/junction structures are systematically (dis)assembled and major driving forces identified. Aquaporin 4 was found to be markedly different from the non-junction forming aquaporin 1. The environmental stabilization resulting from embedding into the biomembrane was identified as the main driving force. This highlights the role of protein-membrane interactions in aquaporin 4. Analysis of the type presented here can help to decipher the biological role of membrane arrays and junctions formed by aquaporin. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Hollow polymer microneedles array resistance and insertion tests.

    Science.gov (United States)

    Lhernould, Marion Sausse; Deleers, Michel; Delchambre, Alain

    2015-03-01

    Microneedles are developed in order to become the transdermal administration method of the future. They however still face numerous challenges. This paper addresses the challenge to effectively insert the microneedle arrays into membranes. A recently proposed model membrane and test method for microneedles insertion, published in International Journal of Pharmaceutics, is used in this aim. A moulded 4 by 4 hollow polymer microneedle array developed at the Université Libre de Bruxelles is tested for insertion using this model. Results show that the array is extremely resistant to insertion, it can withstand very high forces and even multiple insertions without blunting. Different insertion tests were performed on a folded in eight Parafilm® film because it exhibits excellent similarity to porcine skin. The insertion force, the insertion speed and the holding time of the array against membranes must be optimised in order to get efficient reliable insertions at, at least, 500μm depth. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Array Theory and Nial

    DEFF Research Database (Denmark)

    Falster, Peter; Jenkins, Michael

    1999-01-01

    This report is the result of collaboration between the authors during the first 8 months of 1999 when M. Jenkins was visiting professor at DTU. The report documents the development of a tool for the investigation of array theory concepts and in particular presents various approaches to choose...

  6. TANGO Array. 2. Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Bauleo, P. E-mail: pablo.bauleo@colostate.edu; Bonifazi, C.; Filevich, A

    2004-01-11

    The angular and energy resolutions of the TANGO Array were obtained using extensive Monte Carlo simulations performed with a double purpose: (1) to determine the appropriate parameters for the array fitting to the desired range of sensitivity (the knee energy region), and (2) to construct a reliable shower database required for reference in the analysis of experimental data. The AIRES code, with the SIBYLL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (assuming protons and iron nuclei), with energies ranging from 10{sup 14} to 10{sup 18} eV. These data were fed into a realistic code which simulates the response of the detectors (water Cherenkov detectors), including the electronics, pickup noise, and the signal attenuation in the connecting cables. The trigger stage was considered in the simulations in order to estimate the trigger efficiency of the array and to verify the accuracy of the reconstruction codes. This paper delineates the simulations performed to obtain the expected behavior of the array, and describes the simulated data. The results of these simulations suggest that we can expect an error in the energy of the primary cosmic-ray of {approx}60% of the estimated value and that the error in the measurement of the direction of arrival can be estimated as {approx}4 deg. . The present simulations also indicate that unambiguous assignments of the primary energy cannot be obtained because of the uncertainty in the nature of the primary cosmic ray.

  7. TANGO Array.. 2. Simulations

    Science.gov (United States)

    Bauleo, P.; Bonifazi, C.; Filevich, A.

    2004-01-01

    The angular and energy resolutions of the TANGO Array were obtained using extensive Monte Carlo simulations performed with a double purpose: (1) to determine the appropriate parameters for the array fitting to the desired range of sensitivity (the knee energy region), and (2) to construct a reliable shower database required for reference in the analysis of experimental data. The AIRES code, with the SIBYLL hadronic collision package, was used to simulate Extended Air Showers produced by primary cosmic rays (assuming protons and iron nuclei), with energies ranging from 10 14 to 10 18 eV. These data were fed into a realistic code which simulates the response of the detectors (water Cherenkov detectors), including the electronics, pickup noise, and the signal attenuation in the connecting cables. The trigger stage was considered in the simulations in order to estimate the trigger efficiency of the array and to verify the accuracy of the reconstruction codes. This paper delineates the simulations performed to obtain the expected behavior of the array, and describes the simulated data. The results of these simulations suggest that we can expect an error in the energy of the primary cosmic-ray of ˜60% of the estimated value and that the error in the measurement of the direction of arrival can be estimated as ˜4°. The present simulations also indicate that unambiguous assignments of the primary energy cannot be obtained because of the uncertainty in the nature of the primary cosmic ray.

  8. Array processors in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, N.S.

    1980-01-01

    The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

  9. State-to-state chemiluminescence in reactions of Mn atoms with S2Cl2.

    Science.gov (United States)

    Khanniche, Sarah; Levy, Martin Richard

    2011-10-21

    A combined experimental and time-dependent density functional theory (TDDFT) investigation of the title reaction is presented. Both 'hot' and 'cold' laser-ablated Mn atom beams have been employed to determine the translational excitation functions for production of MnCl*(c(5)Σ(+), d(5)Π, e(5)Δ, e(5)Σ(+), A(7)Π). Analysis in terms of the multiple line-of-centres approach shows that the 'hot' results are dominated by reactions of the second metastable state of Mn, z(8)P(J), all with very low thresholds; while the first metastable state, a(6)D(J), and the ground state, a(6)S, are the precursors in the 'cold' results, all with significant excess barriers. The post-threshold behaviour of most z(8)P(J) and a(6)D(J) reaction channels implies that the transition states shift forward with increasing collision energy. The TDDFT calculations suggest that, while Mn*(z(8)P(J), a(6)D(J)) insertion into the S-Cl bond is facile, the observed chemiluminescence channels mostly derive from abstraction in a preferred linear Mn-Cl-S configuration, and that the low z(8)P(J) thresholds originate from attractive but excited reagent potentials which either reach a seam of interactions in the product valley or (in the c(5)Σ(+) case) lead to an octet potential very close in energy to the product sextet. The excess barriers in the Mn*(a(6)D(J)) and Mn(a(6)S) reactions appear for the most part to derive from exit channel mixing with lower-lying product potentials. The observed transition state shifts are consistent with the system being forced to ride up the repulsive wall of the entrance valley as collision energy increases, the location of that wall being different for the z(8)P(J) and a(6)D(J) cases. This journal is © the Owner Societies 2011

  10. Integrated strain array for cellular mechanobiology studies

    Science.gov (United States)

    Simmons, C. S.; Sim, J. Y.; Baechtold, P.; Gonzalez, A.; Chung, C.; Borghi, N.; Pruitt, B. L.

    2011-05-01

    We have developed an integrated strain array for cell culture enabling high-throughput mechano-transduction studies. Biocompatible cell culture chambers were integrated with an acrylic pneumatic compartment and microprocessor-based control system. Each element of the array consists of a deformable membrane supported by a cylindrical pillar within a well. For user-prescribed waveforms, the annular region of the deformable membrane is pulled into the well around the pillar under vacuum, causing the pillar-supported region with cultured cells to be stretched biaxially. The optically clear device and pillar-based mechanism of operation enables imaging on standard laboratory microscopes. Straightforward fabrication utilizes off-the-shelf components, soft lithography techniques in polydimethylsiloxane and laser ablation of acrylic sheets. Proof of compatibility with basic biological assays and standard imaging equipment were accomplished by straining C2C12 skeletal myoblasts on the device for 6 h. At higher strains, cells and actin stress fibers realign with a circumferential preference.

  11. Anti-glomerular basement membrane glomerulonephritis following nintedanib for idiopathic pulmonary fibrosis: a case report.

    Science.gov (United States)

    Ismail, Ibrahim; Nigam, Sonu; Parnham, Alan; Srinivasa, Vinay

    2017-08-06

    We report a previously unrecognized and unreported case of a patient with anti-glomerular basement membrane glomerulonephritis following nintedanib, an orally active small molecule tyrosine kinase inhibitor. A 59-year-old Caucasian woman with a history of idiopathic pulmonary fibrosis presented with severe acute kidney injury (creatinine 285 umol/L) secondary to anti-glomerular basement membrane glomerulonephritis disease 4 months after commencement of nintedanib. She had hematuria with red blood cell casts, nephrotic range proteinuria (3.5g/24 hours) and significantly elevated anti-glomerular basement membrane glomerulonephritis titers at 860 chemiluminescent units. A kidney biopsy confirmed severe crescentic glomerulonephritis with linear immunoglobulin G deposition in glomerular basement membrane. Despite the commencement of treatment with plasma exchange and cyclophosphamide, she remained dialysis dependent. Nintedanib was discontinued. Onset of acute anti-glomerular basement membrane glomerulonephritis was found to be associated with recent nintedanib use suggesting that nintedanib may be a potential trigger for anti-glomerular basement membrane glomerulonephritis. This case highlights the importance of close monitoring of patients receiving new targeted therapies. Management of novel targeted agents in patients receiving dialysis is challenging because of the scarcity of specific data.

  12. Anaerobic membrane bioreactors: Are membranes really necessary?

    NARCIS (Netherlands)

    Davila, M.; Kassab, G.; Klapwijk, A.; Lier, van J.B.

    2008-01-01

    Membranes themselves represent a significant cost for the full scale application of anaerobic membrane bioreactors (AnMBR). The possibility of operating an AnMBR with a self-forming dynamic membrane generated by the substances present in the reactor liquor would translate into an important saving. A

  13. Solid-state chemiluminescence assay for ultrasensitive detection of antimony using on-vial immobilization of CdSe quantum dots combined with liquid–liquid–liquid microextraction

    Energy Technology Data Exchange (ETDEWEB)

    Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos, E-mail: bendicho@uvigo.es

    2013-07-25

    Graphical abstract: -- Highlights: •Solid-state chemiluminescence based on CdSe QDs was developed. •QDs immobilization in a vial was achieved in a simple and fast way. •Antimony detection was achieved by inhibition of the CdSe QDs/H{sub 2}O{sub 2} CL reaction. •LLLME allowed improving the selectivity and sensitivity of the CL assay. •The capping ligand played a critical role in the selectivity of the CL system. -- Abstract: On-vial immobilized CdSe quantum dots (QDs) are applied for the first time as chemiluminescent probes for the detection of trace metal ions. Among 17 metal ions tested, inhibition of the chemiluminescence when CdSe QDs are oxidized by H{sub 2}O{sub 2} was observed for Sb, Se and Cu. Liquid–liquid–liquid microextraction was implemented in order to improve the selectivity and sensitivity of the chemiluminescent assay. Factors influencing both the CdSe QDs/H{sub 2}O{sub 2} chemiluminescent system and microextraction process were optimized for ultrasensitive detection of Sb(III) and total Sb. In order to investigate the mechanism by which Sb ions inhibit the chemiluminescence of the CdSe QDs/H{sub 2}O{sub 2} system, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), UV–vis absorption and fluorescence measurements were performed. The selection of the appropriate CdSe QDs capping ligand was found to be a critical issue. Immobilization of QDs caused the chemiluminescence signal to be enhanced by a factor of 100 as compared to experiments carried out with QDs dispersed in the bulk aqueous phase. Under optimized conditions, the detection limit was 6 ng L{sup −1} Sb and the repeatability expressed as relative standard deviation (N = 7) was about 1.3%. An enrichment factor of 95 was achieved within only 3 min of microextraction. Several water samples including drinking, spring, and river waters were analyzed. The proposed method was validated against CRM NWTM-27.2 fortified lake water, and a recovery study was

  14. Antenna-coupled arrays of voltage-biased superconducting bolometers

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Michael J.; Lee, Adrian T.; Richards, P.L.; Schwan, D.; Skidmore, J.T.; Smith, A.D.; Spieler, H.; Yoon, Jongsoo

    2001-07-23

    We report on the development of antenna-coupled Voltage-biased Superconducting Bolometers (VSBs) which use Transition-edge Sensors (TES). Antenna coupling can greatly simplify the fabrication of large multi-frequency bolometer arrays compared to horn-coupled techniques. This simplification can make it practical to implement 1000+ element arrays that fill the focal plane of mm/sub-mm wave telescopes. We have designed a prototype device with a double-slot dipole antenna, integrated band-defining filters, and a membrane-suspended bolometer. A test chip has been constructed and will be tested shortly.

  15. Concurrent array-based queue

    Science.gov (United States)

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-01-06

    According to one embodiment, a method for implementing an array-based queue in memory of a memory system that includes a controller includes configuring, in the memory, metadata of the array-based queue. The configuring comprises defining, in metadata, an array start location in the memory for the array-based queue, defining, in the metadata, an array size for the array-based queue, defining, in the metadata, a queue top for the array-based queue and defining, in the metadata, a queue bottom for the array-based queue. The method also includes the controller serving a request for an operation on the queue, the request providing the location in the memory of the metadata of the queue.

  16. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  17. Microwave-Driven Multifunctional Capability of Membrane Structures

    Science.gov (United States)

    Choi, Sang H.; Chu, Sang-Hyong; Song, Kyo D.; King, Glen C.

    2002-01-01

    A large, ultra lightweight space structure, such as solar sails and Gossamer spacecrafts, requires a distributed power source to alleviate wire networks, unlike the localized on-board power infrastructures typically found in most small spacecrafts. The concept of microwave-driven multifunctional capability for membrane structures is envisioned as the best option to alleviate the complexity associated with hard-wired control circuitry and on-board power infrastructures. A rectenna array based on a patch configuration for high voltage output was developed to drive membrane actuators, sensors, probes, or other devices. Networked patch rectenna array receives and converts microwave power into a DC power for an array of smart actuators. To use microwave power effectively, the concept of a power allocation and distribution (PAD) circuit is adopted for networking a rectenna/actuator patch array. The use of patch rectennas adds a significant amount of rigidity to membrane flexibility and they are relatively heavy. A dipole rectenna array (DRA) appears to be ideal for thin-film membrane structures, since DRA is flexible and light. Preliminary design and fabrication of PAD circuitry that consists of a few nodal elements were made for laboratory testing. The networked actuators were tested to correlate the network coupling effect, power allocation and distribution, and response time.

  18. Timed arrays wideband and time varying antenna arrays

    CERN Document Server

    Haupt, Randy L

    2015-01-01

    Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The auth

  19. Design of HIFU CMUT Arrays for Treatment of Liver and Renal Cancer

    Science.gov (United States)

    Wong, Serena H.; Ergun, Arif Sanli; Yaralioglu, Goksen G.; Oralkan, Omer; Kupnik, Mario; Pauly, Kim Butts; Khuri-Yakub, B. T.

    2007-05-01

    We present the development of a capacitive micromachined ultrasonic transducer (CMUT) array for noninvasive focused ultrasound ablation of lower abdominal cancers under MR-guidance. While piezoelectric transducers have been traditionally used for HIFU, recent advances in CMUT design have made them highly competitive. Not only are CMUTs cost effective, they allow fabrication flexibility and advantages in efficiency and bandwidth. Current imaging CMUTs have shown capability of HIFU operation through high power and continuous wave operation. In this paper, we will present the development of CMUT membranes designed specifically for HIFU. These membranes are piston-like membranes fabricated by placing a thick layer of silicon or gold at the center of the membrane. The width of the piston layer is usually 60-85% of the membrane width and allows the membrane mass and elasticity to be controlled independently. It also increases the average displacement and average output pressure of the membrane. We patterned these CMUT membranes into an 8 element, 3.5 cm concentric array. We simulated the heating patterns of this array to show it is capable of producing lesions of 5 mm in diameter within 20-30 seconds, which can be imaged using our MR detection software.

  20. Recurrent Memory Array Structures

    OpenAIRE

    Rocki, Kamil

    2016-01-01

    The following report introduces ideas augmenting standard Long Short Term Memory (LSTM) architecture with multiple memory cells per hidden unit in order to improve its generalization capabilities. It considers both deterministic and stochastic variants of memory operation. It is shown that the nondeterministic Array-LSTM approach improves state-of-the-art performance on character level text prediction achieving 1.402 BPC on enwik8 dataset. Furthermore, this report estabilishes baseline neural...

  1. Solar collector array

    Science.gov (United States)

    Hall, John Champlin; Martins, Guy Lawrence

    2015-09-06

    A method and apparatus for efficient manufacture, assembly and production of solar energy. In one aspect, the apparatus may include a number of modular solar receiver assemblies that may be separately manufactured, assembled and individually inserted into a solar collector array housing shaped to receive a plurality of solar receivers. The housing may include optical elements for focusing light onto the individual receivers, and a circuit for electrically connecting the solar receivers.

  2. 3D multifunctional integumentary membranes for spatiotemporal cardiac measurements and stimulation across the entire epicardium

    National Research Council Canada - National Science Library

    Xu, Lizhi; Gutbrod, Sarah R; Bonifas, Andrew P; Su, Yewang; Sulkin, Matthew S; Lu, Nanshu; Chung, Hyun-Joong; Jang, Kyung-In; Liu, Zhuangjian; Ying, Ming; Lu, Chi; Webb, R Chad; Kim, Jong-Seon; Laughner, Jacob I; Cheng, Huanyu; Liu, Yuhao; Ameen, Abid; Jeong, Jae-Woong; Kim, Gwang-Tae; Huang, Yonggang; Efimov, Igor R; Rogers, John A

    2014-01-01

    .... Here we create 3D elastic membranes shaped precisely to match the epicardium of the heart via the use of 3D printing, as a platform for deformable arrays of multifunctional sensors, electronic...

  3. Spaceborne Processor Array

    Science.gov (United States)

    Chow, Edward T.; Schatzel, Donald V.; Whitaker, William D.; Sterling, Thomas

    2008-01-01

    A Spaceborne Processor Array in Multifunctional Structure (SPAMS) can lower the total mass of the electronic and structural overhead of spacecraft, resulting in reduced launch costs, while increasing the science return through dynamic onboard computing. SPAMS integrates the multifunctional structure (MFS) and the Gilgamesh Memory, Intelligence, and Network Device (MIND) multi-core in-memory computer architecture into a single-system super-architecture. This transforms every inch of a spacecraft into a sharable, interconnected, smart computing element to increase computing performance while simultaneously reducing mass. The MIND in-memory architecture provides a foundation for high-performance, low-power, and fault-tolerant computing. The MIND chip has an internal structure that includes memory, processing, and communication functionality. The Gilgamesh is a scalable system comprising multiple MIND chips interconnected to operate as a single, tightly coupled, parallel computer. The array of MIND components shares a global, virtual name space for program variables and tasks that are allocated at run time to the distributed physical memory and processing resources. Individual processor- memory nodes can be activated or powered down at run time to provide active power management and to configure around faults. A SPAMS system is comprised of a distributed Gilgamesh array built into MFS, interfaces into instrument and communication subsystems, a mass storage interface, and a radiation-hardened flight computer.

  4. Solar array construction

    Science.gov (United States)

    Crouthamel, Marvin S.; Coyle, Peter J.

    1982-01-01

    An interconnect tab on each cell of a first set of circular solar cells connects that cell in series with an adjacent cell in the set. This set of cells is arranged in alternate columns and rows of an array and a second set of similar cells is arranged in the remaining alternate columns and rows of the array. Three interconnect tabs on each solar cell of the said second set are employed to connect the cells of the second set to one another, in series and to connect the cells of the second set to those of the first set in parallel. Some tabs (making parallel connections) connect the same surface regions of adjacent cells to one another and others (making series connections) connect a surface region of one cell to the opposite surface region of an adjacent cell; however, the tabs are so positioned that the array may be easily assembled by depositing the cells in a certain sequence and in proper orientation.

  5. Array processor architecture

    Science.gov (United States)

    Barnes, George H. (Inventor); Lundstrom, Stephen F. (Inventor); Shafer, Philip E. (Inventor)

    1983-01-01

    A high speed parallel array data processing architecture fashioned under a computational envelope approach includes a data base memory for secondary storage of programs and data, and a plurality of memory modules interconnected to a plurality of processing modules by a connection network of the Omega gender. Programs and data are fed from the data base memory to the plurality of memory modules and from hence the programs are fed through the connection network to the array of processors (one copy of each program for each processor). Execution of the programs occur with the processors operating normally quite independently of each other in a multiprocessing fashion. For data dependent operations and other suitable operations, all processors are instructed to finish one given task or program branch before all are instructed to proceed in parallel processing fashion on the next instruction. Even when functioning in the parallel processing mode however, the processors are not locked-step but execute their own copy of the program individually unless or until another overall processor array synchronization instruction is issued.

  6. CHEMILUMINESCENT ACTIVITY OF NEUTROPHILIC GRANULOCYTES IN PROGRESSION OF OBSTRUCTIVE JAUNDICE DEPENDING ON ITS ORIGIN AND BILIRUBIN LEVELS

    Directory of Open Access Journals (Sweden)

    O. V. Smirnova

    2016-01-01

    Full Text Available Mechanical jaundice (MJ is a severe pathological condition, caused by obstruction of the bile ducts, requiring immediate surgical intervention. Etiologically, MJ can be of benign (60-80% of the cases, or malignant origin. MJ progression depends on the underlying pathology, and, moreover, on bilirubin levels. Focal inflammation in affected area represents a significant mechanism of the MJ progression. Neutrophilic granulocytes, are primarily involved into the immune response, i.e., pathogen elimination. Hence, the MJ progression may depend on their functional activity. In this context, the aim of our study was to investigate chemiluminescent activity of neutrophil granulocytes in progression of MJ, depending on the bilirubin levels and origin of the jaundice. All the MJ patients showed altered chemiluminescent activity of granulocytes. Both spontaneous and induced chemiluminescence (CL intensity was decreased in the patients with gallstoneassociated MJ. Meanwhile, the CL intensity did not change in MJ caused by benign tumors (BTP. An increased activation index reflected higher induced activity of phagocytes. In patients with MJ of malignant origin, the largest number of changes was found, i.e., an increase in the induced luminescence intensity and higher activation indexes were revealed. The MJ progression depends on blood bilirubin levels. All the patients with gallstone-related MJ exhibited a decrease in spontaneous and induced CL activity of the neutrophils. In cases of BTP-caused MJ, the indexes of spontaneous and induced CL decreased at the bilirubin levels of 60 to 200 mmol/L, with increased activation index suggesting elevated induced activity over its spontaneous levels. In patients with MJ and bilirubin levels >200 mmol/L, distinct unidirectional changes in the granulocyte activation were observed, with increased spontaneous and induced CL intensity. In patients with MJ caused by malignancies with bilirubin levels <60

  7. Composite sensor membrane

    Science.gov (United States)

    Majumdar, Arun [Orinda, CA; Satyanarayana, Srinath [Berkeley, CA; Yue, Min [Albany, CA

    2008-03-18

    A sensor may include a membrane to deflect in response to a change in surface stress, where a layer on the membrane is to couple one or more probe molecules with the membrane. The membrane may deflect when a target molecule reacts with one or more probe molecules.

  8. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  9. Photovoltaic array with minimally penetrating rooftop support system

    Science.gov (United States)

    Lenox, Carl J.S.

    2012-10-23

    A photovoltaic array including a plurality of photovoltaic assemblies and a plurality of mounting units. The mounting units each include an elongate rail and a plurality of leg assemblies. The rail is sized and configured to maintain a portion of at least two of the photovoltaic assemblies, with the leg assemblies extending from the rail in a spaced-apart fashion and terminating in a foot for placement against a rooftop structure for minimally penetration installation. Further, at least one of the leg assemblies can include a retractable leg. When the photovoltaic array is installed to a rooftop structure including a membrane intermittently secured to a rooftop deck, the retractable leg accommodates upward billowing of the membrane under windy conditions.

  10. Nanostructured micro-electrode arrays for electrophysiological measurements

    DEFF Research Database (Denmark)

    Wierzbicki, Rafal Dominik

    -channel and intracellular measurements. In applications that require multichannel measurements, this approach is, however, impractical and planar arrays of metal electrodes are usually employed. Yet, with planar geometry, they allow extracellular measurements only. Several approaches to developing functional three......-dimensional electrode arrays with features able to penetrate cell membrane are currently investigated by various groups. While a number of experimental setups have been recently developed, the question remains whether the nanostructure is in fact penetrating the cellular membrane, and if the measurements are indeed...... intracellular. In my thesis, I approach the problem from two angles. Firstly, I worked on the development of stable and functional three-dimensional electrodes with focus on their electric connectivity, insulation, cell-penetration ability and investigated their electrochemical performance, biocompatibility...

  11. Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere

    Science.gov (United States)

    Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

    1971-01-01

    By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

  12. Determination of itopride hydrochloride by high-performance liquid chromatography with Ru(bpy)3(2+) electrogenerated chemiluminescence detection.

    Science.gov (United States)

    Sun, Yonghua; Zhang, Zhujun; Xi, Zhijun; Shi, Zuolong; Tian, Wei

    2009-08-26

    In this work, a stable electrogenerated chemiluminescence (ECL) detector was developed. The detector was prepared by packing cation-exchanged resin particles in a glass tube, followed by inserting Pt wires (working electrode) in this tube and sealing. The leakage of Ru(bpy)(3)(2+) can be compensated by adding a small amount of Ru(bpy)(3)(2+) into solution phase. Coupled with high-performance liquid chromatography separation, the detector has been used for determination of itopride hydrochloride in human serum. Under the optimal conditions, the ECL intensity has a linear relationship with the concentration of itopride hydrochloride in the range of 1.0 x 10(-8) g mL(-1) to 1.0 x 10(-6) g mL(-1) and the detection limit was 3 x 10(-9) g mL(-1) (S/N=3). The as-prepared ECL detector displayed good sensitivity and stability.

  13. A novel flow injection chemiluminescence method for automated and miniaturized determination of phenols in smoked food samples.

    Science.gov (United States)

    Vakh, Christina; Evdokimova, Ekaterina; Pochivalov, Aleksei; Moskvin, Leonid; Bulatov, Andrey

    2017-12-15

    An easily performed fully automated and miniaturized flow injection chemiluminescence (CL) method for determination of phenols in smoked food samples has been proposed. This method includes the ultrasound assisted solid-liquid extraction coupled with gas-diffusion separation of phenols from smoked food sample and analytes absorption into a NaOH solution in a specially designed gas-diffusion cell. The flow system was designed to focus on automation and miniaturization with minimal sample and reagent consumption by inexpensive instrumentation. The luminol - N-bromosuccinimide system in an alkaline medium was used for the CL determination of phenols. The limit of detection of the proposed procedure was 3·10 -8 ·molL -1 (0.01mgkg -1 ) in terms of phenol. The presented method demonstrated to be a good tool for easy, rapid and cost-effective point-of-need screening phenols in smoked food samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The effect of dietary fish oil-supplementation to healthy young men on oxidative burst measured by whole blood chemiluminescence

    DEFF Research Database (Denmark)

    Bartelt, Stine; Timm, Michael; Damsgaard, Camilla Trab

    2008-01-01

    . At baseline and at the end of the intervention, the fatty acid composition of peripheral blood mononuclear cells (PBMC) was analysed by GLC and oxidative burst was studied in whole blood stimulated with zymosan using luminol-enhanced chemiluminescence. The PBMC content of n-3 LCPUFA was markedly increased...... a randomised 2 £ 2-factorial design in which subjects were randomly assigned to 8-week supplementation with capsules containing fish oil (about 29 g n-3 LCPUFA/d) or olive oil (control). Subjects were also randomly assigned to household use of oils and fat spreads with a high or a low 18 : 2n-6 content...... by the fish oil-supplementation (P,0001, compared to the olive oil groups). No effect of the intervention was observed on neutrophil count, but one measure of the zymosan-induced oxidative burst was higher in the fish oil groups (P¼003) compared to the olive oil groups. The fat intervention did not in itself...

  15. Evaluation of a chemiluminescent enzyme-linked immunosorbent assay for the diagnosis of Trypanosoma cruzi infection in a nonendemic setting

    Directory of Open Access Journals (Sweden)

    Luis Izquierdo

    2013-11-01

    Full Text Available The disappearance of lytic, protective antibodies (Abs from the serum of patients with Chagas disease is accepted as a reliable indicator of parasitological cure. The efficiency of a chemiluminescent enzyme-linked immunosorbent assay based on a purified, trypomastigote-derived glycosylphosphatidylinositol-anchored mucin antigen for the serologic detection of lytic Abs against Trypanosoma cruzi was evaluated in a nonendemic setting using a panel of 92 positive and 58 negative human sera. The technique proved to be highly sensitive {100%; 95% confidence interval (CI = 96-100} and specific (98.3%; 95% CI = 90.7-99.7, with a kappa score of 0.99. Therefore, this assay can be used to detect active T. cruzi infection and to monitor trypanosomicidal treatment.

  16. High magnetic field matching effects in NbN films induced by template grown dense ferromagnetic nanowires arrays

    DEFF Research Database (Denmark)

    Hallet, X.; Mátéfi-Tempfli, Mária; Michotte, S.

    2009-01-01

    Dense arrays of ordered ferromagnetic nanowires have been used to create periodic magnetic pinning centers in thin superconducting NbN films. The nanowires were electrodeposited in a highly ordered porous alumina membrane and the thin NbN film was deposited on top of the perpendicularly oriented...... to the magnetization processes of arrays of interacting single domain ferromagnetic nanowires....

  17. A novel microneedle array for the treatment of hydrocephalus

    Science.gov (United States)

    Oh, Jonghyun; Liu, Kewei; Medina, Tim; Kralick, Francis; Noh, Hongseok (Moses)

    2014-01-01

    We present a microfabricated 10 by 10 array of microneedles for the treatment of a neurological disease called communicating hydrocephalus. Together with the previously reported microvalve array, the current implantable microneedle array completes the microfabricated arachnoid granulations (MAGs) that mimic the function of normal arachnoid granulations (AGs). The microneedle array was designed to enable the fixation of the MAGs through dura mater membrane in the brain and thus provide a conduit for the flow of cerebrospinal fluid (CSF). Cone-shaped microneedles with hollow channels were fabricated using a series of microfabrication techniques: SU-8 photolithography for tapered geometry, reactive ion etching for sharpening the microneedles, 248 nm deep UV excimer laser machining for creating through-hole inside the microneedles, and metal sputtering for improved rigidity. Puncture tests were conducted using porcine dura mater and the results showed that the fabricated microneedle array is strong enough to pierce the dura mater. The in-vitro biocompatibility test result showed that none of the 100 outlets of the microneedles exposed to the bloodstream were clogged significantly by blood cells. We believe that these test results demonstrate the potential use of the microneedle array as a new treatment of hydrocephalus. PMID:25013306

  18. An electrogenerated chemiluminescence sensor based on gold nanoparticles@C60 hybrid for the determination of phenolic compounds.

    Science.gov (United States)

    Lu, Qiyi; Hu, Hongxiang; Wu, Yuanya; Chen, Shihong; Yuan, Dehua; Yuan, Ruo

    2014-10-15

    This paper described a novel strategy for the construction of an electrogenerated chemiluminescence (ECL) sensor based on gold nanoparticles@C60 (AuNPs@C60) hybrid for detecting phenolic compounds. First, C60 was functionalized with l-cysteine. Subsequently, with C60 as the core, gold nanoparticles (AuNPs) are synthesized and grown through an in situ reduction method in the presence of ascorbic acid (AA). The resulted flowerlike AuNPs@C60 nanoparticles were modified onto the glassy carbon electrode to achieve the sensor (AuNPs@C60/GCE). Here, l-cysteine not only can improve the biocompatibility and hydrophilicity of C60 but also can enhance the electrogenerated chemiluminescence (ECL) of peroxydisulfate system. Furthermore, both AuNPs and C60 are also beneficial to the ECL of the peroxydisulfate system. Due to the combination of l-cysteine, AuNPs and C60, the proposed ECL sensor exhibited an excellent analytical performance. Under an optimum condition, the ECL intensity increased linearly with phenolic compounds. The linear ranges of 6.2 × 10(-8)-1.2 × 10(-4)M, 5.0 × 10(-8)-1.1 × 10(-4)M and 5.0 × 10(-8)-1.1 × 10(-4)M were obtained for catechol (CC), hydroquinone (HQ) and p-cresol (PC), respectively, and the detection limits were 2.1 × 10(-8)M, 1.5 × 10(-8)M and 1.7 × 10(-8)M, respectively. The AuNPs@C60 hybrid might hold a new opportunity to develop an ECL sensor. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Comparison of ultraviolet absorbance and NO-chemiluminescence for ozone measurement in wildfire plumes at the Mount Bachelor Observatory

    Science.gov (United States)

    Gao, Honglian; Jaffe, Daniel A.

    2017-10-01

    The goal of this paper is to evaluate the accuracy of the commonly used ozone (O3) instrument (the ultraviolet (UV) photometer) against a Federal Reference Method (Nitric Oxide -chemiluminescence) for ozone measurement in wildfire smoke plumes. We carried out simultaneous ozone measurement with two UV O3 photometers and one nitric oxide-chemiluminescence (NO-CL) ozone detectors during wildfire season (Aug. 1-Sept. 30) in 2015 at the Mount Bachelor Observatory (MBO, 2763 m above mean sea level, Oregon, USA). The UV O3 shows good agreement and excellent correlation to NO-CL O3, with linear regression slopes close to unity and R2 of 0.92 for 1-h average data and R2 of 0.93 for O3 daily maximum 8-h average (MDA8). During this two-month period we identified 35 wildfire events. Ozone enhancements in those wildfire plumes measured by NO-CL O3 and UV O3 monitors also show good agreement and excellent linear correlation, with a slope and R2 of 1.03 and 0.86 for O3 enhancements (ΔO3) and 1.00 and 0.98 for carbon monoxide (CO)-normalized ozone enhancement ratios (ΔO3/ΔCO), respectively. Overall, the UV O3 was found to have a positive bias of 4.7 ± 2.8 ppbv compared to the NO-CL O3. The O3 bias between NO-CL O3 and UV O3 is independent of wildfire plume tracers such as CO, particulate matter (PM1), aerosol scattering, and ultrafine particles. The results demonstrate that the UV O3 absorbance method is reliable, even in highly concentrated wildfire plumes.

  20. Evaluation of seasonal changes of serum and plasma estradiol-17β, progesterone and testosterone in dolphins (Tursiops truncatus) by chemiluminescence.

    Science.gov (United States)

    Fragalà, Santo; Medica, Pietro; Grande, Francesco; Vazzana, Irene; Fazio, Esterina

    2015-08-01

    The purpose of the research was to test and validate an innovative and safe chemiluminescence method to evaluate sexual hormones in serum and plasma samples of Tursiops truncatus. The research was performed on 9 bottlenose dolphins entertained in Oltremare and in Zoomarine aquatic parks, sampled by the tail vein or from the ventral one and an ultrasound monitoring, throughout a 6 months period. Blood samples were analyzed using a chemiluminescence method. Data obtained were compared to radioimmunoassay and enzyme immuno assay reference data, with the purpose to test and validate this method, through the calculation of the coefficient of variability, and its reliability on serum and plasma samples. A one-way analysis of variance was applied to test the effect of time on serum and plasma hormonal changes. Mean concentrations of estradiol-17β in serum were equal to 149.07±6.82 pmol/L, and in plasma equal to 159.14±12.99 pmol/L; mean values of progesterone in serum were equal to 0.69±0.05 pmol/L, and in plasma equal to 0.64±0.05 pmol/L; mean values of testosterone in serum were equal to 44.43±14.42 nmol/L, and in plasma equal to 48.99±11.20 nmol/L. It would be interesting to widen the investigations on a larger number of subjects, in which the relationship between the concentrations of free and binding steroid hormones, with the dosing of binding proteins, would define the physiological ranges of reference in the T. truncatus.

  1. Utility of chemiluminescence (ViziLite™) in the detection of oral potentially malignant disorders and benign keratoses.

    Science.gov (United States)

    Awan, K H; Morgan, P R; Warnakulasuriya, S

    2011-08-01

     Oral potentially malignant disorders (OPMD) are known to precede the development of oral cancer. Detection of OPMD allows delivery of interventions that may reduce the evolution of these disorders to malignancy. Following oral examinations, the accuracy of detection of OPMD by chemiluminescence was evaluated using a commercially available detection kit - ViziLite. Data derived were compared in relation to conventional oral examination and surgical biopsy. A total of 126 patients, 70 men and 56 women (mean age 58.5 ± 11.9 years) attending Oral Medicine Clinics at King's and Guy's Hospitals, London, with oral white, red, and mixed white and red patches were enrolled. Sixty-one patients were current smokers, 28 were ex-smokers, while 92 were alcohol users. In a detailed investigation, these patients underwent ViziLite examination followed by surgical biopsy.  Based on the clinical diagnosis, 70 patients had oral leukoplakia/erythroplakia, 32 had oral lichen planus, nine had chronic hyperplastic candidiasis, and rest had frictional keratosis (13) or oral submucous fibrosis (2). Of 126 lesions, 95 (75.4%) showed aceto-whitening. Most oral leukoplakias had enhanced visibility and sharpness of the lesion when viewed with the ViziLite system. Following biopsy, 44 had oral epithelial dysplasia (29 mild, eight moderate, and seven severe). The sensitivity (se) and specificity (sp) of chemiluminescence for the detection of a dysplastic lesion were 77.3% and 27.8%, respectively. While ViziLite has the ability to detect OPMD, it does not accurately delineate dysplastic lesions. The device can be used as a general oral mucosal examination system and may in particular improve the visualization of leukoplakias. © 2011 John Wiley & Sons A/S.

  2. Diamond microelectrode arrays for in vitro neuronal recordings

    OpenAIRE

    McDonald, Matthew; Monaco, Antonina; Vahidpour, Farnoosh; Haenen, Ken; Giugliano, Michele; Nesladek, Milos

    2017-01-01

    Abstract: A novel microfabrication technique for microelectrode arrays (MEAs) with a full diamondcell interface is demonstrated. Boron-doped nano-crystalline diamond (BNCD) is used as a conductive electrode material on metal tracks insulated by intrinsic NCD. MEAs successfully recorded spontaneous electrical activity in rat primary cortical neuronal cultures. Patch-clamp measurements show no alterations to cell membrane passive properties or active firing response, for cell developing ex vivo...

  3. Golgi GRASPs: moonlighting membrane tethers

    Directory of Open Access Journals (Sweden)

    Jarvela T

    2012-05-01

    Full Text Available Timothy Jarvela, Adam D LinstedtDepartment of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, USAAbstract: The identification of mammalian Golgi reassembly stacking proteins (GRASPs 15 years ago was followed by experiments implicating them in diverse functions, including two differing structural roles in Golgi biogenesis and at least two distinct roles in the secretion of proteins. GRASP55 and GRASP65 are localized to cis and medial/trans Golgi cisternae, respectively. They are both required for stacking of Golgi membranes in a Golgi reassembly assay. Depletion of either GRASP from cultured cells prevents the linking of Golgi membranes into their normal ribbon-like network. While GRASPs are not required for transport of secretory cargo per se, they are required for ER-to-Golgi transport of certain specific cargo, such as those containing a C-terminal valine motif. Surprisingly, GRASPs also promote secretion of cargo by the so-called unconventional secretory pathway, which bypasses the Golgi apparatus where the GRASPs reside. Furthermore, regulation of GRASP activity is now recognized for its connections to cell cycle control, development, and disease. Underlying these diverse activities is the structurally conserved N-terminal GRASP domain whose crystal structure was recently determined. It consists of a tandem array of atypical PSD95–DlgA–Zo–1 (PDZ domains, which are well-known protein–protein interaction motifs. The GRASP PDZ domains are used to localize the proteins to the Golgi as well as GRASP-mediated membrane tethering and cargo interactions. These activities are regulated, in part, by phosphorylation of the large unstructured C-terminal domain.Keywords: GRASP, review, membrane, tether, PDZ domain, secretory chaperone, unconventional secretion

  4. Sheet Membrane Spacesuit Water Membrane Evaporator

    Science.gov (United States)

    Bue, Grant; Trevino, Luis; Zapata, Felipe; Dillion, Paul; Castillo, Juan; Vonau, Walter; Wilkes, Robert; Vogel, Matthew; Frodge, Curtis

    2013-01-01

    A document describes a sheet membrane spacesuit water membrane evaporator (SWME), which allows for the use of one common water tank that can supply cooling water to the astronaut and to the evaporator. Test data showed that heat rejection performance dropped only 6 percent after being subjected to highly contaminated water. It also exhibited robustness with respect to freezing and Martian atmospheric simulation testing. Water was allowed to freeze in the water channels during testing that simulated a water loop failure and vapor backpressure valve failure. Upon closing the backpressure valve and energizing the pump, the ice eventually thawed and water began to flow with no apparent damage to the sheet membrane. The membrane evaporator also serves to de-gas the water loop from entrained gases, thereby eliminating the need for special degassing equipment such as is needed by the current spacesuit system. As water flows through the three annular water channels, water evaporates with the vapor flowing across the hydrophobic, porous sheet membrane to the vacuum side of the membrane. The rate at which water evaporates, and therefore, the rate at which the flowing water is cooled, is a function of the difference between the water saturation pressure on the water side of the membrane, and the pressure on the vacuum side of the membrane. The primary theory is that the hydrophobic sheet membrane retains water, but permits vapor pass-through when the vapor side pressure is less than the water saturation pressure. This results in evaporative cooling of the remaining water.

  5. UAVSAR Phased Array Aperture

    Science.gov (United States)

    Chamberlain, Neil; Zawadzki, Mark; Sadowy, Greg; Oakes, Eric; Brown, Kyle; Hodges, Richard

    2009-01-01

    This paper describes the development of a patch antenna array for an L-band repeat-pass interferometric synthetic aperture radar (InSAR) instrument that is to be flown on an unmanned aerial vehicle (UAV). The antenna operates at a center frequency of 1.2575 GHz and with a bandwidth of 80 MHz, consistent with a number of radar instruments that JPL has previously flown. The antenna is designed to radiate orthogonal linear polarizations in order to facilitate fully-polarimetric measurements. Beam-pointing requirements for repeat-pass SAR interferometry necessitate electronic scanning in azimuth over a range of -20degrees in order to compensate for aircraft yaw. Beam-steering is accomplished by transmit/receive (T/R) modules and a beamforming network implemented in a stripline circuit board. This paper, while providing an overview of phased array architecture, focuses on the electromagnetic design of the antenna tiles and associated interconnects. An important aspect of the design of this antenna is that it has an amplitude taper of 10dB in the elevation direction. This is to reduce multipath reflections from the wing that would otherwise be detrimental to interferometric radar measurements. This taper is provided by coupling networks in the interconnect circuits as opposed to attenuating the output of the T/R modules. Details are given of material choices and fabrication techniques that meet the demanding environmental conditions that the antenna must operate in. Predicted array performance is reported in terms of co-polarized and crosspolarized far-field antenna patterns, and also in terms of active reflection coefficient.

  6. Methanotroph outer membrane preparation.

    Science.gov (United States)

    Karlsen, Odd A; Berven, Frode S; Jensen, Harald B; Fjellbirkeland, Anne

    2011-01-01

    All presently known methanotrophs are gram-negative bacteria suggesting that they are surrounded by a two-layered membrane: an inner or cytoplasmic membrane and an outer membrane. In the methanotroph Methylococcus capsulatus (Bath), separation of the two membranes has allowed studies on protein and lipid composition of the outer membrane. Its outer membrane can be isolated from purified cell envelopes by selective solubilization of the inner membranes with the detergent Triton X-100. The proteins associated with the outer membrane can further be fractionated into integral and tightly associated proteins and peripheral loosely associated proteins. We present here protocols for this fractionation and show how the proteins associated with the outer leaflet of the outer membrane can be isolated and identified by whole-cell biotin surface labeling. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Method for Synthesizing Metal Nanowires in Anodic Alumina Membranes Using Solid State Reduction

    Science.gov (United States)

    Martinez-Inesta, Maria M (Inventor); Feliciano, Jennie (Inventor); Quinones-Fontalvo, Leonel (Inventor)

    2016-01-01

    The invention proposes a novel method for the fabrication of regular arrays of MNWs using solid-state reduction (SSR). Using this method copper (Cu), silver (Ag), and palladium (Pd) nanowire (NWs) arrays were synthesized using anodic alumina membranes (AAMs) as templates. Depending on the metal loading used the NWs reached different diameters.

  8. A Lambda Calculus for Transfinite Arrays: Unifying Arrays and Streams

    OpenAIRE

    Sinkarovs, Artjoms; Scholz, Sven-Bodo

    2017-01-01

    Array programming languages allow for concise and generic formulations of numerical algorithms, thereby providing a huge potential for program optimisation such as fusion, parallelisation, etc. One of the restrictions that these languages typically have is that the number of elements in every array has to be finite. This means that implementing streaming algorithms in such languages requires new types of data structures, with operations that are not immediately compatible with existing array ...

  9. In-situ membrane hydration measurement of proton exchange membrane fuel cells

    Science.gov (United States)

    Lai, Yeh-Hung; Fly, Gerald W.; Clapham, Shawn

    2015-01-01

    Achieving proper membrane hydration control is one of the most critical aspects of PEM fuel cell development. This article describes the development and application of a novel 50 cm2 fuel cell device to study the in-situ membrane hydration by measuring the through-thickness membrane swelling via an array of linear variable differential transducers. Using this setup either as an air/air (dummy) cell or as a hydrogen/air (operating) cell, we performed a series of hydration and dehydration experiments by cycling the RH of the inlet gas streams at 80 °C. From the linear relationship between the under-the-land swelling and the over-the-channel water content, the mechanical constraint within the fuel cell assembly can suppress the membrane water uptake by 11%-18%. The results from the air/air humidity cycling test show that the membrane can equilibrate within 120 s for all RH conditions and that membrane can reach full hydration at a RH higher than 140% in spite of the use of a liquid water impermeable Carbel MP30Z microporous layer. This result confirms that the U.S. DOE's humidity cycling mechanical durability protocol induces sufficient humidity swings to maximize hygrothermal mechanical stresses. This study shows that the novel experimental technique can provide a robust and accurate means to study the in-situ hydration of thin membranes subject to a wide range of fuel cell conditions.

  10. Selecting Sums in Arrays

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jørgensen, Allan Grønlund

    2008-01-01

    In an array of n numbers each of the \\binomn2+nUnknown control sequence '\\binom' contiguous subarrays define a sum. In this paper we focus on algorithms for selecting and reporting maximal sums from an array of numbers. First, we consider the problem of reporting k subarrays inducing the k largest...... sums among all subarrays of length at least l and at most u. For this problem we design an optimal O(n + k) time algorithm. Secondly, we consider the problem of selecting a subarray storing the k’th largest sum. For this problem we prove a time bound of Θ(n · max {1,log(k/n)}) by describing...... an algorithm with this running time and by proving a matching lower bound. Finally, we combine the ideas and obtain an O(n· max {1,log(k/n)}) time algorithm that selects a subarray storing the k’th largest sum among all subarrays of length at least l and at most u....

  11. Electromagnetically Clean Solar Arrays

    Science.gov (United States)

    Stem, Theodore G.; Kenniston, Anthony E.

    2008-01-01

    The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the

  12. Fabrication and Performance of Large Format Transition Edge Sensor Microcalorimeter Arrays

    Science.gov (United States)

    Chervenak, James A.; Adams, James S.; Bandler, Simon R.; Busch, Sara E.; Eckart, M. E.; Ewin, A. E.; Finkbeiner, F. M.; Kilbourne, C. A.; Kelley, R. L.; Porst, Jan-Patrick; hide

    2012-01-01

    We have produced a variety of superconducting transition edge sensor array designs for microcalorimetric detection of x-rays. Designs include kilopixel scale arrays of relatively small sensors (75 micron pitch) atop a thick metal heatsinking layer as well as arrays of membrane-isolated devices on 250 micron pitch and smaller arrays of devices up to 600 micron pitch. We discuss the fabrication techniques used for each type of array focusing on unique aspects where processes vary to achieve the particular designs and required device parameters. For example, we evaluate various material combinations in the production of the thick metal heatsinking, including superconducting and normal metal adhesion layers. We also evaluate the impact of added heatsinking on the membrane isolated devices as it relates to basic device parameters. Arrays can be characterized with a time division SQUID multiplexer such that greater than 10 devices from an array can be measured in the same cooldown. Device parameters can be measured simultaneously so that environmental events such as thermal drifts or changes in magnetic fields can be controlled. For some designs, we will evaluate the uniformity of parameters impacting the intrinsic performance of the microcalorimeters under bias in these arrays and assess the level of thermal crosstalk.

  13. Airfoil-shaped micro-mixers for reducing fouling on membrane surfaces

    Science.gov (United States)

    Ho, Clifford K; Altman, Susan J; Clem, Paul G; Hibbs, Michael; Cook, Adam W

    2012-10-23

    An array of airfoil-shaped micro-mixers that enhances fluid mixing within permeable membrane channels, such as used in reverse-osmosis filtration units, while minimizing additional pressure drop. The enhanced mixing reduces fouling of the membrane surfaces. The airfoil-shaped micro-mixer can also be coated with or comprised of biofouling-resistant (biocidal/germicidal) ingredients.

  14. Electrodynamic Arrays Having Nanomaterial Electrodes

    Science.gov (United States)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  15. Combinatorial aspects of covering arrays

    Directory of Open Access Journals (Sweden)

    Charles J. Colbourn

    2004-11-01

    Full Text Available Covering arrays generalize orthogonal arrays by requiring that t -tuples be covered, but not requiring that the appearance of t -tuples be balanced.Their uses in screening experiments has found application in software testing, hardware testing, and a variety of fields in which interactions among factors are to be identified. Here a combinatorial view of covering arrays is adopted, encompassing basic bounds, direct constructions, recursive constructions, algorithmic methods, and applications.

  16. Transmembrane Signalling: Membrane messengers

    Science.gov (United States)

    Cockroft, Scott L.

    2017-05-01

    Life has evolved elaborate means of communicating essential chemical information across cell membranes. Inspired by biology, two new artificial mechanisms have now been developed that use synthetic messenger molecules to relay chemical signals into or across lipid membranes.

  17. Hybrid adsorptive membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tsotsis, Theodore T [Huntington Beach, CA; Sahimi, Muhammad [Altadena, CA; Fayyaz-Najafi, Babak [Richmond, CA; Harale, Aadesh [Los Angeles, CA; Park, Byoung-Gi [Yeosu, KR; Liu, Paul K. T. [Lafayette Hill, PA

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  18. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  19. Membrane Innovation in Dialysis.

    Science.gov (United States)

    Boschetti-de-Fierro, Adriana; Beck, Werner; Hildwein, Helmut; Krause, Bernd; Storr, Markus; Zweigart, Carina

    2017-01-01

    Despite advances in renal replacement therapy, the adequate removal of uremic toxins over a broad molecular weight range remains one of the unmet needs in hemodialysis. Therefore, membrane innovation is currently directed towards enhanced removal of uremic toxins and increased membrane permeability. This chapter presents a variety of opportunities where innovation is brought into dialysis membranes. It covers the membrane formation from solution, describing different approaches to control the phase inversion process through additives that either swell in the polymer solution or influence the pore shrinkage during the membrane drying process. Additionally, large-scale manufacturing is described, and the influence of raw materials, spinning, and drying processes on membrane selectivity are presented. Finally, new characterization methods developed for the latest innovations around the application of membranes in dialysis are discussed, which allow the membrane performance for removal of a broad range of uremic toxins and the expected albumin loss in clinical use. © 2017 S. Karger AG, Basel.

  20. Composite zeolite membranes

    Science.gov (United States)

    Nenoff, Tina M.; Thoma, Steven G.; Ashley, Carol S.; Reed, Scott T.

    2002-01-01

    A new class of composite zeolite membranes and synthesis techniques therefor has been invented. These membranes are essentially defect-free, and exhibit large levels of transmembrane flux and of chemical and isotopic selectivity.

  1. Supported inorganic membranes

    Science.gov (United States)

    Sehgal, Rakesh; Brinker, Charles Jeffrey

    1998-01-01

    Supported inorganic membranes capable of molecular sieving, and methods for their production, are provided. The subject membranes exhibit high flux and high selectivity. The subject membranes are substantially defect free and less than about 100 nm thick. The pores of the subject membranes have an average critical pore radius of less than about 5 .ANG., and have a narrow pore size distribution. The subject membranes are prepared by coating a porous substrate with a polymeric sol, preferably under conditions of low relative pressure of the liquid constituents of the sol. The coated substrate is dried and calcined to produce the subject supported membrane. Also provided are methods of derivatizing the surface of supported inorganic membranes with metal alkoxides. The subject membranes find use in a variety of applications, such as the separation of constituents of gaseous streams, as catalysts and catalyst supports, and the like.

  2. Molecular Interactions at Membranes

    DEFF Research Database (Denmark)

    Jagalski, Vivien

    Biological membranes are essential and complex structures in every living cell consisting of a fluid lipid bilayer sheet and membrane proteins. Its significance makes biological membranes not only interesting for medical research, but also has made it a target for toxins in the course of evolution...... mechanisms of membrane compounds, including compounds associated with membranes, are still unknown due to the challenges that arise when probing the hydrophobic nature of the membrane's interior. For integral membrane proteins that span through the entire membrane, the amphiphilic environment is essential...... to retain their native structure. This creates a challenge for studying the true structures of such proteins. Here, we present an approach via the immobilization of the transmembrane leucine transporter protein (LeuT) to a functionalized surface. Moreover, we created a native-like lipid environment post...

  3. Compact dynamic microfluidic iris array

    Science.gov (United States)

    Kimmle, Christina; Doering, Christoph; Steuer, Anna; Fouckhardt, Henning

    2011-09-01

    A dynamic microfluidic iris is realized. Light attenuation is achieved by absorption of an opaque liquid (e.g. black ink). The adjustment of the iris diameter is achieved by fluid displacement via a transparent elastomer (silicone) half-sphere. This silicone calotte is hydraulically pressed against a polymethylmethacrylate (PMMA) substrate as the bottom window, such that the opaque liquid is squeezed away, this way opening the iris. With this approach a dynamic range of more than 60 dB can be achieved with response times in the ms to s regime. The design allows the realization of a single iris as well as an iris array. So far the master for the molded silicone structure was fabricated by precision mechanics. The aperture diameter was changed continuously from 0 to 8 mm for a single iris and 0 to 4 mm in case of a 3 x 3 iris array. Moreover, an iris array was combined with a PMMA lens array into a compact module, the distance of both arrays equaling the focal length of the lenses. This way e.g. spatial frequency filter arrays can be realized. The possibility to extend the iris array concept to an array with many elements is demonstrated. Such arrays could be applied e.g. in light-field cameras.

  4. A new chemiluminescence method for determination of clonazepam and diazepam based on 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper as catalyst

    Science.gov (United States)

    Chaichi, M. J.; Alijanpour, S. O.

    2014-01-01

    A novel chemiluminescence (CL) reaction, Benzodiazepines-H2O2-1-Ethyl-3-Methylimidazolium Ethylsulfate/copper, for determination of clonazepam and diazepam at nanogram per milliliter level in batch-type system have been described. The method relies on the catalytic effect of 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper on the chemiluminescence reaction of Benzodiazepines, the oxidation of Benzodiazepines with hydrogen peroxide in natural medium. The influences of various experimental parameters such as solution pH, the ratio of 1-Ethyl-3 Methylimidazolium ethylsulfate concentration to copper ion, the type of buffer and the concentration of CL reagents were investigated. Under the optimum condition, the proposed method was satisfactorily applied for the determination of these drugs in tablets and urine without the interference of their potential impurities.

  5. Low-Temperature Chemiluminescence From cis-1,4-Polybutadiene, 1,2-Polybutadiene, and trans-Polypentenamer at Temperatures Near Ambient

    Science.gov (United States)

    Nathan, Richard A.; Mendenhall, G. David; Birts, Michelle A.; Ogle, Craig A.; Golub, Morton A.

    1978-01-01

    The chemiluminescence emission at 25-60 C was measured from films of cis-1,4-polybutadiene, 1,2-polybutadiene, and trans-polypentenamer. The polymers were autoxidized previously in air 100 C, or allowed to react with singlet molecular oxygen in solution, and then cast into films. Values of beta(or k(sub d,((1)O2 yields (3)03)/k(sub r)((1)O2 + polymer yields products)) were determined in benzene for cis-1,4-polybutadiene and cis-1,4-polyisoprene, and for model compounds cis-3-hexene and cis-3-methyl-3-hexene by independent methods. The chemiluminescence emission from irradiated films of the polymers containing a dye sensitizer showed a complicated time dependence, and the results depended on the length of irradiation.

  6. Effect of Human and Bovine Serum Albumin on kinetic Chemiluminescence of Mn (III-Tetrakis (4-Sulfonatophenyl Porphyrin-Luminol-Hydrogen Peroxide System

    Directory of Open Access Journals (Sweden)

    Sayed Yahya Kazemi

    2012-01-01

    Full Text Available The present work deals with an attempt to study the effect of human and bovine serum albumin on kinetic parameters of chemiluminescence of luminol-hydrogen peroxide system catalyzed by manganese tetrasulfonatophenyl porphyrin (MnTSPP. The investigated parameters involved pseudo-first-order rise and fall rate constant for the chemiluminescence burst, maximum level intensity, time to reach maximum intensity, total light yield, and values of the intensity at maximum CL which were evaluated by nonlinear least square program KINFIT. Because of interaction of metalloporphyrin with proteins, the CL parameters are drastically affected. The systems resulted in Stern-Volmer plots with values of 3.17×105 and 3.7×105M−1 in the quencher concentration range of 1.5×10−6 to 1.5×10−5 M for human serum albumin (HSA and bovine serum albumin (BSA, respectively.

  7. Encapsulation of Hemin in Metal-Organic Frameworks for Catalyzing the Chemiluminescence Reaction of the H2O2-Luminol System and Detecting Glucose in the Neutral Condition.

    Science.gov (United States)

    Luo, Fenqiang; Lin, Yaolin; Zheng, Liyan; Lin, Xiaomei; Chi, Yuwu

    2015-06-03

    Novel metal-organic frameworks (MOFs) based solid catalysts have been synthesized by encapsulating Hemin into the HKUST-1 MOF materials. These have been first applied in the chemiluminescence field with outstanding performance. The functionalized MOFs not only maintain an excellent catalytic activity inheriting from Hemin but also can be cyclically utilized as solid mimic peroxidases in the neutral condition. The synthesized Hemin@HKUST-1 composites have been used to develop practical sensors for H2O2 and glucose with wide response ranges and low detection limits. It was envisioned that catalyst-functionalized MOFs for chemiluminescence sensing would have promising applications in green, selective, and sensitive detection of target analytes in the future.

  8. Application of neutrophils chemiluminescence test in the differential diagnosis of bronchial asthma and recurrent respiratory tract infection in the remission period in children

    Science.gov (United States)

    Lewandowicz-Uszynska, A.; Jankowski, A.

    2001-07-01

    In this study we present the comparison of neutrophils activity, measured in whole blood by a chemiluminescence test in children with bronchial asthma and recurrent respiratory tract infections (RRTI). We estimated five parameters of chemiluminescence: I - a time of spontaneous stabilization of CL (following counts remain on the same level with a tendency to decrease), II - a time of maximal CL excitation (time after addition of stimulator during which the cells emit the highest amounts of photons), III - an average value of spontaneous CL (from the beginning of measurement to the addition of f-MLP), IV - a maximal value of CL after stimulation and V - and area under CL curve. The values of parameters III, IV and V were significantly lower in the children with rrti (pbronchial asthma than that in the control (p<0.0001) and RRTI (p<0.0001) groups. A deterioration of oxygen metabolism of neutrophils, measured by CL test, was demonstrate in children with rrti.

  9. Protein-bound polyphenols create “ghost” band artifacts during chemiluminescence-based antigen detection [version 2; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Nathalie Plundrich

    2017-05-01

    Full Text Available Antigen detection during Western blotting commonly utilizes a horseradish peroxidase-coupled secondary antibody and enhanced chemiluminescent substrate. We utilized this technique to examine the impact of green tea-derived polyphenols on the binding of egg white protein-specific IgE antibodies from allergic human plasma to their cognate antigens. Our experiments unexpectedly showed that green tea-derived polyphenols, when stably complexed with egg white proteins, caused “ghost” band formation in the presence of horseradish peroxide. This study suggests that caution should be taken when evaluating polyphenol-bound proteins by enhanced chemiluminescence Western blotting using horseradish peroxidase and demonstrates that protein-bound polyphenols can be a source of “ghost” band artifacts on Western blots.

  10. Composite fuel cell membranes

    Science.gov (United States)

    Plowman, Keith R.; Rehg, Timothy J.; Davis, Larry W.; Carl, William P.; Cisar, Alan J.; Eastland, Charles S.

    1997-01-01

    A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  11. Cascading Constrained 2-D Arrays using Periodic Merging Arrays

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Laursen, Torben Vaarby

    2003-01-01

    We consider a method for designing 2-D constrained codes by cascading finite width arrays using predefined finite width periodic merging arrays. This provides a constructive lower bound on the capacity of the 2-D constrained code. Examples include symmetric RLL and density constrained codes...

  12. Membrane contactor applications

    NARCIS (Netherlands)

    Klaassen, R.; Feron, P.H.M.; Jansen, A.

    2008-01-01

    In a membrane contactor the membrane separation is completely integrated with an extraction or absorption operation in order to exploit the benefits of both technologies fully. Membrane contactor applications that have been developed can be found in both water and gas treatment. Several recently

  13. Model cell membranes

    DEFF Research Database (Denmark)

    Günther-Pomorski, Thomas; Nylander, Tommy; Cardenas Gomez, Marite

    2014-01-01

    The high complexity of biological membranes has motivated the development and application of a wide range of model membrane systems to study biochemical and biophysical aspects of membranes in situ under well defined conditions. The aim is to provide fundamental understanding of processes control...

  14. Cadmium sulfide membranes

    Science.gov (United States)

    Spanhel, Lubomir; Anderson, Marc A.

    1991-10-22

    A method is described for the creation of novel q-effect cadmium sulfide membranes. The membranes are made by first creating a dilute cadmium sulfide colloid in aqueous suspension and then removing the water and excess salts therefrom. The cadmium sulfide membrane thus produced is luminescent at room temperature and may have application in laser fabrication.

  15. Meniscus Membranes For Separation

    Science.gov (United States)

    Dye, Robert C.; Jorgensen, Betty; Pesiri, David R.

    2005-09-20

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  16. [The criterion prognostic significance of examinations of chemiluminescence of oral fluid under impact of chemical pollutants of manufacture of rubber and rubber technical production].

    Science.gov (United States)

    Galiullina, E F; Valiev, A v; Kamilov, R F; Shakirov, D F; Buliakov, P T

    2013-12-01

    The article presents the results of studies concerning the effect of unfavorable factors of chemical nature on fluid of oral cavity among workers of the Ufa plant of elastomer materials, articles and structures. It is established that in persons contacting with chemical pollutants of manufacture of rubber and rubber technical production the indicators of chemiluminescence of saliva fluid are significantly expressed and depend on professional standing.

  17. Humidification Technique Using New Modified MiniModule Membrane Contactors for Air Cooling

    OpenAIRE

    Mohamed Ali; Obida Zeitoun; Hany Al-Ansary; Abdullah Nuhait

    2013-01-01

    An experimental study is conducted to cool the ambient air using a new humidification technique. A wind tunnel is built with a test section formed by four modified MiniModule membrane contactors. An ambient air passes over the membrane contactors (cross flow) while water pumps through the contactors. Air temperature and relative humidity are measured upstream and downstream of the membrane contactors array which was used to humidify and cool the outdoor air. Five average air velocities (3.03,...

  18. Two chemical approaches for the production of stable solutions of tris(2,2minutes or feet-bipyridyl)ruthenium(III) for analytical chemiluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Gerardi, R.D.; Barnett, N.W. [School of Biological and Chemical Sciences, Deakin University, Geelong (Australia); Jones, P. [Department of Environmental Sciences, University of Plymouth, Plymouth, Devon (United Kingdom)

    1999-05-03

    Two methods for the chemical generation of the chemiluminescence reagent Ru(bipy){sup 3+}{sub 3} are presented, both of which used lead dioxide as the oxidant with various concentrations of sulphuric acid. The temporal stability of several different Ru(bipy){sup 3+}{sub 3} solutions was investigated, with significant extension to their analytically useful lifetime being afforded by simply increasing the acid concentration. Alternatively, recirculation of the reagent through a glass filter assembly containing lead dioxide also extended the stability of Ru(bipy){sup 3+}{sub 3} under mildly acidic conditions. A series of flow injection analysis experiments, using codeine to generate chemiluminescence, were performed to quantify the stability of the various reagents with the useful lifetimes ranging from several hours to more than a week, depending on the acid concentration. The change in concentration of Ru(bipy){sup 3+}{sub 3} versus time was measured spectrophotometrically (at {lambda}{sub max}, 674 nm) in order to evaluate the kinetics of the reagent degradation process and its effects on chemiluminescence response for codeine. These preliminary results are presented as a simple and robust alternative to electrochemical generation for those applications where medium to long term reagent stability is essential, such as in liquid chromatography and process analysis. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  19. A dual-readout chemiluminescent-gold lateral flow test for multiplex and ultrasensitive detection of disease biomarkers in real samples.

    Science.gov (United States)

    Chen, Yiping; Sun, Jiashu; Xianyu, Yunlei; Yin, Binfeng; Niu, Yajing; Wang, Songbai; Cao, Fengjing; Zhang, Xiaoqing; Wang, Yu; Jiang, Xingyu

    2016-08-18

    Even though the gold lateral flow test (GLFT) is low-cost and allows for point-of-care testing (POCT), its intrinsic limitations including low sensitivity and incapability of quantification significantly hinder the clinical application of GLFT for assaying disease biomarkers. To improve the performance of the GLFT without sacrificing its simplicity, we develop a chemiluminescent-gold lateral flow test (C-mode GLFT) for quantitative and multiplex detection of disease biomarkers with an ultrahigh sensitivity at a picomolar level. Horseradish peroxidase (HRP) and antibody (Ab) are simultaneously labeled onto the surface of gold nanoparticles (AuNPs) to achieve a dual-readout (chemiluminescent and visual, C&V-mode GLFT). A red color appears at the test line caused by the accumulation of captured AuNPs in the presence of targets, while HRP on the surface of AuNPs catalyzes the chemiluminescence reaction of luminol to amplify the signal. C-mode GLFT is successfully used for detecting tumor biomarkers (alpha fetoprotein, AFP, and carcino embryonic antigen, CEA) and bacterial infection biomarkers (procalcitonin, PCT) in serum samples as well as whole blood. The excellent features of C-mode GLFT such as straightforward operation, ultrahigh sensitivity and quantitative detection, make it a promising platform for POCT of a variety of disease biomarkers in real samples.

  20. Highly sensitive trivalent copper chelate–luminol chemiluminescence system for capillary electrophoresis chiral separation and determination of ofloxacin enantiomers in urine samples

    Directory of Open Access Journals (Sweden)

    Hao-Yue Xie

    2014-12-01

    Full Text Available A simple, fast and sensitive capillary electrophoresis (CE strategy combined with chemiluminescence (CL detection for analysis of ofloxacin (OF enantiomers was established in the present work. Sulfonated β-cyclodextrin (β-CD was used as the chiral additive being added into the running buffer of luminol–diperiodatocuprate (III (K5[Cu(HIO62], DPC chemiluminescence system. Under the optimum conditions, the proposed method was successfully applied to separation and analysis of OF enantiomers with the detection limits (S/N=3 of 8.0 nM and 7.0 nM for levofloxacin and dextrofloxacin, respectively. The linear ranges were both 0.010–100 μM. The method was utilized for analyzing OF in urine; the results obtained were satisfactory and recoveries were 89.5–110.8%, which demonstrated the reliability of this method. This approach can also be further extended to analyze different commercial OF medicines. Keywords: Ofloxacin, Chiral analysis, Sulfonated-β-CD, Capillary electrophoresis, Chemiluminescence

  1. Effects of optical diagnostic techniques on the accuracy of laminar flame speeds measured from Bunsen flames: OH* chemiluminescence, OH-PLIF and acetone/kerosene-PLIF

    Science.gov (United States)

    Wu, Yi; Modica, Vincent; Yu, Xilong; Li, Fei; Grisch, Frédéric

    2018-01-01

    The effects of optical diagnostic techniques on the accuracy of laminar flame speed measured from Bunsen flames were investigated. Laminar flame speed measurements were conducted for different fuel/air mixtures including CH4/air, acetone/air and kerosene (Jet A-1)/air in applying different optical diagnostic techniques, i.e. OH* chemiluminescence, OH-PLIF and acetone/kerosene-PLIF. It is found that the OH* chemiluminescence imaging technique cannot directly derive the location of the outer edge of the fresh gases and it is necessary to correct the position of the OH* peak to guarantee the accuracy of the measurements. OH-PLIF and acetone/kerosene-PLIF respectively are able to measure the disappearance of the fresh gas contour and the appearance of the reaction zone. It shows that the aromatic-PLIF technique gives similar laminar flame speed values when compared with those obtained from corrected OH* chemiluminescence images. However, discrepancies were observed between the OH-PLIF and the aromatic-PLIF techniques, in that OH-PLIF slightly underestimates laminar flame speeds by up to 5%. The difference between the flame contours obtained from different optical techniques are further analysed and illustrated with 1D flame structure simulation using detailed kinetic mechanisms.

  2. 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.

  3. СHANGES IN PARAMETERS OF LUMINOL-DEPENDENT AND LUCIGENIN-DEPENDENT CHEMILUMINESCENCE OF PERIPHERAL BLOOD NEUTROPHILS IN PATIENTS WITH BLADDER CANCER IN THE DISEASE DYNAMICS

    Directory of Open Access Journals (Sweden)

    L. M. Kurtasova

    2015-01-01

    Full Text Available The study deals with parameters of luminol-dependent and lucigenin-dependent chemiluminescence (CL of peripheral blood neutrophils from patients with bladder cancer (BC prior to surgical treatment. We examined sixty patients (45 to 55 years old with advanced bladder cancer (TNM prior to the operation, and forty-six patients at 10 days after surgical treatment. A control group consisted of 56 healthy donors. Luminol-dependent and lucigenin-dependent chemiluminescence of blood neutrophils was assessed according to De Sole et al. (1983. Chemiluminescence assays of peripheral blood neutrophils from the patients with bladder cancer revealed changes in production of reactive oxygen species (ROS, both for initial stage of oxidation reaction, and total level of active oxygen radicals. We have found disturbed values of primary-to-secondary ROS ratio in the cells. In the patients with bladder cancer, some changes in oxidative metabolism of the blood neutrophils have been registered. These alterations may play an important role in promotion of potential effector cell functions, thus, probably, affecting the whole-scale development of a cytopathic effect exerted by neutrophilic granulocytes. 

  4. Relationship between presynaptic membrane potential and acetylcholine release in synaptosomes from Torpedo electric organ.

    Science.gov (United States)

    Meunier, F M

    1984-01-01

    The membrane potential of purely cholinergic synaptosomes isolated from Torpedo electric organ was monitored with fluorescent carbocyanine dyes. An increased fluorescence was associated with depolarization and a quenching with hyperpolarization. Fluorescence data provided evidence that Torpedo synaptosomes have a membrane potential mainly driven by a K+ diffusion potential and a membrane potential of about -50 mV could be estimated after calibration of fluorescence signals with ionophore antibiotics. The release of acetylcholine (ACh) from Torpedo synaptosomes was monitored continuously by measuring the light emitted by a chemiluminescent method (Israël & Lesbats, 1981 a). Using fluorescence data, the release of ACh was expressed as a function of membrane potential. The relationship between presynaptic potential and transmitter release as determined by biochemical methods at cholinergic nerve endings showed striking similarities to that observed at the squid giant synapse. Several substances were also tested with regard to their depolarizing and releasing properties and it was found that the toxin isolated from the venom of the annelid Glycera convoluta, which induced a large increase in quantal release of transmitter (Manaranche, Thieffry, & Israël, 1980) promoted a depolarization of Torpedo synaptosomes in addition to ACh release. PMID:6207289

  5. Metal membrane with dimer slots as a universal polarizer

    DEFF Research Database (Denmark)

    Zhukovsky, Sergei; Zalkovskij, Maksim; Malureanu, Radu

    2014-01-01

    In this work, we show theoretically and confirm experimentally that thin metal membranes patterned with an array of slot dimers (or their Babinet analogue with metal rods) can function as a versatile spectral and polarization filter. We present a detailed covariant multipole theory for the electr......In this work, we show theoretically and confirm experimentally that thin metal membranes patterned with an array of slot dimers (or their Babinet analogue with metal rods) can function as a versatile spectral and polarization filter. We present a detailed covariant multipole theory......-shaped, and T-shaped. These particular shapes of dimers are found to be sensitive to variations of the slots lengths and orientation of elements. Theoretical results are well supported by full-wave three-dimensional simulations. Our findings were verified experimentally on the metal membranes fabricated using...

  6. Plasma membrane ATPases

    DEFF Research Database (Denmark)

    Palmgren, Michael Broberg; Bækgaard, Lone; Lopez Marques, Rosa Laura

    2011-01-01

    The plasma membrane separates the cellular contents from the surrounding environment. Nutrients must enter through the plasma membrane in order to reach the cell interior, and toxic metabolites and several ions leave the cell by traveling across the same barrier. Biological pumps in the plasma...... membrane include ABC transporters, vacuolar (V-type) H+ pumps, and P-type pumps. These pumps all utilize ATP as a fuel for energizing pumping. This review focuses on the physiological roles of plasma membrane P-type pumps, as they represent the major ATP hydrolytic activity in this membrane....

  7. Separation membrane development

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.W. [Savannah River Technology Center, Aiken, SC (United States)

    1998-08-01

    A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

  8. Frequency Diverse Array Receiver Architectures

    Science.gov (United States)

    2015-06-29

    2009. DSP /SPE 2009. IEEE 13th, pp. 446 –450, Jan. 2009. 60 [19] Fuhrmann, D.R. and Browning, J.P. and Rangaswamy, M., “Adapting a MIMO/phased-array...Diverse Array Radar,” Master’s thesis, Naval Postgraduate School, September 2010. [25] D. Glass, “ Matlab 4-d visualization technique.” Personal

  9. The NOAA TOGA antenna array

    Science.gov (United States)

    Ecklund, W. L.; Carter, D. A.; Balsley, B. B.

    1986-01-01

    The Aeronomy Laboratory recently installed a 100 x 100 meter array antenna with limited beam steering on Christmas Island as a part of the TOGA (Tropical Ocean and Global Atmosphere) program. The array and the associated beam steering and indicating hardware are described.

  10. The OncoArray Consortium

    DEFF Research Database (Denmark)

    Amos, Christopher I; Dennis, Joe; Wang, Zhaoming

    2017-01-01

    BACKGROUND: Common cancers develop through a multistep process often including inherited susceptibility. Collaboration among multiple institutions, and funding from multiple sources, has allowed the development of an inexpensive genotyping microarray, the OncoArray. The array includes a genome-wi...

  11. Antifouling Ultrafiltration Membranes via Post-Fabrication Grafting of Biocidal Nanomaterials

    KAUST Repository

    Mauter, Meagan S.

    2011-08-24

    Figure Presented: Ultrafiltration (UF) membranes perform critical pre-treatment functions in advanced water treatment processes. In operational systems, however, biofouling decreases membrane performance and increases the frequency and cost of chemical cleaning. The present work demonstrates a novel technique for covalently or ionically tethering antimicrobial nanoparticles to the surface of UF membranes. Silver nanoparticles (AgNPs) encapsulated in positively charged polyethyleneimine (PEI) were reacted with an oxygen plasma modified polysulfone UF membrane with and without 1-ethyl-3-(3- dimethylaminopropyl) carbodiimide hydrochloride (EDC) present. The nucleophilic primary amines of the PEI react with the electrophilic carboxyl groups on the UF membrane surface to form electrostatic and covalent bonds. The irreversible modification process imparts significant antimicrobial activity to the membrane surface. Post-synthesis functionalization methods, such as the one presented here, maximize the density of nanomaterials at the membrane surface and may provide a more efficient route for fabricating diverse array of reactive nanocomposite membranes. © 2011 American Chemical Society.

  12. Antifouling ultrafiltration membranes via post-fabrication grafting of biocidal nanomaterials.

    Science.gov (United States)

    Mauter, Meagan S; Wang, Yue; Okemgbo, Kaetochi C; Osuji, Chinedum O; Giannelis, Emmanuel P; Elimelech, Menachem

    2011-08-01

    Ultrafiltration (UF) membranes perform critical pre-treatment functions in advanced water treatment processes. In operational systems, however, biofouling decreases membrane performance and increases the frequency and cost of chemical cleaning. The present work demonstrates a novel technique for covalently or ionically tethering antimicrobial nanoparticles to the surface of UF membranes. Silver nanoparticles (AgNPs) encapsulated in positively charged polyethyleneimine (PEI) were reacted with an oxygen plasma modified polysulfone UF membrane with and without 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) present. The nucleophilic primary amines of the PEI react with the electrophilic carboxyl groups on the UF membrane surface to form electrostatic and covalent bonds. The irreversible modification process imparts significant antimicrobial activity to the membrane surface. Post-synthesis functionalization methods, such as the one presented here, maximize the density of nanomaterials at the membrane surface and may provide a more efficient route for fabricating diverse array of reactive nanocomposite membranes.

  13. A Flow Method for Chemiluminescence Determination of Antimony(III) and Antimony(V) Using a Rhodamine B-Cetyltrimethylammonium Chloride Reversed Micelle System Following On-Line Extraction.

    Science.gov (United States)

    Hasanin, Tamer H A; Yamamoto, Tomoyuki; Okamoto, Yasuaki; Ishizaka, Shoji; Fujiwara, Terufumi

    2016-01-01

    A rapid and sensitive flow method, based on the combination of on-line solvent extraction with reversed micellar mediated chemiluminescence (CL) detection using rhodamine B (RB), was developed for the determination of antimony(III) and antimony(V) in aqueous samples. The on-line extraction procedure involved ion-pair formation of the antimony(V) chloro-complex anion with the protonated RBH(+) ion and its extraction from an aqueous hydrochloric acid solution into toluene, followed by phase separation using a microporous membrane. When in a flow cell of a detector, the ion-pair in the extract driven was mixed with the reversed micellar solution of cetyltrimethylammonium chloride in 1-hexanol-cyclohexane/water (0.60 mol dm(-3) H2SO4) containing cerium(IV), its uptake by the reversed micelles and the subsequent CL oxidation of RB with Ce(IV) occurred easily, then the produced CL signal was measured. Using the proposed flow method under the optimized experimental conditions, a detection limit (DL) of 0.35 μmol dm(-3) and a linear calibration graph with a dynamic range from DL to 16 μmol dm(-3) were obtained for Sb(V) with a precision of 1.4% relative standard deviation (n = 5) at the Sb(V) concentration of 8.2 μmol dm(-3). The present method was successfully applied to the determination of Sb(V) in water samples and to the differential determination of Sb(III) and Sb(V) in copper electrolyte industrial samples, where total antimony Sb(III) + Sb(V) was determined after oxidation of Sb(III) to Sb(V) with Ce(IV) and Sb(III) was calculated by difference, for which the DL was almost the same as that for Sb(V).

  14. Microporous silica membranes

    DEFF Research Database (Denmark)

    Boffa, Vittorio; Yue, Yuanzheng

    2012-01-01

    Hydrothermal stability is a crucial factor for the application of microporous silica-based membranes in industrial processes. Indeed, it is well established that steam exposure may cause densification and defect formation in microporous silica membranes, which are detrimental to both membrane...... permeability and selectivity. Numerous previous studies show that microporous transition metal doped-silica membranes are hydrothermally more stable than pure silica membranes, but less permeable. Here we present a quantitative study on the impact of type and concentration of transition metal ions...... on the microporous structure, stability and permeability of amorphous silica-based membranes, providing information on how to design chemical compositions and synthetic paths for the fabrication of silica-based membranes with a well accessible and highly stabile microporous structure....

  15. Chunking of Large Multidimensional Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Rotem, Doron; Otoo, Ekow J.; Seshadri, Sridhar

    2007-02-28

    Data intensive scientific computations as well on-lineanalytical processing applications as are done on very large datasetsthat are modeled as k-dimensional arrays. The storage organization ofsuch arrays on disks is done by partitioning the large global array intofixed size hyper-rectangular sub-arrays called chunks or tiles that formthe units of data transfer between disk and memory. Typical queriesinvolve the retrieval of sub-arrays in a manner that accesses all chunksthat overlap the query results. An important metric of the storageefficiency is the expected number of chunks retrieved over all suchqueries. The question that immediately arises is "what shapes of arraychunks give the minimum expected number of chunks over a query workload?"In this paper we develop two probabilistic mathematical models of theproblem and provide exact solutions using steepest descent and geometricprogramming methods. Experimental results, using synthetic workloads onreal life data sets, show that our chunking is much more efficient thanthe existing approximate solutions.

  16. Electrogenerated Chemiluminescence Resonance Energy Transfer between Ru(bpy)3(2+) Electrogenerated Chemiluminescence and Gold Nanoparticles/Graphene Oxide Nanocomposites with Graphene Oxide as Coreactant and Its Sensing Application.

    Science.gov (United States)

    Dong, Yong-Ping; Zhou, Ying; Wang, Jiao; Zhu, Jun-Jie

    2016-05-17

    In the present work, strong anodic electrogenerated chemiluminescence (ECL) of Ru(bpy)3(2+) was observed at a graphene oxide modified glassy carbon electrode (GO/GCE) in the absence of coreactants. The electrocatalytical effect of GO on the oxidation of Ru(bpy)3(2+) suggested that GO itself can act as the coreactant of Ru(bpy)3(2+) ECL, which can be used to fabricate the ECL biosensor. Thiol group terminated adenosine triphosphate (ATP) aptamer was immobilized on the GO film via DNA hybridization. When gold nanoparticles/graphene oxide (AuNPs/GO) nanocomposites were modified on the aptamer through the S-Au bond to form a sandwich-like structure, the ECL resonance energy transfer (ECL-RET) could occur between Ru(bpy)3(2+) and AuNPs/GO nanocomposites, resulting in an apparent decrease of ECL signal. After the ECL sensor was incubated in ATP solution, the AuNPs/GO nanocomposites were released from the electrode due to the specific interaction between aptamer and ATP, leading to the increased ECL signal. On the basis of these results, an ECL aptasensor was fabricated and could be used in the sensitive and selective detection of ATP in the range of 0.02-200 pM with a detection limit of 6.7 fM (S/N = 3). The proposed ECL aptasensor can be applied in the detection of ATP in real samples with satisfactory results.

  17. SAQC: SNP Array Quality Control

    Directory of Open Access Journals (Sweden)

    Li Ling-Hui

    2011-04-01

    Full Text Available Abstract Background Genome-wide single-nucleotide polymorphism (SNP arrays containing hundreds of thousands of SNPs from the human genome have proven useful for studying important human genome questions. Data quality of SNP arrays plays a key role in the accuracy and precision of downstream data analyses. However, good indices for assessing data quality of SNP arrays have not yet been developed. Results We developed new quality indices to measure the quality of SNP arrays and/or DNA samples and investigated their statistical properties. The indices quantify a departure of estimated individual-level allele frequencies (AFs from expected frequencies via standardized distances. The proposed quality indices followed lognormal distributions in several large genomic studies that we empirically evaluated. AF reference data and quality index reference data for different SNP array platforms were established based on samples from various reference populations. Furthermore, a confidence interval method based on the underlying empirical distributions of quality indices was developed to identify poor-quality SNP arrays and/or DNA samples. Analyses of authentic biological data and simulated data show that this new method is sensitive and specific for the detection of poor-quality SNP arrays and/or DNA samples. Conclusions This study introduces new quality indices, establishes references for AFs and quality indices, and develops a detection method for poor-quality SNP arrays and/or DNA samples. We have developed a new computer program that utilizes these methods called SNP Array Quality Control (SAQC. SAQC software is written in R and R-GUI and was developed as a user-friendly tool for the visualization and evaluation of data quality of genome-wide SNP arrays. The program is available online (http://www.stat.sinica.edu.tw/hsinchou/genetics/quality/SAQC.htm.

  18. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become

  19. Planning a Global Array of Broadband Seismic Arrays

    Science.gov (United States)

    Koper, Keith D.; Ammon, Charles J.

    2013-08-01

    A diverse group of more than 70 seismologists met for 2 days in Raleigh, N.C., to report on recent innovations in seismic array methods and to discuss the future of seismic arrays in global seismology. The workshop was sponsored by the Incorporated Research Institutions for Seismology (IRIS), with U.S. National Science Foundation funding. Participants included representatives of existing array research groups in Australia, Canada, Germany, Japan, Norway, and the United States, with individuals from academia, government, and industry. The workshop was organized by the authors of this meeting report, Pablo Ampeuro (California Institute of Technology), and Colleen Dalton (Boston University), along with IRIS staff support.

  20. Domain organization of photosystem II in membranes of the cyanobacterium Synechocystis PCC6803 investigated by electron microscopy

    NARCIS (Netherlands)

    Folea, I. Mihaela; Zhang, Pengpeng; Aro, Eva-Mari; Boekema, Egbert J.

    2008-01-01

    The supramolecular organization of photosystem II (PSII) complexes in the photosynthetic membrane of the cyanobacterium Synechocystis 6803 was studied by electron microscopy. After mild detergent solubilization, crystalline PSII arrays were extracted in which dimeric PSII particles associate in

  1. Dependently typed array programs don’t go wrong

    NARCIS (Netherlands)

    Trojahner, K.; Grelck, C.

    2009-01-01

    The array programming paradigm adopts multidimensional arrays as the fundamental data structures of computation. Array operations process entire arrays instead of just single elements. This makes array programs highly expressive and introduces data parallelism in a natural way. Array programming

  2. Dependently typed array programs don't go wrong

    NARCIS (Netherlands)

    Trojahner, K.; Grelck, C.

    2008-01-01

    The array programming paradigm adopts multidimensional arrays as the fundamental data structures of computation. Array operations process entire arrays instead of just single elements. This makes array programs highly expressive and introduces data parallelism in a natural way. Array programming

  3. Emulsification using microporous membranes

    Directory of Open Access Journals (Sweden)

    Goran T. Vladisavljević

    2011-10-01

    Full Text Available Membrane emulsification is a process of injecting a pure dispersed phase or pre-emulsion through a microporous membrane into the continuous phase. As a result of the immiscibility of the two phases, droplets of the dispersed phase are formed at the outlets of membrane pores. The droplets formed in the process are removed from the membrane surface by applying cross-flow or stirring of the continuous phase or using a dynamic (rotating or vibrating membrane. The most commonly used membrane for emulsification is the Shirasu Porous Glass (SPG membrane, fabricated through spinodal decomposition in a melt consisting of Japanese volcanic ash (Shirasu, boric acid and calcium carbonate. Microsieve membranes are increasingly popular as an alternative to highly tortuous glass and ceramic membranes. Microsieves are usually fabricated from nickel by photolithography and electroplating or they can be manufactured from silicon nitride via Reactive Ion Etching (RIE. An advantage of microsieves compared to the SPG membrane is in much higher transmembrane fluxes and higher tolerance to fouling by the emulsion ingredients due to the existence of short, straight through pores. Unlike conventional emulsification devices such as high-pressure valve homogenisers and rotor-stator devices, membrane emulsification devices permit a precise control over the mean pore size over a wide range and during the process insignificant amount of energy is dissipated as heat. The drop size is primarily determined by the pore size, but it depends also on other parameters, such as membrane wettability, emulsion formulation, shear stress on the membrane surface, transmembrane pressure, etc.

  4. Possibility of using salivary ultra-weak chemiluminescence as a biomarker for feelings of anxiety in hospital settings.

    Science.gov (United States)

    Hiramatsu, Mitsuo; Chida, Kingo; Hashimoto, Dai; Takamoto, Hisayoshi; Honzawa, Katsu; Okada, Hiroyuki; Nakamura, Kimitsugu; Takagi, Kuniaki

    2016-11-01

    The aim of this study was to assess whether a particular value of noninvasive salivary ultra-weak chemiluminescence (UCL) could be used as a biomarker of psychological stress. Our study covered two groups. Group 1 comprised six healthy volunteers who stayed in a hospital for one night and group 2 comprised 15 patients with lung cancer and 24 patients with respiratory diseases other than lung cancer who were in hospital for an extended stay. First, we evaluated the UCL of saliva from six healthy volunteers before and after one night in hospital. Immunoglobulin A (IgA) concentrations were also measured. The integrated intensity value of UCL was correlated with the IgA concentration (correlation coefficient 0.90). Second, in the case of a long hospital stay, we found that the maximum salivary UCL intensities were higher in patients with lung cancer than in those with respiratory diseases other than lung cancer or in 28 healthy controls. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. [Determination of sulfur compounds in fluid catalytic cracking gasoline by gas chromatography with a sulfur chemiluminescence detector].

    Science.gov (United States)

    Yang, Yongtan; Wang, Zheng; Zong, Baoning; Yang, Haiying

    2004-05-01

    A method for the separation and determination of sulfur compounds in fluid catalytic cracking gasoline (FCC gasoline) by gas chromatography with a sulfur chemiluminescence detector (GC-SCD) was established. Fifty eight sulfur compounds including mercaptan, sulfide, disulfide, thiophene, alkyl thiophenes, benzothiophene and alkyl benzothiophenes were identified based on their retention indexes and the data obtained from gas chromatography with an atomic emission detector (GC-AED). The effects of flow rate of carrier gas and oven temperature were discussed. Detection reproducibilities of main sulfur compounds (thiophene, n-butyl mercaptan, 2-methylthiophene, 3-methylthiophene, 2,4-dimethylthiophene) in FCC gasoline were satisfactory (RSDs were no more than 5.0%) and detection limit for sulfur was 0.1 mg/L. Using thiophene and benzothiophene as testing samples, it was determined that response factor was independent of the molecular structure of sulfur compounds. The linear range was 0.5-800.0 mg/L sulfur with a correlation coefficient of 0.999.

  6. A lab-on-a-chip device for analysis of amlodipine in biological fluids using peroxyoxalate chemiluminescence system.

    Science.gov (United States)

    Al Lawati, Haider A J; Al-Nadabi, Mira M; Varma, Gouri B; Suliman, Fakhr Eldin O; Al-Abri, Hasnaa

    2014-12-01

    A highly sensitive, rapid and economical method for the determination of amlodipine (AM) in biological fluids was developed using a peroxyoxalate chemiluminescence (CL) system in a lab-on-a-chip device. Peroxyoxalate-CL is an indirect type of CL that allows the detection of native fluorophores or compounds derivatized with fluorescent labels. Here, fluorescamine was reacted with AM, and the derivatization product was used in a bis-(2,4,6-trichlorophenyl)oxalate-CL system. Fluorescamine reacts selectively with aliphatic primary amine at neutral or basic pH. As most of the calcium channel blocker and many cardiovascular drugs do not contain primary amine, the developed method is highly selective. The parameters that influenced the CL signal intensity were studied carefully. These included the chip geometry, pH, concentration of reagents used and flow rates. Moreover, we confirmed our previous observation about the effects of imidazole, which is commonly used in the bis-(2,4,6-trichlorophenyl)oxalate-CL system as a catalyst, and found that the signal was significantly improved when imidazole was absent. Under optimized conditions, a calibration curve was obtained with a linear range (10-100 µg/L). The limit of detection was 3 µg/L, while the limit of quantification was 10 µg/L. Finally the method was applied for the determination of AM in biological fluids successfully. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Development of a wireless, self-sustaining damage detection sensor system based on chemiluminescence for structural health monitoring

    Science.gov (United States)

    Kuang, K. S. C.

    2014-03-01

    A novel application of chemiluminescence resulting from the chemical reaction in a glow-stick as sensors for structural health monitoring is demonstrated here. By detecting the presence of light emitting from these glow-sticks, it is possible to develop a low-cost sensing device with the potential to provide early warning of damage in a variety of engineering applications such as monitoring of cracks or damage in concrete shear walls, detecting of ground settlement, soil liquefaction, slope instability, liquefaction-related damage of underground structure and others. In addition, this paper demonstrates the ease of incorporating wireless capability to the sensor device and the possibility of making the sensor system self-sustaining by means of a renewable power source for the wireless module. A significant advantage of the system compared to previous work on the use of plastic optical fibre (POF) for damage detection is that here the system does not require an electrically-powered light source. Here, the sensing device, embedded in a cement host, is shown to be capable of detecting damage. A series of specimens with embedded glow-sticks have been investigated and an assessment of their damage detection capability will be reported. The specimens were loaded under flexure and the sensor responses were transmitted via a wireless connection.

  8. Novel chemiluminescence immunoassay for the determination of zearalenone in food samples using gold nanoparticles labeled with streptavidin-horseradish peroxidase.

    Science.gov (United States)

    Wang, Yuan-Kai; Yan, Ya-Xian; Ji, Wen-Hui; Wang, Heng-an; Zou, Qi; Sun, Jian-He

    2013-05-08

    A novel highly sensitive chemiluminescence immunoassay (CLIA) was developed to detect zearalenone in food samples by using both biotinylated zearalenone conjugates and gold (Au) nanoparticles labeled with streptavidin-horseradish peroxidase for signal amplification. Biotinylated zearalenone-ovalbumin conjugates and Au nanoparticles labeled with streptavidin-horseradish peroxidase were synthesized separately. The concentrations of immunoreagents and the reaction times of these immunoreagents were optimized to improve the performances of analytical methods. For the CLIA based on biotinylated zearalenone conjugates and Au nanoparticles labeled with streptavidin-horseradish peroxidase, the limit of detection was 0.008 ng/mL and the IC50 was 0.11 ng/mL. The linear working range was 0.02-0.51 ng/mL. The cross-reactivities with the zearalenone analogues (α-zearalanol, zearalanone, α-zearalenol, β-zearalanol, and β-zearalenol) were 32, 17, 12, 0.3, and 0.1%, respectively. The recovery rates in spiked food samples were 97-117%, and the intraday and interday relative standard deviations were both <10%. Parallel analysis of natural food samples showed a good correlation between this novel CLIA and liquid chromatography-tandem mass spectrometry. This method provides a rapid, accurate, and highly sensitive method to determine levels of zearalenone in food samples.

  9. Single and multiplexed immunoassays for the chemiluminescent imaging detection of animal glues in historical paint cross-sections.

    Science.gov (United States)

    Sciutto, G; Dolci, L S; Guardigli, M; Zangheri, M; Prati, S; Mazzeo, R; Roda, A

    2013-01-01

    The characterization of the organic components in a complex, multilayered paint structure is fundamental for studying painting techniques and for authentication and restoration purposes. Proteinaceous materials, such as animal glue, are of particular importance since they are widely used as binders, adhesives and for gilding. Even though proteins are usually detected by chromatographic and proteomic techniques, immunological methods represent an alternative powerful approach to protein analysis thanks to the high specificity of antigen-antibody reactions. Our previous studies demonstrated that ovalbumin and casein could be localized in paint cross-sections with high sensitivity and good spatial resolution (i.e. within the single painting layers) by using chemiluminescent (CL) immunochemical microscope imaging. In the present research work, we describe for the first time the immunolocalization of collagen (the main protein of animal glue) in paint cross-sections by CL imaging microscopy. Two different analytical protocols have been developed, allowing either the detection of collagen or the simultaneous detection of collagen and ovalbumin in the same paint sample. The assays were used to detect collagen and ovalbumin in cross-sections from model samples and historical paintings (a wall painting dated to 1773-1774 and a painted wood panel of the Renaissance period) in order to achieve information on paint techniques and past restoration interventions.

  10. The chemiluminescence determination of 2-chloroethyl ethyl sulfide using luminol-AgNO3-silver nanoparticles system

    Science.gov (United States)

    Maddah, Bozorgmehr; Shamsi, Javad; Barsang, Mehran Jam; Rahimi-Nasrabadi, Mehdi

    2015-05-01

    A highly sensitive chemiluminescence (CL) method for the determination of 2-chloroethyl ethyl sulfide (2-CEES) was presented. It was found that 2-chloroethyl ethyl sulfide (2-CEES) could inhibit the CL of the luminol-AgNO3 system in the presence of silver nanoparticles in alkaline solution, which made it applicable for determination of 2-CEES. The presented method is simple, convenient, rapid and sensitive. Under the optimized conditions, the calibration curve was linear in the range of 0.0001-1 ng mL-1, with the correlation coefficient of 0.992; while the limit of detection (LOD), based on signal-to-noise ratio (S/N) of 3, was 6 × 10-6 ng mL-1. Also, the relative standard deviation (RSD, n = 5) for determination of 2-CEES (0.50 ng mL-1) was 3.1%. The method was successfully applied for the determination of 2-CEES in environmental aqueous samples.

  11. Evaluation of serum bone alkaline phosphatase activity in patients with liver disease: Comparison between electrophoresis and chemiluminescent enzyme immunoassay.

    Science.gov (United States)

    Zhan, Fangjie; Watanabe, Yoshihisa; Shimoda, Aya; Hamada, Etsuko; Kobayashi, Yoshimasa; Maekawa, Masato

    2016-09-01

    Serum bone alkaline phosphatase (ALP) is a marker of bone formation and metabolism. However, existing methods for measuring it have their limitations and their accuracy has not been determined. We measured serum bone ALP activity in 127 patients with liver disease using 2 methods: electrophoresis and chemiluminescent enzyme immunoassay (CLEIA). The results of these 2 methods were compared and analyzed according to gender, age and several serum biochemical markers. When ALP3 (%; bone-type isozyme activity as a percentage of total ALP activity) values were high, the 2 methods showed good correlation. However, with a decrease in ALP3 (%) levels, the correlation coefficient (R) also decreased. Starting with ALP3 (%)0.05). Five outliers displayed low ALP3 (%) activity levels. Furthermore, in regard to genders, there were significant differences in total cholesterol (TC), γ-glutamyltransferase (γ-GTP), ALP and ALP3 (%) levels (pliver disease, the accuracy of electrophoresis was comparable to that of CLEIA. However, the accuracy of electrophoresis needs to be evaluated with further when patient samples under certain conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Development of 1,1'-oxalyldiimidazole chemiluminescent biosensor using the combination of graphene oxide and hairpin aptamer and its application.

    Science.gov (United States)

    Kwun, Joonsuh; Yun, Soyong; Park, Lucienne; Lee, Ji Hoon

    2014-02-01

    Highly sensitive biosensor with 1,1'-oxalyldiimidazole chemiluminescence (ODI-CL) detection was developed to rapidly quantify Vibrio (V) parahaemolyticus without time-consuming procedures such as multiple long-incubations and washings. When V. parahaemolyticus in Tris-HCl (pH 7) and hairpin DNA aptamer conjugated with TEX615 in DNA free deionized water were consecutively added in PBS buffer (pH 7.4) containing graphene oxides (GOs), V. parahaemolyticus and GOs bind competitively to hairpin DNA aptamer conjugated with TEX615 during 10 min of incubation at room temperature. Brightness of light immediately emitted with the addition of ODI-CL reagents (e.g., ODI, H2O2) after the incubation was dependent on the concentration of V. parahaemolyticus in a sample. The dynamic range of linear calibration curve for the quantification of V. parahaemolyticus in a sample was from 4375 to 70,000 cells/ml. The limit of detection (LOD = background + 3 × standard deviation, 2230 cells/ml) of the biosensor operated with good accuracy, precision, and recovery was lower than those of conventional assay methods such as time-consuming and expensive enzyme-linked immunosorbent assays. © 2013 Published by Elsevier B.V.

  13. Increased chemiluminescence and ulcer development in the low blood flow state of the gastric tube for esophageal replacement.

    Science.gov (United States)

    Aiko, S; Ando, N; Shinozawa, Y; Ozawa, S; Kitajima, M; Kurose, I; Tsuchiya, M

    1993-01-01

    Peptic ulcers in the gastric tube for esophageal replacement develop in spite of reduction of acid secretion after truncal vagotomy and often result in serious conditions such as bleeding and perforation. Thirteen cases of gastric tube ulcers were detected endoscopically from 1985 to 1990 in our hospital. Most of these ulcers developed within 20 cm of the anastomosis (esophagogastrostomy), which was an especially hypoxic and ischemic area. Ischemic change due to decreased blood supply is suggested as a causative factor in ulcer development. Recent studies indicate that chemiluminescence (ChL) activity may increase even in the low-flow hypoxic condition. Therefore, we investigated the ChL of regional blood in the hypoxic gastric tube in dogs. The ChL activity of the blood sample collected from the ischemic region in the gastric tube significantly increased after construction of the gastric tube, compared with systemic blood from the femoral vein, and the number of leukocytes decreased in the ischemic region. We believe that oxygen radicals derived from neutrophils adhering to the vascular endothelium may play an important role in the damage to endothelial cells of the gastric tube and suggest the possibility of their causative effects in the process of ulcer formations.

  14. A chemiluminescence reagent free method for the determination of captopril in medicine and urine samples by using trivalent silver

    Directory of Open Access Journals (Sweden)

    Zhaofu Fu

    2017-08-01

    Full Text Available A novel flow-injection chemiluminescence (FI-CL method free of CL reagent was developed for the determination of captopril based on its enhancing effect on the CL derived from diperiodatoargentate(III-sulfuric acid system. Compared with the conventional CL system, the CL system based on trivalent silver was characterized of good selectivity for the absence of CL reagent. The CL mechanism was discussed through CL spectra and UV–vis absorption spectra. The conditions of the FI-CL system were investigated and optimized. Under the optimal conditions, the relative CL intensity was linear with the captopril concentration in the range of 0.3–15.0 μg/mL. The detection limit for captopril was 0.05 μg/mL, and the relative standard deviation (n=11 was 2.0% for 5.0 μg/mL captopril. The proposed method was applied to the analysis of captopril in tablet and human urine with the recoveries of 83.1%–112.5%, and the relative standard deviations of 0.5%–4.4%. The results obtained by the proposed method agreed well with those obtained from HPLC method. The proposed method is fast, convenient, and cost-effective for the determination of captopril in medicine and biological samples.

  15. In vitro inhibitory effects of Moringa oleifera leaf extract and its major components on chemiluminescence and chemotactic activity of phagocytes.

    Science.gov (United States)

    Vongsak, Boonyadist; Gritsanapan, Wandee; Wongkrajang, Yuvadee; Jantan, Ibrahim

    2013-11-01

    The ethanol extract of Moringa oleifera Lam. leaves and its major constituents, crypto-chlorogenic acid, quercetin 3-O-glucoside and kaempferol 3-O-glucoside, were investigated on the respiratory burst of human whole blood and isolated human polymorphonuclear leukocytes (PMNs) using a luminol-based chemiluminescence assay. The chemotactic migration of PMNs was also investigated using the Boyden chamber technique. The ethanol extract demonstrated inhibitory activities on the oxidative burst and the chemotactic migration of PMNs. Quercetin 3-O-glucoside, crypto-chlorogenic acid, and kaempferol 3-O-glucoside, isolated from the extract, expressed relatively strong inhibitory activity on the oxidative burst of PMNs with IC50 values of 4.1, 6.7 and 7.0 microM, respectively, comparable with that of aspirin. They also demonstrated strong inhibition of chemotatic migration of PMNs with IC50 values of 9.5, 15.9 and 18.2 microM, respectively. The results suggest that M. oleifera leaves could modulate the immune response of human phagocytes, linking to its ethnopharmacological use as an anti-inflammatory agent. The immunomodulating activity of the plant was mainly due to its major components.

  16. Assessment of antioxidant activity of spray dried extracts of Psidium guajava leaves by DPPH and chemiluminescence inhibition in human neutrophils.

    Science.gov (United States)

    Fernandes, M R V; Azzolini, A E C S; Martinez, M L L; Souza, C R F; Lucisano-Valim, Y M; Oliveira, W P

    2014-01-01

    This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and β -cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH(•) method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells.

  17. Development of a solid-phase extraction coupling chemiluminescent enzyme immunoassay for determination of organophosphorus pesticides in environmental water samples.

    Science.gov (United States)

    Xu, Zhen-Lin; Sun, Wen-Jia; Yang, Jin-Yi; Jiang, Yue-Ming; Campbell, Katrina; Shen, Yu-Dong; Lei, Hong-Tao; Zeng, Dao-Ping; Wang, Hong; Sun, Yuan-Ming

    2012-03-07

    Solid-phase extraction (SPE) and direct competitive chemiluminescence enzyme immunoassay (dcCL-EIA) were combined for the detection of organophosphorus pesticides (OPs) in environmental water samples. dcCL-EIA based on horseradish peroxidase labeled with a broad-specificity monoclonal antibody against OPs was developed, and the effects of several physicochemical parameters on dcCL-EIA performance were studied. SPE was used for the pretreatment of water samples to remove interfering substances and to concentrate the OP analytes. The coupling of SPE and dcCL-EIA can detect seven OPs (parathion, coumaphos, phoxim, quinalphos, triazophos, dichlofenthion, and azinphos-ethyl) with the limit of quantitation below 0.1 ng/mL. The recoveries of OPs from spiked water samples ranged from 62.5% to 131.7% by SPE-dcCL-EIA and 69.5% to 112.3% by SPE-HPLC-MS/MS. The screening of OP residues in real-world environmental water samples by the developed SPE-dcCL-EIA and their confirmatory analysis using SPE-HPLC-MS/MS demonstrated that the assay is ideally suited as a monitoring method for OP residues prior to chromatographic analysis.

  18. Ultra-sensitive chemiluminescence imaging DNA hybridization method in the detection of mosquito-borne viruses and parasites.

    Science.gov (United States)

    Zhang, Yingjie; Liu, Qiqi; Zhou, Biao; Wang, Xiaobo; Chen, Suhong; Wang, Shengqi

    2017-01-25

    Mosquito-borne viruses (MBVs) and parasites (MBPs) are transmitted through hematophagous arthropods-mosquitoes to homoiothermous vertebrates. This study aims at developing a detection method to monitor the spread of mosquito-borne diseases to new areas and diagnose the infections caused by MBVs and MBPs. In this assay, an ultra-sensitive chemiluminescence (CL) detection method was developed and used to simultaneously detect 19 common MBVs and MBPs. In vitro transcript RNA, virus-like particles (VLPs), and plasmids were established as positive or limit of detection (LOD) reference materials. MBVs and MBPs could be genotyped with high sensitivity and specificity. The cut-off values of probes were calculated. The absolute LODs of this strategy to detect serially diluted in vitro transcribed RNAs of MBVs and serially diluted plasmids of MBPs were 10 2 -10 3 copies/μl and 10 1 -10 2 copies/μl, respectively. Further, the LOD of detecting a strain of pre-quantified JEV was 10 1.8 -10 0.8 PFU/ml, fitted well in a linear regression model (coefficient of determination = 0.9678). Ultra-sensitive CL imaging DNA hybridization was developed and could simultaneously detect various MBVs and MBPs. The method described here has the potential to provide considerable labor savings due to its ability to screen for 19 mosquito-borne pathogens simultaneously.

  19. Paramecium caudatum as a source of nitric oxide: Chemiluminescent detection based on Bluestar(®) Forensic reagent connected with microdialysis.

    Science.gov (United States)

    Bancirova, Martina

    2017-11-01

    Nitric oxide (NO) chemistry inside the body is the most interesting part of its behavior. NO is involved in controlling blood pressure, and in transmitting nerve signals and a variety of other signaling processes. To explain the behavior of NO, it is necessary to determine its immediate concentration or observe time-dependent changes in its concentration. In Paramecium caudatum, NO is formed by calcium-dependent nNOS (NOS1)-like protein, which is distributed in the cytoplasm. NO synthesis affects the ciliary beat and consequent motility of cells and blocked NO synthesis reduces the ability of cells to move. The possibility of online coupling of microdialysis (of P. caudatum solution) with NO detection is demonstrated. Direct measurement of NO is carried out using dilute Bluestar(®) Forensic reagent (luminol-H2 O2 system; one of the NO detections is based upon the chemiluminescent reaction between NO and the luminol-H2 O2 system, which is specifically reactive to NO). The effect of a nitric oxide synthase inhibitor, NG-nitro-l-arginine methyl ester was observed. NO production was inhibited and the movement of P. caudatum was restricted. These effects were time dependent and after a specific time were reversed. Copyright © 2017 John Wiley & Sons, Ltd.

  20. Simultaneous determination of amiodarone and its metabolite desethylamiodarone by high-performance liquid chromatography with chemiluminescent detection

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Ruiz, Tomas [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain)], E-mail: tpr@um.es; Martinez-Lozano, Carmen; Garcia-Martinez, Maria Dolores [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain)

    2008-08-08

    A novel method was developed for the determination of amiodarone and desethylamiodarone by high-performance liquid chromatography (HPLC) coupled with chemiluminescent (CL) detection. The procedure is based on the post-column photolysis of the analytes into photoproducts which are active in the tris(2,2'-bipyridyl)ruthenium(III) [Ru(bpy){sub 3}{sup 3+}] CL system. Ru(bpy){sub 3}{sup 3+} was on-line generated by photo-oxidation of the Ru(II) complex in the presence of peroxydisulfate. The separation was carried out on a Mediterranea C{sub 18} column with isocratic elution using a mixture of methanol and 0.017 mol L{sup -1} ammonium sulfate buffer of pH 6.8. Under the optimum conditions, analytical curves, based on standard solutions, were linear over the range 0.1-50 {mu}g mL{sup -1} for amiodarone and 0.5-25 {mu}g mL{sup -1} for desethylamiodarone. The detection limits of amiodarone and desethylamiodarone were 0.02 and 0.11 {mu}g mL{sup -1}, respectively. Intra- and inter-day precision values of 0.9% relative standard deviation (R.S.D.) (n = 10) and 1.6% R.S.D. (n = 15), respectively, were obtained. The method was applied successfully to the determination of these compounds in serum and pharmaceutical formulations.

  1. 1,10-Phenanthroline-H2O2-KSCN-CuSO4-NaOH oscillating chemiluminescence system.

    Science.gov (United States)

    Sorouraddin, M H; Iranifam, M

    2009-01-01

    In this paper, oscillating chemiluminescence (CL), 1,10-phenanthroline H2O2-KSCN-CuSO4-NaOH system, was studied in a batch reactor. The system described is a novel, slowly damped oscillating CL system, generated by coupling the well-known Epstein-Orban, H2O2-KSCN-CuSO4-NaOH chemical oscillator reaction with the CL reaction involving the oxidation of 1,10-phenanthroline by hydrogen peroxide, catalyzed by copper(II) in alkaline medium. In this system, the CL reaction acts as a detector or indicator system of the far-from-equilibrium dynamic system. Narrow and slightly asymmetric light pulses of 1.2 s half-width are emitted at 440 nm with an emitted light time of 200-1000 s, induction period of 3.5-357 s and oscillation period of 28-304 s depending on the reagent concentrations. In this report the effect of the concentration variation of components involved in the oscillating CL system on the induction period, the oscillation period and amplitude was investigated and the parameters were plotted with respect to reagent concentrations. Copper concentration showed a significant effect on the oscillation period. The possible mechanism for the oscillating CL reaction was also discussed.

  2. Effects of multi-walled carbon nanotubes on the electrogenerated chemiluminescence and fluorescence of CdTe quantum dots.

    Science.gov (United States)

    Wusimanjiang, Yiliyasi; Meyer, Alexander; Lu, Liping; Miao, Wujian

    2016-10-01

    Effects of multi-walled carbon nanotubes (CNTs) that were immobilized on glassy carbon electrode (GCE) on the electrogenerated chemiluminescence (ECL) of CdTe quantum dots (QDs) using tri-n-propylamine (TPrA) and 2-(dibutylamino)ethanol (DBAE) as the anodic coreactant are reported. Depending on the solution concentration of coreactant and QDs, the surface-confined CNTs could either quench or enhance the ECL intensity. Lowering the solution concentration of QDs was found to be beneficial for enhancing ECL. A V-shaped profile of ECL intensity ratio (at CNTs over bare GCE) versus coreactant concentration suggested that either low or high concentrations of coreactant were needed for effective ECL generation. The ECL quenching by CNTs was believed to follow the typical dynamic quenching mechanism, which was confirmed by fluorescent data that provided a Stern-Volmer and an estimated quenching constant of 11.7 g/L and 1.2 × 10(9) L/g•s, respectively, for the excited state CdTe* quenching by CNTs in solution. Furthermore, the ECL performance at CNTs was also affected by the type of the coreactant used, where up to 30 times enhancement in ECL was observed from the CdTe/DBAE system under the given experimental conditions. Graphical Abstract Illustration of anodic quantum dots ECL enhancement and quenching by multi-walled carbon nanotubes.

  3. Solid-phase receptor-based assay for the detection of cyclic imines by chemiluminescence, fluorescence, or colorimetry.

    Science.gov (United States)

    Rodríguez, Laura P; Vilariño, Natalia; Molgó, Jordi; Aráoz, Rómulo; Antelo, Alvaro; Vieytes, Mercedes R; Botana, Luis M

    2011-08-01

    The spirolides and gymnodimines are marine phycotoxins included in the group of cyclic imines. The toxicity of these compounds to humans is still unknown, although their toxicity by intraperitoneal injection in rodents is very high. A receptor-based method was developed using the competition of the 13-desmethyl spirolide C with biotin-labeled α-bungarotoxin for binding to nicotinic acetylcholine receptors and the immobilization of the α-bungarotoxin-receptor complex on streptavidin-coated surfaces. The quantification of the immobilized receptor can be achieved using a specific antibody. Finally, after the addition of a secondary antibody labeled with horseradish peroxidase, three alternative substrates of this enzyme generate a chemiluminescent, fluorescent, or colorimetric signal. The assay performs well in shellfish extracts and the detection range is 5-150 nM of 13-desmethyl spirolide C in shellfish extracts, which is at least 5 times more sensitive than the existing fluorescence polarization assay. This assay can also detect gymnodimine, although with 10 times lower sensitivity than the spirolide. The detection of cyclic imines with microplate assays would be useful for screening purposes in order to reduce the number of samples to be processed by bioassays or analytical methods.

  4. Offering an Array of Improvements

    Science.gov (United States)

    2001-01-01

    Sensors Unlimited, Inc., with SBIR funding from NASA's Langley Research Center, Goddard Space Flight Center, Marshall Space Flight Center, and the Jet Propulsion Laboratory, developed a monolithic focal plane array for near-infrared imaging. The company developed one- (1- D) and two-dimensional (2-D) imaging arrays consisting of a highly reliable InGaAs p-I-n diode as a photodetector for monitoring a variety of applications, including single element device applications in receivers. The InGaAs 1-D and 2-D arrays have many applications. For example, they monitor the performance of dense wavelength division multiplexing (DWDM) systems- the process of packaging many channels into a single fiber-optic cable. Sensors Unlimited commercially offers its LXTM and LYTM Series InGaAs linear arrays for reliable DWDM performance monitoring. The LX and LY arrays enable instrument module designs with no moving parts, which provides for superior uniformity, and fast, linear outputs that remain stable over a wide temperature range. Innovative technologies derived from the monolithic focal plane array have enabled telecommunication companies to optimize existing bandwidth in their fiber-optic networks in order to support a high volume of network traffic. At the same time, the technologies obtained from the array have the potential for reducing costs, while increasing performance from Sensors Unlimited's current product lines.

  5. Efficient array design for sonotherapy

    Science.gov (United States)

    Stephens, Douglas N.; Kruse, Dustin E.; Ergun, Arif S.; Barnes, Stephen; Lu, X. Ming; Ferrara, Katherine W.

    2008-07-01

    New linear multi-row, multi-frequency arrays have been designed, constructed and tested as fully operational ultrasound probes to produce confocal imaging and therapeutic acoustic intensities with a standard commercial ultrasound imaging system. The triple-array probes and imaging system produce high quality B-mode images with a center row imaging array at 5.3 MHz and sufficient acoustic power with dual therapeutic arrays to produce mild hyperthermia at 1.54 MHz. The therapeutic array pair in the first probe design (termed G3) utilizes a high bandwidth and peak pressure, suitable for mechanical therapies. The second multi-array design (termed G4) has a redesigned therapeutic array pair which is optimized for a high time-averaged power output suitable for mild hyperthermia applications. The 'thermal therapy' design produces more than 4 W of acoustic power from the low-frequency arrays with only a 10.5 °C internal rise in temperature after 100 s of continuous use with an unmodified conventional imaging system or substantially longer operation at lower acoustic power. The low-frequency arrays in both probe designs were examined and contrasted for real power transfer efficiency with a KLM model which includes all lossy contributions in the power delivery path from system transmitters to the tissue load. Laboratory verification was successfully performed for the KLM-derived estimates of transducer parallel model acoustic resistance and dissipation resistance, which are the critical design factors for acoustic power output and undesired internal heating, respectively.

  6. Efficient array design for sonotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Stephens, Douglas N; Kruse, Dustin E; Ferrara, Katherine W [University of California, Davis, CA (United States); Ergun, Arif S; Barnes, Stephen [Siemens Corporate Research, Inc., Imaging and Visualization, 755 College Road East, Princeton, New Jersey 08540 (United States); Lu, X Ming [Siemens Medical Solutions, 22010 SE 51st Street, Issaquah, Washington 98029-7298 (United States)], E-mail: dnstephens@ucdavis.edu, E-mail: kwferrara@ucdavis.edu

    2008-07-21

    New linear multi-row, multi-frequency arrays have been designed, constructed and tested as fully operational ultrasound probes to produce confocal imaging and therapeutic acoustic intensities with a standard commercial ultrasound imaging system. The triple-array probes and imaging system produce high quality B-mode images with a center row imaging array at 5.3 MHz and sufficient acoustic power with dual therapeutic arrays to produce mild hyperthermia at 1.54 MHz. The therapeutic array pair in the first probe design (termed G3) utilizes a high bandwidth and peak pressure, suitable for mechanical therapies. The second multi-array design (termed G4) has a redesigned therapeutic array pair which is optimized for a high time-averaged power output suitable for mild hyperthermia applications. The 'thermal therapy' design produces more than 4 W of acoustic power from the low-frequency arrays with only a 10.5 deg. C internal rise in temperature after 100 s of continuous use with an unmodified conventional imaging system or substantially longer operation at lower acoustic power. The low-frequency arrays in both probe designs were examined and contrasted for real power transfer efficiency with a KLM model which includes all lossy contributions in the power delivery path from system transmitters to the tissue load. Laboratory verification was successfully performed for the KLM-derived estimates of transducer parallel model acoustic resistance and dissipation resistance, which are the critical design factors for acoustic power output and undesired internal heating, respectively.

  7. Broadband phased-arrays antennas

    Science.gov (United States)

    Mansky, L.

    1984-09-01

    The actual jamming-to-signal ratio achieved in an electronic countermeasures (ECM) system depends on the effective radiated power (ERP) directed toward the radar by the ECM system. The required ERP may be obtained in a phase-steered array using a variety of transmit-subsystem hardware configurations. Here, tradeoff criteria to aid in the selection of an optimal architecture are discussed. Such selection is based on minimizing the array size, backscattering cross selection, and overall system complexity. Functional elements of typical phased arrays and their principal components are descried.

  8. Pulse Dispersion in Phased Arrays

    Directory of Open Access Journals (Sweden)

    Randy L. Haupt

    2017-01-01

    Full Text Available Phased array antennas cause pulse dispersion when receiving or transmitting wideband signals, because phase shifting the signals does not align the pulse envelopes from the elements. This paper presents two forms of pulse dispersion that occur in a phased array antenna. The first results from the separation distance between the transmit and receive antennas and impacts the definition of far field in the time domain. The second is a function of beam scanning and array size. Time delay units placed at the element and/or subarrays limit the pulse dispersion.

  9. Fundamentals of ultrasonic phased arrays

    CERN Document Server

    Schmerr, Lester W

    2014-01-01

    This book describes in detail the physical and mathematical foundations of ultrasonic phased array measurements.?The book uses linear systems theory to develop a comprehensive model of the signals and images that can be formed with phased arrays. Engineers working in the field of ultrasonic nondestructive evaluation (NDE) will find in this approach a wealth of information on how to design, optimize and interpret ultrasonic inspections with phased arrays. The fundamentals and models described in the book will also be of significant interest to other fields, including the medical ultrasound and

  10. Antenna arrays a computational approach

    CERN Document Server

    Haupt, Randy L

    2010-01-01

    This book covers a wide range of antenna array topics that are becoming increasingly important in wireless applications, particularly in design and computer modeling. Signal processing and numerical modeling algorithms are explored, and MATLAB computer codes are provided for many of the design examples. Pictures of antenna arrays and components provided by industry and government sources are presented with explanations of how they work. Antenna Arrays is a valuable reference for practicing engineers and scientists in wireless communications, radar, and remote sensing, and an excellent textbook for advanced antenna courses.

  11. [Erythrocyte membrane proteins].

    Science.gov (United States)

    Delaunay, J

    1977-01-01

    Proteins are important constituents of the red blood cell plasma membrane. Several important breakthroughs have occurred in their analysis over the past few years. SDS-polyacrylamide gel electrophoresis lead to the separation of the major proteins and glycoproteins. Location of most of these proteins -- either on the external, the internal or both surfaces of the membrane -- was determined. The strenght of the binding of the protein to the membrane was established. Hydrophobicity of membrane proteins has so far hindered their purification. However, the major glycoprotein (glycophorin A) was isolated and recently sequenced. The description of several membrane-associated enzyme activities has been followed by some understanding of their specific role in the red blood cell physiology. Abnormalities of glycoproteins, Ca2+-ATPase and of membrane protein phosphorylation have been reported under various conditions: sickle cell disease, hereditary spherocytoses, progressive muscular dystrophy.

  12. Ion-conducting membranes

    Energy Technology Data Exchange (ETDEWEB)

    Masel, Richard I.; Sajjad, Syed Dawar; Gao, Yan; Liu, Zengcai; Chen, Qingmei

    2017-12-26

    An anion-conducting polymeric membrane comprises a terpolymer of styrene, vinylbenzyl-R.sub.s and vinylbenzyl-R.sub.x. R.sub.s is a positively charged cyclic amine group. R.sub.x is at least one constituent selected from the group consisting Cl, OH and a reaction product between an OH or Cl and a species other than a simple amine or a cyclic amine. The total weight of the vinylbenzyl-R.sub.x groups is greater than 0.3% of the total weight of the membrane. In a preferred embodiment, the membrane is a Helper Membrane that increases the faradaic efficiency of an electrochemical cell into which the membrane is incorporated, and also allows product formation at lower voltages than in cells without the Helper Membrane.

  13. Polyarylether composition and membrane

    Science.gov (United States)

    Hung, Joyce; Brunelle, Daniel Joseph; Harmon, Marianne Elisabeth; Moore, David Roger; Stone, Joshua James; Zhou, Hongyi; Suriano, Joseph Anthony

    2010-11-09

    A composition including a polyarylether copolymer is provided. The copolymer includes a polyarylether backbone; and a sulfonated oligomeric group bonded to the polyarylether suitable for use as a cation conducting membrane. Method of bonding a sulfonated oligomeric group to the polyarylether backbone to form a polyarylether copolymer. The membrane may be formed from the polyarylether copolymer composition. The chain length of the sulfonated oligomeric group may be controlled to affect or control the ion conductivity of the membrane.

  14. Porous ceramic membranes

    OpenAIRE

    Biesheuvel, P. M.; Biesheuvel, Pieter Maarten

    2000-01-01

    Synthetic membranes are increasingly used for energy-efficient separation of liquid and gaseous mixtures in household applications, environmental technology and the chemical and energy industry. Besides, membranes are used in component-specific sensors in gas and liquid streams, preferably combined with micro-electronic devices. Ceramic membranes have a large potential over their polymer counterparts for applications at high temperature, pressure and in aggressive environments. Ceramic membra...

  15. Applications of membrane computing

    CERN Document Server

    Ciobanu, Gabriel; Păun, Gheorghe

    2006-01-01

    Membrane computing is a branch of natural computing which investigates computing models abstracted from the structure and functioning of living cells and from their interactions in tissues or higher-order biological structures. The models considered, called membrane systems (P systems), are parallel, distributed computing models, processing multisets of symbols in cell-like compartmental architectures. In many applications membrane systems have considerable advantages - among these are their inherently discrete nature, parallelism, transparency, scalability and nondeterminism. In dedicated cha

  16. Nanoporous Membrane Immunosensor

    Science.gov (United States)

    2000-01-01

    incubated for 5-10 minutes. The analyte solution was then filtered using a water aspirator for 5 minutes. Unbound analyte was removed by washing the...membrane 3 times with PBST. A sandwiching antibody, rabbit-antibody- 5 ovalbumin (affinity purified), was then added to the membrane (200 /xl) at 2 jug /ml...cfu/ml) for 5-10 minutes and then filtered using a water aspirator for 5 minutes. Unbound analyte was removed by washing the membrane 3 times with

  17. Siloxane-grafted membranes

    Science.gov (United States)

    Friesen, Dwayne T.; Obligin, Alan S.

    1989-01-01

    Composite cellulosic semipermeable membranes are disclosed which are the covalently bonded reaction product of an asymmetric cellulosic semipermeable membrane and a polysiloxane containing reactive functional groups. The two reactants chemically bond by ether, ester, amide or acrylate linkages to form a siloxane-grafted cellulosic membrane having superior selectivity and flux stability. Selectivity may be enhanced by wetting the surface with a swelling agent such as water.

  18. Chelating polymeric membranes

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-01-22

    The present application offers a solution to the current problems associated with recovery and recycling of precious metals from scrap material, discard articles, and other items comprising one or more precious metals. The solution is premised on a microporous chelating polymeric membrane. Embodiments include, but are not limited to, microporous chelating polymeric membranes, device comprising the membranes, and methods of using and making the same.

  19. SQIF Arrays as RF Sensors (Briefing Charts)

    National Research Council Canada - National Science Library

    Yukon, Stanford P

    2007-01-01

    ... (Superconducting Quantum Interference Filter) arrays may be employed as sensitive RF sensors. RF SQIF arrays fabricated with high Tc Josephson junctions can be cooled with small Sterling microcoolers...

  20. Gas separation membranes

    Science.gov (United States)

    Schell, William J.

    1979-01-01

    A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.