WorldWideScience

Sample records for magnetic bead purification

  1. [Development of new magnetic bead separation and purification instrument].

    Science.gov (United States)

    Xu, Yingyuan; Chen, Yi

    2014-05-01

    The article describes the development of new magnetic bead separation and purification instrument. The main application of the instrument is to capture tubercle bacillus from sputum. It is a pretreatment instrument and provides a new platform to help doctors to diagnose bacillary phthisis. Not only could it be used for tubercle bacillus capturing, but also for gene, protein and cell separating and purification. Because the controller of the instrument is 16-bit single chip microcomputer, the cost could be greatly reduced and it will be widely used in China.

  2. Magnetic bead purification of labeled DNA fragments forhigh-throughput capillary electrophoresis sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Elkin, Christopher; Kapur, Hitesh; Smith, Troy; Humphries, David; Pollard, Martin; Hammon, Nancy; Hawkins, Trevor

    2001-09-15

    We have developed an automated purification method for terminator sequencing products based on a magnetic bead technology. This 384-well protocol generates labeled DNA fragments that are essentially free of contaminates for less than $0.005 per reaction. In comparison to laborious ethanol precipitation protocols, this method increases the phred20 read length by forty bases with various DNA templates such as PCR fragments, Plasmids, Cosmids and RCA products. Our method eliminates centrifugation and is compatible with both the MegaBACE 1000 and ABIPrism 3700 capillary instruments. As of September 2001, this method has produced over 1.6 million samples with 93 percent averaging 620 phred20 bases as part of Joint Genome Institutes Production Process.

  3. Fibrous polymer grafted magnetic chitosan beads with strong poly(cation-exchange) groups for single step purification of lysozyme.

    Science.gov (United States)

    Bayramoglu, Gulay; Tekinay, Turgay; Ozalp, V Cengiz; Arica, M Yakup

    2015-05-15

    Lysozyme is an important polypetide used in medical and food applications. We report a novel magnetic strong cation exchange beads for efficient purification of lysozyme from chicken egg white. Magnetic chitosan (MCHT) beads were synthesized via phase inversion method, and then grafted with poly(glycidyl methacrylate) (p(GMA)) via the surface-initiated atom transfer radical polymerization (SI-ATRP). Epoxy groups of the grafted polymer, were modified into strong cation-exchange groups (i.e., sulfonate groups) in the presence of sodium sulfite. The MCTH and MCTH-g-p(GMA)-SO3H beads were characterized by ATR-FTIR, SEM, and VSM. The sulphonate groups content of the modified MCTH-g-p(GMA)-4 beads was found to be 0.53mmolg(-1) of beads by the potentiometric titration method. The MCTH-g-p(GMA)-SO3H beads were first used as an ion-exchange support for adsorption of lysozyme from aqueous solution. The influence of different experimental parameters such as pH, contact time, and temperature on the adsorption process was evaluated. The maximum adsorption capacity was found to be 208.7mgg(-1) beads. Adsorption of lysozyme on the MCTH-g-p(GMA)-SO3H beads fitted to Langmuir isotherm model and followed the pseudo second-order kinetic. More than 93% of the adsorbed lysozyme was desorbed using Na2CO3 solution (pH 11.0). The purity of the lysozyme was checked by HPLC and SDS gel electrophoresis. In addition, the MCTH-g-p(GMA)-SO3H beads prepared in this work showed promising potential for separation of various anionic molecules. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Superparamagnetic poly(methyl methacrylate) beads for nattokinase purification from fermentation broth.

    Science.gov (United States)

    Yang, Chengli; Xing, Jianmin; Guan, Yueping; Liu, Huizhou

    2006-09-01

    An effective method for purification of nattokinase from fermentation broth using magnetic poly(methyl methacrylate) (PMMA) beads immobilized with p-aminobenzamidine was proposed in this study. Firstly, magnetic PMMA beads with a narrow size distribution were prepared by spraying suspension polymerization. Then, they were highly functionalized via transesterification reaction with polyethylene glycol. The surface hydroxyl-modified magnetic beads obtained were further modified with chloroethylamine to transfer the surface amino-modified magnetic functional beads. The morphology and surface functionality of the magnetic beads were examined by scanning electron microscopy and Fourier transform infrared. An affinity ligand, p-aminobenzamidine was covalently immobilized to the amino-modified magnetic beads by the glutaraldehyde method for nattokinase purification directly from the fermentation broth. The purification factor and the recovery of the enzyme activity were found to be 8.7 and 85%, respectively. The purification of nattokinase from fermentation broth by magnetic beads only took 40 min, which shows a very fast purification of nattokinase compared to traditional purification methods.

  5. Microfluidic magnetic bead conveyor belt

    NARCIS (Netherlands)

    van Pelt, S.; Frijns, A.J.H.; den Toonder, J.M.J.

    2017-01-01

    Magnetic beads play an important role in the miniaturization of clinical diagnostics systems. In lab-on-chip platforms, beads can be made to link to a target species and can then be used for the manipulation and detection of this species. Current bead actuation systems utilize complex on-chip coil

  6. Microfabricated Passive Magnetic Bead separators

    DEFF Research Database (Denmark)

    Hansen, Mikkel Fougt; Lund-Olesen, Torsten; Smistrup, Kristian

    2006-01-01

    The use and manipulation of functionalized magnetic beads for bioanalysis in lab-on-a-chip systems is receiving growing interest. We have developed microfluidic systems with integrated magnetic structures for the capture and release of magnetic beads. The systems are fabricated in silicon by deep...

  7. Microfluidic magnetic bead conveyor belt.

    Science.gov (United States)

    van Pelt, Stijn; Frijns, Arjan; den Toonder, Jaap

    2017-11-07

    Magnetic beads play an important role in the miniaturization of clinical diagnostics systems. In lab-on-chip platforms, beads can be made to link to a target species and can then be used for the manipulation and detection of this species. Current bead actuation systems utilize complex on-chip coil systems that offer low field strengths and little versatility. We demonstrate a novel system based on an external rotating magnetic field and on-chip soft-magnetic structures to focus the field locally. These structures were designed and optimized using finite element simulations in order to create a number of local flux density maxima. These maxima, to which the magnetic beads are attracted, move over the chip surface in a continuous way together with the rotation of the external field, resulting in a mechanism similar to that of a conveyor belt. A prototype was fabricated using PDMS molding techniques mixed with iron powder for the magnetic structures. In the subsequent experiments, a quadrupole electromagnet was used to create the rotating external field. We observed that beads formed agglomerates that rolled over the chip surface, just above the magnetic structures. Field rotation frequencies between 0.1-50 Hz were tested resulting in magnetic bead speeds of over 1 mm s -1 for the highest frequency. With this, we have shown that our novel concept works, combining a simple design and simple operation with a powerful and versatile method for bead actuation. This makes it a promising method for further research and utilization in lab-on-chip systems.

  8. Aptamer-Modified Magnetic Beads in Biosensing

    Science.gov (United States)

    Scheper, Thomas; Walter, Johanna-Gabriela

    2018-01-01

    Magnetic beads (MBs) are versatile tools for the purification, detection, and quantitative analysis of analytes from complex matrices. The superparamagnetic property of magnetic beads qualifies them for various analytical applications. To provide specificity, MBs can be decorated with ligands like aptamers, antibodies and peptides. In this context, aptamers are emerging as particular promising ligands due to a number of advantages. Most importantly, the chemical synthesis of aptamers enables straightforward and controlled chemical modification with linker molecules and dyes. Moreover, aptamers facilitate novel sensing strategies based on their oligonucleotide nature that cannot be realized with conventional peptide-based ligands. Due to these benefits, the combination of aptamers and MBs was already used in various analytical applications which are summarized in this article. PMID:29601533

  9. Plasma membrane isolation using immobilized concanavalin A magnetic beads.

    Science.gov (United States)

    Lee, Yu-Chen; Srajer Gajdosik, Martina; Josic, Djuro; Lin, Sue-Hwa

    2012-01-01

    Isolation of highly purified plasma membranes is the key step in constructing the plasma membrane proteome. Traditional plasma membrane isolation method takes advantage of the differential density of organelles. While differential centrifugation methods are sufficient to enrich for plasma membranes, the procedure is lengthy and results in low recovery of the membrane fraction. Importantly, there is significant contamination of the plasma membranes with other organelles. The traditional agarose affinity matrix is suitable for isolating proteins but has limitation in separating organelles due to the density of agarose. Immobilization of affinity ligands to magnetic beads allows separation of affinity matrix from organelles through magnets and could be developed for the isolation of organelles. We have developed a simple method for isolating plasma membranes using lectin concanavalin A (ConA) magnetic beads. ConA is immobilized onto magnetic beads by binding biotinylated ConA to streptavidin magnetic beads. The ConA magnetic beads are used to bind glycosylated proteins present in the membranes. The bound membranes are solubilized from the magnetic beads with a detergent containing the competing sugar alpha methyl mannoside. In this study, we describe the procedure of isolating rat liver plasma membranes using sucrose density gradient centrifugation as described by Neville. We then further purify the membrane fraction by using ConA magnetic beads. After this purification step, main liver plasma membrane proteins, especially the highly glycosylated ones and proteins containing transmembrane domains could be identified by LC-ESI-MS/MS. While not described here, the magnetic bead method can also be used to isolate plasma membranes from cell lysates. This membrane purification method should expedite the cataloging of plasma membrane proteome.

  10. Magnetic bead detection using nano-transformers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Kwon; Ahn, Doyeol [Institute of Quantum Information Processing and Systems, University of Seoul, 90 Jeonnong, Dongdaemun, Seoul 130-743 (Korea, Republic of); Hwang, Jong Seung; Hwang, Sung Woo, E-mail: dahn@uos.ac.kr [Research Center for Time-domain Nano-functional Devices and School of Electrical Engineering, Korea University, 5-1 Anam, Sungbuk, Seoul 136-701 (Korea, Republic of)

    2010-11-19

    A novel scheme to detect magnetic beads using a nano-scale transformer with a femtoweber resolution is reported. We have performed a Faraday's induction experiment with the nano-transformer at room temperature. The transformer shows the linear output voltage responses to the sinusoidal input current. When magnetic beads are placed on the transformer, the output responses are increased by an amount corresponding to the added magnetic flux from the beads when compared with the case of no beads on the transformer. In this way, we could determine whether magnetic beads are on top of the transformer in a single particle level.

  11. Magnetic bead detection using nano-transformers.

    Science.gov (United States)

    Kim, Hyung Kwon; Hwang, Jong Seung; Hwang, Sung Woo; Ahn, Doyeol

    2010-11-19

    A novel scheme to detect magnetic beads using a nano-scale transformer with a femtoweber resolution is reported. We have performed a Faraday's induction experiment with the nano-transformer at room temperature. The transformer shows the linear output voltage responses to the sinusoidal input current. When magnetic beads are placed on the transformer, the output responses are increased by an amount corresponding to the added magnetic flux from the beads when compared with the case of no beads on the transformer. In this way, we could determine whether magnetic beads are on top of the transformer in a single particle level.

  12. Comparison of non-magnetic and magnetic beads in bead-based assays

    NARCIS (Netherlands)

    Hansenová Maňásková, S.; van Belkum, A.; Endtz, H.P.; Bikker, F.J.; Veerman, E.C.I.; van Wamel, W.J.B.

    2016-01-01

    Multiplex bead-based flow cytometry is an attractive way for simultaneous, rapid and cost-effective analysis of multiple analytes in a single sample. Previously, we developed various bead-based assays using non-magnetic beads coated with Staphylococcus aureus and Streptococcus pneumoniae antigens

  13. Bead Capture on Magnetic Sensors in a Microfluidic System

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Dalslet, Bjarke Thomas; Damsgaard, Christian Danvad

    2009-01-01

    The accumulation of magnetic beads by gravitational sedimentation and magnetic capture on a planar Hall-effect sensor integrated in a microfluidic channel is studied systematically as a function of the bead concentration, the fluid flow rate, and the sensor bias current. It is demonstrated...... that the sedimentation flux is proportional to the bead concentration and has a power law relation to the fluid flow rate. The mechanisms for the bead accumulation are investigated and it is found that gravitational sedimentation dominates the bead accumulation, whereas the stability of the sedimented beads against...

  14. Configurational Statistics of Magnetic Bead Detection with Magnetoresistive Sensors

    DEFF Research Database (Denmark)

    Henriksen, Anders Dahl; Ley, Mikkel Wennemoes Hvitfeld; Flyvbjerg, Henrik

    2015-01-01

    Magnetic biosensors detect magnetic beads that, mediated by a target, have bound to a functionalized area. This area is often larger than the area of the sensor. Both the sign and magnitude of the average magnetic field experienced by the sensor from a magnetic bead depends on the location...... of the bead relative to the sensor. Consequently, the signal from multiple beads also depends on their locations. Thus, a given coverage of the functionalized area with magnetic beads does not result in a given detector response, except on the average, over many realizations of the same coverage. We present...... a systematic theoretical analysis of how this location-dependence affects the sensor response. The analysis is done for beads magnetized by a homogeneous in-plane magnetic field. We determine the expected value and standard deviation of the sensor response for a given coverage, as well as the accuracy...

  15. Parallel RNA extraction using magnetic beads and a droplet array.

    Science.gov (United States)

    Shi, Xu; Chen, Chun-Hong; Gao, Weimin; Chao, Shih-Hui; Meldrum, Deirdre R

    2015-02-21

    Nucleic acid extraction is a necessary step for most genomic/transcriptomic analyses, but it often requires complicated mechanisms to be integrated into a lab-on-a-chip device. Here, we present a simple, effective configuration for rapidly obtaining purified RNA from low concentration cell medium. This Total RNA Extraction Droplet Array (TREDA) utilizes an array of surface-adhering droplets to facilitate the transportation of magnetic purification beads seamlessly through individual buffer solutions without solid structures. The fabrication of TREDA chips is rapid and does not require a microfabrication facility or expertise. The process takes less than 5 minutes. When purifying mRNA from bulk marine diatom samples, its repeatability and extraction efficiency are comparable to conventional tube-based operations. We demonstrate that TREDA can extract the total mRNA of about 10 marine diatom cells, indicating that the sensitivity of TREDA approaches single-digit cell numbers.

  16. Towards a programmable magnetic bead microarray in a microfluidic channel

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Bruus, Henrik; Hansen, Mikkel Fougt

    2007-01-01

    to use larger currents and obtain forces of longer range than from thin current lines at a given power limit. Guiding of magnetic beads in the hybrid magnetic separator and the construction of a programmable microarray of magnetic beads in the microfluidic channel by hydrodynamic focusing is presented....

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

    Science.gov (United States)

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

    2017-11-06

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

  18. Graphene Oxide Conjugated Magnetic Beads for RNA Extraction.

    Science.gov (United States)

    Pham, Xuan-Hung; Baek, Ahruem; Kim, Tae Han; Lee, Sang Hun; Rho, Won-Yeop; Chung, Woo-Jae; Kim, Dong-Eun; Jun, Bong-Hyun

    2017-08-04

    A magnetic material that consists of silica-coated magnetic beads conjugated with graphene oxide (GO) was successfully prepared for facile ribonucleic acid (RNA) extraction. When the GO-modified magnetic beads were applied to separate the RNA from the lysed cell, the cellular RNAs were readily adsorbed to and readily desorbed from the surface of the GO-modified magnetic beads by urea. The amount of RNA extracted by the GO-modified magnetic beads was ≈170 % as much as those of the control extracted by a conventional phenol-based chaotropic solution. These results demonstrate that the facile method of RNA separation by using GO-modified magnetic beads as an adsorbent is an efficient and simple way to purify intact cellular RNAs and/or microRNA from cell lysates. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. An approach to implement virtual channels for flowing magnetic beads

    International Nuclear Information System (INIS)

    Tang, Shih-Hao; Chiang, Hung-Wei; Hsieh, Min-Chien; Chang, Yen-Di; Yeh, Po-Fan; Tsai, Jui-che; Shieh, Wung-Yang

    2014-01-01

    This work demonstrates the feasibility of a novel microfluidic system with virtual channels formed by ‘walls’ of magnetic fields, including collecting channels, transporting channels and function channels. The channels are defined by the nickel patterns. With its own ferromagnetism, nickel can be magnetized using an external magnetic field; the nickel structures then generate magnetic fields that can either guide or trap magnetic beads. A glass substrate is sandwiched between the liquid containing magnetic beads and the chip with nickel structures, preventing the liquid from directly contacting the nickel. In this work, collecting channels, transporting channels and function channels are displayed sequentially. In the collecting channel portion, channels with different shapes are compared. Next, in the transporting channel portion we demonstrate I-, S- and Y-shaped channels can steer magnetic beads smoothly. Finally, in the function channel portion, a switchable trapping channel implemented with a bistable mechanism performs the passing and blocking of a magnetic bead. (paper)

  20. Selective manipulation of superparamagnetic beads by a magnetic microchip

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Yassine, Omar; Giouroudi, Ioanna; Kosel, Jü rgen

    2013-01-01

    In this paper, a magnetic microchip (MMC) is presented, to first trap and then selectively manipulate individual, superparamagnetic beads (SPBs) to another trapping site. Trapping sites are realized through soft magnetic micro disks made of Ni80Fe20

  1. Polyvinyl-alcohol-based magnetic beads for rapid and efficient separation of specific or unspecific nucleic acid sequences

    International Nuclear Information System (INIS)

    Oster, J.; Parker, Jeffrey; Brassard, Lothar

    2001-01-01

    The versatile application of polyvinyl-alcohol-based magnetic M-PVA beads is demonstrated in the separation of genomic DNA, sequence specific nucleic acid purification, and binding of bacteria for subsequent DNA extraction and detection. It is shown that nucleic acids can be obtained in high yield and purity using M-PVA beads, making sample preparation efficient, fast and highly adaptable for automation processes

  2. A High-Throughput SU-8Microfluidic Magnetic Bead Separator

    DEFF Research Database (Denmark)

    Bu, Minqiang; Christensen, T. B.; Smistrup, Kristian

    2007-01-01

    We present a novel microfluidic magnetic bead separator based on SU-8 fabrication technique for high through-put applications. The experimental results show that magnetic beads can be captured at an efficiency of 91 % and 54 % at flow rates of 1 mL/min and 4 mL/min, respectively. Integration...... of soft magnetic elements in the chip leads to a slightly higher capturing efficiency and a more uniform distribution of captured beads over the separation chamber than the system without soft magnetic elements....

  3. Plasmid pVAX1-NH36 purification by membrane and bead perfusion chromatography.

    Science.gov (United States)

    Franco-Medrano, Diana Ivonne; Guerrero-Germán, Patricia; Montesinos-Cisneros, Rosa María; Ortega-López, Jaime; Tejeda-Mansir, Armando

    2017-03-01

    The demand for plasmid DNA (pDNA) has increased in response to the rapid advances in vaccines applications to prevent and treat infectious diseases caused by virus, bacteria or parasites, such as Leishmania species. The immunization protocols require large amounts of supercoiled plasmid DNA (sc-pDNA) challenging the development of efficient and profitable processes for capturing and purified pDNA molecules from large volumes of lysates. A typical bioprocess involves four steps: fermentation, primary recovery, intermediate recovery and final purification. Ion-exchange chromatography is one of the key operations in the purification schemes of pDNA owing the chemical structure of these macromolecules. The goal of this research was to compare the performance of the final purification step of pDNA using ion-exchange chromatography on columns packed with Mustang Q membranes or perfusive beads POROS 50 HQ. The experimental results showed that both matrixes could separate the plasmid pVAX1-NH36 (3936 bp) from impurities in clarified Escherichia coli lysates with an adequate resolution. In addition, a 24- and 21-fold global purification factor was obtained. An 88 and 63% plasmid recuperation was achieved with ion-exchange membranes and perfusion beads, respectively. A better understanding of perfusion-based matrices for the purification of pDNA was developed in this research.

  4. Self-organizing magnetic beads for biomedical applications

    International Nuclear Information System (INIS)

    Gusenbauer, Markus; Kovacs, Alexander; Reichel, Franz; Exl, Lukas; Bance, Simon; Özelt, Harald; Schrefl, Thomas

    2012-01-01

    In the field of biomedicine magnetic beads are used for drug delivery and to treat hyperthermia. Here we propose to use self-organized bead structures to isolate circulating tumor cells using lab-on-chip technologies. Typically blood flows past microposts functionalized with antibodies for circulating tumor cells. Creating these microposts with interacting magnetic beads makes it possible to tune the geometry in size, position and shape. We developed a simulation tool that combines micromagnetics and discrete particle dynamics, in order to design micropost arrays made of interacting beads. The simulation takes into account the viscous drag of the blood flow, magnetostatic interactions between the magnetic beads and gradient forces from external aligned magnets. We developed a particle–particle particle–mesh method for effective computation of the magnetic force and torque acting on the particles. - Highlights: ► We propose to use self-organized bead structures to isolate circulating tumor cells. ► Flexible ways are important to get a high probability of catching cancer cells. ► The beads make it possible to tune the geometry in size position and shape.

  5. Beads.

    Science.gov (United States)

    Weewish Tree, 1979

    1979-01-01

    Beads served both as ornaments and as a medium of exchange, and the Indians manufactured them from such natural sources as bones, stones, beans, nuts, animal teeth, and polished antlers. Even after the introduction of European glass beads, the Indians continued to make their favorite beads from the natural sources. (DS)

  6. Superparamagnetic beads in rotating magnetic fields: microfluidic experiments

    NARCIS (Netherlands)

    Den Toonder, J.M.J.; Bokdam, M.

    2008-01-01

    The effect of the Mason number, ratio of viscous and magnetic force, on suspended superparamagnetic micro sized beads was investigated experimentally. Microfluidic experiments were performed in a set-up that generates a rotating homogeneous magnetic field. In the presence of a magnetic field, the

  7. Purification of rhamnolipid using colloidal magnetic nanoparticles ...

    African Journals Online (AJOL)

    Phospholipid-coated colloidal magnetic nanoparticles with mean magnetite core size of 9 nm are shown to be effective ion exchange media for the recovery and purification of Rhaminolipid from culture mixtures. These particles have high adsorption capacity for purification (an order of magnitude larger than the best ...

  8. On-chip measurement of the Brownian relaxation frequency of magnetic beads using magnetic tunneling junctions

    DEFF Research Database (Denmark)

    Donolato, M.; Sogne, E.; Dalslet, Bjarke Thomas

    2011-01-01

    We demonstrate the detection of the Brownian relaxation frequency of 250 nm diameter magnetic beads using a lab-on-chip platform based on current lines for exciting the beads with alternating magnetic fields and highly sensitive magnetic tunnel junction (MTJ) sensors with a superparamagnetic free...

  9. Removal of organic dyes by magnetic alginate beads.

    Science.gov (United States)

    Rocher, Vincent; Siaugue, Jean-Michel; Cabuil, Valérie; Bee, Agnès

    2008-02-01

    This study deals with the development of a clean and safe process for water pollution remediation. We have synthesized a magnetic adsorbent in order to develop a solid-phase extraction process assisted by a magnetic field. To follow an 'ecoconception' approach, magnetic beads containing magnetic nanoparticles and activated carbon are prepared with a biopolymer extracted from algae, sodium alginate. The use of renewable bioresources of low cost and those disposable in large amount allows the development of a product with a low impact on the environment. The adsorption properties of activated carbon and magnetic properties of iron oxide nanoparticles are combined to produce an interesting magnetic composite. Synthesis and characterization of the magnetic beads have been reported. Their adsorption capacity was investigated by measuring the removal of two dyes (methylene blue and methyl orange) of different charges from aqueous solutions. The efficiency of the beads has been compared with that of non-encapsulated activated carbon. The effects of initial dye concentration, pH and calcium content of the beads have been studied. Adsorption kinetics experiments have been carried out and the data have been well fitted by a pseudo-second-order equation.

  10. A magnetic bead-based ligand binding assay to facilitate human kynurenine 3-monooxygenase drug discovery.

    Science.gov (United States)

    Wilson, Kris; Mole, Damian J; Homer, Natalie Z M; Iredale, John P; Auer, Manfred; Webster, Scott P

    2015-02-01

    Human kynurenine 3-monooxygenase (KMO) is emerging as an important drug target enzyme in a number of inflammatory and neurodegenerative disease states. Recombinant protein production of KMO, and therefore discovery of KMO ligands, is challenging due to a large membrane targeting domain at the C-terminus of the enzyme that causes stability, solubility, and purification difficulties. The purpose of our investigation was to develop a suitable screening method for targeting human KMO and other similarly challenging drug targets. Here, we report the development of a magnetic bead-based binding assay using mass spectrometry detection for human KMO protein. The assay incorporates isolation of FLAG-tagged KMO enzyme on protein A magnetic beads. The protein-bound beads are incubated with potential binding compounds before specific cleavage of the protein-compound complexes from the beads. Mass spectrometry analysis is used to identify the compounds that demonstrate specific binding affinity for the target protein. The technique was validated using known inhibitors of KMO. This assay is a robust alternative to traditional ligand-binding assays for challenging protein targets, and it overcomes specific difficulties associated with isolating human KMO. © 2014 Society for Laboratory Automation and Screening.

  11. An integrated open-cavity system for magnetic bead manipulation.

    Science.gov (United States)

    Abu-Nimeh, F T; Salem, F M

    2013-02-01

    Superparamagnetic beads are increasingly used in biomedical assays to manipulate, transport, and maneuver biomaterials. We present a low-cost integrated system designed in bulk CMOS to manipulate and separate biomedical magnetic beads. The system consists of 8 × 8 coil-arrays suitable for single bead manipulation, or collaborative multi-bead manipulation, using pseudo-parallel executions. We demonstrate the flexibility of the design in terms of different coil sizes, DC current levels, and layout techniques. In one array module example, the size of a single coil is 30 μm × 30 μm and the full array occupies an area of 248 μm × 248 μm in 0.5 μm CMOS technology. The programmable DC current source supports 8 discrete levels up to 1.5 mA. The total power consumption of the entire module is 9 mW when running at full power.

  12. Magnetic bead micromixer: Influence of magnetic element geometry and field amplitude

    DEFF Research Database (Denmark)

    Lund-Olesen, Torsten; Buus, Bjarke B.; Howalt, Jakob

    2008-01-01

    A scheme for the silicon microfabrication of lab-on-a-chip systems with mixing based on dynamic plugs of magnetic beads is presented. The systems consist of a microfluidic channel integrated with a number of soft magnetic elements by the sides of the channel. The elements are magnetized by a homo......A scheme for the silicon microfabrication of lab-on-a-chip systems with mixing based on dynamic plugs of magnetic beads is presented. The systems consist of a microfluidic channel integrated with a number of soft magnetic elements by the sides of the channel. The elements are magnetized...... by a homogeneous external ac magnetic field. The systems are scalable with respect to the number of magnetic bead plugs and number of parallel channels, and thus they have high potential for use in biological separation using functionalized magnetic beads. The mixing efficiency is characterized for two different...

  13. Selective manipulation of superparamagnetic beads by a magnetic microchip

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2013-07-01

    In this paper, a magnetic microchip (MMC) is presented, to first trap and then selectively manipulate individual, superparamagnetic beads (SPBs) to another trapping site. Trapping sites are realized through soft magnetic micro disks made of Ni80Fe20, and SPB motion is controlled by current-carrying, tapered, conducting lines made of Au. The MMC was realized using standard microfabrication techniques and provides a cheap and versatile platform for microfluidic systems for cell manipulation. © 2013 IEEE.

  14. Magnetization of large polystyrene peptide beads for capturing and expanding cancer cells

    International Nuclear Information System (INIS)

    Marik, Jan; Lau, D.H.; Song Aimin; Wang Xiaobing; Liu Ruiwu; Lam, K.S.

    2003-01-01

    A method is described for preparation of large magnetic polystyrene beads coupled with peptide ligands for surface receptors of lung cancer cells. We have demonstrated the feasibility of using these magnetic peptide beads for capturing and enriching lung cancer cells spiked into blood. These magnetic peptide beads potentially can be used to efficiently isolate cancer cells from body fluids

  15. A planar conducting microstructure to guide and confine magnetic beads to a sensing zone

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2011-08-01

    A novel planar conducting microstructure is proposed to transport and confine magnetic micro/nano beads to a sensing zone. Manipulation and concentration of magnetic beads are achieved by employing square-shaped conducting micro-loops, with a few hundred nano-meters in thickness, arranged in a unique fashion. These microstructures are designed to produce high magnetic field gradients which are directly proportional to the force applied to manipulate the magnetic beads. Furthermore, the size of the microstructures allows greater maneuverability and control of magnetic beads than what could be achieved by permanent magnets. The aim of the microstructures is to guide magnetic beads from a large area and confine them to a smaller area where for example quantification would take place. Experiments were performed with different concentrations of 2 μm diameter magnetic beads. Experimental results showed that magnetic beads could be successfully guided and confined to the sensing zone. © 2011 Elsevier B.V. All rights reserved.

  16. Comparison between simulation and experimentally observed interactions between two magnetic beads in a fluidic system

    Energy Technology Data Exchange (ETDEWEB)

    Oduwole, Olayinka, E-mail: olayinka.oduwole@eng.ox.ac.uk; Grob, David Tim, E-mail: tim.grob@eng.ox.ac.uk; Sheard, Steve, E-mail: steve.sheard@eng.ox.ac.uk

    2016-06-01

    Continuous flow separation of magnetic particles within a microfluidic device could lead to improved performance of magnetic bead-based assays but the undesirable formation of bead clusters reduces its efficiency; this efficiency refers to the ability to separate bound magnetic beads from a mixture of particles. Such agglomerates are formed due to magnetic binding forces while hydrodynamic interactions strongly influence the particles' movement. This paper presents a model for interactions between a pair of equal sized super-paramagnetic beads suspended in water within a uniform magnetic field. To the best of our knowledge, we present for the first time a comparison between simulated trajectories and the beads' movement captured on video; the beads were suspended in a stationary fluid placed within a uniform magnetic field. In conclusion, the model is a good approximation for beads interacting with their nearest neighbours and is able to predict the trajectory pattern of these particles in a magnetic bead-based assay. Predicting the magnetically induced interaction of nearby beads will help in determining the density of beads in an assay and in avoiding agglomeration over a fixed time duration. - Highlights: • We modelled the interactions between a pair of super-paramagnetic beads suspended in water within a uniform magnetic field. • We tracked the movement of the bead pair and captured it on video. • We compared the numerical results with the video data and achieved a good agreement. • We predicted the agglomeration time as a function of the separation distance.

  17. Influence of Immobilized Biomolecules on Magnetic Bead Plug Formation and Retention in Capillary Electrophoresis

    Science.gov (United States)

    Henken, Rachel L.; Chantiwas, Rattikan; Gilman, S. Douglass

    2012-01-01

    Significant changes in the formation and retention of magnetic bead plugs in a capillary during electrophoresis were studied, and it was demonstrated that these effects were due to the type of biological molecule immobilized on the surface of these beads. Three biological molecules, an antibody, an oligonucleotide and alkaline phosphatase, were attached to otherwise identical streptavidin-coated magnetic beads through biotin-avidin binding in order to isolate differences in bead immobilization in a magnetic field resulting from the type of biological molecule immobilized on the bead surface. Alkaline phosphatase also was attached to the magnetic beads using epoxy groups on the bead surfaces (instead of avidin-biotin binding) to study the impact of immobilization chemistry. The formation and retention of magnetic bead plugs were studied quantitatively using light scattering detection of magnetic particles eluting from the bead plugs and qualitatively using microscopy. Both the type of biomolecule immobilized on the magnetic bead surface and the chemistry used to link the biomolecule to the magnetic bead impacted the formation and retention of the bead plugs. PMID:22437880

  18. Induced movement of the magnetic beads and DNA-based dumbbell in a micro fluidic channel

    Science.gov (United States)

    Babić, B.; Ghai, R.; Dimitrov, K.

    2007-12-01

    We have explored controlled movement of magnetic beads and a dumbbell structure composed of DNA, a magnetic and a non-magnetic bead in a micro fluidic channel. Movement of the beads and dumbbells is simulated assuming that a net force is described as a superposition between the magnetic and hydrodynamic drag forces. Trajectories of beads and dumbbells are observed with optical light microscopy. The experimentally measured data show a good agreement with the simulations. This dynamical approach offers the prospect to stretch the DNA within the dumbbell and investigate its conformational changes. Further on, we demonstrate that short sonication can reduce multiple attachments of DNA to the beads.

  19. Polymerase chain reaction system using magnetic beads for analyzing a sample that includes nucleic acid

    Science.gov (United States)

    Nasarabadi, Shanavaz [Livermore, CA

    2011-01-11

    A polymerase chain reaction system for analyzing a sample containing nucleic acid includes providing magnetic beads; providing a flow channel having a polymerase chain reaction chamber, a pre polymerase chain reaction magnet position adjacent the polymerase chain reaction chamber, and a post pre polymerase magnet position adjacent the polymerase chain reaction chamber. The nucleic acid is bound to the magnetic beads. The magnetic beads with the nucleic acid flow to the pre polymerase chain reaction magnet position in the flow channel. The magnetic beads and the nucleic acid are washed with ethanol. The nucleic acid in the polymerase chain reaction chamber is amplified. The magnetic beads and the nucleic acid are separated into a waste stream containing the magnetic beads and a post polymerase chain reaction mix containing the nucleic acid. The reaction mix containing the nucleic acid flows to an analysis unit in the channel for analysis.

  20. Magnet polepiece design for uniform magnetic force on superparamagnetic beads

    OpenAIRE

    Fallesen, Todd; Hill, David B.; Steen, Matthew; Macosko, Jed C.; Bonin, Keith; Holzwarth, George

    2010-01-01

    Here we report construction of a simple electromagnet with novel polepieces which apply a spatially uniform force to superparamagnetic beads in an optical microscope. The wedge-shaped gap was designed to keep ∂Bx∕∂y constant and B large enough to saturate the bead. We achieved fields of 300–600 mT and constant gradients of 67 T∕m over a sample space of 0.5×4 mm2 in the focal plane of the microscope and 0.05 mm along the microscope optic axis. Within this space the maximum force on a 2.8 μm di...

  1. A novel magnet focusing plate for matrix-assisted laser desorption/ionization analysis of magnetic bead-bound analytes.

    Science.gov (United States)

    Gode, David; Volmer, Dietrich A

    2013-05-15

    Magnetic beads are often used for serum profiling of peptide and protein biomarkers. In these assays, the bead-bound analytes are eluted from the beads prior to mass spectrometric analysis. This study describes a novel matrix-assisted laser desorption/ionization (MALDI) technique for direct application and focusing of magnetic beads to MALDI plates by means of dedicated micro-magnets as sample spots. Custom-made MALDI plates with magnetic focusing spots were made using small nickel-coated neodymium micro-magnets integrated into a stainless steel plate in a 16 × 24 (384) pattern. For demonstrating the proof-of-concept, commercial C-18 magnetic beads were used for the extraction of a test compound (reserpine) from aqueous solution. Experiments were conducted to study focusing abilities, the required laser energies, the influence of a matrix compound, dispensing techniques, solvent choice and the amount of magnetic beads. Dispensing the magnetic beads onto the micro-magnet sample spots resulted in immediate and strong binding to the magnetic surface. Light microscope images illustrated the homogeneous distribution of beads across the surfaces of the magnets, when the entire sample volume containing the beads was pipetted onto the surface. Subsequent MALDI analysis of the bead-bound analyte demonstrated excellent and reproducible ionization yields. The surface-assisted laser desorption/ionization (SALDI) properties of the strongly light-absorbing γ-Fe2O3-based beads resulted in similar ionization efficiencies to those obtained from experiments with an additional MALDI matrix compound. This feasibility study successfully demonstrated the magnetic focusing abilities for magnetic bead-bound analytes on a novel MALDI plate containing small micro-magnets as sample spots. One of the key advantages of this integrated approach is that no elution steps from magnetic beads were required during analyses compared with conventional bead experiments. Copyright © 2013 John Wiley

  2. Theoretical study of in-plane response of magnetic field sensor to magnetic beads magnetized by the sensor self-field

    DEFF Research Database (Denmark)

    Hansen, Troels Borum Grave; Damsgaard, Christian Danvad; Dalslet, Bjarke Thomas

    2010-01-01

    We present a theoretical study of the spatially averaged in-plane magnetic field on square and rectangular magnetic field sensors from a single magnetic bead, a monolayer of magnetic beads, and a half-space filled with magnetic beads being magnetized by the magnetic self-field due to the applied...... bias current through the sensor. The analysis of the single bead response shows that beads always contribute positively to the average magnetic field as opposed to the case for an applied homogeneous magnetic field where the sign of the signal depends on the bead position. General expressions...... and analytical approximations are derived for the sensor response to beads as function of the bead distribution, the bias current, the geometry and size of the sensor, and the bead characteristics. Consequences for the sensor design are exemplified and it is described how the contribution from the self...

  3. Effects of Magnetic Particles Entrance Arrangements on Mixing Efficiency of a Magnetic Bead Micromixer

    Institute of Scientific and Technical Information of China (English)

    Reza Kamali; Seyed Alireza Shekoohi; Alireza Binesh

    2014-01-01

    In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter the micromixer by fluid flows and are actuated by an alternating magnetic field normal to the main flow. An important feature of micromixer which is not considered before by researchers is the particle entrance arrangement into the micromixer. This parameter could effectively affect the micromixer efficiency. There are two general micro magnetic particle entrance arrangements in magnetic bead micromixers: determined position entrance and random position entrance. In the case of determined position entrances, micro magnetic particles enter the micromixer at specific positions of entrance cross section. However, in a random position entrance,particles enter the microchannel with no order. In this study mixing efficiencies of identical magnetic bead micromixers which only differ in particle entrance arrangement are numerically investigated and compared.The results reported in this paper illustrate that the prepared computer code can be one of the most powerful and beneficial tools for the magnetic bead micromixer performance analysis. In addition, the results show that some features of the magnetic bead micromixer are strongly affected by the entrance arrangement of the particles.

  4. Magnetic measurements of suspended functionalised ferromagnetic beads under DC applied fields

    International Nuclear Information System (INIS)

    De Los Santos V, Luis; Llandro, Justin; Lee, Dongwook; Mitrelias, Thanos; Palfreyman, Justin J.; Hayward, Thomas J.; Cooper, Jos; Bland, J.A.C.; Barnes, Crispin H.W.; Arroyo C, Juan L.; Lees, Martin

    2009-01-01

    In this work, a simple technique to obtain the hysteresis loops of magnetic beads (Spherotech Inc.) in liquid suspension is presented. The magnetic measurements were taken in a DC Magnetic Property Measurement System (MPMS-SQUID sensor). Samples were based on ferromagnetic beads (surface-functionalized NH 2 , mean diameter 4.32 μm) prepared in three conditions: dry, suspended in sucrose solution and in suspension after functionalization with fluorophore. Special small containers (1.3 cm long) made of non magnetic plastic were designed to hold the beads in liquid. The results indicate that the bead's remnant magnetization is half of the value at maximum applied field in all cases. However, due to the additional degrees of rotational freedom, beads suspended in a liquid do not present coercivity. The use of ferromagnetic beads and magnetic elements of different architectures for applications in bioassays is also discussed.

  5. Bead Capture and Release on a Magnetic Sensor in a Microfluidic System

    DEFF Research Database (Denmark)

    Dalslet, Bjarke Thomas; Damsgaard, Christian Danvad; Freitas, S.C.

    Planar Hall effect magnetic sensors for detection of biological agents using surface treated magnetic beads are integrated with a fluid injection system. The response of the sensors is used to evaluate bead capture rates for different bead concentrations c and fluid flow rates Q, and to monitor...... subsequent removal of the beads. It is found that the capture rate scales directly with c and that it depends linearly on Q. At low Q the capture rate is only partially due to gravitational sedimentation of beads. At higher Q an additional term proportional to Q becomes important, which is attributed...... to capture of beads by the magnetic fields near the sensor. It is shown that beads can be washed off the sensor surface....

  6. "On-chip magnetic bead microarray using hydrodynamic focusing in a passive magnetic separator"

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Kjeldsen, B.; Reimers, R.L.

    2005-01-01

    Implementing DNA and protein microarrays into lab-on-a-chip systems can be problematic since these are sensitive to heat and strong chemicals. Here, we describe the functionalization of a microchannel with two types of magnetic beads using hydrodynamic focusing combined with a passive magnetic...

  7. Planar Hall effect sensor bridge geometries optimized for magnetic bead detection

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Rizzi, Giovanni; Henriksen, Anders Dahl

    2014-01-01

    Novel designs of planar Hall effect bridge sensors optimized for magnetic bead detection are presented and characterized. By constructing the sensor geometries appropriately, the sensors can be tailored to be sensitive to an external magnetic field, the magnetic field due to beads being magnetized...... by the sensor self-field or a combination thereof. The sensors can be made nominally insensitive to small external magnetic fields, while being maximally sensitive to magnetic beads, magnetized by the sensor self-field. Thus, the sensor designs can be tailored towards specific applications with minimal...... of the dynamic magnetic response of suspensions of magnetic beads with a nominal diameter of 80 nm are performed. Furthermore, a method to amplify the signal by appropriate combinations of multiple sensor segments is demonstrated....

  8. Use of magnetic beads for Gram staining of bacteria in aqueous suspension.

    Science.gov (United States)

    Yazdankhah, S P; Sørum, H; Larsen, H J; Gogstad, G

    2001-12-01

    A Gram staining technique was developed using monodisperse magnetic beads in concentrating bacteria in suspension for downstream application. The technique does not require heat fixation of organisms, electrical power, or a microscope. Gram-negative and Gram-positive bacteria were identified macroscopically based on the colour of the suspension. The bacteria concentrated on magnetic beads may also be identified microscopically.

  9. Capture of DNA in microfluidic channel using magnetic beads: increasing capture efficiency with integrated microfluidic mixer

    DEFF Research Database (Denmark)

    Lund-Olesen, Torsten; Dufva, Hans Martin; Hansen, Mikkel Fougt

    2007-01-01

    We have studied the hybridization of target DNA in solution with probe DNA on magnetic beads immobilized on the channel sidewalls in a magnetic bead separator. The hybridization is carried out under a liquid flow and is diffusion limited. Two systems are compared: one with a straight microfluidic...... place on the surface in a microfluidic system....

  10. Using Magnets and Magnetic Beads to Dissect Signaling Pathways Activated by Mechanical Tension Applied to Cells

    Science.gov (United States)

    Marjoram, R.J.; Guilluy, C; Burridge, K.

    2015-01-01

    Cellular tension has implications in normal biology and pathology. Membrane adhesion receptors serve as conduits for mechanotransduction that lead to cellular responses. Ligand-conjugated magnetic beads are a useful tool in the study of how cells sense and respond to tension. Here we detail methods for their use in applying tension to cells and strategies for analyzing the results. We demonstrate the methods by analyzing mechanotransduction through VE-cadherin on endothelial cells using both permanent magnets and magnetic tweezers. PMID:26427549

  11. Theoretical study of in-plane response of magnetic field sensor to magnetic beads in an in-plane homogeneous field

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Hansen, Mikkel Fougt

    2008-01-01

    We present a systematic theoretical study of the average in-plane magnetic field on square and rectangular magnetic field sensors from a single magnetic bead and a monolayer of magnetic beads magnetized by an in-plane externally applied homogeneous magnetic field. General theoretical expressions...... are derived such that the sensor response and its dependence on the sensor size, spacer layer thickness, bead diameter, and bead susceptibility can easily be evaluated. The average magnetic field from a single bead close to the sensor shows a strong dependence on the position of the bead and a change of sign...... when the bead passes the edge of the sensor in the direction of the applied field. Analytical approximations are derived for the average field from a homogeneous monolayer of beads for beads much smaller than the sensor dimension and for a bead size chosen to minimize the position sensitivity...

  12. Magnetic tweezers with high permeability electromagnets for fast actuation of magnetic beads

    Energy Technology Data Exchange (ETDEWEB)

    Chen, La; Offenhäusser, Andreas; Krause, Hans-Joachim [Institute of Bioelectronics (ICS-8/PGI-8), Forschungszentrum Jülich GmbH, 52425 Jülich (Germany)

    2015-04-15

    As a powerful and versatile scientific instrument, magnetic tweezers have been widely used in biophysical research areas, such as mechanical cell properties and single molecule manipulation. If one wants to steer bead position, the nonlinearity of magnetic properties and the strong position dependence of the magnetic field in most magnetic tweezers lead to quite a challenge in their control. In this article, we report multi-pole electromagnetic tweezers with high permeability cores yielding high force output, good maneuverability, and flexible design. For modeling, we adopted a piece-wise linear dependence of magnetization on field to characterize the magnetic beads. We implemented a bi-linear interpolation of magnetic field in the work space, based on a lookup table obtained from finite element simulation. The electronics and software were custom-made to achieve high performance. In addition, the effects of dimension and defect on structure of magnetic tips also were inspected. In a workspace with size of 0.1 × 0.1 mm{sup 2}, a force of up to 400 pN can be applied on a 2.8 μm superparamagnetic bead in any direction within the plane. Because the magnetic particle is always pulled towards a tip, the pulling forces from the pole tips have to be well balanced in order to achieve control of the particle’s position. Active video tracking based feedback control is implemented, which is able to work at a speed of up to 1 kHz, yielding good maneuverability of the magnetic beads.

  13. Magnetic nanoparticle-loaded alginate beads for local micro-actuation of in vitro tissue constructs.

    Science.gov (United States)

    Alshehri, Awatef M; Wilson, Otto C; Dahal, Bishnu; Philip, John; Luo, Xiaolong; Raub, Christopher B

    2017-11-01

    Magnetic nanoparticles (MNPs) self-align and transduce magnetic force, two properties which lead to promising applications in cell and tissue engineering. However, the toxicity of MNPs to cells which uptake them is a major impediment to applications in engineered tissue constructs. To address this problem, MNPs were embedded in millimeter-scale alginate beads, coated with glutaraldehyde cross-linked chitosan, and loaded in acellular and MDA-MB-231 cancer cell-seeded collagen hydrogels, providing local micro-actuation under an external magnetic field. Brightfield microscopy was used to assess nanoparticle diffusion from the bead. Phase contrast microscopy and digital image correlation were used to track collagen matrix displacement and estimate intratissue strain under magnetic actuation. Coating the magnetic alginate beads with glutaraldehyde-chitosan prevents bulk diffusion of nanoparticles into the surrounding microenvironment. Further, the beads exert force on the surrounding collagen gel and cells, resulting in intratissue strains of 0-10% tunable with bead dimensions, collagen density, and distance from the bead. Cells seeded adjacent to the embedded beads are subjected to strain gradients without loss of cell viability over two days culture. This study describes a simple way to fabricate crosslinked magnetic alginate beads to load in a collagen tissue construct without direct exposure of the construct to nanoparticles. The findings are significant to in vitro studies of mechanobiology in enabling precise control over dynamic mechanical loading of tissue constructs. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Magnetic composite beads for sorption of cesium ions from aqueous streams

    International Nuclear Information System (INIS)

    Shinde, Rakesh N.; Pandey, A.K.; Acharya, R.; Rajurkar, N.S.

    2014-01-01

    Magnetic separation of metal ions is one of the promising methods due to simple, fast, efficient and cost effective technology. Highly selective magnetic sorbents can be designed by immobilizing functional groups in magnetic carrier which binds to the target specific ions. In the present work chitosan-(3-aminopropyl) triethoxysilane (APTS)- copperferrocyanide (CFC) composite beads have been synthesized for sorption of 137 Cs ions from aqueous streams. Physical characterization of the best resulted polymer beads was carried out by SEM-EDX and VSM technique. Sorption of Cs ions in the various magnetic polymer beads were studied in different aqueous condition by 137 Cs (662 KeV) radiotracer assay

  15. Rapid detection and purification of sequence specific DNA binding proteins using magnetic separation

    Directory of Open Access Journals (Sweden)

    TIJANA SAVIC

    2006-02-01

    Full Text Available In this paper, a method for the rapid identification and purification of sequence specific DNA binding proteins based on magnetic separation is presented. This method was applied to confirm the binding of the human recombinant USF1 protein to its putative binding site (E-box within the human SOX3 protomer. It has been shown that biotinylated DNA attached to streptavidin magnetic particles specifically binds the USF1 protein in the presence of competitor DNA. It has also been demonstrated that the protein could be successfully eluted from the beads, in high yield and with restored DNA binding activity. The advantage of these procedures is that they could be applied for the identification and purification of any high-affinity sequence-specific DNA binding protein with only minor modifications.

  16. On-Chip Manipulation of Protein-Coated Magnetic Beads via Domain-Wall Conduits

    DEFF Research Database (Denmark)

    Donolato, Marco; Vavassori, Paolo; Gobbi, Marco

    2010-01-01

    Geometrically constrained magnetic domain walls (DWs) in magnetic nanowires can be manipulated at the nanometer scale. The inhomogeneous magnetic stray field generated by a DW can capture a magnetic nanoparticle in solution. On-chip nanomanipulation of individual magnetic beads coated with proteins...

  17. On-chip magnetic bead-based DNA melting curve analysis using a magnetoresistive sensor

    DEFF Research Database (Denmark)

    Rizzi, Giovanni; Østerberg, Frederik Westergaard; Henriksen, Anders Dahl

    2014-01-01

    We present real-time measurements of DNA melting curves in a chip-based system that detects the amount of surface-bound magnetic beads using magnetoresistive magnetic field sensors. The sensors detect the difference between the amount of beads bound to the top and bottom sensor branches....... The beads are magnetized by the field arising from the bias current passed through the sensors. We demonstrate the first on-chip measurements of the melting of DNA hybrids upon a ramping of the temperature. This overcomes the limitation of using a single washing condition at constant temperature. Moreover...

  18. Silica-supported Macroporous Chitosan Bead for Affinity Purification of Trypsin Inhibitor

    Institute of Scientific and Technical Information of China (English)

    Feng Na XI; Jian Min WU; Ming Ming LUAN

    2005-01-01

    Macroporous cross-linking chitosan layer coated on silica gel (CTS-SiO2) was prepared by phase inversion and polyethylene glycol (PEG) molecular imprinting methods. Formation of macroporous surface was investigated by scanning electron microscopy (SEM) and BET analysis.The prepared bead was activated by reacting with 1,2-ethylene diglycidyl ether for introducing epoxy groups, and trypsin could be efficiently immobilized on the bead as a biospecific ligand.The bead bearing trypsin was employed to purify trypsin inhibitor (TIs) from egg white as affinity adsorbent.

  19. On-chip measurements of Brownian relaxation vs. concentration of 40nm magnetic beads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Rizzi, Giovanni; Hansen, Mikkel Fougt

    2012-01-01

    We present on-chip Brownian relaxation measurements on a logarithmic dilution series of 40 nm beads dispersed in water with bead concentrations between 16 mu g/ml and 4000 mu g/ml. The measurements are performed using a planar Hall effect bridge sensor at frequencies up to 1 MHz. No external fields...... are needed as the beads are magnetized by the field generated by the applied sensor bias current. We show that the Brownian relaxation frequency can be extracted from fitting the Cole-Cole model to measurements for bead concentrations of 64 mu g/ml or higher and that the measured dynamic magnetic response...... is proportional to the bead concentration. For bead concentrations higher than or equal to 500 mu g/ml, we extract a hydrodynamic diameter of 47(1) nm for the beads, which is close to the nominal bead size of 40 nm. Furthermore, we study the signal vs. bead concentration at a fixed frequency close to the Brownian...

  20. Enzyme-linked electrochemical DNA ligation assay using magnetic beads.

    Science.gov (United States)

    Stejskalová, Eva; Horáková, Petra; Vacek, Jan; Bowater, Richard P; Fojta, Miroslav

    2014-07-01

    DNA ligases are essential enzymes in all cells and have been proposed as targets for novel antibiotics. Efficient DNA ligase activity assays are thus required for applications in biomedical research. Here we present an enzyme-linked electrochemical assay based on two terminally tagged probes forming a nicked junction upon hybridization with a template DNA. Nicked DNA bearing a 5' biotin tag is immobilized on the surface of streptavidin-coated magnetic beads, and ligated product is detected via a 3' digoxigenin tag recognized by monoclonal antibody-alkaline phosphatase conjugate. Enzymatic conversion of napht-1-yl phosphate to napht-1-ol enables sensitive detection of the voltammetric signal on a pyrolytic graphite electrode. The technique was tested under optimal conditions and various situations limiting or precluding the ligation reaction (such as DNA substrates lacking 5'-phosphate or containing a base mismatch at the nick junction, or application of incompatible cofactor), and utilized for the analysis of the nick-joining activity of a range of recombinant Escherichia coli DNA ligase constructs. The novel technique provides a fast, versatile, specific, and sensitive electrochemical assay of DNA ligase activity.

  1. One-step isolation of plasma membrane proteins using magnetic beads with immobilized concanavalin A

    DEFF Research Database (Denmark)

    Lee, Yu-Chen; Block, Gregory; Chen, Huiwen

    2008-01-01

    We have developed a simple method for isolating and purifying plasma membrane proteins from various cell types. This one-step affinity-chromatography method uses the property of the lectin concanavalin A (ConA) and the technique of magnetic bead separation to obtain highly purified plasma membrane...... proteins from crude membrane preparations or cell lines. ConA is immobilized onto magnetic beads by binding biotinylated ConA to streptavidin magnetic beads. When these ConA magnetic beads were used to enrich plasma membranes from a crude membrane preparation, this procedure resulted in 3.7-fold enrichment...... of plasma membrane marker 5'-nucleotidase activity with 70% recovery of the activity in the crude membrane fraction of rat liver. In agreement with the results of 5'-nucleotidase activity, immunoblotting with antibodies specific for a rat liver plasma membrane protein, CEACAM1, indicated that CEACAM1...

  2. A micro-pillar array to trap magnetic beads in microfluidic systems

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2012-01-01

    A micro-pillar array (MPA) is proposed in this paper to trap and separate magnetic beads (MBs) in microfluidic systems. MBs are used in many biomedical applications due to being compatible in dimension to biomolecules, the large surface area

  3. [DNA extraction from decomposed tissue by double-digest and magnetic beads methods].

    Science.gov (United States)

    Yang, Dian; Liu, Chao; Liu, Hong

    2011-12-01

    To study the effect of the double-digest and magnetic beads method for DNA extraction from 3 types of decomposed tissues. DNA of cartilages, nails and joint capsule in 91 highly decomposed corpses which had not been extracted by common magnetic beads method, were prepared with the double-digest and magnetic beads methods, and quantified with Quantifiler kit, followed by amplification with Sinofiler kit or Minifiler kit. DNA concentration extracted from the 91 highly decomposed cartilages, nails and joint capsule samples was 0-0.225 ng/microL. Sixty-two samples whose DNA concentration were more than 0.020 ng/microL had obtained 9 or more STR loci successfully. The detection rate was 68.13%. The successful rate of STR genotyping for the 3 types of decomposed tissues can be significantly improved by the double-digest and magnetic beads methods.

  4. On-chip measurements of Brownian relaxation of magnetic beads with diameters from 10 nm to 250 nm

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Rizzi, Giovanni; Hansen, Mikkel Fougt

    2013-01-01

    We demonstrate the use of planar Hall effect magnetoresistive sensors for AC susceptibility measurements of magnetic beads with frequencies ranging from DC to 1 MHz. This wide frequency range allows for measuring Brownian relaxation of magnetic beads with diameters ranging from 10 nm to 250 nm....... Brownian relaxation is measured for six different magnetic bead types and their hydrodynamic diameters are determined. The hydrodynamic diameters are found to be within 40% of the nominal bead diameters. We discuss the applicability of the different bead types for volume-based biosensing with respect...... to sedimentation, magnetic trapping, and signal per bead. Among the investigated beads, we conclude that the beads with a nominal diameter of 80 nm are best suited for future on-chip volume-based biosensing experiments using planar Hall effect sensors....

  5. Magnetic actuator for the control and mixing of magnetic bead-based reactions on-chip.

    Science.gov (United States)

    Berenguel-Alonso, Miguel; Granados, Xavier; Faraudo, Jordi; Alonso-Chamarro, Julián; Puyol, Mar

    2014-10-01

    While magnetic bead (MB)-based bioassays have been implemented in integrated devices, their handling on-chip is normally either not optimal--i.e. only trapping is achieved, with aggregation of the beads--or requires complex actuator systems. Herein, we describe a simple and low-cost magnetic actuator to trap and move MBs within a microfluidic chamber in order to enhance the mixing of a MB-based reaction. The magnetic actuator consists of a CD-shaped plastic unit with an arrangement of embedded magnets which, when rotating, generate the mixing. The magnetic actuator has been used to enhance the amplification reaction of an enzyme-linked fluorescence immunoassay to detect Escherichia coli O157:H7 whole cells, an enterohemorrhagic strain, which have caused several outbreaks in food and water samples. A 2.7-fold sensitivity enhancement was attained with a detection limit of 603 colony-forming units (CFU) /mL, when employing the magnetic actuator.

  6. Magnetic Bead Based Immunoassay for Autonomous Detection of Toxins

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-01

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

  7. Investigation on rare earth magnets recycling by organophosphoric extractant encapsulated polymeric beads for separation of dysprosium

    International Nuclear Information System (INIS)

    Yadav, Kartikey K.; Singh, D.K.; Kain, V.

    2017-01-01

    Rare earth elements (REEs) are a basic requirement of the electronics and new industries including green technology. In the present work an organophosphoric extractant encapsulating polyethersulfone (PES) beads has been developed and employed for dysprosium (Dy) separation from aqueous stream. Polyethersulfonic beads encapsulating PC88A were prepared by phase inversion method. During the synthesis of the beads, preparatory parameters were also optimized to obtain best suited beads which were subsequently characterized for their encapsulation capacity and micro structural investigation. The results obtained in the present investigation suggested that PES/PVAJPC88A composite beads could be used for separation of rare earths from aqueous medium obtained from the solubilisation of magnetic scrap materials

  8. Preparation of Immuno-magnetic Beads and Their Separation & Detection to Ovary Cancer Cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The organic monomer-molecule with nanometer magnetic powder by means of reforming the surface of nanometer magnetic powder have been synthesized.Magnetic beads in diameter of 2μm or so are obtained by controlling conditions.Ovary cancer cells of ascites are separated and ovary cancer cells of blood are detected by using immuno-magnetic beads linked with ovary cancer cell mono-antibodies.Results show that the specificity is 85%,sensitivity is 87%,accuracy is 84%,cells acquiring purity is 90%,cells activity is 92% and detection sensitivity is 25×10-7.

  9. Concanavalin A immobilized magnetic poly(glycidyl methacrylate) beads for prostate specific antigen binding.

    Science.gov (United States)

    Idil, Neslihan; Perçin, Işık; Karakoç, Veyis; Yavuz, Handan; Aksöz, Nilüfer; Denizli, Adil

    2015-10-01

    The aim of this study was to prepare Concanavalin A (Con A) immobilized magnetic poly(glycidyl methacrylate) (mPGMA) beads for prostate specific antigen (PSA) binding and to study binding capacities of the beads using lectin-glycoprotein interactions. Firstly, iron oxide nanoparticles were synthesized by co-precipitation method and then, beads were synthesized by dispersion polymerization in the presence of iron oxide nanoparticles. Con A molecules were both covalently immobilized onto the beads directly and through the spacer arm (1,6-diaminohexane-HDMA). The total PSA and free PSA binding onto the mPGMA-HDMA-Con A beads were higher than that of the mPGMA-Con A beads. Maximum PSA binding capacity was observed as 91.2 ng/g. Approximately 45% of the bound PSA was eluted by using 0.1 M mannose as elution agent. The mPGMA-HDMA-Con A beads could be reused without a remarkable decrease in the binding capacities after 5 binding-desorption cycles. Serum fractions were analyzed using SDS-PAGE. The mPGMA-HDMA-Con A beads could be useful for the detection of PSA and suggested as a model system for other glycoprotein biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Chip-Based Measurements of Brownian Relaxation of Magnetic Beads Using a Planar Hall Effect Magnetic Field Sensor

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Dalslet, Bjarke Thomas; Snakenborg, Detlef

    2010-01-01

    using only the self-field arising from the bias current applied to the sensors as excitation field. We present measurements on a suspension of magnetic beads with a nominal diameter of 250 nm vs. temperature and find that the observations are consistent with the Cole-Cole model for Brownian relaxation...... with a constant hydrodynamic bead diameter when the temperature dependence of the viscosity of water is taken into account. These measurements demonstrate the feasibility of performing measurements of the Brownian relaxation response in a lab-on-a-chip system and constitute the first step towards an integrated...... biosensor based on the detection of the dynamic response of magnetic beads....

  11. Magnetic chitosan/clay beads: A magsorbent for the removal of cationic dye from water

    Energy Technology Data Exchange (ETDEWEB)

    Bée, Agnès, E-mail: agnes.bee@upmc.fr [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX, F-75005 Paris (France); Obeid, Layaly, E-mail: lghannoum@hotmail.fr [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX, F-75005 Paris (France); CertiNergy Solutions, 33 avenue du Maine, BP 195, 75755 Paris Cedex 15 (France); Mbolantenaina, Rakotomalala, E-mail: mbolantenaina@yahoo.fr [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX, F-75005 Paris (France); Welschbillig, Mathias, E-mail: welschbillig@certinergysolutions.com [CertiNergy Solutions, 33 avenue du Maine, BP 195, 75755 Paris Cedex 15 (France); Talbot, Delphine, E-mail: delphine.talbot@upmc.fr [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Laboratoire PHENIX, F-75005 Paris (France)

    2017-01-01

    A magnetic composite material composed of magnetic nanoparticles and clay encapsulated in cross-linked chitosan beads was prepared, characterized and used as a magsorbent for the removal of a cationic dye, methylene blue (MB), from aqueous solutions. The magnetic properties of these beads represent an advantage to recover them at the end of the depollution process. The optimal weight ratio R=clay:chitosan for the removal of MB in a large range of pH was determined. For beads without clay, the maximal adsorption capacity of MB occurs in the pH range [9–12], while for beads with clay, the pH range extends by increasing the amount of clay to reach [3–12] for R>0.5. Adsorption isotherms show that the adsorption capacity of magnetic beads is equal to 82 mg/g. Moreover, the kinetics of dye adsorption is relatively fast since 50% of the dye is removed in the first 13 min for an initial MB concentration equal to 100 mg/L. The estimation of the number of adsorption sites at a given pH shows that the main driving force for adsorption of MB in a large range of pH is the electrostatic interaction between the positively charged dye and the permanent negative charges of clay. - Highlights: • A magsorbent based on magnetic nanoparticles and clay encapsulated in chitosan beads was prepared and characterized. • Clay played significant role for the removal of a cationic dye. • The magnetic beads exhibit a maximum adsorption capacity of 82 mg/g for methylene blue. • The pH range of the maximum adsorption extends from [9–12] to [3–12] by increasing the amount of clay. • The magsorbent could be magnetically removed from solution.

  12. Effect of patterned micro-magnets on superparamagnetic beads in microchannels

    International Nuclear Information System (INIS)

    Guo, S S; Deng, Y L; Zhao, L B; Zhao, X-Z; Chan, H L W

    2008-01-01

    The trapping response of patterned micro-magnets (PMMs) was studied based on the parameters affecting superparamagnetic beads in microfluidic channels. Using replica moulding and electroplating technologies, the PMMs were fabricated on the microchannel bottom, which generated sufficient magnetic forces to bias the moments of magnetic particles in a flowing stream. A simplified physical principle was used to analyse the relative velocity of the magnetic particle in the confined space of a microchannel. The results revealed that the magnetic force contributed to the fluidic flow rate as well as to the hydrodynamic drag force. The relative velocity of magnetic particles was dependent on the frequency under an external magnetic field driven by an alternate current (ac) source. It showed that the magnetic gradient induced hysteresis characteristics of the transmission spectrum, associated with the interaction of superparamagnetic beads and magnetic field

  13. Effects of Magnetic Particles Entrance Arrange-ments on Mixing Efficiency of a Magnetic Bead Micromixer

    Institute of Scientific and Technical Information of China (English)

    Reza Kamali∗; Seyed Alireza Shekoohi; Alireza Binesh

    2014-01-01

    In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter the micromixer by fluid flows and are actuated by an alternating magnetic field normal to the main flow. An important feature of micromixer which is not considered before by researchers is the particle entrance arrangement into the micromixer. This parameter could effectively affect the micromixer efficiency. There are two general micro magnetic particle entrance arrangements in magnetic bead micromixers: determined position entrance and random position entrance. In the case of determined position entrances, micro magnetic particles enter the micromixer at specific positions of entrance cross section. However, in a random position entrance, particles enter the microchannel with no order. In this study mixing efficiencies of identical magnetic bead micromixers which only differ in particle entrance arrangement are numerically investigated and compared. The results reported in this paper illustrate that the prepared computer code can be one of the most powerful and beneficial tools for the magnetic bead micromixer performance analysis. In addition, the results show that some features of the magnetic bead micromixer are strongly affected by the entrance arrangement of the particles.

  14. Method and device for thermal control of biological and chemical reactions using magnetic particles or magnetic beads and variable magnetic fields

    OpenAIRE

    Zilch, C.; Gerdes, W.; Bauer, J.; Holschuh, K.

    2009-01-01

    The invention relates to a method for the thermal control of at least one temperature-dependent enzymatic reaction in the presence of magnetic particles, particularly nanoparticles, or magnetic beads, in vitro by heating the magnetic beads or magnetic particles to at least one defined target temperature using alternating magnetic fields. The thermally controllable enzymatic reaction carried out with the method according to the invention is preferably a PCR reaction or another reaction for elo...

  15. Removal of diethyl phthalate from aqueous phase using magnetic poly(EGDMA-VP) beads

    Energy Technology Data Exchange (ETDEWEB)

    Tuemay Oezer, Elif [Department of Chemistry, Uludag University, Bursa (Turkey); Osman, Bilgen, E-mail: bilgeno@uludag.edu.tr [Department of Chemistry, Uludag University, Bursa (Turkey); Kara, Ali; Besirli, Necati; Guecer, Seref [Department of Chemistry, Uludag University, Bursa (Turkey); Soezeri, Hueseyin [TUBITAK-UME, National Metrology Institute, PO Box 54 TR-41470, Gebze/Kocaeli (Turkey)

    2012-08-30

    Highlights: Black-Right-Pointing-Pointer Magnetic beads were prepared for removal of diethyl phthalate (DEP). Black-Right-Pointing-Pointer Total capacity of the beads was determined as 98.9 mg DEP per gram polymer. Black-Right-Pointing-Pointer Magnetic beads were regenerated easily and reused for DEP adsorption. Black-Right-Pointing-Pointer Adsorption isotherms, kinetics and thermodynamics were elucidated. - Abstract: The barium hexaferrite (BaFe{sub 12}O{sub 19}) containing magnetic poly(ethylene glycol dimethacrylate-vinyl pyridine), (mag-poly(EGDMA-VP)) beads (average diameter = 53-212 {mu}m) were synthesized and characterized. Their use as an adsorbent in the removal of diethyl phthalate (DEP) from an aqueous solution was investigated. The mag-poly(EGDMA-VP) beads were prepared by copolymerizing of 4-vinyl pyridine (VP) with ethylene glycol dimethacrylate (EGDMA). The mag-poly(EGDMA-VP) beads were characterized by N{sub 2} adsorption/desorption isotherms (BET), vibrating sample magnetometer (VSM), X-ray powder diffraction (XRD), elemental analysis, scanning electron microscope (SEM) and swelling studies. At a fixed solid/solution ratio, the various factors affecting the adsorption of DEP from aqueous solutions such as pH, initial concentration, contact time and temperature were analyzed. The maximum DEP adsorption capacity of the mag-poly(EGDMA-VP) beads was determined as 98.9 mg/g at pH 3.0, 25 Degree-Sign C. All the isotherm data can be fitted with both the Langmuir and the Dubinin-Radushkevich isotherm models. The pseudo first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models were used to describe the adsorption kinetics. The thermodynamic parameters obtained indicated the exothermic nature of the adsorption. The DEP adsorption capacity did not change after 10 batch successive reactions, demonstrating the usefulness of the magnetic beads in applications.

  16. Comparison of La3+ and mixed rare earths-loaded magnetic chitosan beads for fluoride adsorption

    DEFF Research Database (Denmark)

    Liang, Peng; An, Ruiqi; Li, Ruifen

    2018-01-01

    La3+ and mixed-rare earth magnetic chitosan beads (MCLB and MCLRB) were successfully prepared for fluoride removal, respectively. The adsorbents were characterized by scanning electron microscope and magnetic response. Batch experiments were carried out to investigate the adsorbent performance...

  17. Kinase-loaded magnetic beads for sequential in vitro phosphorylation of peptides and proteins.

    Science.gov (United States)

    Hromadkova, Lenka; Kupcik, Rudolf; Vajrychova, Marie; Prikryl, Petr; Charvatova, Andrea; Jankovicova, Barbora; Ripova, Daniela; Bilkova, Zuzana; Slovakova, Marcela

    2018-01-15

    Post-translational modifications, including phosphorylation, greatly impact the physiological function of proteins, especially those that are natively unfolded and implicated in many neurodegenerative diseases. However, structural and functional studies of such proteins require fully defined phosphorylation, including those that are not physiological. Thus, the kinases ERK2 and GSK-3β were immobilized to various superparamagnetic beads with carboxylic, aldehyde, Ni 2+ , or Co 3+ functional groups, with a view to efficiently phosphorylate peptides and proteins in vitro. Full phosphorylation of specific synthetic peptides confirmed that beads were successfully loaded with kinases. Remarkably, enzymes covalently immobilized on carboxylated SeraMag beads remained active upon reuse, with residual activity after 10 uses 99.5 ± 0.34% for GSK-3β and 36.2 ± 2.01% for ERK2. The beads were also used to sequentially phosphorylate recombinant tau, which in vivo is a biomarker of Alzheimer's disease. Thus, a system consisting of two fully active kinases immobilized to magnetic beads is demonstrated for the first time. In comparison to soluble enzymes, the beads are easier to handle, reusable, and thus low-cost. Importantly, these beads are also convenient to remove from reactions to minimize contamination of phosphorylated products or to exchange with other kinases.

  18. Applied Study on Magnetic Nanometer Beads in Preparation of Genechip Samples

    Institute of Scientific and Technical Information of China (English)

    陈慧; 高华方; 谢欣; 马雪梅; 杨渝珍

    2004-01-01

    Summary: A protocol for enrichment and adsorption of karyocyte from whole blood by using magnetic nanometer beads as solid-phase absorbents was presented. The PCR amplification could be accomplished by using the nanobeads with karyocyte as template directly and the PCR products were applied on an oligonucleotide array to do gene typing. The HLA-A PCR amplification system and a small HLA-A oligonucleotide microarray were applied as the platform and an experiment protocol of separating karyocyte from whole blood using the magnetic nanometer beads (Fe2O3) were set up.The experimental conditions were also discussed. It showed that pH level of PBS eluent, Taq enzyme quantity and fragment length of products could influent the amplification results, and the magnetic nano-beads could succeed in sample preparation in microarray to provide a promising way in automatic detection and lab-on-a-chip.

  19. Polyaniline coated magnetic carboxymethylcellulose beads for selective removal of uranium ions from aqueous solution

    International Nuclear Information System (INIS)

    Yakup Arica, M.; Gulay Bayramoglu; Gazi University, Ankara

    2016-01-01

    Magnetic carboxymethylcellulose (CMC) beads were prepared via ionic cross-linking. Then CMC beads were coated with polyaniline (PANI). The results of FTIR, SEM, DTA and N 2 adsorption-desorption demonstrated that aniline was successfully grafted onto the surface of mCMC beads. The potential use of the prepared adsorbent was used for removal of U(VI) ions. The determined maximum adsorption capacities of the mCMC and mCMC-g-PANI beads for U(VI) ions were 129.4 and 386.5 mg/g dry weight at pH 4.5, respectively. The thermodynamic parameters (ΔH°, ΔS° and ΔG°) were evaluated. The adsorbent systems were regenerated using 0.1 M HCl. (author)

  20. Asynchronous Magnetic Bead Rotation (AMBR Microviscometer for Label-Free DNA Analysis

    Directory of Open Access Journals (Sweden)

    Yunzi Li

    2014-03-01

    Full Text Available We have developed a label-free viscosity-based DNA detection system, using paramagnetic beads as an asynchronous magnetic bead rotation (AMBR microviscometer. We have demonstrated experimentally that the bead rotation period is linearly proportional to the viscosity of a DNA solution surrounding the paramagnetic bead, as expected theoretically. Simple optical measurement of asynchronous microbead motion determines solution viscosity precisely in microscale volumes, thus allowing an estimate of DNA concentration or average fragment length. The response of the AMBR microviscometer yields reproducible measurement of DNA solutions, enzymatic digestion reactions, and PCR systems at template concentrations across a 5000-fold range. The results demonstrate the feasibility of viscosity-based DNA detection using AMBR in microscale aqueous volumes.

  1. Synthesis and characterization of monosize magnetic poly(glycidyl methacrylate) beads

    Institute of Scientific and Technical Information of China (English)

    Evrim Banu Alt1nta(s); Lokman Uzun; Adil Denizli

    2007-01-01

    Monosize, 1.6 μm, magnetic beads of poly(glycidyl methacrylate) [M-poly(GMA)], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly(GMA) beads were characterized by swelling tests, density measurements, electron spin resonance (ESR), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). The characteristic functional groups of M-poly(GMA)beads were analyzed by Fourier transform infrared spectrometer (FTIR). The M-poly(GMA) beads are highly uniform in size and have a spherical shape and non-porous structure. Polydispersity index (PDI) of M-poly(GMA) beads was calculated to be around 1.008. The hydrated density of the M-poly(GMA) beads measured at 25 ℃ was 1.14 g/cm3. The content of oxirane groups on the surface of the M-poly(GMA) sample was found to be 3.46 mmol/g by using perchloric acid titration. The specific surface area of the M-poly(GMA) beads was determined to be 3.2 m2/g.The equilibrium swelling ratio was 52%. The volume fraction of magnetite nanopowder in the M-poly(GMA) beads was found to be 4.5%. The g factor, that can be considered as a quantity characteristic of the molecules in which the unpaired electrons are located, was found to be 2.28for M-poly(GMA). The external magnetic field at resonance was calculated to be 2055 Gs which was found sufficient to excite all of the dipole moments present in 1.0 g of M-poly(GMA) sample.

  2. Construction of microscale structures in enclosed microfluidic networks by using a magnetic beads based method.

    Science.gov (United States)

    Wang, Zhenyu; Zhang, Xiaojuan; Yang, Jun; Yang, Zhong; Wan, Xiaoping; Hu, Ning; Zheng, Xiaolin

    2013-08-20

    A large number of microscale structures have been used to elaborate flowing control or complex biological and chemical reaction on microfluidic chips. However, it is still inconvenient to fabricate microstructures with different heights (or depths) on the same substrate. These kinds of microstructures can be fabricated by using the photolithography and wet-etching method step by step, but involves time-consuming design and fabrication process, as well as complicated alignment of different masters. In addition, few existing methods can be used to perform fabrication within enclosed microfluidic networks. It is also difficult to change or remove existing microstructures within these networks. In this study, a magnetic-beads-based approach is presented to build microstructures in enclosed microfluidic networks. Electromagnetic field generated by microfabricated conducting wires (coils) is used to manipulate and trap magnetic beads on the bottom surface of a microchannel. These trapped beads are accumulated to form a microscale pile with desired shape, which can adjust liquid flow, dock cells, modify surface, and do some other things as those fabricated microstructures. Once the electromagnetic field is changed, trapped beads may form new shapes or be removed by a liquid flow. Besides being used in microfabrication, this magnetic-beads-based method can be used for novel microfluidic manipulation. It has been validated by forming microscale dam structure for cell docking and modified surface for cell patterning, as well as guiding the growth of neurons. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Alginate/magnetite hybrid beads for magnetically stimulated release of dopamine.

    Science.gov (United States)

    Kondaveeti, Stalin; Cornejo, Daniel R; Petri, Denise Freitas Siqueira

    2016-02-01

    Hybrid beads composed of magnetite nanoparticles (MNP) and alginate (Alg) were synthesized and coded as Alg-MNP. They were incubated in dopamine (DOPA) solution (5 g/L), at pH 7.4 and 8 °C, during 12 h, promoting the DOPA loaded magnetic beads, coded as Alg-MNP/DOPA. The release of DOPA was further evaluated in the absence and the presence of external magnetic field (EMF) of 0.4 T. The products Alg-MNP and Alg-MNP/DOPA were characterized by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared vibrational spectroscopy (FTIR), UV spectrophotometry, thermogravimetric analyses (TGA), inductively coupled plasma atomic emission spectroscopy (ICP-AES) analyses and superconducting quantum interference device (SQUID) magnetometer. The magnetic and chemical properties of Alg-MNP beads were not affected by DOPA loading. The incorporation of DOPA into the beads depended on the pH and on the negative charge density. At pH 7.4 38% of DOPA were loaded into Alg-MNP beads, whereas at pH 2 or using neat Alg beads (lower charge density than Alg-MNP) the loading efficiency decreased to one third or less. In the absence of EMF, 24% of the loaded DOPA was released from Alg-MNP at pH 7.4 over a period of 26 h. The released amount increased to 33% under the stimulus of EMF. A model was proposed to explain the loading efficiency of charged drugs, as DOPA, into hybrid beads and the role played by EMF on delivery systems, where drug and matrix are oppositely charged. The results suggest that the alginate combined with magnetite nanoparticles is a promising system for release of DOPA in the presence of EMF. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Synthesis and Characterisation of Biocompatible Polymer-Conjugated Magnetic Beads for Enhancement Stability of Urease.

    Science.gov (United States)

    Doğaç, Yasemin Ispirli; Teke, Mustafa

    2016-04-01

    We reported natural polymer-conjugated magnetic featured urease systems for removal of urea effectively. The optimum temperature (20-60 °C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70 °C), pH stability (4.0-9.0), operational stability (0-250 min), reusability (18 times) and storage stability (24 weeks) were studied for characterisation of the urease-encapsulated biocompatible polymer-conjugated magnetic beads. Also, the surface groups and chemical structure of the magnetic beads were determined by using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The all urease-encapsulated magnetic beads protected their stability of 30-45 % relative activity at 70 °C. A significant increase was observed at their pH stability compared with the free urease for both acidic and alkaline medium. Besides this, their repeatability activity were approximately 100 % during 4(th) run. They showed residual activity of 50 % after 16 weeks. The importance of this work is enhancement stability of immobilised urease by biocompatible polymer-conjugated magnetic beads for the industrial application based on removal of urea.

  5. Establishing a novel automated magnetic bead-based method for the extraction of DNA from a variety of forensic samples.

    Science.gov (United States)

    Witt, Sebastian; Neumann, Jan; Zierdt, Holger; Gébel, Gabriella; Röscheisen, Christiane

    2012-09-01

    Automated systems have been increasingly utilized for DNA extraction by many forensic laboratories to handle growing numbers of forensic casework samples while minimizing the risk of human errors and assuring high reproducibility. The step towards automation however is not easy: The automated extraction method has to be very versatile to reliably prepare high yields of pure genomic DNA from a broad variety of sample types on different carrier materials. To prevent possible cross-contamination of samples or the loss of DNA, the components of the kit have to be designed in a way that allows for the automated handling of the samples with no manual intervention necessary. DNA extraction using paramagnetic particles coated with a DNA-binding surface is predestined for an automated approach. For this study, we tested different DNA extraction kits using DNA-binding paramagnetic particles with regard to DNA yield and handling by a Freedom EVO(®)150 extraction robot (Tecan) equipped with a Te-MagS magnetic separator. Among others, the extraction kits tested were the ChargeSwitch(®)Forensic DNA Purification Kit (Invitrogen), the PrepFiler™Automated Forensic DNA Extraction Kit (Applied Biosystems) and NucleoMag™96 Trace (Macherey-Nagel). After an extensive test phase, we established a novel magnetic bead extraction method based upon the NucleoMag™ extraction kit (Macherey-Nagel). The new method is readily automatable and produces high yields of DNA from different sample types (blood, saliva, sperm, contact stains) on various substrates (filter paper, swabs, cigarette butts) with no evidence of a loss of magnetic beads or sample cross-contamination. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  6. Magnetic bead manipulation in a sub-microliter fluid volume applicable for biosensing

    NARCIS (Netherlands)

    Derks, R.J.S.; Wimberger-Friedl, R.; Prins, M.W.J.; Dietzel, A.H.

    2007-01-01

    Magnetic actuation principles using superparamagnetic beads suspended in a fluid are studied in this paper. An exptl. setup contg. a submicroliter fluid vol. surrounded by four miniaturized electromagnets was designed and fabricated. On the basis of optical velocity measurements, the induced

  7. On-chip magnetic bead-based DNA melting curve analysis using a magnetoresistive sensor

    International Nuclear Information System (INIS)

    Rizzi, Giovanni; Østerberg, Frederik W.; Henriksen, Anders D.; Dufva, Martin; Hansen, Mikkel F.

    2015-01-01

    We present real-time measurements of DNA melting curves in a chip-based system that detects the amount of surface-bound magnetic beads using magnetoresistive magnetic field sensors. The sensors detect the difference between the amount of beads bound to the top and bottom sensor branches of the differential sensor geometry. The sensor surfaces are functionalized with wild type (WT) and mutant type (MT) capture probes, differing by a single base insertion (a single nucleotide polymorphism, SNP). Complementary biotinylated targets in suspension couple streptavidin magnetic beads to the sensor surface. The beads are magnetized by the field arising from the bias current passed through the sensors. We demonstrate the first on-chip measurements of the melting of DNA hybrids upon a ramping of the temperature. This overcomes the limitation of using a single washing condition at constant temperature. Moreover, we demonstrate that a single sensor bridge can be used to genotype a SNP. - Highlights: • We apply magnetoresistive sensors to study solid-surface hybridization kinetics of DNA. • We measure DNA melting profiles for perfectly matching DNA duplexes and for a single base mismatch. • We present a procedure to correct for temperature dependencies of the sensor output. • We reliably extract melting temperatures for the DNA hybrids. • We demonstrate direct measurement of differential binding signal for two probes on a single sensor

  8. Magnetic polymer beads: Recent trends and developments in synthetic design and applications

    KAUST Repository

    Philippova, Olga

    2011-04-01

    The paper describes the synthesis, properties and applications of magnetic polymer beads. State-of-the-art, future challenges, and promising trends in this field are analyzed. New applications in oil recovery are described. © 2010 Elsevier Ltd. All rights reserved.

  9. Magnetic polymer beads: Recent trends and developments in synthetic design and applications

    KAUST Repository

    Philippova, Olga; Barabanova, Anna; Molchanov, Vyacheslav; Khokhlov, Alexei

    2011-01-01

    The paper describes the synthesis, properties and applications of magnetic polymer beads. State-of-the-art, future challenges, and promising trends in this field are analyzed. New applications in oil recovery are described. © 2010 Elsevier Ltd. All rights reserved.

  10. Antibody-integrated and functionalized graphite-encapsulated magnetic beads, produced using ammonia gas plasma technology, for capturing Salmonella.

    Science.gov (United States)

    Sakudo, Akikazu; Chou, Han; Nagatsu, Masaaki

    2015-03-01

    Salmonella spp. is the single and most important causative agent of foodborne infections, especially involving foods such as eggs, milk and meat. To prevent infection, a reliable surveillance system is required that can quickly and sensitively detect Salmonella. Here, we describe the development of antibody-integrated magnetic beads that are functionalized by a novel strategy using ammonia gas plasma. Ammonia plasma, produced by a radio frequency (RF) power supply, was allowed to react with the surface of graphite-encapsulated magnetic beads, resulting in the introduction of amino groups. An anti-Salmonella antibody was then anchored by sulfide groups present on the protein surface to the amino groups of the magnetic beads via N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP). The potential usefulness of these magnetic beads for capturing Salmonella was examined as follows. The beads were incubated with Salmonella in liquid medium and then separated from the supernatant by applying a magnetic field. After thorough washing, adsorption of Salmonella to the beads was confirmed by immunochromatography, polymerase chain reaction and a direct culture assay. Our findings indicate that the capture and concentration of Salmonella using the antibody-integrated magnetic beads was more efficient than commercial Dynabeads® anti-Salmonella, which are conventionally used for concentrating Salmonella from liquid cultures. We believe this novel bead technology will contribute to the enhanced detection of Salmonella. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. A multi-purpose ultrasonic streaming mixer for integrated magnetic bead ELISAs

    International Nuclear Information System (INIS)

    Brandhoff, Lukas; Lang, Walter; Vellekoop, Michael J; Zirath, Helene; Peham, Johannes; Wiesinger-Mayr, Herbert; Salas, Mariugenia; Haller, Anna; Spittler, Andreas; Schnetz, Guntram

    2015-01-01

    We present an ultrasonic streaming mixer for disposable and on-chip magnetic bead ELISAs. The ultrasonic transducer is placed at system-level to keep cost per chip as low as possible, and is coupled to the chip by means of a solid ultrasonic horn. The system provides mixing of liquids, as well as dispersion of the superparamagnetic beads in the ELISA. Additionally it can be used clean the chamber surface from nonspecifically bound proteins during the washing steps in the ELISA protocol. Using our system the time for the ELISA protocol has been greatly reduced down to 30 min. (paper)

  12. Protein purification using magnetic adsorbent particles

    DEFF Research Database (Denmark)

    Franzreb, M; Siemann-Herzberg, M.; Hobley, Timothy John

    2006-01-01

    The application of functionalised magnetic adsorbent particles in combination with magnetic separation techniques has received considerable attention in recent years. The magnetically responsive nature of such adsorbent particles permits their selective manipulation and separation in the presence...... separations are fast, gentle, scaleable, easily automated, can achieve separations that would be impossible or impractical to achieve by other techniques, and have demonstrated credibility in a wide range of disciplines, including minerals processing, wastewater treatment, molecular biology, cell sorting...

  13. Development of a magnetic bead-based method for the collection of circulating extracellular vesicles.

    Science.gov (United States)

    Shih, Chun-Liang; Chong, Kowit-Yu; Hsu, Shih-Che; Chien, Hsin-Jung; Ma, Ching-Ting; Chang, John Wen-Cheng; Yu, Chia-Jung; Chiou, Chiuan-Chian

    2016-01-25

    Cells release different types of extracellular vesicles (EVs). These EVs contain biomolecules, including proteins and nucleic acids, from their parent cells, which can be useful for diagnostic applications. The aim of this study was to develop a convenient procedure to collect circulating EVs with detectable mRNA or other biomolecules. Magnetic beads coated with annexin A5 (ANX-beads), which bound to phosphatidylserine moieties on the surfaces of most EVs, were tested for their ability to capture induced apoptotic bodies in vitro and other phosphatidylserine-presenting vesicles in body fluids. Our results show that up to 60% of induced apoptotic bodies could be captured by the ANX-beads. The vesicles captured from cultured media or plasma contained amplifiable RNA. Suitable blood samples for EV collection included EDTA-plasma and serum but not heparin-plasma. In addition, EVs in plasma were labile to freeze-and-thaw cycles. In rodents xenografted with human cancer cells, tumor-derived mRNA could be detected in EVs captured from serum samples. Active proteins could be detected in EVs captured from ascites but not from plasma. In conclusion, we have developed a magnetic bead-based procedure for the collection of EVs from body fluids and proved that captured EVs contain biomolecules from their parent cells, and therefore have great potential for disease diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. A half-ring GMR sensor for detection of magnetic beads immobilized on a circular micro-trap

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2011-11-01

    Utilizing magnetic principles in biological immunoassays is an attractive option given its ability to remotely and non-invasively manipulate and detect cells tagged with micro/nano size superparamagnetic type beads and due to the fact that even the most complex biological immunoassays will have very little magnetic effect. The presence of magnetic beads can be detected by a magnetic sensor which quantifies the amount of target cells present in the immunoassay. In order to increase the detection rate a circular conducting micro-trap is employed to attract, trap and transport the magnetic beads to the sensing area. In this research we propose a half-ring spin valve type giant magnetoresistance (GMR) sensor for the measurement of stray fields produced by 2 μm magnetic beads which are around the circular micro-trap. A couple of half-ring GMR sensors can be used to cover the entire circular border width, in order to detect the majority of the immobilized magnetic beads. Analytical and numerical analysis leading towards the fabrication of the half-ring GMR sensor are presented. DC characterization of the fabricated sensor showed a magnetoresistance of 5.9 %. Experimental results showed that the half-ring GMR sensor detected the presence of 2 μm magnetic beads. Hence, half-ring GMR sensors integrated with a circular micro-trap have great potential to be used as an effective disease diagnostic device. © 2011 IEEE.

  15. A half-ring GMR sensor for detection of magnetic beads immobilized on a circular micro-trap

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Liang, Cai; Useinov, Arthur; Kosel, Jü rgen; Giouroudi, Ioanna

    2011-01-01

    Utilizing magnetic principles in biological immunoassays is an attractive option given its ability to remotely and non-invasively manipulate and detect cells tagged with micro/nano size superparamagnetic type beads and due to the fact that even the most complex biological immunoassays will have very little magnetic effect. The presence of magnetic beads can be detected by a magnetic sensor which quantifies the amount of target cells present in the immunoassay. In order to increase the detection rate a circular conducting micro-trap is employed to attract, trap and transport the magnetic beads to the sensing area. In this research we propose a half-ring spin valve type giant magnetoresistance (GMR) sensor for the measurement of stray fields produced by 2 μm magnetic beads which are around the circular micro-trap. A couple of half-ring GMR sensors can be used to cover the entire circular border width, in order to detect the majority of the immobilized magnetic beads. Analytical and numerical analysis leading towards the fabrication of the half-ring GMR sensor are presented. DC characterization of the fabricated sensor showed a magnetoresistance of 5.9 %. Experimental results showed that the half-ring GMR sensor detected the presence of 2 μm magnetic beads. Hence, half-ring GMR sensors integrated with a circular micro-trap have great potential to be used as an effective disease diagnostic device. © 2011 IEEE.

  16. Automated solid-phase subcloning based on beads brought into proximity by magnetic force.

    Science.gov (United States)

    Hudson, Elton P; Nikoshkov, Andrej; Uhlen, Mathias; Rockberg, Johan

    2012-01-01

    In the fields of proteomics, metabolic engineering and synthetic biology there is a need for high-throughput and reliable cloning methods to facilitate construction of expression vectors and genetic pathways. Here, we describe a new approach for solid-phase cloning in which both the vector and the gene are immobilized to separate paramagnetic beads and brought into proximity by magnetic force. Ligation events were directly evaluated using fluorescent-based microscopy and flow cytometry. The highest ligation efficiencies were obtained when gene- and vector-coated beads were brought into close contact by application of a magnet during the ligation step. An automated procedure was developed using a laboratory workstation to transfer genes into various expression vectors and more than 95% correct clones were obtained in a number of various applications. The method presented here is suitable for efficient subcloning in an automated manner to rapidly generate a large number of gene constructs in various vectors intended for high throughput applications.

  17. Synthesis of magnetic hollow silica using polystyrene bead as a template

    International Nuclear Information System (INIS)

    Wu, W.; Caruntu, D.; Martin, A.; Yu, M.H.; O'Connor, C.J.; Zhou, W.L.; Chen, J.-F.

    2007-01-01

    In this paper, we report a new route to synthesize novel magnetic hollow silica nanospheres (MHSNs) using polystyrene particles as sacrificial templates, and TEOS and Fe 3 O 4 as precursors. TEM, EDS, XRD, and SQUID were applied to characterize MHSNs. TEM and EDS results show that the MHSNs consist of about 200 nm of hollow cores and ∼35 nm shells with ∼10 nm of Fe 3 O 4 nanoparticles embedded. The polystyrene beads were successfully removed by immersing the as-prepared silica nanocomposite in a toluene solution. XRD results demonstrate that the Fe 3 O 4 magnetic nanoparticles still keep spinel structure even heated at low temperature. The surface status of the polystyrene beads and Fe 3 O 4 nanoparticles has an important effect on the formation of the MHSNs. The MHSNs present a superparamagnetism at room temperature by SQUID measurement. The MHSNs have potential applications in biosystem and nanomedicine

  18. A micro-pillar array to trap magnetic beads in microfluidic systems

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2012-12-01

    A micro-pillar array (MPA) is proposed in this paper to trap and separate magnetic beads (MBs) in microfluidic systems. MBs are used in many biomedical applications due to being compatible in dimension to biomolecules, the large surface area available to attach biomolecules, and the fact that they can be controlled by a magnetic field. Trapping and separating these labeled biomolecules is an important step toward achieving reliable and accurate quantification for disease diagnostics. Nickel Iron (Ni50Fe 50) micro-pillars were fabricated on a Silicon (Si) substrate by standard microfabrication techniques. Experimental results showed that MBs could be trapped on the MPA at the single bead level and separated from other non-target particles. This principle can easily be extended to trap and separate target biomolecules in heterogeneous biological samples. © 2012 IEEE.

  19. [Evaluation of TB-beads assay utilizing the technique of magnetic beads--an innovative assay method for detection of acid fast bacilli].

    Science.gov (United States)

    Ohkuma, Masanori; Ikeda, Katsuyoshi; Obayashi, Konen; Ando, Yukio; Koriyama, Toyoyasu; Kimu, Minhi; Hirose, Nobuyuki; Nagasawa, Zenzo; Miyamoto, Hiroshi

    2012-01-01

    The centrifuge method with the use of Semi-Alkalin Proteinase (SAP) and NALC-NaOH, recommended by the "2007 edition of the assay guideline for detection of Mycobacterium tuberculosis," has significantly contributed to improving the sensitivities and specificities of both smear and culture tests for detection of acid fast bacilli (AFB). However, this method poses some challenges in terms of its cumbersome and time-consuming assay protocol. "TB-beads (Kyokuto Pharmaceutical Industrial Co., Ltd.)" is a newly-developed method for detection of AFB utilizing magnetic beads. We evaluated the quality of this method in comparison with the centrifuge method, focusing on the results of smear and culture tests. This evaluation study was conducted using both 5 positive and 5 negative sputum samples. The sensitivity of TB-beads for fluorescent smear tests, conducted using "Acri-stain," was almost the same as that of the centrifuge method. One advantage of TB-beads, however, was that it was very convenient to practice microscopic observation due to the clear background of the smeared glass slides. The comparison of the contamination rates between the two methods showed that TB-beads suggested significantly lower contamination rates. The centrifuge method resulted in 50% and 60% of contamination rates for HK Semisolid Isolation Medium and BacT/ALERT MP, respectively. On the other hand, the contamination rates of TB-beads for both of the culture methods were only 10%. With regard to the 5 positive sputum samples, the comparison of the detection rates between the centrifuge and TB-Beads method was made utilizing Myco Acid, Ogawa K, and BacT/ALERT MP. The TB-Beads method suggested higher detection rates for Myco Acid and Ogawa K, while there were no significant differences between the two methods for BacT/ALERT MP (16-23 days). TB-beads is an easy method that allows to simplify the process of smear tests, and contributes to significantly reducing the contamination rate of culture

  20. A tosyl-activated magnetic bead cellulose as solid support for sensitive protein detection

    Czech Academy of Sciences Publication Activity Database

    Yan, J.; Horák, Daniel; Lenfeld, Jiří; Hammond, M.; Kamali-Moghaddam, M.

    2013-01-01

    Roč. 167, č. 3 (2013), s. 235-240 ISSN 0168-1656 R&D Projects: GA ČR GAP503/10/0664; GA MŠk 7E12054 EU Projects: European Commission(XE) 259796 - DIATOOLS Institutional support: RVO:61389013 Keywords : bead cellulose * magnetic * protein detection Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.884, year: 2013

  1. Yersinia pestis detection by loop-mediated isothermal amplification combined with magnetic bead capture of DNA

    Directory of Open Access Journals (Sweden)

    Na Feng

    Full Text Available ABSTRACT We developed a loop-mediated isothermal amplification (LAMP assay for the detection of Y. pestis by targeting the 3a sequence on chromosome. All 11 species of the genus Yersinia were used to evaluate the specificity of LAMP and PCR, demonstrating that the primers had a high level of specificity. The sensitivity of LAMP or PCR was 2.3 or 23 CFU for pure culture, whereas 2.3 × 104 or 2.3 × 106 CFU for simulated spleen and lung samples. For simulated liver samples, the sensitivity of LAMP was 2.3 × 106 CFU, but PCR was negative at the level of 2.3 × 107 CFU. After simulated spleen and lung samples were treated with magnetic beads, the sensitivity of LAMP or PCR was 2.3 × 103 or 2.3 × 106 CFU, whereas 2.3 × 105 or 2.3 × 107 CFU for magnetic bead-treated liver samples. These results indicated that some components in the tissues could inhibit LAMP and PCR, and liver tissue samples had a stronger inhibition to LAMP and PCR than spleen and lung tissue samples. LAMP has a higher sensitivity than PCR, and magnetic bead capture of DNAs could remarkably increase the sensitivity of LAMP. LAMP is a simple, rapid and sensitive assay suitable for application in the field or poverty areas.

  2. Salmonella detection in a microfluidic channel using orbiting magnetic beads

    Science.gov (United States)

    Ballard, Matt; Mills, Zachary; Owen, Drew; Hanasoge, Srinivas; Hesketh, Peter; Alexeev, Alexander

    2015-03-01

    We use three-dimensional simulations to model the detection of salmonella in a complex fluid sample in a microfluidic channel. Salmonella is captured using magnetic microbeads orbiting around soft ferromagnetic discs at the microchannel bottom subjected to a rotating external magnetic field. Numerical simulations are used to model the dynamics of salmonella and microbeads throughout the detection process. We examine the effect of the channel geometry on the salmonella capture, and the forces applied to the salmonella as it is dragged through the fluid after capture. Our findings guide the design of a lab-on-a-chip device to be used for detection of salmonella in food samples in a way that ensures that salmonella captured by orbiting microbeads are preserved until they can be extracted from the system for testing, and are not washed away by the fluid flow or damaged due to the experience of excessive stresses. Such a device is needed to detect bacteria at the food source and prevention of consumption of contaminated food, and also can be used for the detection of a variety of biomaterials of interest from complex fluid samples. Support from USDA and NSF is gratefully acknowledged.

  3. Rapid and reagent-saving immunoassay using innovative stirring actions of magnetic beads in microreactors in the sequential injection mode.

    Science.gov (United States)

    Tanaka, K; Imagawa, H

    2005-12-15

    We developed new ELISA techniques in sequential injection analysis (SIA) mode using microreactors with content of a few microliters. We immobilized antibodies on magnetic beads 1.0mum in diameter, injected the beads into microreactors and applied rotating magnetic fields of several hundred gauss. Magnetic beads, suspended in liquid in density of approximately 10(9)-10(10) particles per millilitre, form a large number of thin rod clusters, whose length-wise axes are oriented in parallel with the magnetic field. We rotate the Nd magnets below the center of the microreactor by a tiny motor at about 2000-5000rpm. These rotating clusters remarkably accelerate the binding rate of the antibodies with antigens in the liquid. The beads are trapped around the center of the rotating magnetic field even in the flowing liquid. This newly found phenomenon enables easy bead handling in microreactors. Modification of reactor walls with selected blocking reagents was essential, because protein-coated beads often stick to the wall surface and cannot move freely. Washing steps were also shortened.

  4. Bioinspired methodology for preparing magnetic responsive chitosan beads to be integrated in a tubular bioreactor for biomedical applications.

    Science.gov (United States)

    Song, Wenlong; Oliveira, Mariana B; Sher, Praveen; Gil, Sara; Nóbrega, J Miguel; Mano, João F

    2013-08-01

    Magnetic responsive chitosan beads were prepared using a methodology inspired by the rolling of water droplets over lotus leaves. Liquid precursors containing chitosan and magnetic microparticles were dispensed in the form of spherical droplets and crosslinked with genipin over synthetic superhydrophobic surfaces. Scanning electronic microscopy, histology and micro-computed tomography were employed to characterize the structure of the prepared composite beads and the inner distribution of the magnetic particles. Cellular metabolic activity tests showed that fibroblasts-like (L929 cell line) can adhere and proliferate on the prepared chitosan beads. We hypothesize that such spherical biomaterials could be integrated in a new concept of tubular bioreactor. The magnetic beads can be immobilized by an external magnetic field at specific positions and may be transported along the bioreactor by the drag of the culture medium flow. The system behavior was also studied through numerical modeling, which allowed to identify the relative importance of the main parameters, and to conclude that the distance between carrier beads plays a major role on their interaction with the culture medium and, consequently, on the overall system performance. In an up-scaled version of this bioreactor, the herein presented system may comprise different chambers in serial or parallel configurations. This constitutes a simple way of preparing magnetic responsive beads combined with a new design of bioreactor, which may find application in biomedicine and biotechnology, including in cell expansion for tissue engineering or for the production of therapeutic proteins to be used in cell therapies.

  5. Zanamivir immobilized magnetic beads for voltammetric measurement of neuraminidase at gold-modified boron doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wahyuni, Wulan Tri, E-mail: wulantriws@gmail.com [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Kampus IPB Darmaga, Bogor 16680 (Indonesia); Department of Chemistry, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Ivandini, Tribidasari A.; Saepudin, Endang [Department of Chemistry, FMIPA, Universitas Indonesia, Kampus UI Depok (Indonesia); Einaga, Yasuaki [Department of Chemistry, Faculty of Science and Technology, Keio University, Hiyoshi 3-14-1, Yokohama 223-8522 (Japan); CREST, JST, 3-14-1 Hiyoshi, Yokohama 223-8522 (Japan)

    2016-04-19

    Biomolecule modified magnetic beads has been widely used in separation and sensing process. This study used streptavidin modified magnetic beads to immobilize biotin modified zanamivir. Biotin-streptavidin affinity facilitates immobilization of zanamivir on magnetic beads. Then interaction of zanamivir and neuraminidase was adopted as basic for enzyme detection. Detection of neuraminidase was performed at gold modified BDD using cyclic voltammetry technique. The measurement was carried out based on alteration of electrochemical signals of working electrode as neuraminidase response. The result showed that zanamivir was successfully immobilized on magnetic beads. The optimum amount of magnetic beads for zanamivir immobilization was 120 ug. Linear responses of neuraminidase were detected in concentration range of 0-15 mU. Detection limit (LOD) of measurement was 2.32 mU (R2 = 0.959) with precision as % RSD of 1.41%. Measurement of neuraminidase on magnetic beads could be also performed in the presence of mucin matrix. The linearity range was 0-8 mU with LOD of 0.64 mU (R2 = 0.950) and % RSD of 7.25%.

  6. Bioinspired methodology for preparing magnetic responsive chitosan beads to be integrated in a tubular bioreactor for biomedical applications

    International Nuclear Information System (INIS)

    Song, Wenlong; Oliveira, Mariana B; Sher, Praveen; Gil, Sara; Mano, João F; Nóbrega, J Miguel

    2013-01-01

    Magnetic responsive chitosan beads were prepared using a methodology inspired by the rolling of water droplets over lotus leaves. Liquid precursors containing chitosan and magnetic microparticles were dispensed in the form of spherical droplets and crosslinked with genipin over synthetic superhydrophobic surfaces. Scanning electronic microscopy, histology and micro-computed tomography were employed to characterize the structure of the prepared composite beads and the inner distribution of the magnetic particles. Cellular metabolic activity tests showed that fibroblasts-like (L929 cell line) can adhere and proliferate on the prepared chitosan beads. We hypothesize that such spherical biomaterials could be integrated in a new concept of tubular bioreactor. The magnetic beads can be immobilized by an external magnetic field at specific positions and may be transported along the bioreactor by the drag of the culture medium flow. The system behavior was also studied through numerical modeling, which allowed to identify the relative importance of the main parameters, and to conclude that the distance between carrier beads plays a major role on their interaction with the culture medium and, consequently, on the overall system performance. In an up-scaled version of this bioreactor, the herein presented system may comprise different chambers in serial or parallel configurations. This constitutes a simple way of preparing magnetic responsive beads combined with a new design of bioreactor, which may find application in biomedicine and biotechnology, including in cell expansion for tissue engineering or for the production of therapeutic proteins to be used in cell therapies. (paper)

  7. Purification of power plant waters with high gradient magnetic filters

    International Nuclear Information System (INIS)

    Rosenberg, R.

    1993-04-01

    This is a report of a literature survey. Magnetic high gradient filtration is suitable for separations in difficult surroundings because it can be used in high pressure and temperature, the filtration can be automated and the filter does not contain components which have to be replaced. Magnetic separators for purification of power plant waters have been manufactured commercially for a long time, but they have not always worked satisfactorily especially when separating small particles. The corrosion products in power plant waters are usually ferrimagnetic or paramagnetic and are well suited for magnetic separation. The particle sizes varies considerable but at least in nuclear power plants they are mostly in the range 0.1-30 μ, some even smaller. According to different publications most 60 Co is in particles, while other publications indicate that more than 70 % is in solution. Similarly the data on the purification efficiency of 60 Co varies significantly. Even small magnetic fields are sufficient to separate large ferrimagnetic particles, but the separation of small and paramagnetic particles requires a field more than 20 kT and the high gradient. Presently available commercial separators are so efficient that its seems not to be economically worthwhile to develop them further to improve the filtration efficiency for small particles. Instead it might be worthwhile to investigate methods to increase the particle size by water chemistry methods. (Au). (25 refs., 2 figs.)

  8. Detection of a magnetic bead by hybrid nanodevices using scanning gate microscopy

    Science.gov (United States)

    Corte-León, H.; Krzysteczko, P.; Marchi, F.; Motte, J.-F.; Manzin, A.; Schumacher, H. W.; Antonov, V.; Kazakova, O.

    2016-05-01

    Hybrid ferromagnetic(Py)/non-magnetic metal(Au) junctions with a width of 400 nm are studied by magnetotransport measurements, magnetic scanning gate microscopy (SGM) with a magnetic bead (MB) attached to the probe, and micromagnetic simulations. In the transverse geometry, the devices demonstrate a characteristic magnetoresistive behavior that depends on the direction of the in plane magnetic field, with minimum/maximum variation when the field is applied parallel/perpendicular to the Py wire. The SGM is performed with a NdFeB bead of 1.6 μm diameter attached to the scanning probe. Our results demonstrate that the hybrid junction can be used to detect this type of MB. A rough approximation of the sensing volume of the junction has the shape of elliptical cylinder with the volume of ˜1.51 μm3. Micromagnetic simulations coupled to a magnetotransport model including anisotropic magnetoresistance and planar Hall effects are in good agreement with the experimental findings, enabling the interpretation of the SGM images.

  9. Detection of a magnetic bead by hybrid nanodevices using scanning gate microscopy

    Directory of Open Access Journals (Sweden)

    H. Corte-León

    2016-05-01

    Full Text Available Hybrid ferromagnetic(Py/non-magnetic metal(Au junctions with a width of 400 nm are studied by magnetotransport measurements, magnetic scanning gate microscopy (SGM with a magnetic bead (MB attached to the probe, and micromagnetic simulations. In the transverse geometry, the devices demonstrate a characteristic magnetoresistive behavior that depends on the direction of the in plane magnetic field, with minimum/maximum variation when the field is applied parallel/perpendicular to the Py wire. The SGM is performed with a NdFeB bead of 1.6 μm diameter attached to the scanning probe. Our results demonstrate that the hybrid junction can be used to detect this type of MB. A rough approximation of the sensing volume of the junction has the shape of elliptical cylinder with the volume of ∼1.51 μm3. Micromagnetic simulations coupled to a magnetotransport model including anisotropic magnetoresistance and planar Hall effects are in good agreement with the experimental findings, enabling the interpretation of the SGM images.

  10. A magnetic bead-based method for concentrating DNA from human urine for downstream detection.

    Science.gov (United States)

    Bordelon, Hali; Russ, Patricia K; Wright, David W; Haselton, Frederick R

    2013-01-01

    Due to the presence of PCR inhibitors, PCR cannot be used directly on most clinical samples, including human urine, without pre-treatment. A magnetic bead-based strategy is one potential method to collect biomarkers from urine samples and separate the biomarkers from PCR inhibitors. In this report, a 1 mL urine sample was mixed within the bulb of a transfer pipette containing lyophilized nucleic acid-silica adsorption buffer and silica-coated magnetic beads. After mixing, the sample was transferred from the pipette bulb to a small diameter tube, and captured biomarkers were concentrated using magnetic entrainment of beads through pre-arrayed wash solutions separated by small air gaps. Feasibility was tested using synthetic segments of the 140 bp tuberculosis IS6110 DNA sequence spiked into pooled human urine samples. DNA recovery was evaluated by qPCR. Despite the presence of spiked DNA, no DNA was detectable in unextracted urine samples, presumably due to the presence of PCR inhibitors. However, following extraction with the magnetic bead-based method, we found that ∼50% of spiked TB DNA was recovered from human urine containing roughly 5×10(3) to 5×10(8) copies of IS6110 DNA. In addition, the DNA was concentrated approximately ten-fold into water. The final concentration of DNA in the eluate was 5×10(6), 14×10(6), and 8×10(6) copies/µL for 1, 3, and 5 mL urine samples, respectively. Lyophilized and freshly prepared reagents within the transfer pipette produced similar results, suggesting that long-term storage without refrigeration is possible. DNA recovery increased with the length of the spiked DNA segments from 10±0.9% for a 75 bp DNA sequence to 42±4% for a 100 bp segment and 58±9% for a 140 bp segment. The estimated LOD was 77 copies of DNA/µL of urine. The strategy presented here provides a simple means to achieve high nucleic acid recovery from easily obtained urine samples, which does not contain inhibitors of PCR.

  11. A magnetic bead-based method for concentrating DNA from human urine for downstream detection.

    Directory of Open Access Journals (Sweden)

    Hali Bordelon

    Full Text Available Due to the presence of PCR inhibitors, PCR cannot be used directly on most clinical samples, including human urine, without pre-treatment. A magnetic bead-based strategy is one potential method to collect biomarkers from urine samples and separate the biomarkers from PCR inhibitors. In this report, a 1 mL urine sample was mixed within the bulb of a transfer pipette containing lyophilized nucleic acid-silica adsorption buffer and silica-coated magnetic beads. After mixing, the sample was transferred from the pipette bulb to a small diameter tube, and captured biomarkers were concentrated using magnetic entrainment of beads through pre-arrayed wash solutions separated by small air gaps. Feasibility was tested using synthetic segments of the 140 bp tuberculosis IS6110 DNA sequence spiked into pooled human urine samples. DNA recovery was evaluated by qPCR. Despite the presence of spiked DNA, no DNA was detectable in unextracted urine samples, presumably due to the presence of PCR inhibitors. However, following extraction with the magnetic bead-based method, we found that ∼50% of spiked TB DNA was recovered from human urine containing roughly 5×10(3 to 5×10(8 copies of IS6110 DNA. In addition, the DNA was concentrated approximately ten-fold into water. The final concentration of DNA in the eluate was 5×10(6, 14×10(6, and 8×10(6 copies/µL for 1, 3, and 5 mL urine samples, respectively. Lyophilized and freshly prepared reagents within the transfer pipette produced similar results, suggesting that long-term storage without refrigeration is possible. DNA recovery increased with the length of the spiked DNA segments from 10±0.9% for a 75 bp DNA sequence to 42±4% for a 100 bp segment and 58±9% for a 140 bp segment. The estimated LOD was 77 copies of DNA/µL of urine. The strategy presented here provides a simple means to achieve high nucleic acid recovery from easily obtained urine samples, which does not contain inhibitors of PCR.

  12. Binding kinetics of magnetic nanoparticles on latex beads and yeast cells studied by magnetorelaxometry

    International Nuclear Information System (INIS)

    Eberbeck, Dietmar; Bergemann, Christian; Hartwig, Stefan; Steinhoff, Uwe; Trahms, Lutz

    2005-01-01

    The ion exchange mediated binding of magnetic nanoparticles (MNP) to modified latex spheres and yeast cells was quantified using magnetorelaxometry. By fitting subsequently recorded relaxation curves, the kinetics of the binding reactions was extracted. The signal of MNP with weak ion exchanger groups bound to latex and yeast cells scales linearly with the concentration of latex beads or yeast cells whereas that of MNP with strong ion exchanger groups is proportional to the square root of concentration. The binding of the latter leads to a much stronger aggregation of yeast cells than the former MNP

  13. Fabrication of a pen-shaped portable biochemical reaction system based on magnetic bead manipulation

    International Nuclear Information System (INIS)

    Shikida, Mitsuhiro; Inagaki, Noriyuki; Okochi, Mina; Honda, Hiroyuki; Sato, Kazuo

    2011-01-01

    A pen-shaped platform that is similar to a mechanical pencil is proposed for producing a portable reaction system. A reaction unit, as the key component in the system, was produced by using a heat shrinkable tube. A mechanical pencil supplied by Mitsubishi Pencil Co. Ltd was used as the pen-shaped platform for driving the reaction cylinder. It was actuated using an inchworm motion. We confirmed that the magnetic beads were successfully manipulated in the droplet in the cylinder-shaped reaction units. (technical note)

  14. A Phos-tag-based magnetic-bead method for rapid and selective separation of phosphorylated biomolecules.

    Science.gov (United States)

    Tsunehiro, Masaya; Meki, Yuma; Matsuoka, Kanako; Kinoshita-Kikuta, Emiko; Kinoshita, Eiji; Koike, Tohru

    2013-04-15

    A simple and efficient method based on magnetic-bead technology has been developed for the separation of phosphorylated and nonphosphorylated low-molecular-weight biomolecules, such as nucleotides, phosphorylated amino acids, or phosphopeptides. The phosphate-binding site on the bead is an alkoxide-bridged dinuclear zinc(II) complex with 1,3-bis(pyridin-2-ylmethylamino)propan-2-olate (Phos-tag), which is linked to a hydrophilic cross-linked agarose coating on a magnetic core particle. All steps for the phosphate-affinity separation are conducted in buffers of neutral pH with 50 μL of the magnetic beads in a 1.5-mL microtube. The entire separation protocol for phosphomonoester-type compounds, from addition to elution, requires less than 12 min per sample if the buffers and the zinc(II)-bound Phos-tag magnetic beads have been prepared in advance. The phosphate-affinity magnetic beads are reusable at least 15 times without a decrease in their phosphate-binding ability and they are stable for three months in propan-2-ol. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Caffeine: A novel green precursor for synthesis of magnetic CoFe2O4 nanoparticles and pH-sensitive magnetic alginate beads for drug delivery.

    Science.gov (United States)

    Amiri, Mahnaz; Salavati-Niasari, Masoud; Pardakhty, Abbas; Ahmadi, Meysam; Akbari, Ahmad

    2017-07-01

    Hydrogel beads are promising delivery systems for encapsulation and release of drugs due to the mild process of their fabrication from biopolymers. Magnetic CoFe 2 O 4 nanoparticles (MCFO, 9.72nm in diameter) were synthesized via a co-precipitation method using caffeine as a new environmentally friendly material in order to alkalinize the medium. Drug-targeting Magnetic beads based on CoFe 2 O 4 nanoparticles, sodium alginate and chlorpheniramine maleate (CPAM) were synthesized in the presence of Ca 2+ ions to obtain ionic cross-linked magnetic hydrogel beads. Nanoparticles as well as produced magnetic beads were thoroughly characterized by FTIR, XRD, SEM, nanosizer and VSM techniques. The swelling ratio of beads indicated pH-dependent property with maximum water absorbing at pH7.4. The in vitro release of beads exhibited significant behavior on the subject of nanoparticles concentration and alginate content. Biocompatibility of the CFO nanoparticles and MCFO/Alg beads are demonstrated through cytotoxicity test via MTT assay on U87 cell lines. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Electrospun magnetically separable calcium ferrite nanofibers for photocatalytic water purification

    International Nuclear Information System (INIS)

    EL-Rafei, A.M.; El-Kalliny, Amer S.; Gad-Allah, Tarek A.

    2017-01-01

    Three-dimensional random calcium ferrite, CaFe 2 O 4 , nanofibers (NFs) were successfully prepared via the electrospinning method. The effect of calcination temperature on the characteristics of the as-spun NFs was investigated. X-ray diffraction analysis showed that CaFe 2 O 4 phase crystallized as a main phase at 700 °C and as a sole phase at 1000 °C. Field emission scanning electron microscopy emphasized that CaFe 2 O 4 NFs were fabricated with diameters in the range of 50–150 nm and each fiber was composed of 20–50 nm grains. Magnetic hysteresis loops revealed superparamagnetic behavior for the prepared NFs. These NFs produced active hydroxyl radicals under simulated solar light irradiation making them recommendable for photocatalysis applications in water purification. In the meantime, these NFs can be easily separated from the treated water by applying an external magnetic field. - Highlights: • Three-dimensional porous random CaFe 2 O 4 NFs were successfully produced via electrospinning method. • These NFs exhibited typical superparamagnetic behavior for the ferromagnetic materials. • The low band-gap energy of these NFs (~1.6 eV) allows them to absorb a wide range of the solar spectrum. • These NFs can produce the active • OH under solar light and can be recovered easily by applying an external magnetic field. • These NFs can be used solely as magnetically separable photocatalyst or as magnetic additive for another photocatalyst.

  17. Multiscale evaluation of cellular adhesion alteration and cytoskeleton remodeling by magnetic bead twisting.

    Science.gov (United States)

    Isabey, Daniel; Pelle, Gabriel; André Dias, Sofia; Bottier, Mathieu; Nguyen, Ngoc-Minh; Filoche, Marcel; Louis, Bruno

    2016-08-01

    Cellular adhesion forces depend on local biological conditions meaning that adhesion characterization must be performed while preserving cellular integrity. We presently postulate that magnetic bead twisting provides an appropriate stress, i.e., basically a clamp, for assessment in living cells of both cellular adhesion and mechanical properties of the cytoskeleton. A global dissociation rate obeying a Bell-type model was used to determine the natural dissociation rate ([Formula: see text]) and a reference stress ([Formula: see text]). These adhesion parameters were determined in parallel to the mechanical properties for a variety of biological conditions in which either adhesion or cytoskeleton was selectively weakened or strengthened by changing successively ligand concentration, actin polymerization level (by treating with cytochalasin D), level of exerted stress (by increasing magnetic torque), and cell environment (by using rigid and soft 3D matrices). On the whole, this multiscale evaluation of the cellular and molecular responses to a controlled stress reveals an evolution which is consistent with stochastic multiple bond theories and with literature results obtained with other molecular techniques. Present results confirm the validity of the proposed bead-twisting approach for its capability to probe cellular and molecular responses in a variety of biological conditions.

  18. Magnetic purification of curcumin from Curcuma longa rhizome by novel naked maghemite nanoparticles.

    Science.gov (United States)

    Magro, Massimiliano; Campos, Rene; Baratella, Davide; Ferreira, Maria Izabela; Bonaiuto, Emanuela; Corraducci, Vittorino; Uliana, Maíra Rodrigues; Lima, Giuseppina Pace Pereira; Santagata, Silvia; Sambo, Paolo; Vianello, Fabio

    2015-01-28

    Naked maghemite nanoparticles, namely, surface active maghemite nanoparticles (SAMNs), characterized by a diameter of about 10 nm, possessing peculiar colloidal stability, surface chemistry, and superparamagnetism, present fundamental requisites for the development of effective magnetic purification processes for biomolecules in complex matrices. Polyphenolic molecules presenting functionalities with different proclivities toward iron chelation were studied as probes for testing SAMN suitability for magnetic purification. Thus, the binding efficiency and reversibility on SAMNs of phenolic compounds of interest in the pharmaceutical and food industries, namely, catechin, tyrosine, hydroxytyrosine, ferulic acid, coumaric acid, rosmarinic acid, naringenin, curcumin, and cyanidin-3-glucoside, were evaluated. Curcumin emerged as an elective compound, suitable for magnetic purification by SAMNs from complex matrices. A combination of curcumin, demethoxycurcumin, and bis-demethoxycurcumin was recovered by a single magnetic purification step from extracts of Curcuma longa rhizomes, with a purity >98% and a purification yield of 45%, curcumin being >80% of the total purified curcuminoids.

  19. Electrospun magnetically separable calcium ferrite nanofibers for photocatalytic water purification

    Energy Technology Data Exchange (ETDEWEB)

    EL-Rafei, A.M., E-mail: am.amin@nrc.sci.eg [Refractories, Ceramics and Building Materials Department, National Research Centre, 33 EL Bohouth St. (former EL Tahrir St.), P.O. 12622, Dokki, Giza (Egypt); El-Kalliny, Amer S.; Gad-Allah, Tarek A. [Water Pollution Research Department, National Research Centre, 33 EL Bohouth St. (former EL Tahrir St.), P.O. 12622, Dokki, Giza (Egypt)

    2017-04-15

    Three-dimensional random calcium ferrite, CaFe{sub 2}O{sub 4}, nanofibers (NFs) were successfully prepared via the electrospinning method. The effect of calcination temperature on the characteristics of the as-spun NFs was investigated. X-ray diffraction analysis showed that CaFe{sub 2}O{sub 4} phase crystallized as a main phase at 700 °C and as a sole phase at 1000 °C. Field emission scanning electron microscopy emphasized that CaFe{sub 2}O{sub 4} NFs were fabricated with diameters in the range of 50–150 nm and each fiber was composed of 20–50 nm grains. Magnetic hysteresis loops revealed superparamagnetic behavior for the prepared NFs. These NFs produced active hydroxyl radicals under simulated solar light irradiation making them recommendable for photocatalysis applications in water purification. In the meantime, these NFs can be easily separated from the treated water by applying an external magnetic field. - Highlights: • Three-dimensional porous random CaFe{sub 2}O{sub 4} NFs were successfully produced via electrospinning method. • These NFs exhibited typical superparamagnetic behavior for the ferromagnetic materials. • The low band-gap energy of these NFs (~1.6 eV) allows them to absorb a wide range of the solar spectrum. • These NFs can produce the active {sup •} OH under solar light and can be recovered easily by applying an external magnetic field. • These NFs can be used solely as magnetically separable photocatalyst or as magnetic additive for another photocatalyst.

  20. Separation of magnetic beads in a hybrid continuous flow microfluidic device

    Energy Technology Data Exchange (ETDEWEB)

    Samanta, Abhishek [Haldia Institute of Technology, Production Engineering Department, Haldia (India); Ganguly, Ranjan; Datta, Amitava [Jadavpur University, Power Engineering Department (India); Modak, Nipu, E-mail: nmechju@gmail.com [Jadavpur University, Mechanical Engineering Department (India)

    2017-04-01

    Magnetic separation of biological entities in microfluidic environment is a key task for a large number of bio-analytical protocols. In magnetophoretic separation, biochemically functionalized magnetic beads are allowed to bind selectively to target analytes, which are then separated from the background stream using a suitably imposed magnetic field. Here we present a numerical study, characterizing the performance of a magnetophoretic hybrid microfluidic device having two inlets and three outlets for immunomagnetic isolation of three different species from a continuous flow. The hybrid device works on the principle of split-flow thin (SPLITT) fractionation and field flow fractionation (FFF) mechanisms. Transport of the magnetic particles in the microchannel has been predicted following an Eulerian-Lagrangian model and using an in-house numerical code. Influence of the salient geometrical parameters on the performance of the separator is studied by characterizing the particle trajectories and their capture and separation indices. Finally, optimum channel geometry is identified that yields the maximum capture efficiency and separation index. - Highlights: • Immunomagnetic separation in a hybrid microchannel design is investigated numerically. • Influence of salient geometric parameters on the device performance is analysed. • Optimum device dimension for best separation parameters are identified. • Optimized design of hybrid separator performs better than FFF or SPLITT devices.

  1. Rapid Detection of Ricin in Serum Based on Cu-Chelated Magnetic Beads Using Mass Spectrometry

    Science.gov (United States)

    Zhao, Yong-Qiang; Song, Jian; Wang, Hong-Li; Xu, Bin; Liu, Feng; He, Kun; Wang, Na

    2016-04-01

    The protein toxin ricin obtained from castor bean plant (Ricinus communis) seeds is a potent biological warfare agent due to its ease of availability and acute toxicity. In this study, we demonstrated a rapid and simple method to detect ricin in serum in vitro. The ricin was mixed with serum and digested by trypsin, then all the peptides were efficiently extracted using Cu-chelated magnetic beads and were detected with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The specific ricin peptides were identified by Nanoscale Ultra Performance liquid chromatography coupled to tandem mass spectrometry according to their sequences. The assay required 2.5 hours, and a characteristic peptide could be detected down to 4 ng/μl and used as a biomarker to detect ricin in serum. The high sensitivity and simplicity of the procedure makes it valuable in clinical practice.

  2. A giant magnetoresistance ring-sensor based microsystem for magnetic bead manipulation and detection

    KAUST Repository

    Gooneratne, Chinthaka P.

    2011-03-28

    In this paper a novel spin valvegiant magnetoresistance(GMR) ring-sensor integrated with a microstructure is proposed for concentrating, trapping, and detecting superparamagnetic beads (SPBs). Taking advantage of the fact that SPBs can be manipulated by an external magnetic field, a unique arrangement of conducting microrings is utilized to manipulate the SPBs toward the GMR sensing area in order to increase the reliability of detection. The microrings are arranged and activated in such a manner so as to enable the detection of minute concentrations of SPBs in a sample. Precise manipulation is achieved by applying current sequentially to the microrings. The fabricated ring-shaped GMR element is located underneath the innermost ring and has a magnetoresistance of approximately 5.9%. By the performed experiments it was shown that SPBs could be successfully manipulated toward the GMR sensing zone.

  3. A giant magnetoresistance ring-sensor based microsystem for magnetic bead manipulation and detection

    KAUST Repository

    Gooneratne, Chinthaka P.; Giouroudi, Ioanna; Liang, Cai; Kosel, Jü rgen

    2011-01-01

    In this paper a novel spin valvegiant magnetoresistance(GMR) ring-sensor integrated with a microstructure is proposed for concentrating, trapping, and detecting superparamagnetic beads (SPBs). Taking advantage of the fact that SPBs can be manipulated by an external magnetic field, a unique arrangement of conducting microrings is utilized to manipulate the SPBs toward the GMR sensing area in order to increase the reliability of detection. The microrings are arranged and activated in such a manner so as to enable the detection of minute concentrations of SPBs in a sample. Precise manipulation is achieved by applying current sequentially to the microrings. The fabricated ring-shaped GMR element is located underneath the innermost ring and has a magnetoresistance of approximately 5.9%. By the performed experiments it was shown that SPBs could be successfully manipulated toward the GMR sensing zone.

  4. Quantitative and multiplexed detection for blood typing based on quantum dot-magnetic bead assay.

    Science.gov (United States)

    Xu, Ting; Zhang, Qiang; Fan, Ya-Han; Li, Ru-Qing; Lu, Hua; Zhao, Shu-Ming; Jiang, Tian-Lun

    2017-01-01

    Accurate and reliable blood grouping is essential for safe blood transfusion. However, conventional methods are qualitative and use only single-antigen detection. We overcame these limitations by developing a simple, quantitative, and multiplexed detection method for blood grouping using quantum dots (QDs) and magnetic beads. In the QD fluorescence assay (QFA), blood group A and B antigens were quantified using QD labeling and magnetic beads, and the blood groups were identified according to the R value (the value was calculated with the fluorescence intensity from dual QD labeling) of A and B antigens. The optimized performance of QFA was established by blood typing 791 clinical samples. Quantitative and multiplexed detection for blood group antigens can be completed within 35 min with more than 10 5 red blood cells. When conditions are optimized, the assay performance is satisfactory for weak samples. The coefficients of variation between and within days were less than 10% and the reproducibility was good. The ABO blood groups of 791 clinical samples were identified by QFA, and the accuracy obtained was 100% compared with the tube test. Receiver-operating characteristic curves revealed that the QFA has high sensitivity and specificity toward clinical samples, and the cutoff points of the R value of A and B antigens were 1.483 and 1.576, respectively. In this study, we reported a novel quantitative and multiplexed method for the identification of ABO blood groups and presented an effective alternative for quantitative blood typing. This method can be used as an effective tool to improve blood typing and further guarantee clinical transfusion safety.

  5. A novel automated device for rapid nucleic acid extraction utilizing a zigzag motion of magnetic silica beads

    International Nuclear Information System (INIS)

    Yamaguchi, Akemi; Matsuda, Kazuyuki; Uehara, Masayuki; Honda, Takayuki; Saito, Yasunori

    2016-01-01

    We report a novel automated device for nucleic acid extraction, which consists of a mechanical control system and a disposable cassette. The cassette is composed of a bottle, a capillary tube, and a chamber. After sample injection in the bottle, the sample is lysed, and nucleic acids are adsorbed on the surface of magnetic silica beads. These magnetic beads are transported and are vibrated through the washing reagents in the capillary tube under the control of the mechanical control system, and thus, the nucleic acid is purified without centrifugation. The purified nucleic acid is automatically extracted in 3 min for the polymerase chain reaction (PCR). The nucleic acid extraction is dependent on the transport speed and the vibration frequency of the magnetic beads, and optimizing these two parameters provided better PCR efficiency than the conventional manual procedure. There was no difference between the detection limits of our novel device and that of the conventional manual procedure. We have already developed the droplet-PCR machine, which can amplify and detect specific nucleic acids rapidly and automatically. Connecting the droplet-PCR machine to our novel automated extraction device enables PCR analysis within 15 min, and this system can be made available as a point-of-care testing in clinics as well as general hospitals. - Highlights: • Automatic nucleic acid extraction is performed in 3 min. • Zigzag motion of magnetic silica beads yields rapid and efficient extraction. • The present our device provides better performance than the conventional procedure.

  6. Optimization of magnetoresistive sensor current for on-chip magnetic bead detection using the sensor self-field

    DEFF Research Database (Denmark)

    Henriksen, Anders Dahl; Rizzi, Giovanni; Østerberg, Frederik Westergaard

    2015-01-01

    We investigate the self-heating of magnetoresistive sensors used for measurements on magnetic beads in magnetic biosensors. The signal from magnetic beads magnetized by the field due to the sensor bias current is proportional to the bias current squared. Therefore, we aim to maximize the bias...... current while limiting the sensor self-heating. We systematically characterize and model the Joule heating of magnetoresistive sensors with different sensor geometries and stack compositions. The sensor heating is determined using the increase of the sensor resistance as function of the bias current......, thus the heat conductance is proportional to the sensor area and inversely proportional to the oxide thickness. This simple heat conductance determines the relationship between bias current and sensor temperature, and we show that View the MathML source25μm wide sensor on a View the MathML source1μm...

  7. Waste water purification by magnetic separation technique using HTS bulk magnet system

    International Nuclear Information System (INIS)

    Oka, T.; Kanayama, H.; Tanaka, K.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M.; Terasawa, T.; Itoh, Y.; Yabuno, R.

    2009-01-01

    We have investigated the feasibility of strong magnetic field generators composed of the high temperature superconducting (HTS) bulk magnet systems to the magnetic separation techniques for the waste water including thin emulsion bearing the cutting oil. Two types of the strong field generators were prepared by the face-to-face HTS bulk magnet systems, which emit the magnetic field density of 1 and 2 T in the open spaces between the magnetic poles activated by the pulsed field magnetization and the field cooling methods, respectively. A couple of water channels containing iron balls were settled in the strong field to trap the magnetized flocks in the waste water. The separation ratios of flocks containing 200 ppm magnetite powder were evaluated with respect to the flow rates of the waste water. The performances of bulk magnet system have kept showing values of around 100% until the flowing rate reached up to 18 l/min. This suggests that the magnetic separation by using bulk magnets is effective for the practical water purification systems.

  8. Electrochemical biotin detection based on magnetic beads and a new magnetic flow cell for screen printed electrode.

    Science.gov (United States)

    Biscay, Julien; González García, María Begoña; Costa García, Agustín

    2015-01-01

    The use of the first flow-cell for magnetic assays with an integrated magnet is reported here. The flow injection analysis system (FIA) is used for biotin determination. The reaction scheme is based on a one step competitive assay between free biotin and biotin labeled with horseradish peroxidase (B-HRP). The mixture of magnetic beads modified with streptavidin (Strep-MB), biotin and B-HRP is left 15 min under stirring and then a washing step is performed. After that, 100 μL of the mixture is injected and after 30s 100 μL of 3,3',5,5'-Tetramethylbenzidine (TMB) is injected and the FIAgram is recorded applying a potential of -0.2V. The linear range obtained is from 0.01 to 1 nM of biotin and the sensitivity is 758 nA/nM. The modification and cleaning of the electrode are performed in an easy way due to the internal magnet of the flow cell. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2013-05-01

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

  10. A planar conducting micro-loop structure for transportation of magnetic beads: An approach towards rapid sensing and quantification of biological entities

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2012-03-01

    Magnetic beads are utilized effectively in a wide variety of medical applications due to their small size, biocompatibility and large surface to volume ratio. Microfluidic lab-on-a-chip (LOC) devices, which utilize magnetic beads, are promising tools for accurate and rapid cell sorting and counting. Effective manipulation of beads is a critical factor for the performance of LOC devices. In this paper we propose a planar conducting micro-loop structure to trap, manipulate and transport magnetic beads. Current through the micro-loops produces magnetic field gradients that are proportional to the force required to manipulate the beads. Numerical analyses were performed to study the magnetic forces and their spatial distributions. Experimental results showed that magnetic beads could not only be transported towards a target region, e.g., for sensing purposes, but also the trapping rate could be increased by switching current between the different loops in the micro-loop structure. This method could lead to rapid and accurate quantification of biological entities tagged with magnetic beads. Copyright © 2012 American Scientific Publishers. All rights reserved.

  11. Boronic acid-modified magnetic materials for antibody purification

    Science.gov (United States)

    Dhadge, Vijaykumar L.; Hussain, Abid; Azevedo, Ana M.; Aires-Barros, Raquel; Roque, Ana C. A.

    2014-01-01

    Aminophenyl boronic acids can form reversible covalent ester interactions with cis-diol-containing molecules, serving as a selective tool for binding glycoproteins as antibody molecules that possess oligosaccharides in both the Fv and Fc regions. In this study, amino phenyl boronic acid (APBA) magnetic particles (MPs) were applied for the magnetic separation of antibody molecules. Iron oxide MPs were firstly coated with dextran to avoid non-specific binding and then with 3-glycidyloxypropyl trimethoxysilane to allow further covalent coupling of APBA (APBA_MP). When contacted with pure protein solutions of human IgG (hIgG) and bovine serum albumin (BSA), APBA_MP bound 170 ± 10 mg hIgG g−1 MP and eluted 160 ± 5 mg hIgG g−1 MP, while binding only 15 ± 5 mg BSA g−1 MP. The affinity constant for the interaction between hIgG and APBA_MP was estimated as 4.9 × 105 M−1 (Ka) with a theoretical maximum capacity of 492 mg hIgG adsorbed g−1 MP (Qmax), whereas control particles bound a negligible amount of hIgG and presented an estimated theoretical maximum capacity of 3.1 mg hIgG adsorbed g−1 MP (Qmax). APBA_MPs were also tested for antibody purification directly from CHO cell supernatants. The particles were able to bind 98% of IgG loaded and to recover 95% of pure IgG (purity greater than 98%) at extremely mild conditions. PMID:24258155

  12. Heterogeneous time-resolved electrochemiluminoimmunoassay of thyroid stimulating hormone with magnetic beads at oxide-covered aluminum electrode

    Energy Technology Data Exchange (ETDEWEB)

    Ala-Kleme, Timo, E-mail: timo.ala-kleme@utu.fi

    2017-06-15

    The heterogeneous immunoassay of thyroid stimulating hormone (TSH) was detected by the time-resolved cathodic electrochemiluminescence immunoassay (tr-CECLIA) method using magnetic beads as a mobile support. The magnetic beads coated with sandwich type TSH immunoassay were captured with a magnet for washing and detection processes. The time-resolved cathodic electrochemiluminescence (tr-CECL) signal of Tb(III) chelate label was generated by cathodic pulse polarization in the aluminum working electrode and platinum counter electrode system. The detection method causes injection of high energy electrons into the aqueous solution near the aluminum electrode and creates rigid simultaneous oxidative and reductive conditions that excitate the Tb(III) chelate used as a label luminophore in the heterogeneous sandwich type immunoassay of TSH in the surface of the magnetic beads. The limit of detection of the method was about 50 mIU L{sup −1}. The precision of it was noticed to be good; the coefficient variation percentage was realized to be lower than 10 %. Unfortunately the limit of detection is not good enough for determination of analyte levels of very low concentrations for instance TSH in body fluids. The possible application areas of the method are in highly sophisticated micro or nano fluidic detection and sensor systems where the aspiration level of the analyte detection limit is not very high and the mobility and manageability and the large surface area of the magnetic beads can be utilized efficiently in separating, washing, moving, coating and detecting processes. In the case of tr-CECLIA the presented method makes possible to use multipurpose working electrodes instead of disposable ones.

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

    Science.gov (United States)

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

    2009-10-27

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

  14. Acetylcholinesterase immobilized capillary reactors coupled to protein coated magnetic beads: A new tool for plant extract ligand screening

    Science.gov (United States)

    Vanzolini, Kenia Lourenço; Jiang, Zhengjin; Zhang, Xiaoqi; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalvez; Cardoso, Carmen Lucia; Cass, Quezia Bezerra; Moaddel, Ruin

    2013-01-01

    The use of immobilized capillary enzyme reactors (ICERs) and enzymes coated to magnetic beads ((NT or CT)-MB) for ligand screening has been adopted as a new technique of high throughput screening (HTS). In this work the selected target was the enzyme acetylcholinesterase (AChE), which acts on the central nervous system and is a validated target for the treatment of Alzheimer’s disease, as well as for new insecticides. A new approach for the screening of plant extracts was developed based on the ligand fishing experiments and zonal chromatography. For that, the magnetic beads were used for the ligand fishing experiments and capillary bioreactors for the activity assays. The latter was employed also under non-linear conditions to determine the affinity constants of known ligands, for the first time, as well as for the active fished ligand. PMID:24148457

  15. Serum protein profiling and proteomics in autistic spectrum disorder using magnetic bead-assisted mass spectrometry.

    Science.gov (United States)

    Taurines, Regina; Dudley, Edward; Conner, Alexander C; Grassl, Julia; Jans, Thomas; Guderian, Frank; Mehler-Wex, Claudia; Warnke, Andreas; Gerlach, Manfred; Thome, Johannes

    2010-04-01

    The pathophysiology of autistic spectrum disorder (ASD) is not fully understood and there are no diagnostic or predictive biomarkers. Proteomic profiling has been used in the past for biomarker research in several non-psychiatric and psychiatric disorders and could provide new insights, potentially presenting a useful tool for generating such biomarkers in autism. Serum protein pre-fractionation with C8-magnetic beads and protein profiling by matrix-assisted laser desorption/ionisation-time of flight-mass spectrometry (MALDI-ToF-MS) were used to identify possible differences in protein profiles in patients and controls. Serum was obtained from 16 patients (aged 8-18) and age-matched controls. Three peaks in the MALDI-ToF-MS significantly differentiated the ASD sample from the control group. Sub-grouping the ASD patients into children with and without comorbid Attention Deficit and Hyperactivity Disorder, ADHD (ASD/ADHD+ patients, n = 9; ASD/ADHD- patients, n = 7), one peak distinguished the ASD/ADHD+ patients from controls and ASD/ADHD- patients. Our results suggest that altered protein levels in peripheral blood of patients with ASD might represent useful biomarkers for this devastating psychiatric disorder.

  16. Angiotensin converting enzyme immobilized on magnetic beads as a tool for ligand fishing.

    Science.gov (United States)

    de Almeida, Fernando G; Vanzolini, Kenia L; Cass, Quezia B

    2017-01-05

    Angiotensin converting enzyme (ACE) presents an important role in blood pressure regulation, since that converts angiotensin I to the vasoconstrictor angiotensin II. Some commercially available ACE inhibitors are captopril, lisinopril and enalapril; due to their side effects, naturally occurring inhibitors have been prospected. In order to endorse this research field we have developed a new tool for ACE ligand screening. To this end, ACE was extracted from bovine lung, purified and chemically immobilized in modified ferrite magnetic beads (ACE-MBs). The ACE-MBs have shown a Michaelian kinetic behavior towards hippuryl-histidyl-leucine. Moreover, as proof of concept, the ACE-MBs was inhibited by lisinopril with a half maximal inhibitory concentration (IC 50 ) of 10nM. At the fishing assay, ACE-MBs were able not only to fish out the reference inhibitor, but also one peptide from a pool of tryptic digested BSA. In conclusion, ACE-MBs emerge as new straightforward tool for ACE kinetics determination, inhibition and binder screening. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Magnetic Bead-Based Serum Peptidome Profiling in Patients with Gestational Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Tingting Ai

    2015-01-01

    Full Text Available Gestational diabetes mellitus (GDM is a frequent medical condition during pregnancy. Early diagnosis and treatment of GDM are crucial for both the mother and the baby. In the present study, we aimed to identify specific biomarkers to assist in the early detection of GDM and give some clues to the possible causes of GDM by comparing serum peptide profile differences between GDM patients and healthy controls. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS was used in combination with weak cation exchange magnetic bead (WCX-MB. Levels of four peptides (4418.9, 2219.7, 2211.5, and 1533.4 Da were significantly different. Interestingly, three of them (4418.9, 2211.5, and 1533.4 Da were identified when GDM patients with two degrees of glucose intolerance were compared. Additionally, peptides 2211.5 and 1533.4 Da showed a decreasing trend as glucose intolerance increased, while peptide 4418.9 Da exhibited the reverse tendency. In conclusion, our study provides novel insights into the altered serum peptide profile of GDM patients. The specific candidate biomarkers may contribute to the development of GDM.

  18. Profiling and quantitative evaluation of three Nickel-Coated magnetic matrices for purification of recombinant proteins: lelpful hints for the optimized nanomagnetisable matrix preparation

    Directory of Open Access Journals (Sweden)

    Zarei Saeed

    2011-08-01

    Full Text Available Abstract Background Several materials are available in the market that work on the principle of protein magnetic fishing by their histidine (His tags. Little information is available on their performance and it is often quoted that greatly improved purification of histidine-tagged proteins from crude extracts could be achieved. While some commercial magnetic matrices could be used successfully for purification of several His-tagged proteins, there are some which have been proved to operate just for a few extent of His-tagged proteins. Here, we address quantitative evaluation of three commercially available Nickel nanomagnetic beads for purification of two His-tagged proteins expressed in Escherichia coli and present helpful hints for optimized purification of such proteins and preparation of nanomagnetisable matrices. Results Marked differences in the performance of nanomagnetic matrices, principally on the basis of their specific binding capacity, recovery profile, the amount of imidazole needed for protein elution and the extent of target protein loss and purity were obtained. Based on the aforesaid criteria, one of these materials featured the best purification results (SiMAG/N-NTA/Nickel for both proteins at the concentration of 4 mg/ml, while the other two (SiMAC-Nickel and SiMAG/CS-NTA/Nickel did not work well with respect to specific binding capacity and recovery profile. Conclusions Taken together, functionality of different types of nanomagnetic matrices vary considerably. This variability may not only be dependent upon the structure and surface chemistry of the matrix which in turn determine the affinity of interaction, but, is also influenced to a lesser extent by the physical properties of the protein itself. Although the results of the present study may not be fully applied for all nanomagnetic matrices, but provide a framework which could be used to profiling and quantitative evaluation of other magnetisable matrices and also

  19. Iron Nanoparticles (Fe3O4 Used to Synthesize Magnetic Sodium Alginate Hydrogel Beads for the Removal of Basic Blue 159 from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Atiyeh Ghajarieh

    2017-11-01

    Full Text Available Dyes are a main source of pollutants in textile plant effluents. Due to their molecular structure, they are usually toxic, carcinogenous, and persistent in the environment. The aim of the present work was to explore the removal of basic blue159 (BB159 using magnetic sodium alginate hydrogel beads. Magnetic sodium alginate hydrogel beads were initially synthesized  accoriodng to Rocher method using CaCl2 as a crosslink agent. Fourier transform infrared spectroscopy (FTIR was then employed to examine the functional groups on the surface of the magnetic sodium alginate hydrogel beads. In a third stage, the magnetic properties of the beads were measured using a vibrating sample magnetometer (VSM and the magnetic parameters were calculated. Subsequently, the effects of such parameters as adsorbent dosage, pH, initial concentration of dye, and contact time were evaluated on the BB159 removal efficiency of the adsorbent used. Finally, the Langmuir, Freundlich, Temkin, and B.E.T models were exploited to study the adsorption isotherm of BB159 onto the magnetic sodium alginate hydrogel beads. It was found that the magnetic sodium alginate beads possess both –COO and –OH groups that play important roles in the adsorption of the positively charged BB159 dye. A saturation magnetization equal to 21/8(emu/g was obtained for the sodium alginate beads/nano Fe3O4. Results also revealed that the highest dye removal from aqueous solutions was achieved at pH=11 in 120 minutes for 9 grams of the adsorbent. The study indicated that BB159 removal using the magnetic sodium alginate hydrogel beads as the adsorbent obeys the Langmuir model. Moreover, it was shown that the efficiency of the process for BB159 removal from aqueous solutions was satisfactory (85%.

  20. Purification

    DEFF Research Database (Denmark)

    Andersen, Astrid Oberborbeck

    2017-01-01

    In Arequipa, Peru’s second largest city, engineers work hard to control water flows and provide different sectors with clean and sufficient water. In 2011, only 10 percent of the totality of water used daily by Arequipa’s then close to 1 million people—in households, tourism, industry, and mining......—was treated before it was returned to the river where it continues its flow downstream towards cultivated fields and, finally, into the Pacific Ocean. It takes specialized knowledge and manifold technologies to manage water and sustain life in Arequipa, and engineers are central actors for making water flow...... of categories can be understood as practices of purification. However, a purely technical grip on water is never possible. Unruly elements, like weather, contamination, urban dwellers, and competing interests, interfere and make processes of intervention unstable. Water is never completely cleaned, and, equally...

  1. Magnetic iron oxide nanoparticles (MIONs) cross-linked natural polymer-based hybrid gel beads: Controlled nano anti-TB drug delivery application.

    Science.gov (United States)

    Kesavan, Mookkandi Palsamy; Ayyanaar, Srinivasan; Vijayakumar, Vijayaparthasarathi; Dhaveethu Raja, Jeyaraj; Annaraj, Jamespandi; Sakthipandi, Kathiresan; Rajesh, Jegathalaprathaban

    2018-04-01

    The nanosized rifampicin (RIF) has been prepared to increase the solubility in aqueous solution, which leads to remarkable enhancement of its bioavailability and their convenient delivery system studied by newly produced nontoxic, biodegradable magnetic iron oxide nanoparticles (MIONs) cross-linked polyethylene glycol hybrid chitosan (mCS-PEG) gel beads. The functionalization of both nano RIF and mCS-PEG gel beads were studied using various spectroscopic and microscopic techniques. The size of prepared nano RIF was found to be 70.20 ± 3.50 nm. The mechanical stability and swelling ratio of the magnetic gel beads increased by the addition of PEG with a maximum swelling ratio of 38.67 ± 0.29 g/g. Interestingly, this magnetic gel bead has dual responsive assets in the nano drug delivery application (pH and the magnetic field). As we expected, magnetic gel beads show higher nano drug releasing efficacy at acidic medium (pH = 5.0) with maximum efficiency of 71.00 ± 0.87%. This efficacy may also be tuned by altering the external magnetic field and the weight percentage (wt%) of PEG. These results suggest that such a dual responsive magnetic gel beads can be used as a potential system in the nano drug delivery applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1039-1050, 2018. © 2017 Wiley Periodicals, Inc.

  2. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kistrup, Kasper, E-mail: kkis@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Skotte Sørensen, Karen, E-mail: karen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Center for Integrated Point of Care Technologies (CiPoC), DELTA, Venlighedsvej 4, DK-2870 Hørsholm (Denmark); Wolff, Anders, E-mail: anders.wolff@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark); Fougt Hansen, Mikkel, E-mail: mikkel.hansen@nanotech.dtu.dk [Department of Micro- and Nanotechnology, Technical University of Denmark, DTU Nanotech, Building 345 East, DK-2800 Kongens Lyngby (Denmark)

    2015-04-15

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively. - Highlights: • We present an all-polymer mass producible passive filled microfluidic chip system. • Rapid system fabrication is obtained by injection moulding and ultrasonic welding. • The system is made for single-use nucleic acid extraction using magnetic beads. • We systematically map compatibility of the chip system with various surfactants. • We quantify the volume carry-over of magnetic beads in water and 0.1% triton-X solution.

  3. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    International Nuclear Information System (INIS)

    Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

    2015-01-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis-binding buffer, respectively. - Highlights: • We present an all-polymer mass producible passive filled microfluidic chip system. • Rapid system fabrication is obtained by injection moulding and ultrasonic welding. • The system is made for single-use nucleic acid extraction using magnetic beads. • We systematically map compatibility of the chip system with various surfactants. • We quantify the volume carry-over of magnetic beads in water and 0.1% triton-X solution

  4. Observation of the dynamics of magnetically induced chains of sub-micron superparamagnetic beads in aqueous solutions by laser light scattering

    International Nuclear Information System (INIS)

    Tanizawa, Y; Tashiro, T; Sandhu, A; Ko, P J

    2013-01-01

    Optical monitoring the behaviour of magnetically induced self-assembled chains of superparamagnetic beads (SPBs) are of interest for biomedical applications such as biosensors. However, it is difficult to directly monitor magnetically induced self-assembly of sub-micron nano-beads with conventional optical microscopes. Here, we describe the optical observation of the dynamics of magnetically induced self-assembled rotating chains of 130 nm SPBs in aqueous solutions by laser light scattering. Magnetic fields of ∼1 kOe were applied to control the self-assembly chains of SPBs and their behaviour analyzed by monitoring the intensity of laser light scattered from the chain structures. We compared the light scattering from chains that were formed only by the application of external fields with chains formed by beads functionalized by EDC, where chemical reactions lead to the bonding of individual beads to form chains. The EDC experiments are a precursor to experiments on molecular recognition applications for biomedical diagnostics.

  5. Magnetic particles as powerful purification tool for high sensitive mass spectrometric screening procedures.

    Science.gov (United States)

    Peter, Jochen F; Otto, Angela M

    2010-02-01

    The effective isolation and purification of proteins from biological fluids is the most crucial step for a successful protein analysis when only minute amounts are available. While conventional purification methods such as dialysis, ultrafiltration or protein precipitation often lead to a marked loss of protein, SPE with small-sized particles is a powerful alternative. The implementation of particles with superparamagnetic cores facilitates the handling of those particles and allows the application of particles in the nanometer to low micrometer range. Due to the small diameters, magnetic particles are advantageous for increasing sensitivity when using subsequent MS analysis or gel electrophoresis. In the last years, different types of magnetic particles were developed for specific protein purification purposes followed by analysis or screening procedures using MS or SDS gel electrophoresis. In this review, the use of magnetic particles for different applications, such as, the extraction and analysis of DNA/RNA, peptides and proteins, is described.

  6. Improved Peak Capacity for Capillary Electrophoretic Separations of Enzyme Inhibitors with Activity-Based Detection Using Magnetic Bead Microreactors

    Science.gov (United States)

    Yan, Xiaoyan; Gilman, S. Douglass

    2010-01-01

    A technique for separating and detecting enzyme inhibitors was developed using capillary electrophoresis with an enzyme microreactor. The on-column enzyme microreactor was constructed using NdFeB magnet(s) to immobilize alkaline phosphatase-coated superparamagnetic beads (2.8 μm diameter) inside a capillary before the detection window. Enzyme inhibition assays were performed by injecting a plug of inhibitor into a capillary filled with the substrate, AttoPhos. Product generated in the enzyme microreactor was detected by laser-induced fluorescence. Inhibitor zones electrophoresed through the capillary, passed through the enzyme microreactor, and were observed as negative peaks due to decreased product formation. The goal of this study was to improve peak capacities for inhibitor separations relative to previous work, which combined continuous engagement electrophoretically mediated microanalysis (EMMA) and transient engagement EMMA to study enzyme inhibition. The effects of electric field strength, bead injection time and inhibitor concentrations on peak capacity and peak width were investigated. Peak capacities were increased to ≥20 under optimal conditions of electric field strength and bead injection time for inhibition assays with arsenate and theophylline. Five reversible inhibitors of alkaline phosphatase (theophylline, vanadate, arsenate, L-tryptophan and tungstate) were separated and detected to demonstrate the ability of this technique to analyze complex inhibitor mixtures. PMID:20024913

  7. Planar Hall effect bridge sensors with NiFe/Cu/IrMn stack optimized for self-field magnetic bead detection

    DEFF Research Database (Denmark)

    Henriksen, Anders Dahl; Rizzi, Giovanni; Hansen, Mikkel Fougt

    2016-01-01

    , and 30 nm, and 0 ≤ tCu ≤ 0.6 nm. The sensors were characterized by magnetic hysteresis measurements, by measurements of the sensor response vs. applied field, and by measurements of the sensor response to a suspension of magnetic beads magnetized by the sensor self-field due to the sensor bias current....... The exchange bias field was found to decay exponentially with tCu and inversely with tFM. The reduced exchange field for larger values of tFM and tCu resulted in higher sensitivities to both magnetic fields and magnetic beads. We argue that the maximum magnetic bead signal is limited by Joule heating...

  8. Generation of Internal-Image Functional Aptamers of Okadaic Acid via Magnetic-Bead SELEX

    Directory of Open Access Journals (Sweden)

    Chao Lin

    2015-12-01

    Full Text Available Okadaic acid (OA is produced by Dinophysis and Prorocentrum dinoflagellates and primarily accumulates in bivalves, and this toxin has harmful effects on consumers and operators. In this work, we first report the use of aptamers as novel non-toxic probes capable of binding to a monoclonal antibody against OA (OA-mAb. Aptamers that mimic the OA toxin with high affinity and selectivity were generated by the magnetic bead-assisted systematic evolution of ligands by exponential enrichment (SELEX strategy. After 12 selection rounds, cloning, sequencing and enzyme-linked immunosorbent assay (ELISA analysis, four candidate aptamers (O24, O31, O39, O40 were selected that showed high affinity and specificity for OA-mAb. The affinity constants of O24, O31, O39 and O40 were 8.3 × 108 M−1, 1.47 × 109 M−1, 1.23 × 109 M−1 and 1.05 × 109 M−1, respectively. Indirect competitive ELISA was employed to determine the internal-image function of the aptamers. The results reveal that O31 has a similar competitive function as free OA toxin, whereas the other three aptamers did not bear the necessary internal-image function. Based on the derivation of the curvilinear equation for OA/O31, the equation that defined the relationship between the OA toxin content and O31 was Y = 2.185X − 1.78. The IC50 of O31 was 3.39 ng·mL−1, which was close to the value predicted by the OA ELISA (IC50 = 4.4 ng·mL−1; the IC10 was 0.33 ng·mL−1. The above data provides strong evidence that internal-image functional aptamers could be applicable as novel probes in a non-toxic assay.

  9. Enhanced quality factors and force sensitivity by attaching magnetic beads to cantilevers for atomic force microscopy in liquid

    Science.gov (United States)

    Hoof, Sebastian; Nand Gosvami, Nitya; Hoogenboom, Bart W.

    2012-12-01

    Dynamic-mode atomic force microscopy (AFM) in liquid remains complicated due to the strong viscous damping of the cantilever resonance. Here, we show that a high-quality resonance (Q >20) can be achieved in aqueous solution by attaching a microgram-bead at the end of the nanogram-cantilever. The resulting increase in cantilever mass causes the resonance frequency to drop significantly. However, the force sensitivity—as expressed via the minimum detectable force gradient—is hardly affected, because of the enhanced quality factor. Through the enhancement of the quality factor, the attached bead also reduces the relative importance of noise in the deflection detector. It can thus yield an improved signal-to-noise ratio when this detector noise is significant. We describe and analyze these effects for a set-up that includes magnetic actuation of the cantilevers and that can be easily implemented in any AFM system that is compatible with an inverted optical microscope.

  10. One pot synthesis of new poly(vinyl alcohol) blended natural polymer based magnetic hydrogel beads: Controlled natural anticancer alkaloid delivery system.

    Science.gov (United States)

    Kesavan, Mookkandi Palsamy; Ayyanaar, Srinivasan; Lenin, Nayagam; Sankarganesh, Murugesan; Dhaveethu Raja, Jeyaraj; Rajesh, Jegathalaprathaban

    2018-02-01

    Facile one-pot synthesis has been demonstrated for new biocompatible and dual responsive magnetic iron oxide nanoparticles cross-linked poly(vinyl alcohol) (PVA) blended natural polymer chitosan (CS) based hydrogel beads (mCS-PVA) as a controlled natural anticancer alkaloid Luotonin A (LuA) delivery system. The prepared magnetic hydrogel beads were characterized using powder X-ray diffraction measurement, Fourier transform-infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and vibrating sample magnetometer. The magnetic hydrogel beads are exhibited significant water retention and follow the second order kinetic model in swelling study. The swelling ratio of the magnetic gel beads increased by the addition of PVA and showed a maximum swelling ratio of 40.83 ± 1.01 g/g and follows non-Fickian water transport mechanism. Stimuli responsive mCS and mCS-PVA hydrogel beads functionalized with LuA is demonstrated for controlled release at physiological pH and under magnetic field. The magnetic hydrogel beads show highest LuA releasing efficacy at acidic medium (pH = 5.0) with maximum efficiency of 73.33 ± 1.44%. This efficacy may also be tuned by altering the external magnetic field as well as the weight percentage (wt %) of polyethylene glycol. It is clearly that the newly produced magnetic hydrogel beads can be served as an effective intestinal LuA delivery system. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 543-551, 2018. © 2017 Wiley Periodicals, Inc.

  11. The synthesis, magnetic purification and evaluation of 99mTc-labeled microbubbles

    International Nuclear Information System (INIS)

    Lazarova, Neva; Causey, Patrick W.; Lemon, Jennifer A.; Czorny, Shannon K.; Forbes, John R.; Zlitni, Aimen; Genady, Afaf; Foster, F. Stuart; Valliant, John F.

    2011-01-01

    Introduction: Ultrasound (US) contrast agents based on microbubbles (MBs) are being investigated as platforms for drug and gene delivery. A methodology for determining the distribution and fate of modified MBs quantitatively in vivo can be achieved by tagging MBs directly with 99m Tc. This creates the opportunity to employ dual-modality imaging using both US and small animal SPECT along with quantitative ex vivo tissue counting to evaluate novel MB constructs. Methods: A 99m Tc-labeled biotin derivative ( 99m TcL1) was prepared and incubated with streptavidin-coated MBs. The 99m Tc-labeled bubbles were isolated using a streptavidin-coated magnetic-bead purification strategy that did not disrupt the MBs. A small animal scintigraphic/CT imaging study as well as a quantitative biodistribution study was completed using 99m TcL1 and 99m Tc-labeled bubbles in healthy C57Bl-6 mice. Results: The imaging and biodistribution data showed rapid accumulation and retention of 99m Tc-MBs in the liver (68.2±6.6 %ID/g at 4 min; 93.3±3.2 %ID/g at 60 min) and spleen (214.2±19.7 %ID/g at 4 min; 213.4±19.7 %ID/g at 60 min). In contrast, 99m TcL1 accumulated in multiple organs including the small intestine (22.5±3.6 %ID/g at 4 min; 83.4±5.9 %ID/g at 60 min) and bladder (184.0±88.1 %ID/g at 4 min; 24.2±17.7 %ID/g at 60 min). Conclusion: A convenient means to radiolabel and purify MBs was developed and the distribution of the labeled products determined. The result is a platform which can be used to assess the pharmacokinetics and fate of novel MB constructs both regionally using US and throughout the entire subject in a quantitative manner by employing small animal SPECT and tissue counting.

  12. Bifunctional groups grafted polyethersulfone magnetic beads for selective sequestration of plutonium

    International Nuclear Information System (INIS)

    Paul, Sumana; Aggarwal, S.K.; Pandey, A.K.

    2014-01-01

    The present study involves synthesis of polyethersulfone (PES) beads grafted with two different monomers viz. 2-hydroxyethylmethacrylate phosphoric acid ester (HEMP) and 2-acrylamido-2-methyl-1-propane sulphonic acid (AMPS) by photo-induced free radical polymerization method. The selection of bifunctional polymer was based on our previous studies, which indicated its efficacy for selective preconcentration of Pu from 3-4 mol L -1 HNO 3 . The HEMP-co-AMPS grafted PES beads were used for selective extraction of plutonium from dissolver solution

  13. Integration of antibody by surface functionalization of graphite-encapsulated magnetic beads using ammonia gas plasma technology for capturing influenza A virus.

    Science.gov (United States)

    Sakudo, Akikazu; Chou, Han; Ikuta, Kazuyoshi; Nagatsu, Masaaki

    2015-05-01

    Antibody-integrated magnetic beads have been functionalized for influenza A virus capture. First, ammonia plasma produced by a radio frequency power source was reacted with the surface of graphite-encapsulated magnetic beads to introduce amino groups. Anti-influenza A virus hemagglutinin antibody was then anchored by its surface sulfide groups to the amino groups on the beads via N-succinimidyl 3-(2-pyridyldithio) propionate. After incubation with influenza A virus, adsorption of the virus to the beads was confirmed by immunochromatography, polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and inoculation of chicken embryonated eggs, indicating that virus infectivity is maintained and that the proposed method is useful for the enhanced detection and isolation of influenza A virus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. High heat generation ability in AC magnetic field for nano-sized magnetic Y3Fe5O12 powder prepared by bead milling

    International Nuclear Information System (INIS)

    Aono, Hiromichi; Ebara, Hiroki; Senba, Ryota; Naohara, Takashi; Maehara, Tsunehiro; Hirazawa, Hideyuki; Watanabe, Yuji

    2012-01-01

    Nano-sized magnetic Y 3 Fe 5 O 12 ferrite having a high heat generation ability in an AC magnetic field was prepared by bead milling. A commercial powder sample (non-milled sample) of ca. 2.9 μm in particle size did not show any temperature enhancement in the AC magnetic field. The heat generation ability in the AC magnetic field improved with a decrease in the average crystallite size for the bead-milled Y 3 Fe 5 O 12 ferrites. The highest heat ability in the AC magnetic field was for the fine Y 3 Fe 5 O 12 powder with a 15-nm crystallite size (the samples were milled for 4 h using 0.1 mmφ beads). The heat generation ability of the excessively milled Y 3 Fe 5 O 12 samples decreased. The main reason for the high heat generation property of the milled samples was ascribed to an increase in the Néel relaxation of the superparamagnetic material. The heat generation ability was not influenced by the concentration of the ferrite powder. For the samples milled for 4 h using 0.1 mmφ beads, the heat generation ability (W g −1 ) was estimated using a 3.58×10 −4 fH 2 frequency (f/kHz) and the magnetic field (H/kA m −1 ), which is the highest reported value of superparamagnetic materials. - Highlights: ► The nano-sized Y 3 Fe 5 O 12 powder prepared by bead-milling has the highest heat generation ability in an AC magnetic field. ► The heat generation properties are ascribed to an increase in the Néel relaxation of the superparamagnetic material. ► The heat ability (W g −1 ) can be estimated using 3.58×10 −4 fH 2 (f=kHz, H=kA m −1 ). ► This is an expectable material for use in a drug delivery system for the thermal coagulation therapy of cancer tumors.

  15. Acetylcholinesterase immobilized capillary reactors coupled to protein coated magnetic beads: A new tool for plant extract ligand screening

    OpenAIRE

    Vanzolini, Kenia Lourenço; Jiang, Zhengjin; Zhang, Xiaoqi; Vieira, Lucas Campos Curcino; Corrêa, Arlene Gonçalvez; Cardoso, Carmen Lucia; Cass, Quezia Bezerra; Moaddel, Ruin

    2013-01-01

    The use of immobilized capillary enzyme reactors (ICERs) and enzymes coated to magnetic beads ((NT or CT)-MB) for ligand screening has been adopted as a new technique of high throughput screening (HTS). In this work the selected target was the enzyme acetylcholinesterase (AChE), which acts on the central nervous system and is a validated target for the treatment of Alzheimer’s disease, as well as for new insecticides. A new approach for the screening of plant extracts was developed based on t...

  16. New advances in electrochemical biosensors for the detection of toxins: Nanomaterials, magnetic beads and microfluidics systems. A review

    Energy Technology Data Exchange (ETDEWEB)

    Reverté, Laia [IRTA, Carretera Poble Nou km. 5.5, 43540 Sant Carles de la Ràpita, Tarragona (Spain); Prieto-Simón, Beatriz [ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Future Industries Institute, University of South Australia, SA 5095 (Australia); Campàs, Mònica, E-mail: monica.campas@irta.cat [IRTA, Carretera Poble Nou km. 5.5, 43540 Sant Carles de la Ràpita, Tarragona (Spain)

    2016-02-18

    The use of nanotechnology in bioanalytical devices has special advantages in the detection of toxins of interest in food safety and environmental applications. The low levels to be detected and the small size of toxins justify the increasing number of publications dealing with electrochemical biosensors, due to their high sensitivity and design versatility. The incorporation of nanomaterials in their development has been exploited to further increase their sensitivity, providing simple and fast devices, with multiplexed capabilities. This paper gives an overview of the electrochemical biosensors that have incorporated carbon and metal nanomaterials in their configurations for the detection of toxins. Biosensing systems based on magnetic beads or integrated into microfluidics systems have also been considered because of their contribution to the development of compact analytical devices. The roles of these materials, the methods used for their incorporation in the biosensor configurations as well as the advantages they provide to the analyses are summarised. - Highlights: • Nanomaterials improve the performance of electrochemical biosensors. • Carbon nanomaterials can act as electrocatalysts or label supports in biosensors. • Metal nanomaterials can act as nanostructured supports or labels in biosensors. • Magnetic beads are exploited as immobilisation supports and/or label carriers.

  17. New advances in electrochemical biosensors for the detection of toxins: Nanomaterials, magnetic beads and microfluidics systems. A review

    International Nuclear Information System (INIS)

    Reverté, Laia; Prieto-Simón, Beatriz; Campàs, Mònica

    2016-01-01

    The use of nanotechnology in bioanalytical devices has special advantages in the detection of toxins of interest in food safety and environmental applications. The low levels to be detected and the small size of toxins justify the increasing number of publications dealing with electrochemical biosensors, due to their high sensitivity and design versatility. The incorporation of nanomaterials in their development has been exploited to further increase their sensitivity, providing simple and fast devices, with multiplexed capabilities. This paper gives an overview of the electrochemical biosensors that have incorporated carbon and metal nanomaterials in their configurations for the detection of toxins. Biosensing systems based on magnetic beads or integrated into microfluidics systems have also been considered because of their contribution to the development of compact analytical devices. The roles of these materials, the methods used for their incorporation in the biosensor configurations as well as the advantages they provide to the analyses are summarised. - Highlights: • Nanomaterials improve the performance of electrochemical biosensors. • Carbon nanomaterials can act as electrocatalysts or label supports in biosensors. • Metal nanomaterials can act as nanostructured supports or labels in biosensors. • Magnetic beads are exploited as immobilisation supports and/or label carriers.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  19. Simultaneous Determination of the Main Peanut Allergens in Foods Using Disposable Amperometric Magnetic Beads-Based Immunosensing Platforms

    Directory of Open Access Journals (Sweden)

    Víctor Ruiz-Valdepeñas Montiel

    2016-06-01

    Full Text Available In this work, a novel magnetic beads (MBs-based immunosensing approach for the rapid and simultaneous determination of the main peanut allergenic proteins (Ara h 1 and Ara h 2 is reported. It involves the use of sandwich-type immunoassays using selective capture and detector antibodies and carboxylic acid-modified magnetic beads (HOOC-MBs. Amperometric detection at −0.20 V was performed using dual screen-printed carbon electrodes (SPdCEs and the H2O2/hydroquinone (HQ system. This methodology exhibits high sensitivity and selectivity for the target proteins providing detection limits of 18.0 and 0.07 ng/mL for Ara h 1 and Ara h 2, respectively, with an assay time of only 2 h. The usefulness of the approach was evaluated by detecting the endogenous content of both allergenic proteins in different food extracts as well as trace amounts of peanut allergen (0.0001% or 1.0 mg/kg in wheat flour spiked samples. The developed platform provides better Low detection limits (LODs in shorter assay times than those claimed for the allergen specific commercial ELISA kits using the same immunoreagents and quantitative information on individual food allergen levels. Moreover, the flexibility of the methodology makes it readily translate to the detection of other food-allergens.

  20. Magnetic Bead and Fluorescent Silica Nanoparticles Based Optical Immunodetection of Staphylococcal Enterotoxin B (SEB in Bottled Water

    Directory of Open Access Journals (Sweden)

    Shiva K. RASTOGI

    2009-10-01

    Full Text Available Staphylococcal enterotoxins (SEs are a major cause of food-borne diseases, most commonly SEs assayed immunologically with ELISA. An immunoassay based on fluorescein dye doped silica dioxide nanoparticles (F-SiNPs and magnetic bead (MB is described here for the detection of staphylococcal enterotoxin B (SEB. F-SiNPs have unique optical properties which make them attractive for biosensing. The water-in-oil (W/O reverse microemulsion method was used for the synthesis of F-SiNPs (~ 95 nm of diameter. The F-SiNPs were characterized using SEM, TEM and FTIR spectroscopy. The detection of SEB is preformed in PBS buffer, and bottled drinking water using sandwich immunoassay format. Target analytes were captured using MBs modified with the antigen-specific “capture” antibody, and detected using F-SiNP labeled secondary antigen-specific antibody. We report a limit of detection down to 1 ng/mL SEB spiked sample in less than 2 hr assay time using fluorocount method. This study demonstrates the bio warfare agent SEB capture by magnetic beads and detection using F-SiNPs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-27

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

  2. Magnetic separation technique for environmental water purification by strong magnetic field generator loading HTS bulk magnets

    International Nuclear Information System (INIS)

    Oka, T.; Tanaka, K.; Kimura, T.; Mimura, D.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M.; Yokoyama, K.; Yamaguchi, M.

    2010-01-01

    The magnetic separation technique in combination with high temperature superconducting bulk magnets has been investigated to purify the ground water which has been used in the coolant system for the incinerator furnace to cool the burning gas. The experiment has been operated by means of the newly-built alternating channel type magnetic separating device. The separation ratios of ferromagnetic flocks including fine magnetite powder have been estimated by means of the high gradient magnetic separation method with small iron balls filled in the water channels. As the magnetic force acting on the magnetic particle is given by the product of a magnetization of the material and a gradient of magnetic field, and as the ferromagnetic stainless steel balls yield the steep gradient of magnetic field around them in a strong magnetic field, the system has exhibited a quite excellent performance with respect to the separation ratios. The separation ratios of the flocks which contain the magnetite powder with the values more than 50 ppm have remained over 80% for under the flow rates less than 5 L/min.

  3. Purification of condenser water in thermal power station by superconducting magnetic separation

    International Nuclear Information System (INIS)

    Ha, D.W.; Kwon, J.M.; Baik, S.K.; Lee, Y.J.; Han, K.S.; Ko, R.K.; Sohn, M.H.; Seong, K.C.

    2011-01-01

    Magnetic separation using cryo-cooled Nb-Ti superconducting magnet was applied for the purification of condenser water. Iron oxides in condenser water were effectively removed by superconducting magnetic separation. The effect of magnetic field strength and filter size was determined. Thermal power station is made up of a steam turbine and a steam condenser which need a lot of water. The water of steam condenser should be replaced, since scales consisting of iron oxide mainly are accumulated on the surface of condenser pipes as it goes. Superconducting high gradient magnetic separation (HGMS) system has merits to remove paramagnetic substance like iron oxides because it can generate higher magnetic field strength than electromagnet or permanent magnet. In this paper, cryo-cooled Nb-Ti superconducting magnet that can generate up to 6 T was used for HGMS systems. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The result of X-ray analysis showed contaminants were mostly α-Fe 2 O 3 (hematite) and γ-Fe 2 O 3 (maghemite). The higher magnetic field was applied up to 6 T, the more iron oxides were removed. As the wire diameter of magnetic filter decreased, the turbidity removal of the sample was enhanced.

  4. A Rapid Detection Method of Brucella with Quantum Dots and Magnetic Beads Conjugated with Different Polyclonal Antibodies

    Science.gov (United States)

    Song, Dandan; Qu, Xiaofeng; Liu, Yushen; Li, Li; Yin, Dehui; Li, Juan; Xu, Kun; Xie, Renguo; Zhai, Yue; Zhang, Huiwen; Bao, Hao; Zhao, Chao; Wang, Juan; Song, Xiuling; Song, Wenzhi

    2017-03-01

    Brucella spp. are facultative intracellular bacteria that cause zoonotic disease of brucellosis worldwide. Traditional methods for detection of Brucella spp. take 48-72 h that does not meet the need of rapid detection. Herein, a new rapid detection method of Brucella was developed based on polyclonal antibody-conjugating quantum dots and antibody-modified magnetic beads. First, polyclonal antibodies IgG and IgY were prepared and then the antibody conjugated with quantum dots (QDs) and immunomagnetic beads (IMB), respectively, which were activated by N-(3-dimethylaminopropyl)- N'-ethylcar-bodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to form probes. We used the IMB probe to separate the Brucella and labeled by the QD probe, and then detected the fluorescence intensity with a fluorescence spectrometer. The detection method takes 105 min with a limit of detection of 103 CFU/mL and ranges from 10 to 105 CFU/mL ( R 2 = 0.9983), and it can be well used in real samples.

  5. Peptidome profiling of human serum of uveal melanoma patients based on magnetic bead fractionation and mass spectrometry

    Directory of Open Access Journals (Sweden)

    Xiang-Yu Shi

    2017-06-01

    Full Text Available AIM: To find new biomarkers for uveal melanoma (UM by analyzing the serum peptidome profile. METHODS: Proteomic spectra in patients with UM before and after operation were analyzed and compared with those of healthy controls. Magnetic affinity beads were used to capture serum peptides and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF mass spectrometer were used to compile serum peptide profiles. RESULTS: A panel of 49 peptides were differentially expressed between UM patients and controls, of which 33 peptides were of higher intensities in patient group and 16 peptides were of higher intensities in control group. Based on combined use of these potential markers, peptides with mean molecular masses of 1467 and 9289.0 Da provide high sensitivity (83.3%, specificity (100% and accuracy rate (93.0% together to differentiate melanoma patients from healthy controls. At the time point of 6mo postoperatively, the levels of many peptides differentially expressed before surgery showed no more statistical difference between the patients and the control group. Fibrinogen α-chain precursors were identified as potential UM markers. CONCLUSION: We have shown that a convenient and fast proteomic technique, affinity bead separation and MALDI-TOF analysis combined with bioinformatic software, facilitates the identification of novel biomarkers for UM.

  6. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    Science.gov (United States)

    Kistrup, Kasper; Skotte Sørensen, Karen; Wolff, Anders; Fougt Hansen, Mikkel

    2015-04-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible phase filtration and features passive liquid filling and magnetic bead manipulation using an external magnet. In this work, we determine the system compatibility with various surfactants. Moreover, we quantify the volume of liquid co-transported with magnetic bead clusters from Milli-Q water or a lysis-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/μg and 1.72(14) nL/μg were found for Milli-Q water and lysis-binding buffer, respectively.

  7. On the use of magnetic separation for purification of aqueous radioactive solutions from oils

    International Nuclear Information System (INIS)

    Shchebetkovskij, V.N.; Vyatkin, V.E.; Gurevich, D.M.; Bochkov, A.A.

    1984-01-01

    Using model systems, simulating oiled condensate that is formed during evaporation of water radioactive wastes, a possibility is shown to use the method of magnetic separation for waste purification from oil. Introduction of a dispersed ferromagnetic powder in the system to stabilize oil drops and to impart ''quasiferromagnetic'' properties to them, is a necessary condition for the efficient oil separation. Using as an example 137 Cs absorption, the adsorbability of ferromagnetic powders relative to radionuclides in the system investigated is assessed

  8. Enzymatic removal of phenol and p-chlorophenol in enzyme reactor: Horseradish peroxidase immobilized on magnetic beads

    International Nuclear Information System (INIS)

    Bayramoglu, Guelay; Arica, M. Yakup

    2008-01-01

    Horseradish peroxidase was immobilized on the magnetic poly(glycidylmethacrylate-co-methylmethacrylate) (poly(GMA-MMA)), via covalent bonding and used for the treatment of phenolic wastewater in continuous systems. For this purposes, horseradish peroxidase (HRP) was covalently immobilized onto magnetic poly(GMA-MMA) beds using glutaraldehyde (GA) as a coupling agent. The maximum HRP immobilization capacity of the magnetic poly(GMA-MMA)-GA beads was 3.35 mg g -1 . The immobilized HRP retained 79% of the activity of the free HRP used for immobilization. The immobilized HRP was used for the removal of phenol and p-chlorophenol via polymerization of dissolved phenols in the presence of hydrogen peroxide (H 2 O 2 ). The effect of pH and temperature on the phenol oxidation rate was investigated. The results were compared with the free HRP, which showed that the optimum pH value for the immobilized HRP is similar to that for the free HRP. The optimum pH value for free and immobilized HRP was observed at pH 7.0. The optimum temperature for phenols oxidation with immobilized HRP was between 25 and 35 deg. C and the immobilized HRP has more resistance to temperature inactivation than that of the free form. Finally, the immobilized HRP was operated in a magnetically stabilized fluidized bed reactor, and phenols were successfully removed in the enzyme reactor

  9. Microwave synthesis of gibberellin acid 3 magnetic molecularly imprinted polymer beads for the trace analysis of gibberellin acids in plant samples by liquid chromatography-mass spectrometry detection.

    Science.gov (United States)

    Zhang, Zhuomin; Tan, Wei; Hu, Yuling; Li, Gongke; Zan, Song

    2012-02-21

    In this study, novel GA3 magnetic molecularly imprinted polymer (mag-MIP) beads were synthesized by a microwave irradiation method, and the beads were applied for the trace analysis of gibberellin acids (GAs) in plant samples including rice and cucumber coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS). The microwave synthetic procedure was optimized in detail. In particular, the interaction between GA3 and functional monomers was further studied for the selection of the optimal functional monomers during synthesis. It can be seen that the interaction between GA3 and acrylamide (AM) finally selected was stronger than that between GA3 and other functional monomers. GA3 mag-MIP beads were characterized by a series of physical tests. GA3 mag-MIP beads had a porous and homogeneous surface morphology with stable chemical, thermal and magnetic properties. Moreover, GA3 mag-MIP beads demonstrated selective and specific absorption behavior for the target compounds during unsaturated extraction, which resulted in a higher extraction capacity (∼708.4 pmol for GA3) and selectivity than GA3 mag-non-imprinted polymer beads. Finally, an analytical method of GA3 mag-AM-MIP bead extraction coupled with HPLC-MS detection was established and applied for the determination of trace GA1, GA3, GA4 and GA7 in rice and cucumber samples. It was satisfactory that GA4 could be actually found to be 121.5 ± 1.4 μg kg(-1) in real rice samples by this novel analytical method. The recoveries of spiked rice and cucumber samples were found to be 76.0-109.1% and 79.9-93.6% with RSDs of 2.8-8.8% and 3.1-7.7% (n = 3), respectively. The proposed method is efficient and applicable for the trace analysis of GAs in complicated plant samples.

  10. Beneficial effects of semen purification with magnetic nanoparticles

    Science.gov (United States)

    Current techniques for sperm quality evaluation are mostly informative. They become useful when ejaculates of high index males not meeting quality standard are still discarded. Here we developed a molecular-based magnetic conjugates allowing selective elimination of damaged spermatozoa from semen ej...

  11. Novel highly porous magnetic hydrogel beads composed of chitosan and sodium citrate: an effective adsorbent for the removal of heavy metals from aqueous solutions.

    Science.gov (United States)

    Pu, Shengyan; Ma, Hui; Zinchenko, Anatoly; Chu, Wei

    2017-07-01

    This research focuses on the removal of heavy metal ions from aqueous solutions using magnetic chitosan hydrogel beads as a potential sorbent. Highly porous magnetic chitosan hydrogel (PMCH) beads were prepared by a combination of in situ co-precipitation and sodium citrate cross-linking. Fourier transform infrared spectroscopy indicated that the high sorption efficiency of metal cations is attributable to the hydroxyl, amino, and carboxyl groups in PMCH beads. Thermogravimetric analysis demonstrated that introducing Fe 3 O 4 nanoparticles increases the thermal stability of the adsorbent. Laser confocal microscopy revealed highly uniform porous structure of the resultant PMCH beads, which contained a high moisture content (93%). Transmission electron microscopy micrographs showed that the Fe 3 O 4 nanoparticles, with a mean diameter of 5 ± 2 nm, were well dispersed inside the chitosan beads. Batch adsorption experiments and adsorption kinetic analysis revealed that the adsorption process obeys a pseudo-second-order model. Isotherm data were satisfactorily described by the Langmuir equation, and the maximum adsorption capacity of the adsorbent was 84.02 mg/g. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectra analyses were performed to confirm the adsorption of Pb 2+ and to identify the adsorption mechanism.

  12. Proteomic profiling of renal allograft rejection in serum using magnetic bead-based sample fractionation and MALDI-TOF MS.

    Science.gov (United States)

    Sui, Weiguo; Huang, Liling; Dai, Yong; Chen, Jiejing; Yan, Qiang; Huang, He

    2010-12-01

    Proteomics is one of the emerging techniques for biomarker discovery. Biomarkers can be used for early noninvasive diagnosis and prognosis of diseases and treatment efficacy evaluation. In the present study, the well-established research systems of ClinProt Micro solution incorporated unique magnetic bead sample preparation technology, which, based on matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), have become very successful in bioinformatics due to its outstanding performance and reproducibility for discovery disease-related biomarker. We collected fasting blood samples from patients with biopsy-confirmed acute renal allograft rejection (n = 12), chronic rejection (n = 12), stable graft function (n = 12) and also from healthy volunteers (n = 13) to study serum peptidome patterns. Specimens were purified with magnetic bead-based weak cation exchange chromatography and analyzed with a MALDI-TOF mass spectrometer. The results indicated that 18 differential peptide peaks were selected as potential biomarkers of acute renal allograft rejection, and 6 differential peptide peaks were selected as potential biomarkers of chronic rejection. A Quick Classifier Algorithm was used to set up the classification models for acute and chronic renal allograft rejection. The algorithm models recognize 82.64% of acute rejection and 98.96% of chronic rejection episodes, respectively. We were able to identify serum protein fingerprints in small sample sizes of recipients with renal allograft rejection and establish the models for diagnosis of renal allograft rejection. This preliminary study demonstrated that proteomics is an emerging tool for early diagnosis of renal allograft rejection and helps us to better understand the pathogenesis of disease process.

  13. Ultra-sensitive chemiluminescent detection of Staphylococcus aureus based on competitive binding of Staphylococcus protein A-modified magnetic beads to immunoglobulin G

    International Nuclear Information System (INIS)

    Xiong, Jie; Wang, Wenwen; Zhou, Yali; Kong, Weijun; Wang, Zhenxing; Fu, Zhifeng

    2016-01-01

    Staphylococcus protein A (SPA) is a surface protein only expressed naturally in the cell walls of Staphylococcus aureus (S. aureus) and binds specifically to the Fc region of immunoglobulin G (IgG). This fact can be utilized for the detection of S. aureus. Specifically, SPA-modified magnetic beads, compete with S. aureus pathogens for binding to rabbit IgG that previously was labeled with horseradish peroxidase (HRP). The beads were then magnetically separated, and chemiluminescence (CL) was generated by adding the reagents luminol and H_2O_2. Under optimal conditions, the intensity of CL decreases with increasing concentration of S. aureus over a very wide linear range (10 to 1.0 × 10"9 cfu·mL"−"1), with a limit of detection of 6.0 cfu·mL"−"1 at an S/N ratio of 3. The assay (including binding reaction, magnetic separation, washing of beads and detection) is completed within 50 min which is faster than many reported methods. It can well distinguish S. aureus from other Gram-positive and Gram-negative bacteria. The magnetic beads have the beneficial effect of eliminating undesired matrix effects and of concentrating the sample. The method was applied to the analysis of urine, apple juice and glucose injection samples spiked with S. aureus, and recoveries ranged from 85 to 107 %. (author)

  14. A planar conducting micro-loop structure for transportation of magnetic beads: An approach towards rapid sensing and quantification of biological entities

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Giouroudi, Ioanna; Kosel, Jü rgen

    2012-01-01

    tools for accurate and rapid cell sorting and counting. Effective manipulation of beads is a critical factor for the performance of LOC devices. In this paper we propose a planar conducting micro-loop structure to trap, manipulate and transport magnetic

  15. Efficient isolation of pure and functional mitochondria from mouse tissues using automated tissue disruption and enrichment with anti-TOM22 magnetic beads.

    Directory of Open Access Journals (Sweden)

    Andras Franko

    Full Text Available To better understand molecular mechanisms regulating changes in metabolism, as observed e.g. in diabetes or neuronal disorders, the function of mitochondria needs to be precisely determined. The usual isolation methods such as differential centrifugation result in isolates of highly variable quality and quantity. To fulfill the need of a reproducible isolation method from solid tissues, which is suitable to handle parallel samples simultaneously, we developed a protocol based on anti-TOM22 (translocase of outer mitochondrial membrane 22 homolog antibody-coupled magnetic beads. To measure oxygen consumption rate in isolated mitochondria from various mouse tissues, a traditional Clark electrode and the high-throughput XF Extracellular Flux Analyzer were used. Furthermore, Western blots, transmission electron microscopic and proteomic studies were performed to analyze the purity and integrity of the mitochondrial preparations. Mitochondrial fractions isolated from liver, brain and skeletal muscle by anti-TOM22 magnetic beads showed oxygen consumption capacities comparable to previously reported values and little contamination with other organelles. The purity and quality of isolated mitochondria using anti-TOM22 magnetic beads was compared to traditional differential centrifugation protocol in liver and the results indicated an obvious advantage of the magnetic beads method compared to the traditional differential centrifugation technique.

  16. Heat generation ability in AC magnetic field of nano MgFe2O4-based ferrite powder prepared by bead milling

    International Nuclear Information System (INIS)

    Hirazawa, Hideyuki; Aono, Hiromichi; Naohara, Takashi; Maehara, Tsunehiro; Sato, Mitsunori; Watanabe, Yuji

    2011-01-01

    Nanosized MgFe 2 O 4 -based ferrite powder having heat generation ability in an AC magnetic field was prepared by bead milling and studied for thermal coagulation therapy applications. The crystal size and the particle size significantly decreased by bead milling. The heat generation ability in an AC magnetic field improved with the milling time, i.e. a decrease in crystal size. However, the heat generation ability decreased for excessively milled samples with crystal sizes of less than 5.5 nm. The highest heat ability (ΔT=34 o C) in the AC magnetic field (370 kHz, 1.77 kA/m) was obtained for fine MgFe 2 O 4 powder having a ca. 6 nm crystal size (the samples were milled for 6-8 h using 0.1 mm φ beads). The heat generation of the samples was closely related to hysteresis loss, a B-H magnetic property. The reason for the high heat generation properties of the samples milled for 6-8 h using 0.1 mm φ beads was ascribed to the increase in hysteresis loss by the formation of a single domain. Moreover, the improvement in heating ability was obtained by calcination of the bead-milled sample at low temperature. In this case, the maximum heat generation (ΔT=41 o C) ability was obtained for a ca. 11 nm crystal size sample was prepared by crystal growth during the sample calcination. On the other hand, the ΔT value for Mg 0.5 Ca 0.5 Fe 2 O 4 was synthesized using a reverse precipitation method decreased by bead milling. - Research Highlights: →The crystal and particle size for MgFe 2 O 4 based ferrite were decreased by bead milling. →The highest heat ability was obtained for MgFe 2 O 4 having a ca. 6 nm crystal size. →This high heat generation ability was ascribed to the increase in hysteresis loss. →Hysteresis loss was increased by the formation of a single domain.

  17. The hydroxyl-functionalized magnetic particles for purification of glycan-binding proteins.

    Science.gov (United States)

    Sun, Xiuxuan; Yang, Ganglong; Sun, Shisheng; Quan, Rui; Dai, Weiwei; Li, Bin; Chen, Chao; Li, Zheng

    2009-12-01

    Glycan-protein interactions play important biological roles in biological processes. Although there are some methods such as glycan arrays that may elucidate recognition events between carbohydrates and protein as well as screen the important glycan-binding proteins, there is a lack of simple effectively separate method to purify them from complex samples. In proteomics studies, fractionation of samples can help to reduce their complexity and to enrich specific classes of proteins for subsequent downstream analyses. Herein, a rapid simple method for purification of glycan-binding proteins from proteomic samples was developed using hydroxyl-coated magnetic particles coupled with underivatized carbohydrate. Firstly, the epoxy-coated magnetic particles were further hydroxyl functionalized with 4-hydroxybenzhydrazide, then the carbohydrates were efficiently immobilized on hydroxyl functionalized surface of magnetic particles by formation of glycosidic bond with the hemiacetal group at the reducing end of the suitable carbohydrates via condensation. All conditions of this method were optimized. The magnetic particle-carbohydrate conjugates were used to purify the glycan-binding proteins from human serum. The fractionated glycan-binding protein population was displayed by SDS-PAGE. The result showed that the amount of 1 mg magnetic particles coupled with mannose in acetate buffer (pH 5.4) was 10 micromol. The fractionated glycan-binding protein population in human serum could be eluted from the magnetic particle-mannose conjugates by 0.1% SDS. The methodology could work together with the glycan microarrays for screening and purification of the important GBPs from complex protein samples.

  18. Fabrication of magnetic alginate beads with uniform dispersion of CoFe2O4 by the polydopamine surface functionalization for organic pollutants removal

    Science.gov (United States)

    Li, Xiaoli; Lu, Haijun; Zhang, Yun; He, Fu; Jing, Lingyun; He, Xinghua

    2016-12-01

    A simple and efficient method for production of magnetic composites by decorating CoFe2O4 with polydopamine (PDA) through oxidative polymerization of dopamine was conducted. Further, magnetic alginate beads with porous structure containing well-dispersed CoFe2O4-PDA were fabricated by ionic crosslinking technology. The resulting SA@CoFe2O4-PDA beads were characterized using scanning electron microscopy, Fourier transform infrared spectrometry, X-ray diffractometer, vibrating sample magnetometer and X-ray photoelectron spectroscopy. Adsorption potential of SA@CoFe2O4-PDA beads for organic dyes including Methylene Blue (MB), Crystal Violet (CV) and Malachite Green (MG) was evaluated. SA@CoFe2O4-PDA beads exhibited excellent adsorption performances due to the composite effect, large surface area and porous structure. Organic dyes could be removed from water solution with high efficiency in a wide pH range of 4.0-9.0. Moreover, it exhibited much higher adsorptivity towards MB and CV with the maximum adsorption capacities of 466.60 and 456.52 mg/g, respectively, which were much higher than that of MG (248.78 mg/g). Ca-electrolyte had obvious adverse effects on MB and CV adsorption than MG. FTIR and XPS demonstrated that carboxylate, catechol, hydroxyl and amine groups might be involved in adsorption of organic dyes. The characteristics of wide pH range, high adsorption capacity and convenient magnetic separation would make SA@CoFe2O4-PDA beads as effective adsorbent for removal of organic dyes from wastewater.

  19. Magnetic beads-based electrochemical immunosensor for monitoring allergenic food proteins

    Czech Academy of Sciences Publication Activity Database

    Čadková, M.; Metelka, R.; Holubová, L.; Horák, Daniel; Dvořáková, V.; Bílková, Z.; Korecká, L.

    2015-01-01

    Roč. 484, 1 September (2015), s. 4-8 ISSN 0003-2697 R&D Projects: GA ČR GAP206/12/0381 Institutional support: RVO:61389013 Keywords : electrochemical immunosensor * magnetic particles * ovalbumin Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.243, year: 2015

  20. Flow-orthogonal bead oscillation in a microfluidic chip with a magnetic anisotropic flux-guide array

    DEFF Research Database (Denmark)

    Van Pelt, Stijn; Derks, Roy; Matteucci, Marco

    2011-01-01

    A new concept for the manipulation of superparamagnetic beads inside a microfluidic chip is presented in this paper. The concept allows for bead actuation orthogonal to the flow direction inside a microchannel. Basic manipulation functionalities were studied by means of finite element simulations...

  1. Enhanced extraction and purification of plasmid DNA from escherichia coli by applying a hybrid magnetic nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.J. da; Chavez-Guajardo, A.E.; Medina-llamas, J.C.; Alcaraz-Espinoza, J.J.; Melo, C.P. de [Universidade Federal de Pernambuco (UFPE), PE (Brazil)

    2016-07-01

    Full text: Plasmid DNA (pDNA), a special kind of nucleic acid usually found in bacteria, is a small molecule physically distinct from chromosomal DNA that can replicate independently. This genetic material has been used in a wide set of biotechnological methodologies, such as genetic engineering, production of recombinant drugs and gene therapy, among others. In all these applications, the extraction and purification of pDNA appears as a crucial step. In this work, we describe the synthesis of a polyaniline and maghemite (PANI/?-Fe2O3) magnetic nanocomposite (MNC) and its use in a new Escherichia coli (E. coli) pDNA extraction and purification protocol. We have used transmission electron microscopy (TEM), UV-Vis spectroscopy, infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and magnetic measurements to characterize the MNC, which was synthesized through an emulsion polymerization method. The yield, purity and quality of the pDNA extracted by using our proposed MNC protocol were evaluated through UV-Vis, agarose gel electrophoreses and PCR techniques, respectively. After comparing our results to those obtained by use of a commercial kit (Promega Wizard Plus SV Minipreps), we suggest that the novel protocol here proposed appears as a competitive alternative methodology. Not only the purification step can be completed within only 10 min, but the high adsorption capacity of the MNC results in pDNA yields that are almost twice the best values obtained by using the commercial kit. Hence, this new MNC methodology can be of general interest and find widespread use in different types of biomedical applications. (author)

  2. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    DEFF Research Database (Denmark)

    Kistrup, Kasper; Sørensen, Karen Skotte; Wolff, Anders

    2014-01-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible......-binding buffer for nucleic acid extraction (0.1 (v/v)% Triton X-100 in 5 M guanidine hydrochloride). A linear relationship was found between the liquid carry-over and mass of magnetic beads used. Interestingly, similar average carry-overs of 1.74(8) nL/µg and 1.72(14) nL/µg were found for Milli-Q water and lysis...

  3. Adsorptive removal of Lead from water by the effective and reusable magnetic cellulose nanocomposite beads entrapping activated bentonite.

    Science.gov (United States)

    Luo, Xiaogang; Lei, Xiaojuan; Xie, Xiuping; Yu, Bo; Cai, Ning; Yu, Faquan

    2016-10-20

    Many efforts have been driven to decontaminate the drinking water, and the development of efficient adsorbents with the advantages of cost-effectiveness and operating convenience for the removal of Pb(2+) from water is a major challenge. This work was aimed to explore the possibility of using cellulose-based adsorbents for efficient adsorption of Pb(2+). The millimeter-scale magnetic cellulose-based nanocomposite beads were fabricated via an optimal extrusion dropping technology by blending cellulose with the carboxyl-functionalized magnetite nanoparticles and acid-activated bentonite in NaOH/urea aqueous solution, and then they had been tested to evaluate the effectiveness in the removal of Pb(2+) from water. The effects of contact time, initial heavy metal ion concentrations, adsorption isotherms and solution pH on the sorption behavior were studied. The thermodynamic parameters (ΔG, ΔH and ΔS) indicated that the adsorption processes were feasible, spontaneous, endothermic and mainly controlled by chemical mechanisms. The reusability of the adsorbent was also studied. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Development of an in situ magnetic beads based RT-PCR method for electrochemiluminescent detection of rotavirus

    Science.gov (United States)

    Zhan, Fangfang; Zhou, Xiaoming

    2012-12-01

    Rotaviruses are double-stranded RNA viruses belonging to the family of enteric pathogens. It is a major cause of diarrhoeal disease in infants and young children worldwide. Consequently, rapid and accurate detection of rotaviruses is of great importance in controlling and preventing food- and waterborne diseases and outbreaks. Reverse transcription-polymerase chain reaction (RT-PCR) is a reliable method that possesses high specificity and sensitivity. It has been widely used to detection of viruses. Electrochemiluminescence (ECL) can be considered as an important and powerful tool in analytical and clinical application with high sensitivity, excellent specificity, and low cost. Here we have developed a method for the detection of rotavirus by combining in situ magnetic beads (MBs) based RT-PCR with ECL. RT of rotavirus RNA was carried out in a traditional way and the resulting cDNA was directly amplified on MBs. Forward primers were covalently bounded to MBs and reverse primers were labeled with tris-(2, 2'-bipyridyl) ruthenium (TBR). During the PCR cycling, the TBR labeled products were directly loaded and enriched on the surface of MBs. Then the MBs-TBR complexes could be analyzed by a magnetic ECL platform without any post-modification or post-incubation which avoid some laborious manual operations and achieve rapid yet sensitive detection. In this study, rotavirus from fecal specimens was successfully detected within 2 h, and the limit of detection was estimated to be 104copies/μL. This novel in situ MBs based RT-PCR with ECL detection method can be used for pathogen detection in food safety field and clinical diagnosis.

  5. Strep-Tagged Protein Purification.

    Science.gov (United States)

    Maertens, Barbara; Spriestersbach, Anne; Kubicek, Jan; Schäfer, Frank

    2015-01-01

    The Strep-tag system can be used to purify recombinant proteins from any expression system. Here, protocols for lysis and affinity purification of Strep-tagged proteins from E. coli, baculovirus-infected insect cells, and transfected mammalian cells are given. Depending on the amount of Strep-tagged protein in the lysate, a protocol for batch binding and subsequent washing and eluting by gravity flow can be used. Agarose-based matrices with the coupled Strep-Tactin ligand are the resins of choice, with a binding capacity of up to 9 mg ml(-1). For purification of lower amounts of Strep-tagged proteins, the use of Strep-Tactin magnetic beads is suitable. In addition, Strep-tagged protein purification can also be automated using prepacked columns for FPLC or other liquid-handling chromatography instrumentation, but automated purification is not discussed in this protocol. The protocols described here can be regarded as an update of the Strep-Tag Protein Handbook (Qiagen, 2009). © 2015 Elsevier Inc. All rights reserved.

  6. Repetitive Immunosensor with a Fiber-Optic Device and Antibody-Coated Magnetic Beads for Semi-Continuous Monitoring of Escherichia coli O157:H7.

    Science.gov (United States)

    Taniguchi, Midori; Saito, Hirokazu; Mitsubayashi, Kohji

    2017-09-19

    A rapid and reproducible fiber-optic immunosensor for Escherichia coli O157:H7 ( E. coli O157:H7) was described. The biosensor consisted of a flow cell, an optical fiber with a thin Ni layer, and a PC linked fluorometer. First, the samples with E. coli O157:H7 were incubated with magnetic beads coated with anti- E. coli O157:H7 antibodies and anti- E. coli O157:H7 antibodies labeled cyanine 5 (Cy5) to make sandwich complexes. Then the Cy5-( E. coli O157:H7)-beads were injected into a flow cell and pulled to the magnetized Ni layer on the optical fiber set in the flow cell. An excitation light (λ = 635 nm) was used to illuminate the optical fiber, and the Cy5 florescent molecules facing the optical fiber were exposed to an evanescent wave from the optical fiber. The 670 nm fluorescent light was measured using a photodiode. Finally, the magnetic intensity of the Ni layer was removed and the Cy5- E. coli O157:H7-beads were washed out for the next immunoassay. E. coli O157:H7, diluted with phosphate buffer (PB), was measured from 1 × 10⁵ to 1 × 10⁷ cells/mL. The total time required for an assay was less than 15 min (except for the pretreatment process) and repeating immunoassay on one optical fiber was made possible.

  7. On-Chip Magnetic Bead Manipulation and Detection Using a Magnetoresistive Sensor-Based Micro-Chip: Design Considerations and Experimental Characterization

    KAUST Repository

    Gooneratne, Chinthaka Pasan; Kodzius, Rimantas; Li, Fuquan; Foulds, Ian G.; Kosel, Jü rgen

    2016-01-01

    The remarkable advantages micro-chip platforms offer over cumbersome, time-consuming equipment currently in use for bio-analysis are well documented. In this research, a micro-chip that includes a unique magnetic actuator (MA) for the manipulation of superparamagnetic beads (SPBs), and a magnetoresistive sensor for the detection of SPBs is presented. A design methodology, which takes into account the magnetic volume of SPBs, diffusion and heat transfer phenomena, is presented with the aid of numerical analysis to optimize the parameters of the MA. The MA was employed as a magnetic flux generator and experimental analysis with commercially available COMPEL™ and Dynabeads® demonstrated the ability of the MA to precisely transport a small number of SPBs over long distances and concentrate SPBs to a sensing site for detection. Moreover, the velocities of COMPEL™ and Dynabead® SPBs were correlated to their magnetic volumes and were in good agreement with numerical model predictions. We found that 2.8 μm Dynabeads® travel faster, and can be attracted to a magnetic source from a longer distance, than 6.2 μm COMPEL™ beads at magnetic flux magnitudes of less than 10 mT. The micro-chip system could easily be integrated with electronic circuitry and microfluidic functions, paving the way for an on-chip biomolecule quantification device

  8. On-Chip Magnetic Bead Manipulation and Detection Using a Magnetoresistive Sensor-Based Micro-Chip: Design Considerations and Experimental Characterization

    KAUST Repository

    Gooneratne, Chinthaka Pasan

    2016-08-26

    The remarkable advantages micro-chip platforms offer over cumbersome, time-consuming equipment currently in use for bio-analysis are well documented. In this research, a micro-chip that includes a unique magnetic actuator (MA) for the manipulation of superparamagnetic beads (SPBs), and a magnetoresistive sensor for the detection of SPBs is presented. A design methodology, which takes into account the magnetic volume of SPBs, diffusion and heat transfer phenomena, is presented with the aid of numerical analysis to optimize the parameters of the MA. The MA was employed as a magnetic flux generator and experimental analysis with commercially available COMPEL™ and Dynabeads® demonstrated the ability of the MA to precisely transport a small number of SPBs over long distances and concentrate SPBs to a sensing site for detection. Moreover, the velocities of COMPEL™ and Dynabead® SPBs were correlated to their magnetic volumes and were in good agreement with numerical model predictions. We found that 2.8 μm Dynabeads® travel faster, and can be attracted to a magnetic source from a longer distance, than 6.2 μm COMPEL™ beads at magnetic flux magnitudes of less than 10 mT. The micro-chip system could easily be integrated with electronic circuitry and microfluidic functions, paving the way for an on-chip biomolecule quantification device

  9. On-Chip Magnetic Bead Manipulation and Detection Using a Magnetoresistive Sensor-Based Micro-Chip: Design Considerations and Experimental Characterization

    Directory of Open Access Journals (Sweden)

    Chinthaka P. Gooneratne

    2016-08-01

    Full Text Available The remarkable advantages micro-chip platforms offer over cumbersome, time-consuming equipment currently in use for bio-analysis are well documented. In this research, a micro-chip that includes a unique magnetic actuator (MA for the manipulation of superparamagnetic beads (SPBs, and a magnetoresistive sensor for the detection of SPBs is presented. A design methodology, which takes into account the magnetic volume of SPBs, diffusion and heat transfer phenomena, is presented with the aid of numerical analysis to optimize the parameters of the MA. The MA was employed as a magnetic flux generator and experimental analysis with commercially available COMPEL™ and Dynabeads® demonstrated the ability of the MA to precisely transport a small number of SPBs over long distances and concentrate SPBs to a sensing site for detection. Moreover, the velocities of COMPEL™ and Dynabead® SPBs were correlated to their magnetic volumes and were in good agreement with numerical model predictions. We found that 2.8 μm Dynabeads® travel faster, and can be attracted to a magnetic source from a longer distance, than 6.2 μm COMPEL™ beads at magnetic flux magnitudes of less than 10 mT. The micro-chip system could easily be integrated with electronic circuitry and microfluidic functions, paving the way for an on-chip biomolecule quantification device.

  10. Magnetic bead/capture DNA/glucose-loaded nanoliposomes for amplifying the glucometer signal in the rapid screening of hepatitis C virus RNA.

    Science.gov (United States)

    Tu, Haijian; Lin, Kun; Lun, Yongzhi; Yu, Liuming

    2018-06-01

    A digital detection strategy based on a portable personal glucometer (PGM) was developed for the simple, rapid, and sensitive detection of hepatitis C virus (HCV) RNA, involving the release of glucose-loaded nanoliposomes due to coupling-site-specific cleavage by the endonuclease BamHI. The glucose-loaded nanoliposomes were synthesized using a reversed-phase evaporation method and provided an amplified signal at the PGM in the presence of HCV RNA. Initially, a 21-mer oligonucleotide complementary to HCV RNA was covalently conjugated to a magnetic bead through the amino group at the 5' end of the oligonucleotide, and then bound to a glucose-loaded liposome by typical carbodiimide coupling at its 3' end. In the presence of the target HCV RNA, the target hybridized with the oligonucleotide to form double-stranded DNA. The symmetrical duplex sequence 5'-GGATCC-3' between guanines was then catalytically cleaved by BamHI, which detached the glucose-loaded liposome from the magnetic bead. Following magnetic separation of the bead, the detached glucose-loaded liposome was lysed using Triton X-100 to release the glucose molecules within it, which were then detected as an amplified signal at the digital PGM. Under optimal conditions, the PGM signal increased with increasing HCV RNA, and displayed a strongly linear dependence on the level of HCV RNA for concentrations ranging from 10 pM to 1.0 μM. The detection limit (LOD) of the system was 1.9 pM. Good reproducibility and favorable specificity were achieved in the analysis of the target HCV RNA. Human serum samples containing HCV RNA were analyzed using this strategy, and the developed sensing platform was observed to yield satisfactory results based on a comparison with the corresponding results from a Cobas ® Amplicor HCV Test Analyzer. Graphical abstract A digital detection strategy utilizing a personal glucometer was developed for the detection of hepatitis C virus RNA. The strategy involved the use of the

  11. Study on magnetic separation system using high Tc superconducting bulk magnets for water purification technique

    International Nuclear Information System (INIS)

    Oka, T; Kanayama, H; Tanaka, K; Fukui, S; Ogawa, J; Sato, T; Ooizumi, M; Yamaguchi, M; Yokoyama, K; Noto, K

    2009-01-01

    The application of superconducting bulk magnets to the magnetic separation techniques has been investigated for the Mn-bearing waste water drained from the university laboratories. The research has been conducted in comparison with the electromagnets, and the cryo-cooled superconducting solenoid magnet. The separation ratios of ferrite precipitates including Mn element in the waste slurry were estimated by means of the high gradient magnetic separation method with ferromagnetic iron filters in the water channel and open gradient magnetic separation without them. As the magnetic force acting on the particles is given by the product of a magnetization of particles and a gradient of magnetic field, and a superconducting bulk magnet shows a sharp gradient of the magnetic field on the surface, the performances of the bulk magnet system were almost equivalent to those of the superconducting solenoid magnet with wide bore with respect to the magnetic separation ratios. The separation ratios for Mn have reached over 80 % for HGMS and 10 % for OGMS under the flow rates less than 3 liter/min.

  12. On-bead combinatorial synthesis and imaging of chemical exchange saturation transfer magnetic resonance imaging agents to identify factors that influence water exchange.

    Science.gov (United States)

    Napolitano, Roberta; Soesbe, Todd C; De León-Rodríguez, Luis M; Sherry, A Dean; Udugamasooriya, D Gomika

    2011-08-24

    The sensitivity of magnetic resonance imaging (MRI) contrast agents is highly dependent on the rate of water exchange between the inner sphere of a paramagnetic ion and bulk water. Normally, identifying a paramagnetic complex that has optimal water exchange kinetics is done by synthesizing and testing one compound at a time. We report here a rapid, economical on-bead combinatorial synthesis of a library of imaging agents. Eighty different 1,4,7,10-tetraazacyclododecan-1,4,7,10-tetraacetic acid (DOTA)-tetraamide peptoid derivatives were prepared on beads using a variety of charged, uncharged but polar, hydrophobic, and variably sized primary amines. A single chemical exchange saturation transfer image of the on-bead library easily distinguished those compounds having the most favorable water exchange kinetics. This combinatorial approach will allow rapid screening of libraries of imaging agents to identify the chemical characteristics of a ligand that yield the most sensitive imaging agents. This technique could be automated and readily adapted to other types of MRI or magnetic resonance/positron emission tomography agents as well.

  13. Magnetic nanoparticle based purification and enzyme-linked immunosorbent assay using monoclonal antibody against enrofloxacin

    Science.gov (United States)

    Kim, Nam-Gun; Kim, Myeong-Ae; Park, Young-Il; Jung, Tae-Sung; Son, Seong-Wan; So, ByungJae

    2015-01-01

    Monoclonal anti-enrofloxacin antibody was prepared for a direct competitive enzyme-linked immunosorbent assay (ELISA) and purification system using monoclonal antibody (mAb) coupled magnetic nanoparticles (MNPs). The IC50 values of the developed mAb for enrofloxacin (ENR), ciprofloxacin, difloxacin, sarafloxacin, pefloxacin, and norfloxacin were 5.0, 8.3, 9.7, 21.7, 36.0, and 63.7 ng/mL, respectively. The lowest detectable level of ENR was 0.7 ng/mL in the prepared ELISA system. To validate the developed ELISA in the food matrix, known amounts of ENR were spiked in meat and egg samples at 10, 20 and 30 ng/mL. Recoveries for ENR ranged from 72.9 to 113.16% with a coefficient of variation (CV) of 2.42 to 10.11%. The applicability of the mAb-MNP system was verified by testing the recoveries for ENR residue in three different matrices. Recoveries for ENR ranged from 75.16 to 86.36%, while the CV ranged from 5.08 to 11.53%. Overall, ENR-specific monoclonal antibody was prepared and developed for use in competitive to ELISAs for the detection of ENR in animal meat samples. Furthermore, we suggest that a purification system for ENR using mAb-coupled MNPs could be useful for determination of ENR residue in food. PMID:26040610

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

    Science.gov (United States)

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

    2015-04-15

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

  15. Fabrication of magnetic alginate beads with uniform dispersion of CoFe{sub 2}O{sub 4} by the polydopamine surface functionalization for organic pollutants removal

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaoli, E-mail: lixiaoli@lzu.edu.cn [Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Lu, Haijun, E-mail: 784616040@qq.com [Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); Zhang, Yun, E-mail: zhangyun@lzu.edu.cn [Institute of Biochemical Engineering & Environmental Technology, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); He, Fu, E-mail: hef15@lzu.edu.cn [Institute of Biochemical Engineering & Environmental Technology, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China); Jing, Lingyun, E-mail: jingly12@lzu.edu.cn [Gansu Key Laboratory for Environmental Pollution Prediction and Control, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000 (China); He, Xinghua, E-mail: 466410250@qq.com [Institute of Biochemical Engineering & Environmental Technology, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000 (China)

    2016-12-15

    Highlights: • SA@CoFe{sub 2}O{sub 4}-PDA with magnetic particles and biopolymers were used for dye removal. • SA@CoFe{sub 2}O{sub 4}-PDA exhibited the synergistic effect. • High adsorption capacities and fast kinetics were obtained. • Cationic dyes could be removed with high efficiency in a wide pH range. • Possible mechanism of adsorption was investigated. - Abstract: A simple and efficient method for production of magnetic composites by decorating CoFe{sub 2}O{sub 4} with polydopamine (PDA) through oxidative polymerization of dopamine was conducted. Further, magnetic alginate beads with porous structure containing well-dispersed CoFe{sub 2}O{sub 4}-PDA were fabricated by ionic crosslinking technology. The resulting SA@CoFe{sub 2}O{sub 4}-PDA beads were characterized using scanning electron microscopy, Fourier transform infrared spectrometry, X-ray diffractometer, vibrating sample magnetometer and X-ray photoelectron spectroscopy. Adsorption potential of SA@CoFe{sub 2}O{sub 4}-PDA beads for organic dyes including Methylene Blue (MB), Crystal Violet (CV) and Malachite Green (MG) was evaluated. SA@CoFe{sub 2}O{sub 4}-PDA beads exhibited excellent adsorption performances due to the composite effect, large surface area and porous structure. Organic dyes could be removed from water solution with high efficiency in a wide pH range of 4.0–9.0. Moreover, it exhibited much higher adsorptivity towards MB and CV with the maximum adsorption capacities of 466.60 and 456.52 mg/g, respectively, which were much higher than that of MG (248.78 mg/g). Ca-electrolyte had obvious adverse effects on MB and CV adsorption than MG. FTIR and XPS demonstrated that carboxylate, catechol, hydroxyl and amine groups might be involved in adsorption of organic dyes. The characteristics of wide pH range, high adsorption capacity and convenient magnetic separation would make SA@CoFe{sub 2}O{sub 4}-PDA beads as effective adsorbent for removal of organic dyes from wastewater.

  16. Purification of human induced pluripotent stem cell-derived neural precursors using magnetic activated cell sorting.

    Science.gov (United States)

    Rodrigues, Gonçalo M C; Fernandes, Tiago G; Rodrigues, Carlos A V; Cabral, Joaquim M S; Diogo, Maria Margarida

    2015-01-01

    Neural precursor (NP) cells derived from human induced pluripotent stem cells (hiPSCs), and their neuronal progeny, will play an important role in disease modeling, drug screening tests, central nervous system development studies, and may even become valuable for regenerative medicine treatments. Nonetheless, it is challenging to obtain homogeneous and synchronously differentiated NP populations from hiPSCs, and after neural commitment many pluripotent stem cells remain in the differentiated cultures. Here, we describe an efficient and simple protocol to differentiate hiPSC-derived NPs in 12 days, and we include a final purification stage where Tra-1-60+ pluripotent stem cells (PSCs) are removed using magnetic activated cell sorting (MACS), leaving the NP population nearly free of PSCs.

  17. New Detection Modality for Label-Free Quantification of DNA in Biological Samples via Superparamagnetic Bead Aggregation

    Science.gov (United States)

    Leslie, Daniel C.; Li, Jingyi; Strachan, Briony C.; Begley, Matthew R.; Finkler, David; Bazydlo, Lindsay L.; Barker, N. Scott; Haverstick, Doris; Utz, Marcel; Landers, James P.

    2012-01-01

    Combining DNA and superparamagnetic beads in a rotating magnetic field produces multiparticle aggregates that are visually striking, and enables label-free optical detection and quantification of DNA at levels in the picogram per microliter range. DNA in biological samples can be quantified directly by simple analysis of optical images of microfluidic wells placed on a magnetic stirrer without DNA purification. Aggregation results from DNA/bead interactions driven either by the presence of a chaotrope (a nonspecific trigger for aggregation) or by hybridization with oligonucleotides on functionalized beads (sequence-specific). This paper demonstrates quantification of DNA with sensitivity comparable to that of the best currently available fluorometric assays. The robustness and sensitivity of the method enable a wide range of applications, illustrated here by counting eukaryotic cells. Using widely available and inexpensive benchtop hardware, the approach provides a highly accessible low-tech microscale alternative to more expensive DNA detection and cell counting techniques. PMID:22423674

  18. Magnetic Beads-Based Sensor with Tailored Sensitivity for Rapid and Single-Step Amperometric Determination of miRNAs

    Directory of Open Access Journals (Sweden)

    Eva Vargas

    2017-11-01

    Full Text Available This work describes a sensitive amperometric magneto-biosensor for single-step and rapid determination of microRNAs (miRNAs. The developed strategy involves the use of direct hybridization of the target miRNA (miRNA-21 with a specific biotinylated DNA probe immobilized on streptavidin-modified magnetic beads (MBs, and labeling of the resulting heteroduplexes with a specific DNA–RNA antibody and the bacterial protein A (ProtA conjugated with an horseradish peroxidase (HRP homopolymer (Poly-HRP40 as an enzymatic label for signal amplification. Amperometric detection is performed upon magnetic capture of the modified MBs onto the working electrode surface of disposable screen-printed carbon electrodes (SPCEs using the H2O2/hydroquinone (HQ system. The magnitude of the cathodic signal obtained at −0.20 V (vs. the Ag pseudo-reference electrode demonstrated linear dependence with the concentration of the synthetic target miRNA over the 1.0 to 100 pM range. The method provided a detection limit (LOD of 10 attomoles (in a 25 μL sample without any target miRNA amplification in just 30 min (once the DNA capture probe-MBs were prepared. This approach shows improved sensitivity compared with that of biosensors constructed with the same anti-DNA–RNA Ab as capture instead of a detector antibody and further labeling with a Strep-HRP conjugate instead of the Poly-HRP40 homopolymer. The developed strategy involves a single step working protocol, as well as the possibility to tailor the sensitivity by enlarging the length of the DNA/miRNA heteroduplexes using additional probes and/or performing the labelling with ProtA conjugated with homopolymers prepared with different numbers of HRP molecules. The practical usefulness was demonstrated by determination of the endogenous levels of the mature target miRNA in 250 ng raw total RNA (RNAt extracted from human mammary epithelial normal (MCF-10A and cancer (MCF-7 cells and tumor tissues.

  19. Magnetic Parkia pendula seed gum as matrix for Concanavalin A lectin immobilization and its application in affinity purification

    Directory of Open Access Journals (Sweden)

    MOACYR J.B.M. RÊGO

    2014-09-01

    Full Text Available The present work aimed to magnetize Parkia pendula seeds gum and use it as a matrix for Concanavalin A covalent immobilization. This composite was applied in affinity purification of glycoconjugates. Parkia pendula seeds were hydrated and the gum provenient from the supernatant was precipitated and washed with ethanol and dried. The gum was magnetized in co-precipitation using solutions of Fe+2 and Fe+3. Matrix activation was accomplished with NaIO4. Magnetized Parkia pendula seeds gum with covalently immobilized Concanavalin A was used as an affinity matrix for the recognition of bovine serum fetuin glycoprotein. Fetuin elution was carried out with a solution of glucose (300mM and evaluated through SDS-PAGE. The efficiency of lectin immobilization and fetuin purification were 63% and 14%, respectively. These results indicate that the composite produced is a promising magnetic polysaccharide matrix for lectins immobilization. Thus, such system can be applied for affinity purification allowing an easy recovery by magnetic field.

  20. New Evidence for the Mechanism of Action of a Type-2 Diabetes Drug Using a Magnetic Bead-Based Automated Biosensing Platform

    DEFF Research Database (Denmark)

    Uddin, Rokon; Nur-E-Habiba; Rena, Graham

    2017-01-01

    The mechanism of action (MOA) of the first line type-2 diabetes drug metformin remains unclear despite its widespread usage. However, recent evidence suggests that the mitochondrial copper (Cu)-binding action of metformin may contribute toward the drug's MOA. Here, we present a novel biosensing...... of metformin's blood-glucose lowering action. In this assay, cysteine-functionalized magnetic beadswere agglutinated in the presence of Cu due to cysteine's Cu-chelation property. Addition of clinically relevant doses of metformin resulted in disaggregation of Cu-bridged bead-clusters, whereas the effect...

  1. Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisherTM magnetic particle processor prior to genome sequencing

    International Nuclear Information System (INIS)

    Maekinen, Johanna; Marttila, Harri; Viljanen, Matti K.

    2001-01-01

    Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher TM magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher TM magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification

  2. Comparison of Influenza Virus Particle Purification Using Magnetic Sulfated Cellulose Particles with an Established Centrifugation Method for Analytics.

    Science.gov (United States)

    Serve, Anja; Pieler, Michael Martin; Benndorf, Dirk; Rapp, Erdmann; Wolff, Michael Werner; Reichl, Udo

    2015-11-03

    A method for the purification of influenza virus particles using novel magnetic sulfated cellulose particles is presented and compared to an established centrifugation method for analytics. Therefore, purified influenza A virus particles from adherent and suspension MDCK host cell lines were characterized on the protein level with mass spectrometry to compare the viral and residual host cell proteins. Both methods allowed one to identify all 10 influenza A virus proteins, including low-abundance proteins like the matrix protein 2 and nonstructural protein 1, with a similar impurity level of host cell proteins. Compared to the centrifugation method, use of the novel magnetic sulfated cellulose particles reduced the influenza A virus particle purification time from 3.5 h to 30 min before mass spectrometry analysis.

  3. Poly(hydroxyethyl methacrylate) based magnetic nanoparticles for plasmid DNA purification from Escherichia coli lysate

    Energy Technology Data Exchange (ETDEWEB)

    Percin, Is Latin-Small-Letter-Dotless-I k [Department of Biology, Hacettepe University, Ankara (Turkey); Karakoc, Veyis [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey); Akgoel, Sinan [Department of Biochemistry, Ege University, Izmir (Turkey); Aksoez, Erol [Department of Biology, Hacettepe University, Ankara (Turkey); Denizli, Adil, E-mail: denizli@hacettepe.edu.tr [Department of Chemistry, Biochemistry Division, Hacettepe University, Ankara (Turkey)

    2012-07-01

    The aim of this study is to prepare poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine) [PHEMAH] magnetic nanoparticles for plasmid DNA (pDNA) purification from Escherichia coli (E. coli) cell lysate. Magnetic nanoparticles were produced by surfactant free emulsion polymerization. mPHEMAH nanoparticles were characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), electron spin resonance (ESR), thermogravimetric analyses (TGA) and transmission electron microscopy (TEM). Surface area, average particle size and size distribution were also performed. Specific surface area of the mPHEMAH nanoparticles was found to be 1180 m{sup 2}/g. Elemental analysis of MAH for nitrogen was estimated as 0.18 mmol/g polymer. The amount of pDNA adsorbed onto the mPHEMAH nanoparticles first increased and then reached a saturation value at around 1.0 mg/mL of pDNA concentration. Compared with the mPHEMA nanoparticles (50 {mu}g/g polymer), the pDNA adsorption capacity of the mPHEMAH nanoparticles (154 mg/g polymer) was improved significantly due to the MAH incorporation into the polymeric matrix. The maximum pDNA adsorption was achieved at 25 Degree-Sign C. The overall recovery of pDNA was calculated as 92%. The mPHEMAH nanoparticles could be used six times without decreasing the pDNA adsorption capacity significantly. The results indicate that the PHEMAH nanoparticles promise high selectivity for pDNA. - Highlights: Black-Right-Pointing-Pointer Magnetic nanoparticles have several advantages over conventional adsorbents. Black-Right-Pointing-Pointer MAH acted as the pseudospecific ligand, ligand immobilization step was eliminated. Black-Right-Pointing-Pointer pDNA adsorption amount was 154 mg/g. Black-Right-Pointing-Pointer Fifty-fold capacity increase was obtained when compared to conventional matrices.

  4. Poly(hydroxyethyl methacrylate) based magnetic nanoparticles for plasmid DNA purification from Escherichia coli lysate

    International Nuclear Information System (INIS)

    Perçin, Işık; Karakoç, Veyis; Akgöl, Sinan; Aksöz, Erol; Denizli, Adil

    2012-01-01

    The aim of this study is to prepare poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine) [PHEMAH] magnetic nanoparticles for plasmid DNA (pDNA) purification from Escherichia coli (E. coli) cell lysate. Magnetic nanoparticles were produced by surfactant free emulsion polymerization. mPHEMAH nanoparticles were characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), vibrating sample magnetometer (VSM), electron spin resonance (ESR), thermogravimetric analyses (TGA) and transmission electron microscopy (TEM). Surface area, average particle size and size distribution were also performed. Specific surface area of the mPHEMAH nanoparticles was found to be 1180 m 2 /g. Elemental analysis of MAH for nitrogen was estimated as 0.18 mmol/g polymer. The amount of pDNA adsorbed onto the mPHEMAH nanoparticles first increased and then reached a saturation value at around 1.0 mg/mL of pDNA concentration. Compared with the mPHEMA nanoparticles (50 μg/g polymer), the pDNA adsorption capacity of the mPHEMAH nanoparticles (154 mg/g polymer) was improved significantly due to the MAH incorporation into the polymeric matrix. The maximum pDNA adsorption was achieved at 25 °C. The overall recovery of pDNA was calculated as 92%. The mPHEMAH nanoparticles could be used six times without decreasing the pDNA adsorption capacity significantly. The results indicate that the PHEMAH nanoparticles promise high selectivity for pDNA. - Highlights: ► Magnetic nanoparticles have several advantages over conventional adsorbents. ► MAH acted as the pseudospecific ligand, ligand immobilization step was eliminated. ► pDNA adsorption amount was 154 mg/g. ► Fifty-fold capacity increase was obtained when compared to conventional matrices.

  5. [Detection of serum proteins in the patients of lung adenocarcinoma by the method of magnetic bead based sample fractionation and MALDI-TOF-MS].

    Science.gov (United States)

    Liu, Dan; Liu, Lun-Xu; Yuan, Quan; Li, Xiao-Liang; Huang, Na; Yang, Xiao-Dong

    2010-05-01

    To screen the serum proteins related to human lung adenocarcinoma using matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) technology. The blood samples were collected from 10 patients of lung adenocarcinoma before and one week after the surgery, while 10 healthy subjects were used as control. The differential protein expression between the two groups and the change of those proteins after surgery were studied by ClinProt magnetic bead enrichment and MALDI-TOF-MS. Six protein peaks were identified, 2 of them were highly expressed protein biomarkers with relative molecular weights of 2661, 2991, and increased after the surgery, 4 of them were lowly expressed protein biomarkers with relative molecular weights of 4091, 4210, 4644, 5336, which continuously decreased after the surgery. ClinProt magnetic bead enrichment and MALDI-TOF-MS is a quick, easy and sensitive method of proteomics. The differential expressed proteins may be the latent tumor marker of lung adenocarcinoma. The alteration of those proteins after surgery might be helpful to assess the therapeutic effect and prognosis.

  6. Early Diagnosis of Irkut Virus Infection Using Magnetic Bead-Based Serum Peptide Profiling by MALDI-TOF MS in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Nan Li

    2014-03-01

    Full Text Available Early diagnosis is important for the prompt post-exposure prophylaxis of lyssavirus infections. To diagnose Irkut virus (IRKV infection during incubation in mice, a novel method using magnetic bead-based serum peptide profiling by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS has been established. For this test, serum peptides were concentrated by adsorption to and elution from the magnetic bead-based weak cation ion exchanger. Mass spectrograms obtained by MALDI-TOF MS were analyzed using ClinProTools bioinformatics software. Construction of the diagnostic model was performed using serum samples from mice infected with IRKV and rabies virus (RABV BD06, Flury-LEP, and SRV9 (as controls. The method accurately diagnosed sera 2, 4 and 8 days after IRKV and RABV infections. The sensitivity, specificity, and total accuracy of diagnosis were 86.7%, 95.2%, and 92.9%, respectively. However, IRKV could not be differentiated from RABV 1 day after infection. The results of the present study indicate that serum peptide profiling by MALDI-TOF MS is a promising technique for the early clinical diagnosis of lyssavirus infections and needs to be further tested in humans and farm animals.

  7. In vivo biotinylation of recombinant beta-glucosidase enables simultaneous purification and immobilization on streptavidin coated magnetic particles

    DEFF Research Database (Denmark)

    Alftrén, Johan; Ottow, Kim Ekelund; Hobley, Timothy John

    2013-01-01

    Beta-glucosidase from Bacillus licheniformis was in vivo biotinylated in Escherichia coli and subsequently immobilized directly from cell lysate on streptavidin coated magnetic particles. In vivo biotinylation was mediated by fusing the Biotin Acceptor Peptide to the C-terminal of beta......-glucosidase and co-expressing the BirA biotin ligase. The approach enabled simultaneous purification and immobilization of the enzyme from crude cell lysate on magnetic particles because of the high affinity and strong interaction between biotin and streptavidin. After immobilization of the biotinylated beta...

  8. Fluxing purification and its effect on magnetic properties of high-B{sub s} FeBPSiC amorphous alloy

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Jing [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang, Liaoning 110870 (China); Wang, Anding, E-mail: anding@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Yue, Shiqiang [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Kong, Fengyu [School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315016 (China); Qiu, Keqiang, E-mail: kqqiu@163.com [School of Materials Science and Engineering, Shenyang University of Technology, Shenyang, Liaoning 110870 (China); Chang, Chuntao; Wang, Xinmin [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201 (China); Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Liu, Chain-Tsuan, E-mail: chainliu@cityu.edu.hk [Center for Advanced Structural Materials, Department of Mechanical and Biomedical Engineering, College of Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong (China)

    2017-07-01

    Highlights: • Surface crystallization in Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} ribbon was inhibited by flux purification. • Amorphous Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} ribbon was made with industrial process and materials. • The ribbons exhibit high B{sub s} of 1.65 T, low H{sub c} of 2 A/m, and high μ{sub e} of 9.7 × 10{sup 3}. • High melting point inclusions trigger the surface crystallization as nuclei. - Abstract: A high-B{sub s} amorphous alloy with the base composition Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} was used to study the effects of fluxing purification on amorphous forming ability and magnetic properties of the alloy prepared with raw materials in industrialization. By using fluxing purification, the surface crystallization was suppressed and fully amorphous Fe{sub 83}B{sub 11}P{sub 3}Si{sub 2}C{sub 1} ribbons with a maximum thickness of 48 μm were successfully achieved by using an industrial process and materials. The amorphous ribbons made with industrial-purified alloys exhibit excellent magnetic properties, containing high-B{sub s} of 1.65 T, low H{sub c} of 2.0 A/m, and high μ{sub e} of 9.7 × 10{sup 3} at 1 kHz. Impurities in the melting alloys exist in three forms and have different effluences on magnetic properties. The surface crystallization was triggered by the impurities which exist as high melting point inclusions serving as nuclei. Thus, fluxing purification is a feasible way for industrialization of high-B{sub s} FeBPSiC amorphous alloys.

  9. Highly specific and rapid immuno-fluorescent visualization and detection of E. coli O104:H4 with protein-A coated magnetic beads based LST-MUG assay.

    Science.gov (United States)

    Barizuddin, Syed; Balakrishnan, Baskar; Stringer, R Cody; Dweik, Majed

    2015-08-01

    A method combining immunomagnetic separation and fluorescent sensing was developed to detect Escherichia coli (E. coli) O104:H4. The antibody specific to E. coli O104:H4 was immobilized on protein A-coated magnetic beads. This protein-A-anti E. coli O104:H4 complex was used to bind Fluorescein IsoThioCyanate (FITC) labeled E. coli O104:H4 antigen (whole cell) on it. The goal was to achieve a fluorescently detectable protein-A-anti E. coli O104:H4-E. coli O104:H4 complex on the magnetic beads. Fluorescent microscopy was used to image the magnetic beads. The resulting fluorescence on the beads was due to the FITC labeled antigen binding on the protein-A-anti E. coli O104:H4 immobilized magnetic beads. This visually proves the antigen-antibody binding. The fluorescent imaging results were obtained in 2 h if the minimum available bacteria in the sample were at least 10(5) CFU/ml. If no fluorescence was observed on the magnetic beads during fluorescent imaging, it indicates the bacterial concentration in the sample to be too low for it to have bound to the magnetic beads and hence no detection was possible. To detect bacterial concentration less than 10(5) CFU/ml in the sample, an additional step was required for detection. The magnetic bead complex was added to the LST-MUG (lauryl sulfate tryptose-4-methylumbelliferyl-β-D-glucuronide), a signaling reporter. The E. coli O104:H4 grows in LST-MUG and releases β-glucuronidase enzyme. This enzyme cleaves the MUG substrate that produces 4-methylumbelliferone, a highly fluorescent species. This fluorescence was detected using a spectrofluorometer. The emission peak in the fluorescent spectrum was found to be at 450 nm. The lower and upper detection range for this LST-MUG assay was found to be 2.05×10(5)-4.09×10(8) CFU/ml. The results for the LST-MUG assay for concentrations below 10(5) CFU/ml were ascertained in 8h. The advantages of this technique include the specific detection of bacteria without an enrichment step and

  10. Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

    Science.gov (United States)

    Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

    2015-08-14

    Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment.

  11. Development of a PCR/LDR/flow-through hybridization assay using a capillary tube, probe DNA-immobilized magnetic beads and chemiluminescence detection.

    Science.gov (United States)

    Hommatsu, Manami; Okahashi, Hisamitsu; Ohta, Keisuke; Tamai, Yusuke; Tsukagoshi, Kazuhiko; Hashimoto, Masahiko

    2013-01-01

    A polymerase chain reaction (PCR)/ligase detection reaction (LDR)/flow-through hybridization assay using chemiluminescence (CL) detection was developed for analyzing point mutations in gene fragments with high diagnostic value for colorectal cancers. A flow-through hybridization format using a capillary tube, in which probe DNA-immobilized magnetic beads were packed, provided accelerated hybridization kinetics of target DNA (i.e. LDR product) to the probe DNA. Simple fluid manipulations enabled both allele-specific hybridization and the removal of non-specifically bound DNA in the wash step. Furthermore, the use of CL detection greatly simplified the detection scheme, since CL does not require a light source for excitation of the fluorescent dye tags on the LDR products. Preliminary results demonstrated that this analytical system could detect both homozygous and heterozygous mutations, without the expensive instrumentation and cumbersome procedures required by conventional DNA microarray-based methods.

  12. Controlled torque on superparamagnetic beads for functional biosensors

    NARCIS (Netherlands)

    Janssen, X.J.A.; Schellekens, A.J.; van Ommering, K.; IJzendoorn, van L.J.; Prins, M.W.J.

    2009-01-01

    We demonstrate that a rotating magnetic field can be used to apply a controlled torque on superparamagnetic beads which leads to a tunable bead rotation frequency in fluid. Smooth rotation is obtained for field rotation frequencies many orders of magnitude higher than the bead rotation frequency. A

  13. Effect of algal density in bead, bead size and bead concentrations ...

    African Journals Online (AJOL)

    Effect of algal density in bead, bead size and bead concentrations on wastewater nutrient removal. ... African Journal of Biotechnology ... The bioreactor containing algal beads (4 mm diameter) with 1.5 x 106 cells bead-1 (cell stocking) at concentration of 10.66 beads ml-1 wastewater (1:3 bead: wastewater, v/v) achieved ...

  14. Isolating Sperm from Cell Mixtures Using Magnetic Beads Coupled with an Anti-PH-20 Antibody for Forensic DNA Analysis.

    Directory of Open Access Journals (Sweden)

    Xing-Chun Zhao

    Full Text Available Vaginal swabs taken in rape cases usually contain epithelial cells from the victim and sperm from the assailant and forensic DNA analysis requires separation of sperm from these cell mixtures. PH-20, which is a glycosylphosphatidylinositol-anchored hyaluronidase located on the head of sperm, has important functions in fertilization. Here we describe a newly developed method for sperm isolation using anti-PH-20 antibody-coupled immunomagnetic beads (anti-PH-20 IMBs. Optical microscopy and scanning electron microscopy showed the IMBs recognized the head of sperm specifically and exhibited a great capacity to capture sperm cells. However, we found it necessary to incubate the IMB-sperm complex with DNase I before sperm lysis in order to remove any female DNA completely. We compared the sensitivity of anti-PH-20 IMBs in sperm and epithelial cell discrimination to those coated with a different anti-sperm antibody (anti-SP-10, anti-ADAM2 or anti-JLP. Only the anti-PH-20 IMBs succeeded in isolating sperm from cell mixtures at a sperm/epithelial cell ratio of 103:105. Further, our method exhibited greater power and better stability for sperm isolation compared to the traditional differential lysis strategy. Taken together, the anti-PH-20 IMB method described here could be effective for the isolation of sperm needed to obtain a single-sourced DNA profile as an aid to identifying the perpetrator in sexual assault cases.

  15. Sandwich immunoassay for alpha-fetoprotein in human sera using gold nanoparticle and magnetic bead labels along with resonance Rayleigh scattering readout

    International Nuclear Information System (INIS)

    Lu, Yao; Huang, Xiangyi; Ren, Jicun

    2013-01-01

    We describe a sensitive sandwich immunoassay for alpha-fetoprotein (AFP). It is making use of gold nanoparticles (GNPs) and magnetic beads (MBs) as labels, and of resonance Rayleigh scattering for detection. Two antibodies were labeled with GNPs and MBs, respectively, and MB-antigen-GNP complexes were formed in the presence of antigens. The MB labels also serve as solid phase carriers that can be used to magnetically separate the immuno complex. The GNP labels are used as optical probes, and Rayleigh scattering was used to determine the concentration of free GNPs-antibody after separation of the MB-antigen-GNP complexes. The concentration of AFP is related to the intensity of light scattered by free GNPs in the 13.6 pM to 436 pM concentration range, and the limit of detection is 13.6 pM. The method was applied to the determination of AFP in sera of cancer patients, and the results agree well with those obtained by conventional ELISA. (author)

  16. Bead magnetorelaxometry with an on-chip magnetoresistive sensor

    DEFF Research Database (Denmark)

    Dalslet, Bjarke Thomas; Damsgaard, Christian Danvad; Donolato, Marco

    2011-01-01

    Magnetorelaxometry measurements on suspensions of magnetic beads are demonstrated using a planar Hall effect sensor chip embedded in a microfluidic system. The alternating magnetic field used for magnetizing the beads is provided by the sensor bias current and the complex magnetic susceptibility...... spectra are recorded as the 2nd harmonic of the sensor response. The complex magnetic susceptibility signal appears when a magnetic bead suspension is injected, it scales with the bead concentration, and it follows the Cole-Cole expression for Brownian relaxation. The complex magnetic susceptibility...... signal resembles that from conventional magnetorelaxometry done on the same samples apart from an offset in Brownian relaxation frequency. The time dependence of the signal can be rationalized as originating from sedimented beads....

  17. Development and validation of a novel diagnostic test for human brucellosis using a glyco-engineered antigen coupled to magnetic beads.

    Directory of Open Access Journals (Sweden)

    Andrés E Ciocchini

    Full Text Available Brucellosis is a highly contagious zoonosis and still a major human health problem in endemic areas of the world. Although several diagnostic tools are available, most of them are difficult to implement especially in developing countries where complex health facilities are limited. Taking advantage of the identical structure and composition of the Brucella spp. and Yersinia enterocolitica O:9 O-polysaccharide, we explored the application of a recombinant Y. enterocolitica O:9-polysaccharide-protein conjugate (OAg-AcrA as a novel antigen for diagnosis of human brucellosis. We have developed and validated an indirect immunoassay using OAg-AcrA coupled to magnetic beads. OAg-AcrA was produced and purified with high yields in Y. enterocolitica O:9 cells co-expressing the oligosaccharyltransferase PglB and the protein acceptor AcrA of Campylobacter jejuni without the need for culturing Brucella. Expression of PglB and AcrA in Y. enterocolitica resulted in the transfer of the host O-polysaccharide from its lipid carrier to AcrA. To validate the assay and determine the cutoff values, a receiver-operating characteristic analysis was performed using a panel of characterized serum samples obtained from healthy individuals and patients of different clinical groups. Our results indicate that, using this assay, it is possible to detect infection caused by the three main human brucellosis agents (B. abortus, B. melitensis and B. suis and select different cutoff points to adjust sensitivity and specificity levels as needed. A cutoff value of 13.20% gave a sensitivity of 100% and a specificity of 98.57%, and a cutoff value of 16.15% resulted in a test sensitivity and specificity of 93.48% and 100%, respectively. The high diagnostic accuracy, low cost, reduced assay time and simplicity of this new glycoconjugate-magnetic beads assay makes it an attractive diagnostic tool for using not only in clinics and brucellosis reference laboratories but also in locations

  18. Development and Validation of a Novel Diagnostic Test for Human Brucellosis Using a Glyco-engineered Antigen Coupled to Magnetic Beads

    Science.gov (United States)

    Ciocchini, Andrés E.; Rey Serantes, Diego A.; Melli, Luciano J.; Iwashkiw, Jeremy A.; Deodato, Bettina; Wallach, Jorge; Feldman, Mario F.; Ugalde, Juan E.; Comerci, Diego J.

    2013-01-01

    Brucellosis is a highly contagious zoonosis and still a major human health problem in endemic areas of the world. Although several diagnostic tools are available, most of them are difficult to implement especially in developing countries where complex health facilities are limited. Taking advantage of the identical structure and composition of the Brucella spp. and Yersinia enterocolitica O:9 O-polysaccharide, we explored the application of a recombinant Y. enterocolitica O:9-polysaccharide-protein conjugate (OAg-AcrA) as a novel antigen for diagnosis of human brucellosis. We have developed and validated an indirect immunoassay using OAg-AcrA coupled to magnetic beads. OAg-AcrA was produced and purified with high yields in Y. enterocolitica O:9 cells co-expressing the oligosaccharyltransferase PglB and the protein acceptor AcrA of Campylobacter jejuni without the need for culturing Brucella. Expression of PglB and AcrA in Y. enterocolitica resulted in the transfer of the host O-polysaccharide from its lipid carrier to AcrA. To validate the assay and determine the cutoff values, a receiver-operating characteristic analysis was performed using a panel of characterized serum samples obtained from healthy individuals and patients of different clinical groups. Our results indicate that, using this assay, it is possible to detect infection caused by the three main human brucellosis agents (B. abortus, B. melitensis and B. suis) and select different cutoff points to adjust sensitivity and specificity levels as needed. A cutoff value of 13.20% gave a sensitivity of 100% and a specificity of 98.57%, and a cutoff value of 16.15% resulted in a test sensitivity and specificity of 93.48% and 100%, respectively. The high diagnostic accuracy, low cost, reduced assay time and simplicity of this new glycoconjugate-magnetic beads assay makes it an attractive diagnostic tool for using not only in clinics and brucellosis reference laboratories but also in locations with limited

  19. Dual Recognition Strategy for Specific and Sensitive Detection of Bacteria Using Aptamer-Coated Magnetic Beads and Antibiotic-Capped Gold Nanoclusters.

    Science.gov (United States)

    Cheng, Dan; Yu, Mengqun; Fu, Fei; Han, Weiye; Li, Gan; Xie, Jianping; Song, Yang; Swihart, Mark T; Song, Erqun

    2016-01-05

    Food poisoning and infectious diseases caused by pathogenic bacteria such as Staphylococcus aureus (SA) are serious public health concerns. A method of specific, sensitive, and rapid detection of such bacteria is essential and important. This study presents a strategy that combines aptamer and antibiotic-based dual recognition units with magnetic enrichment and fluorescent detection to achieve specific and sensitive quantification of SA in authentic specimens and in the presence of much higher concentrations of other bacteria. Aptamer-coated magnetic beads (Apt-MB) were employed for specific capture of SA. Vancomycin-stabilized fluorescent gold nanoclusters (AuNCs@Van) were prepared by a simple one-step process and used for sensitive quantification of SA in the range of 32-10(8) cfu/mL with the detection limit of 16 cfu/mL via a fluorescence intensity measurement. And using this strategy, about 70 cfu/mL of SA in complex samples (containing 3 × 10(8) cfu/mL of other different contaminated bacteria) could be successfully detected. In comparison to prior studies, the developed strategy here not only simplifies the preparation procedure of the fluorescent probes (AuNCs@Van) to a great extent but also could sensitively quantify SA in the presence of much higher concentrations of other bacteria directly with good accuracy. Moreover, the aptamer and antibiotic used in this strategy are much less expensive and widely available compared to common-used antibodies, making it cost-effective. This general aptamer- and antibiotic-based dual recognition strategy, combined with magnetic enrichment and fluorescent detection of trace bacteria, shows great potential application in monitoring bacterial food contamination and infectious diseases.

  20. Development of an aptamer-based affinity purification method for vascular endothelial growth factor

    Directory of Open Access Journals (Sweden)

    Maren Lönne

    2015-12-01

    Full Text Available Since aptamers bind their targets with high affinity and specificity, they are promising alternative ligands in protein affinity purification. As aptamers are chemically synthesized oligonucleotides, they can be easily produced in large quantities regarding GMP conditions allowing their application in protein production for therapeutic purposes. Several advantages of aptamers compared to antibodies are described in general within this paper. Here, an aptamer directed against the human Vascular Endothelial Growth Factor (VEGF was used as affinity ligand for establishing a purification platform for VEGF in small scale. The aptamer was covalently immobilized on magnetic beads in a controlled orientation resulting in a functional active affinity matrix. Target binding was optimized by introduction of spacer molecules and variation of aptamer density. Further, salt-induced target elution was demonstrated as well as VEGF purification from a complex protein mixture proving the specificity of protein-aptamer binding.

  1. Magnetic bionanoparticles of Penicillium sp. yz11-22N2 doped with Fe3O4 and encapsulated within PVA-SA gel beads for atrazine removal.

    Science.gov (United States)

    Yu, Jiaping; He, Huijun; Yang, William L; Yang, Chunping; Zeng, Guangming; Wu, Xin

    2018-07-01

    A novel magnetic bionanomaterial, Penicillium sp. yz11-22N2 doped with nano Fe 3 O 4 entrapped in polyvinyl alcohol-sodium alginate gel beads (PFEPS), was successfully synthesized. The factors including nutrient substance, temperature, pH, initial concentrations of atrazine and rotational speeds were presented and discussed in detail. Results showed that the highest removal efficiency of atrazine by PFEPS was 91.2% at 8.00 mg/L atrazine. The maximum removal capacity for atrazine was 7.94 mg/g. Meanwhile, it has been found that most of atrazine were removed by metabolism and degradation of Penicillium sp. yz11-22N2, which could use atrazine as the sole source of either carbon or nitrogen. Degradation kinetics of atrazine conformed to first-order kinetics model. The intermediates indicated that the possible pathway for atrazine degradation by PFEPS mainly included hydrolysis dechlorination, dealkylation, side-chain oxidation and ring-opening. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Electrochemical enzyme sensor arrays for the detection of the biogenic amines histamine, putrescine and cadaverine using magnetic beads as immobilisation supports

    International Nuclear Information System (INIS)

    Leonardo, Sandra; Campàs, Mònica

    2016-01-01

    Electrochemical biosensors based on diamine oxidase (DAO) conjugated to magnetic beads (MBs) were developed for the detection of histamine (Hist), putrescine (Put) and cadaverine (Cad), the most relevant biogenic amines (BAs) related to food safety and quality. DAO-MBs were immobilised on Co(II)-phthalocyanine/carbon and Prussian Blue/carbon electrodes to obtain mono-enzymatic biosensors, and on Os-wired HRP-modified carbon electrodes to obtain bi-enzymatic biosensors. The three sensor have low working potentials (+0.4 V, −0.1 V and −0.05 V vs Ag/AgCl, respectively), a linear range of two orders of magnitude (from 0.01 to 1 mM BA), good reproducibility (variability lower than 10 %), high repeatability (up to 8 consecutive measurements), limits of detection in the µM concentration range for Hist and in the sub-µM concentration range for Put and Cad, and no response from possible interfering compounds. The DAO-MB conjugates display excellent long-term stability (at least 3 months). The biosensor has been applied to the determination of BAs in spiked and naturally-spoiled fish, demonstrating its suitability both as screening tool and for BAs quantification. The use of MBs as supports for enzyme immobilisation is advantageous because the resulting biosensors are simple, fast, stable, affordable, and can be integrated into array platforms. This makes them suitable for high-throughput analysis of BAs in the food industry. (author)

  3. Glyco-centric lectin magnetic bead array (LeMBA − proteomics dataset of human serum samples from healthy, Barrett׳s esophagus and esophageal adenocarcinoma individuals

    Directory of Open Access Journals (Sweden)

    Alok K. Shah

    2016-06-01

    Full Text Available This data article describes serum glycoprotein biomarker discovery and qualification datasets generated using lectin magnetic bead array (LeMBA – mass spectrometry techniques, “Serum glycoprotein biomarker discovery and qualification pipeline reveals novel diagnostic biomarker candidates for esophageal adenocarcinoma” [1]. Serum samples collected from healthy, metaplastic Barrett׳s esophagus (BE and esophageal adenocarcinoma (EAC individuals were profiled for glycoprotein subsets via differential lectin binding. The biomarker discovery proteomics dataset consisting of 20 individual lectin pull-downs for 29 serum samples with a spiked-in internal standard chicken ovalbumin protein has been deposited in the PRIDE partner repository of the ProteomeXchange Consortium with the data set identifier PRIDE: http://www.ebi.ac.uk/pride/archive/projects/PXD002442. Annotated MS/MS spectra for the peptide identifications can be viewed using MS-Viewer (〈http://prospector2.ucsf.edu/prospector/cgi-bin/msform.cgi?form=msviewer〉 using search key “jn7qafftux”. The qualification dataset contained 6-lectin pulldown-coupled multiple reaction monitoring-mass spectrometry (MRM-MS data for 41 protein candidates, from 60 serum samples. This dataset is available as a supplemental files with the original publication [1].

  4. Development and characterization of a magnetic bead-quantum dot nanoparticles based assay capable of Escherichia coli O157:H7 quantification

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gha-Young [Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States); Son, Ahjeong, E-mail: ason@auburn.edu [Department of Civil Engineering, Auburn University, Auburn, AL 36849 (United States)

    2010-09-10

    The development and characterization of a magnetic bead (MB)-quantum dot (QD) nanoparticles based assay capable of quantifying pathogenic bacteria is presented here. The MB-QD assay operates by having a capturing probe DNA selectively linked to the signaling probe DNA via the target genomic DNA (gDNA) during DNA hybridization. The signaling probe DNA is labeled with fluorescent QD{sub 565} which serves as a reporter. The capturing probe DNA is conjugated simultaneously to a MB and another QD{sub 655}, which serve as a carrier and an internal standard, respectively. Successfully captured target gDNA is separated using a magnetic field and is quantified via a spectrofluorometer. The use of QDs (i.e., QD{sub 565}/QD{sub 655}) as both a fluorescence label and an internal standard increased the sensitivity of the assay. The passivation effect and the molar ratio between QD and DNA were optimized. The MB-QD assay demonstrated a detection limit of 890 zeptomolar (i.e., 10{sup -21} mol L{sup -1}) concentration for the linear single stranded DNA (ssDNA). It also demonstrated a detection limit of 87 gene copies for double stranded DNA (dsDNA) eaeA gene extracted from pure Escherichia coli (E. coli) O157:H7 culture. Its corresponding dynamic range, sensitivity, and selectivity were also presented. Finally, the bacterial gDNA of E. coli O157:H7 was used to highlight the MB-QD assay's ability to detect below the minimum infective dose (i.e., 100 organisms) of E. coli O157:H7 in water environment.

  5. Magnetic beads-based DNAzyme recognition and AuNPs-based enzymatic catalysis amplification for visual detection of trace uranyl ion in aqueous environment.

    Science.gov (United States)

    Zhang, Hongyan; Lin, Ling; Zeng, Xiaoxue; Ruan, Yajuan; Wu, Yongning; Lin, Minggui; He, Ye; Fu, FengFu

    2016-04-15

    We herein developed a novel biosensor for the visual detection of trace uranyl ion (UO2(2+)) in aqueous environment with high sensitivity and specificity by using DNAzyme-functionalized magnetic beads (MBs) for UO2(2+) recognition and gold nano-particles (AuNPs)-based enzymatic catalysis oxidation of TMB (3,3',5,5'-tetramethylbenzidine sulfate) for signal generation. The utilization of MBs facilitates the magnetic separation and collection of sensing system from complex sample solution, which leads to more convenient experimental operation and more strong resistibility of the biosensor to the matrix of sample, and the utilization of AuNPs-based enzymatic catalysis amplification greatly improved the sensitivity of the biosensor. Compared with the previous DNAzyme-based UO2(2+) sensors, the proposed biosensor has outstanding advantages such as relative high sensitivity and specificity, operation convenience, low cost and more strong resistibility to the matrix of sample. It can be used to detect as low as 0.02 ppb (74 pM) of UO2(2+) in aqueous environment by only naked-eye observation and 1.89 ppt (7.0 pM) of UO2(2+) by UV-visible spectrophotometer with a recovery of 93-99% and a RSD ≤ 5.0% (n=6) within 3h. Especially, the visual detection limit of 0.02 ppb (74 pM) is much lower than the maximum allowable level of UO2(2+) (130 nM) in the drinking water defined by the U.S. Environmental Protection Agency (EPA), indicating that our method meets the requirement of rapid and on-site detection of UO2(2+) in the aqueous environment by only naked-eye observation. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. PCR and magnetic bead-mediated target capture for the isolation of short interspersed nucleotide elements in fishes.

    Science.gov (United States)

    Liu, Dong; Zhu, Guoli; Tang, Wenqiao; Yang, Jinquan; Guo, Hongyi

    2012-01-01

    Short interspersed nucleotide elements (SINEs), a type of retrotransposon, are widely distributed in various genomes with multiple copies arranged in different orientations, and cause changes to genes and genomes during evolutionary history. This can provide the basis for determining genome diversity, genetic variation and molecular phylogeny, etc. SINE DNA is transcribed into RNA by polymerase III from an internal promoter, which is composed of two conserved boxes, box A and box B. Here we present an approach to isolate novel SINEs based on these promoter elements. Box A of a SINE is obtained via PCR with only one primer identical to box B (B-PCR). Box B and its downstream sequence are acquired by PCR with one primer corresponding to box A (A-PCR). The SINE clone produced by A-PCR is selected as a template to label a probe with biotin. The full-length SINEs are isolated from the genomic pool through complex capture using the biotinylated probe bound to magnetic particles. Using this approach, a novel SINE family, Cn-SINE, from the genomes of Coilia nasus, was isolated. The members are 180-360 bp long. Sequence homology suggests that Cn-SINEs evolved from a leucine tRNA gene. This is the first report of a tRNA(Leu)-related SINE obtained without the use of a genomic library or inverse PCR. These results provide new insights into the origin of SINEs.

  7. PCR and Magnetic Bead-Mediated Target Capture for the Isolation of Short Interspersed Nucleotide Elements in Fishes

    Directory of Open Access Journals (Sweden)

    Dong Liu

    2012-02-01

    Full Text Available Short interspersed nucleotide elements (SINEs, a type of retrotransposon, are widely distributed in various genomes with multiple copies arranged in different orientations, and cause changes to genes and genomes during evolutionary history. This can provide the basis for determining genome diversity, genetic variation and molecular phylogeny, etc. SINE DNA is transcribed into RNA by polymerase III from an internal promoter, which is composed of two conserved boxes, box A and box B. Here we present an approach to isolate novel SINEs based on these promoter elements. Box A of a SINE is obtained via PCR with only one primer identical to box B (B-PCR. Box B and its downstream sequence are acquired by PCR with one primer corresponding to box A (A-PCR. The SINE clone produced by A-PCR is selected as a template to label a probe with biotin. The full-length SINEs are isolated from the genomic pool through complex capture using the biotinylated probe bound to magnetic particles. Using this approach, a novel SINE family, Cn-SINE, from the genomes of Coilia nasus, was isolated. The members are 180–360 bp long. Sequence homology suggests that Cn-SINEs evolved from a leucine tRNA gene. This is the first report of a tRNALeu-related SINE obtained without the use of a genomic library or inverse PCR. These results provide new insights into the origin of SINEs.

  8. Magnetic separation: its application in mining, waste purification, medicine, biochemistry and chemistry.

    Science.gov (United States)

    Iranmanesh, M; Hulliger, J

    2017-10-02

    The use of strong magnetic field gradients and high magnetic fields generated by permanent magnets or superconducting coils has found applications in many fields such as mining, solid state chemistry, biochemistry and medical research. Lab scale or industrial implementations involve separation of macro- and nanoparticles, cells, proteins, and macromolecules down to small molecules and ions. Most promising are those attempts where the object to be separated is attached to a strong magnetic nanoparticle. Here, all kinds of specific affinity interactions are used to attach magnetic carrier particles to mainly objects of biological interest. Other attempts use a strong paramagnetic suspension for the separation of purely diamagnetic objects, such as bio-macromolecules or heavy metals. The application of magnetic separation to superconducting inorganic phases is of particular interest in combination with ceramic combinatorial chemistry to generate a library of e.g. cuprate superconductors.

  9. Immuno-magnetic beads-based extraction-capillary zone electrophoresis-deep UV laser-induced fluorescence analysis of erythropoietin.

    Science.gov (United States)

    Wang, Heye; Dou, Peng; Lü, Chenchen; Liu, Zhen

    2012-07-13

    Erythropoietin (EPO) is an important glycoprotein hormone. Recombinant human EPO (rhEPO) is an important therapeutic drug and can be also used as doping reagent in sports. The analysis of EPO glycoforms in pharmaceutical and sports areas greatly challenges analytical scientists from several aspects, among which sensitive detection and effective and facile sample preparation are two essential issues. Herein, we investigated new possibilities for these two aspects. Deep UV laser-induced fluorescence detection (deep UV-LIF) was established to detect the intrinsic fluorescence of EPO while an immuno-magnetic beads-based extraction (IMBE) was developed to specifically extract EPO glycoforms. Combined with capillary zone electrophoresis (CZE), CZE-deep UV-LIF allows high resolution glycoform profiling with improved sensitivity. The detection sensitivity was improved by one order of magnitude as compared with UV absorbance detection. An additional advantage is that the original glycoform distribution can be completely preserved because no fluorescent labeling is needed. By combining IMBE with CZE-deep UV-LIF, the overall detection sensitivity was 1.5 × 10⁻⁸ mol/L, which was enhanced by two orders of magnitude relative to conventional CZE with UV absorbance detection. It is applicable to the analysis of pharmaceutical preparations of EPO, but the sensitivity is insufficient for the anti-doping analysis of EPO in blood and urine. IMBE can be straightforward and effective approach for sample preparation. However, antibodies with high specificity were the key for application to urine samples because some urinary proteins can severely interfere the immuno-extraction. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. A String of Beads

    Science.gov (United States)

    Mead, Kelly C.

    2006-01-01

    In this article, the author relates how she designed a math activity she called Beads to use in conjunction with their school's 100th day celebration. Beads has provided her kindergarten class with many opportunities to practice a variety of math skills - counting, patterning, sorting, comparing, making sets, predicting, identifying numerals,…

  11. Weak cation exchange magnetic beads coupled with matrix-assisted laser desorption ionization-time of flight-mass spectrometry in screening serum protein markers in osteopenia.

    Science.gov (United States)

    He, Wei-Tao; Liang, Bo-Cheng; Shi, Zhen-Yu; Li, Xu-Yun; Li, Chun-Wen; Shi, Xiao-Lin

    2016-01-01

    The present study aimed at investigating the weak cation magnetic separation technology and matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) in screening serum protein markers of osteopenia from ten postmenopausal women and ten postmenopausal women without osteopenia as control group, to find a new method for screening biomarkers and establishing a diagnostic model for primary type I osteoporosis. Serum samples were collected from postmenopausal women with osteopenia and postmenopausal women with normal bone mass. Proteins were extracted from serum samples by weak cation exchange magnetic beads technology, and mass spectra acquisition was done by MALDI-TOF-MS. The visualization and comparison of data sets, statistical peak evaluation, model recognition, and discovery of biomarker candidates were handled by the proteinchip data analysis system software(ZJU-PDAS). The diagnostic models were established using genetic arithmetic based support vector machine (SVM). The SVM result with the highest Youden Index was selected as the model. Combinatorial Peaks having the highest accuracy in distinguishing different samples were selected as potential biomarker. From the two group serum samples, a total of 133 differential features were selected. Ten features with significant intensity differences were screened. In the pair-wise comparisons, processing of MALDI-TOF spectra resulted in the identification of ten differential features between postmenopausal women with osteopenia and postmenopausal women with normal bone mass. The difference of features by Youden index showed that the highest features had a mass to charge ratio of 1699 and 3038 Da. A diagnosis model was established with these two peaks as the candidate marker, and the specificity of the model is 100 %, the sensitivity was 90 % by leave-one-out cross validation test. The two groups of specimens in SVM results on the scatter plot could be clearly distinguished. The peak

  12. Magnetic biosensor system to detect biological targets

    KAUST Repository

    Li, Fuquan; Gooneratne, Chinthaka Pasan; Kosel, Jü rgen

    2012-01-01

    magnetic concentration, magnetic as well as mechanical trapping and magnetic sensing. Target detection is based on the size difference between bare magnetic beads and magnetic beads with targets attached. This method remedies the need for a coating layer

  13. Magnetic cell sorting purification of differentiated embryonic stem cells stably expressing truncated human CD4 as surface marker.

    Science.gov (United States)

    David, Robert; Groebner, Michael; Franz, Wolfgang-Michael

    2005-04-01

    Embryonic stem (ES) cells offer great potential in regenerative medicine and tissue engineering. Clinical applications are still hampered by the lack of protocols for gentle, high-yield isolation of specific cell types for transplantation expressing no immunogenic markers. We describe labeling of stably transfected ES cells expressing a human CD4 molecule lacking its intracellular domain (DeltaCD4) under control of the phosphoglycerate kinase promoter for magnetic cell sorting (MACS). To track the labeled ES cells, we fused DeltaCD4 to an intracellular enhanced green fluorescent protein domain (DeltaCD4EGFP). We showed functionality of the membrane-bound fluorescent fusion protein and its suitability for MACS leading to purities greater than 97%. Likewise, expression of DeltaCD4 yielded up to 98.5% positive cells independently of their differentiation state. Purities were not limited by the initial percentage of DeltaCD4(+) cells, ranging from 0.6%-16%. The viability of MACS-selected cells was demonstrated by reaggregation and de novo formation of embryoid bodies developing all three germ layers. Thus, expression of DeltaCD4 in differentiated ES cells may enable rapid, high-yield purification of a desired cell type for tissue engineering and transplantation studies.

  14. Single-step affinity purification for fungal proteomics.

    Science.gov (United States)

    Liu, Hui-Lin; Osmani, Aysha H; Ukil, Leena; Son, Sunghun; Markossian, Sarine; Shen, Kuo-Fang; Govindaraghavan, Meera; Varadaraj, Archana; Hashmi, Shahr B; De Souza, Colin P; Osmani, Stephen A

    2010-05-01

    A single-step protein affinity purification protocol using Aspergillus nidulans is described. Detailed protocols for cell breakage, affinity purification, and depending on the application, methods for protein release from affinity beads are provided. Examples defining the utility of the approaches, which should be widely applicable, are included.

  15. Single-Step Affinity Purification for Fungal Proteomics ▿ †

    OpenAIRE

    Liu, Hui-Lin; Osmani, Aysha H.; Ukil, Leena; Son, Sunghun; Markossian, Sarine; Shen, Kuo-Fang; Govindaraghavan, Meera; Varadaraj, Archana; Hashmi, Shahr B.; De Souza, Colin P.; Osmani, Stephen A.

    2010-01-01

    A single-step protein affinity purification protocol using Aspergillus nidulans is described. Detailed protocols for cell breakage, affinity purification, and depending on the application, methods for protein release from affinity beads are provided. Examples defining the utility of the approaches, which should be widely applicable, are included.

  16. Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads

    DEFF Research Database (Denmark)

    Uddin, Rokon; Burger, Robert; Donolato, Marco

    2016-01-01

    30 s) using the two differently sized beads for the two detection methods. In both cases a sample volume of only 10 μl is required. The demonstrated automation, low sample-to-answer time and portability of both detection instruments as well as integration of the assay on a low-cost disc are important...

  17. In-bead screening

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to screening of one-bead-one-compound (OBOC) combinatorial libraries which is useful for the discovery of compounds displaying molecular interactions with a biological or a physicochemical system, such as substrates and inhibitors of enzymes and the like. The invention...... provides a method for screening a library of compounds for their interaction with a physico- chemical or biological system and a corresponding kit for performing the method of screening a one-bead-one-compound library of compounds....

  18. Effect of algal density in bead, bead size and bead concentrations ...

    African Journals Online (AJOL)

    Laboratory experiments were performed to study nitrogen and phosphorus uptake by the unicellular green microalga Chlorella vulgaris immobilized in calcium alginate beads. Different cell stockings in beads, different bead sizes and different algal bead concentrations in wastewaters were tested. Significant higher nutrients ...

  19. Ferrite bead effect on Class-D amplifier audio quality

    OpenAIRE

    Haddad , Kevin El; Mrad , Roberto; Morel , Florent; Pillonnet , Gael; Vollaire , Christian; Nagari , Angelo

    2014-01-01

    International audience; This paper studies the effect of ferrite beads on the audio quality of Class-D audio amplifiers. This latter is a switch-ing circuit which creates high frequency harmonics. Generally, a filter is used at the amplifier output for the sake of electro-magnetic compatibility (EMC). So often, in integrated solutions, this filter contains ferrite beads which are magnetic components and present nonlinear behavior. Time domain measurements and their equivalence in frequency do...

  20. Hydrodynamic Torques and Rotations of Superparamagnetic Bead Dimers

    Science.gov (United States)

    Pease, Christopher; Etheridge, J.; Wijesinghe, H. S.; Pierce, C. J.; Prikockis, M. V.; Sooryakumar, R.

    Chains of micro-magnetic particles are often rotated with external magnetic fields for many lab-on-a-chip technologies such as transporting beads or mixing fluids. These applications benefit from faster responses of the actuated particles. In a rotating magnetic field, the magnetization of superparamagnetic beads, created from embedded magnetic nano-particles within a polymer matrix, is largely characterized by induced dipoles mip along the direction of the field. In addition there is often a weak dipole mop that orients out-of-phase with the external rotating field. On a two-bead dimer, the simplest chain of beads, mop contributes a torque Γm in addition to the torque from mip. For dimers with beads unbound to each other, mop rotates individual beads which generate an additional hydrodynamic torque on the dimer. Whereas, mop directly torques bound dimers. Our results show that Γm significantly alters the average frequency-dependent dimer rotation rate for both bound and unbound monomers and, when mop exceeds a critical value, increases the maximum dimer rotation frequency. Models that include magnetic and hydrodynamics torques provide good agreement with the experimental findings over a range of field frequencies.

  1. Antimicrobial peptide from mucus of Andrias davidianus: screening and purification by magnetic cell membrane separation technique.

    Science.gov (United States)

    Pei, Jinjin; Jiang, Lei

    2017-07-01

    Andrias davidianus, the Chinese giant salamander, has been used in traditional Chinese medicine for many decades. However, no antimicrobial peptides (AMPs) have been described from A. davidianus until now. Here we describe a novel AMP (andricin 01) isolated from the mucus of A. davidianus. The peptide was recovered using an innovative magnetic cell membrane separation technique and was characterised using mass spectrometry and circular dichroism (CD) spectroscopy. Andricin 01 is comprised of ten amino acid residues with a total molecular mass of 955.1 Da. CD spectrum analysis gave results similar to the archetypal random coil spectrum, consistent with the three-dimensional rendering calculated by current bioinformatics tools. Andricin 01 was found to be inhibitory both to Gram-negative and Gram-positive bacteria. Furthermore, the peptide at the minimal bacterial concentration did not show cell cytotoxicity against human hepatocytes or renal cells and did not show haemolytic activity against red blood cells, indicating that is potentially safe and effective for human use. Andricin 01 shows promise as a novel antibacterial that may provide an insight into the development of new drugs. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  2. Sangadzhi Kononov, Buddhist Prayer Beads

    OpenAIRE

    Churyumov, Anton; Kovaeva, Bair

    2016-01-01

    Prayer beads have special dividers that divide the beads into 7, 21 and 33. Apart from using in prayers, the Kalmyks also keep beads as amulets that are believed to have strong energy. After prayers, old people often bless their children and grandchildren with their beads. Such beads are also kept in families from one generation to the next. Sangadzhi believes that prayer beads store inside them the energy of mantras that have been read with them. There is an interesting story about the pray...

  3. Half bead welding technique

    International Nuclear Information System (INIS)

    Canonico, D.A.; Holz, P.P.

    1978-05-01

    The ORNL has employed the Section XI half-bead procedure for six repair welds. Table 2 identifies the repairs and the components upon which they were accomplished. The weld repairs were performed to permit us to evaluate material properties, residual stresses, weld repair procedures, and structural behavior of repaired pressure vessels. As a consequence of our study we concluded that when the half bead procedure is correctly applied: (1) there is no metallurgical degradation of the base material, (2) residual stresses of yield point magnitude will be present, and (3) the structural integrity of the pressure vessel is not impaired at Charpy V-notch upper shelf temperatures

  4. Glass bead cultivation of fungi

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, H.

    2013-01-01

    Production of bioactive compounds and enzymes from filamentous fungi is highly dependent on cultivation conditions. Here we present an easy way to cultivate filamentous fungi on glass beads that allow complete control of nutrient supply. Secondary metabolite production in Fusarium graminearum...... and Fusarium solani cultivated on agar plates, in shaking liquid culture or on glass beads was compared. Agar plate culture and glass bead cultivation yielded comparable results while liquid culture had lower production of secondary metabolites. RNA extraction from glass beads and liquid cultures was easier...... to specific nutrient factors. •Fungal growth on glass beads eases and improves fungal RNA extraction....

  5. Comparative analysis of environmental DNA extraction and purification methods from different humic acid rich soils

    CSIR Research Space (South Africa)

    Lakay, FM

    2007-01-01

    Full Text Available Three different soil DNA isolation and four purification strategies were compared on different soil samples with variable rates of success. Bead beating extraction gave significantly higher DNA yields than microwave-based and liquid nitrogen...

  6. Coated Aerogel Beads

    Science.gov (United States)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2014-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  7. Simulation of non-linear coaxial line using ferrite beads

    International Nuclear Information System (INIS)

    Furuya, S.; Matsumoto, H.; Tachi, K.; Takano, S.; Irisawa, J.

    2002-01-01

    A ferrite sharpener is a non-linear coaxial line using ferrite beads, which produces high-voltage, high-dV/dt pulses. We have been examining the characteristics of ferrite sharpeners experimentally, varying various parameters. Also we have made the simulation of the ferrite sharpener and compared the predictions with the experimental results in detail to analyze the characteristics of the sharpener. In this report, calculating the magnetization M of the ferrite bead, we divide the bead into n sections radially instead of adopting M at the average radius in the previous report. (author)

  8. Fabrication of micromagnetic beads with molecular recognition/electron-transfer peptides for the sensing of ovalbumin

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, Kazuharu, E-mail: kzsuga@maebashi-it.ac.jp [Maebashi Institute of Technology, Gunma, 371-0816 (Japan); Kuramitz, Hideki [Department of Environmental Biology and Chemistry, Graduate School of Science and Engineering for Research, University of Toyama, Toyama, 930-8555 (Japan); Shinohara, Hiroki [Maebashi Institute of Technology, Gunma, 371-0816 (Japan)

    2017-03-15

    Electrochemical sensing of ovalbumin (OVA) was performed using magnetic beads with OVA recognition (RNRCKGTDVQAW)/electron-transfer (YYYYC) peptides. The focus of this study was to construct a highly sensitive and regenerative tool for OVA detection based on the interaction between a protein and peptide-1(RNRCKGTDVQAWYYYYC). The peptide-1 was introduced to the bead through four types of cross-linking reagents. Magnetic beads of different sizes with N-(6-maleimidocaproyloxy)sulfosuccinimide (Sulfo-EMCS) were also prepared. An oxidation peak due to tyrosine residues at 0.65 V depended on the distance of the electron-transfer peptide from the bead surface and on the surface area of the magnetic beads that contacted the electrode surface. The response of the electro-transfer peptide moiety was decreased because the protein was accumulated via the recognition peptide on the beads. When using Sulfo-EMCS and beads that were 6.0–6.9 μm in diameter, the calibration curve of OVA was linear and ranged from 8.0 × 10{sup −13} to 2.0 × 10{sup −11} M. To regenerate the magnetic beads, the measurements were achieved after removal of the OVA using a denaturing reagent. When OVA was added to fetal bovine serum containing a complex matrix, OVA was recovered at a rate of 98–100%. Consequently, these magnetic beads could be a powerful tool for the sensing of OVA in real samples. - Highlights: • Ovalbumin recognition/electron-transfer peptides were immobilized on magnetic beads. • The accumulation of the protein through the peptides on the beads caused the change of electrode response. • The magnetic beads could be reused for sensing of ovalbumin.

  9. A simple method to recover Norovirus from fresh produce with large sample size by using histo-blood group antigen-conjugated to magnetic beads in a recirculating affinity magnetic separation system (RCAMS).

    Science.gov (United States)

    Tian, Peng; Yang, David; Mandrell, Robert

    2011-06-30

    Human norovirus (NoV) outbreaks are major food safety concerns. The virus has to be concentrated from food samples in order to be detected. PEG precipitation is the most common method to recover the virus. Recently, histo-blood group antigens (HBGA) have been recognized as receptors for human NoV, and have been utilized as an alternative method to concentrate human NoV for samples up to 40 mL in volume. However, to wash off the virus from contaminated fresh food samples, at least 250 mL of wash volume is required. Recirculating affinity magnetic separation system (RCAMS) has been tried by others to concentrate human NoV from large-volume samples and failed to yield consistent results with the standard procedure of 30 min of recirculation at the default flow rate. Our work here demonstrates that proper recirculation time and flow rate are key factors for success in using the RCAMS. The bead recovery rate was increased from 28% to 47%, 67% and 90% when recirculation times were extended from 30 min to 60 min, 120 min and 180 min, respectively. The kinetics study suggests that at least 120 min recirculation is required to obtain a good recovery of NoV. In addition, different binding and elution conditions were compared for releasing NoV from inoculated lettuce. Phosphate-buffered saline (PBS) and water results in similar efficacy for virus release, but the released virus does not bind to RCAMS effectively unless pH was adjusted to acidic. Either citrate-buffered saline (CBS) wash, or water wash followed by CBS adjustment, resulted in an enhanced recovery of virus. We also demonstrated that the standard curve generated from viral RNA extracted from serially-diluted virus samples is more accurate for quantitative analysis than standard curves generated from serially-diluted plasmid DNA or transcribed-RNA templates, both of which tend to overestimate the concentration power. The efficacy of recovery of NoV from produce using RCAMS was directly compared with that of the

  10. Lab-on-a-disc agglutination assay for protein detection by optomagnetic readout and optical imaging using nano- and micro-sized magnetic beads

    DEFF Research Database (Denmark)

    Uddin, Rokon; Burger, Robert; Donolato, Marco

    2016-01-01

    of manual steps involved. The detection of the target protein was achieved in two ways: (1) optomagnetic readout using magnetic nanobeads (MNBs); (2) optical imaging using magnetic microbeads (MMBs). The optomagnetic readout of agglutination is based on optical measurement of the dynamics of MNB aggregates...... whereas the imaging method is based on direct visualization and quantification of the average size of MMB aggregates. By enhancing magnetic particle agglutination via application of strong magnetic field pulses, we obtained identical limits of detection of 25 pM with the same sample-to-answer time (15 min...

  11. Evaluation of magnetic- and carbon-based nano-adsorbents application in pre-purification of paclitaxel from needles of Taxus baccata

    Energy Technology Data Exchange (ETDEWEB)

    Naghavi, M. R., E-mail: mnaghavi@ut.ac.ir; Motamedi, E., E-mail: motamedi.elaheh@gmail.com; Nasiri, J., E-mail: jaber.nasiri@ut.ac.ir; Alizadeh, H., E-mail: halizade@ut.ac.ir [University of Tehran, Division of Molecular Plant Genetics, Department of Agronomy and Plant Breeding, College of Agricultural & Natural Resources (Iran, Islamic Republic of); Fattahi Moghadam, M. R., E-mail: fattahi@ut.ac.ir [University of Tehran, Department of Horticultural Sciences, College of Agricultural & Natural Resources (Iran, Islamic Republic of); Mashouf, A., E-mail: mashouf-alireza@yahoo.com [Shahid Beheshti University, Medicinal Plants and Drugs Research Institute (Iran, Islamic Republic of)

    2015-01-15

    In this investigation, the proficiency of a number of magnetic carbon-based nano-adsorbents is evaluated in pre-purification process of the crude paclitaxel extract obtained from fresh needles of yew tree (Taxus baccata L.). The effectiveness and removal ability of color and impurities from crude extracts, for three novel candidate nano-adsorbents (i.e., Fe{sub 3}O{sub 4} nanoparticles (Fe{sub 3}O{sub 4}Nps), graphite oxide (GO), and their hybrids Fe{sub 3}O{sub 4}Nps/GO) are compared with commercial graphite in three different solvents. In general, both HPLC and UV–Vis spectroscopy results demonstrate that in less polar solvent (i.e., dichloromethane), the adsorption is greatly affected by the electrostatic attractions, while in more polar solvents (i.e., acetone and ethanol) π–π electron interactions taking place between adsorbent and adsorbate are the most dominant factors in sorption. Considering decolorization efficiency, purity of taxol, recovery and reusability of adsorbents, Fe{sub 3}O{sub 4}Nps/GO (50 g/L) in dichloromethane is selected as the best medium for pre-purification of paclitaxel. Additionally, in kinetic studies the sorption equilibrium can be reached within 120 min, and the experimental data are well fitted by the pseudo-second-order model. The Langmuir sorption isotherm model correlates well with the sorption equilibrium data for the crude extract concentration (500–2,000 mg/L). Our findings display promising applications of Fe{sub 3}O{sub 4}Nps/GO, as a cost-effective nano-adsorbent, to provide a suitable vehicle toward improvement of paclitaxel pre-purification.

  12. Magnetic poly(2-hydroxyethyl methacrylate) microspheres for affinity purification of monospecific anti-p46 kDa/Myo1C antibodies for early diagnosis of multiple sclerosis patients

    Czech Academy of Sciences Publication Activity Database

    Horák, Daniel; Hlídková, Helena; Kit, Y.; Antonyuk, V.; Myronovsky, S.; Stoika, R.

    2017-01-01

    Roč. 37, č. 2 (2017), s. 1-10, č. článku BSR20160526. ISSN 0144-8463 R&D Projects: GA MŠk(CZ) LH14318 Institutional support: RVO:61389013 Keywords : poly(2-hydroxyethyl methacrylate) * magnetic microspheres * affinity purification Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 2.906, year: 2016

  13. Bead-probe complex capture a couple of SINE and LINE family from genomes of two closely related species of East Asian cyprinid directly using magnetic separation

    Science.gov (United States)

    Tong, Chaobo; Guo, Baocheng; He, Shunping

    2009-01-01

    Background Short and long interspersed elements (SINEs and LINEs, respectively), two types of retroposons, are active in shaping the architecture of genomes and powerful tools for studies of phylogeny and population biology. Here we developed special protocol to apply biotin-streptavidin bead system into isolation of interspersed repeated sequences rapidly and efficiently, in which SINEs and LINEs were captured directly from digested genomic DNA by hybridization to bead-probe complex in solution instead of traditional strategy including genomic library construction and screening. Results A new couple of SINEs and LINEs that shared an almost identical 3'tail was isolated and characterized in silver carp and bighead carp of two closely related species. These SINEs (34 members), designated HAmo SINE family, were little divergent in sequence and flanked by obvious TSD indicated that HAmo SINE was very young family. The copy numbers of this family was estimated to 2 × 105 and 1.7 × 105 per haploid genome by Real-Time qPCR, respectively. The LINEs, identified as the homologs of LINE2 in other fishes, had a conserved primary sequence and secondary structures of the 3'tail region that was almost identical to that of HAmo SINE. These evidences suggest that HAmo SINEs are active and amplified recently utilizing the enzymatic machinery for retroposition of HAmoL2 through the recognition of higher-order structures of the conserved 42-tail region. We analyzed the possible structures of HAmo SINE that lead to successful amplification in genome and then deduced that HAmo SINE, SmaI SINE and FokI SINE that were similar in sequence each other, were probably generated independently and created by LINE family within the same lineage of a LINE phylogeny in the genomes of different hosts. Conclusion The presented results show the advantage of the novel method for retroposons isolation and a pair of young SINE family and its partner LINE family in two carp fishes, which strengthened

  14. Bead-probe complex capture a couple of SINE and LINE family from genomes of two closely related species of East Asian cyprinid directly using magnetic separation

    Directory of Open Access Journals (Sweden)

    Guo Baocheng

    2009-02-01

    Full Text Available Abstract Background Short and long interspersed elements (SINEs and LINEs, respectively, two types of retroposons, are active in shaping the architecture of genomes and powerful tools for studies of phylogeny and population biology. Here we developed special protocol to apply biotin-streptavidin bead system into isolation of interspersed repeated sequences rapidly and efficiently, in which SINEs and LINEs were captured directly from digested genomic DNA by hybridization to bead-probe complex in solution instead of traditional strategy including genomic library construction and screening. Results A new couple of SINEs and LINEs that shared an almost identical 3'tail was isolated and characterized in silver carp and bighead carp of two closely related species. These SINEs (34 members, designated HAmo SINE family, were little divergent in sequence and flanked by obvious TSD indicated that HAmo SINE was very young family. The copy numbers of this family was estimated to 2 × 105 and 1.7 × 105 per haploid genome by Real-Time qPCR, respectively. The LINEs, identified as the homologs of LINE2 in other fishes, had a conserved primary sequence and secondary structures of the 3'tail region that was almost identical to that of HAmo SINE. These evidences suggest that HAmo SINEs are active and amplified recently utilizing the enzymatic machinery for retroposition of HAmoL2 through the recognition of higher-order structures of the conserved 42-tail region. We analyzed the possible structures of HAmo SINE that lead to successful amplification in genome and then deduced that HAmo SINE, SmaI SINE and FokI SINE that were similar in sequence each other, were probably generated independently and created by LINE family within the same lineage of a LINE phylogeny in the genomes of different hosts. Conclusion The presented results show the advantage of the novel method for retroposons isolation and a pair of young SINE family and its partner LINE family in two carp

  15. Magnetic Beads Enhance Adhesion of NIH 3T3 Fibroblasts: A Proof-of-Principle In Vitro Study for Implant-Mediated Long-Term Drug Delivery to the Inner Ear.

    Science.gov (United States)

    Aliuos, Pooyan; Schulze, Jennifer; Schomaker, Markus; Reuter, Günter; Stolle, Stefan R O; Werner, Darja; Ripken, Tammo; Lenarz, Thomas; Warnecke, Athanasia

    2016-01-01

    Long-term drug delivery to the inner ear may be achieved by functionalizing cochlear implant (CI) electrodes with cells providing neuroprotective factors. However, effective strategies in order to coat implant surfaces with cells need to be developed. Our vision is to make benefit of electromagnetic field attracting forces generated by CI electrodes to bind BDNF-secreting cells that are labelled with magnetic beads (MB) onto the electrode surfaces. Thus, the effect of MB-labelling on cell viability and BDNF production were investigated. Murine NIH 3T3 fibroblasts-genetically modified to produce BDNF-were labelled with MB. Atomic force and bright field microscopy illustrated the internalization of MB by fibroblasts after 24 h of cultivation. Labelling cells with MB did not expose cytotoxic effects on fibroblasts and allowed adhesion on magnetic surfaces with sufficient BDNF release. Our data demonstrate a novel approach for mediating enhanced long-term adhesion of BDNF-secreting fibroblasts on model electrode surfaces for cell-based drug delivery applications in vitro and in vivo. This therapeutic strategy, once transferred to cells suitable for clinical application, may allow the biological modifications of CI surfaces with cells releasing neurotrophic or other factors of interest.

  16. Magnetic Beads Enhance Adhesion of NIH 3T3 Fibroblasts: A Proof-of-Principle In Vitro Study for Implant-Mediated Long-Term Drug Delivery to the Inner Ear.

    Directory of Open Access Journals (Sweden)

    Pooyan Aliuos

    Full Text Available Long-term drug delivery to the inner ear may be achieved by functionalizing cochlear implant (CI electrodes with cells providing neuroprotective factors. However, effective strategies in order to coat implant surfaces with cells need to be developed. Our vision is to make benefit of electromagnetic field attracting forces generated by CI electrodes to bind BDNF-secreting cells that are labelled with magnetic beads (MB onto the electrode surfaces. Thus, the effect of MB-labelling on cell viability and BDNF production were investigated.Murine NIH 3T3 fibroblasts-genetically modified to produce BDNF-were labelled with MB.Atomic force and bright field microscopy illustrated the internalization of MB by fibroblasts after 24 h of cultivation. Labelling cells with MB did not expose cytotoxic effects on fibroblasts and allowed adhesion on magnetic surfaces with sufficient BDNF release.Our data demonstrate a novel approach for mediating enhanced long-term adhesion of BDNF-secreting fibroblasts on model electrode surfaces for cell-based drug delivery applications in vitro and in vivo. This therapeutic strategy, once transferred to cells suitable for clinical application, may allow the biological modifications of CI surfaces with cells releasing neurotrophic or other factors of interest.

  17. Necessity of purification during bacterial DNA extraction with environmental soils

    Directory of Open Access Journals (Sweden)

    Hyun Jeong Lim

    2017-08-01

    Full Text Available Complexity and heterogeneity of soil samples have often implied the inclusion of purification steps in conventional DNA extraction for polymerase chain reaction (PCR assays. Unfortunately the purification steps are also time and labor intensive. Therefore the necessity of DNA purification was re-visited and investigated for a variety of environmental soil samples that contained various amounts of PCR inhibitors. Bead beating and centrifugation was used as the baseline (without purification method for DNA extraction. Its performance was compared with that of conventional DNA extraction kit (with purification. The necessity criteria for DNA purification were established with environmental soil samples. Using lysis conditions at 3000 rpm for 3 minutes with 0.1 mm glass beads, centrifugation time of 10 minutes and 1:10 dilution ratio, the baseline method outperformed conventional DNA extraction on cell seeded sand samples. Further investigation with PCR inhibitors (i.e., humic acids, clay, and magnesium [Mg] showed that sand samples containing less than 10 μg/g humic acids and 70% clay may not require purifications. Interestingly, the inhibition pattern of Mg ion was different from other inhibitors due to the complexation interaction of Mg ion with DNA fragments. It was concluded that DNA extraction method without purification is suitable for soil samples that have less than 10 μg/g of humic acids, less than 70% clay content and less than 0.01% Mg ion content.

  18. Switchable cell trapping using superparamagnetic beads

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, M. T.; Smith, K. H.; Real, M. E.; Bashir, M. A.; Fry, P. W.; Fischer, P.; Im, M.-Y.; Schrefl, T.; Allwood, D. A.; Haycock, J. W.

    2010-04-30

    Ni{sub 81}Fe{sub 19} microwires are investigated as the basis of a switchable template for positioning magnetically-labeled neural Schwann cells. Magnetic transmission X-ray microscopy and micromagnetic modeling show that magnetic domain walls can be created or removed in zigzagged structures by an applied magnetic field. Schwann cells containing superparamagnetic beads are trapped by the field emanating from the domain walls. The design allows Schwann cells to be organized on a surface to form a connected network and then released from the surface if required. As aligned Schwann cells can guide nerve regeneration, this technique is of value for developing glial-neuronal co-culture models in the future treatment of peripheral nerve injuries.

  19. Preparation of chitosan/amino multiwalled carbon nanotubes nanocomposite beads for bilirubin adsorption in hemoperfusion.

    Science.gov (United States)

    Zong, Wenhui; Chen, Jian; Han, Wenyan; Chen, Jie; Wang, Yue; Wang, Weichao; Cheng, Guanghui; Ou, Lailiang; Yu, Yaoting

    2018-01-01

    Chitosan-carbon nanotube composite beads combines the advantages of chitosan in forming a stable biocompatible framework and carbon nanotube that provide nanometer effects (high strength and high specific surface area etc.). In this study, chitosan/amino multiwalled carbon nanotubes (CS/AMWCNT) composite beads was prepared by phase-inversion method, in which CS and AMWCNT was crosslinked by ethylene glycol diglycidyl ether (EGDE). The CS/AMWCNT nanocomposite beads produced has been characterized by BET, SEM, TGA, and Raman spectroscopy which exhibited enhanced thermal stability due to the incorporation of AMWCNT. Mechanical test results showed that mechanical strength of the CS/AMWCNT composite beads was significantly enhanced when comparing to unmodified chitosan beads, the breakage percentage decreased from 34.1% to 0.67%. The adsorption capacity for bilirubin was measured in PBS and BSA solutions, and the CS/AMWCNT composite beads with 5 wt% AMWCNT showed much higher adsorption capacity (12.7 mg/g in PBS and 7.6 mg/g in BSA) to bilirubin than chitosan beads (8.5 mg/g in PBS and 4.2 mg/g in BSA). Our nanocomposite beads with excellent hemocompatibility has a high potential application in blood purification as an efficient adsorbent for bilirubin. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 96-103, 2018. © 2016 Wiley Periodicals, Inc.

  20. bEADS

    DEFF Research Database (Denmark)

    Williams, Peter Leslie; Overholt, Daniel

    2017-01-01

    While there are a great variety of digital musical interfaces available to the working musician, few offer the level of immediate, nuanced and instinctive interaction that one finds in an acoustic shaker. bEADS is a prototype of a digital musical instrument that utilises the gestural vocabulary...... associated with shaken idiophones and expands on the techniques and sonic possibilities associated with them. By using a bespoke physically informed synthesis engine, in conjunction with accelerometer and pressure sensor data, an actuated handheld instrument has been built that allows for quickly switching...... between widely differing percussive sound textures. The prototype has been evaluated by three experts with different levels of involvement in professional music making....

  1. Super magnetic nanoparticles NiFe2O4, coated with aluminum-nickel oxide sol-gel lattices to safe, sensitive and selective purification of his-tagged proteins.

    Science.gov (United States)

    Mirahmadi-Zare, Seyede Zohreh; Allafchian, Alireza; Aboutalebi, Fatemeh; Shojaei, Pendar; Khazaie, Yahya; Dormiani, Kianoush; Lachinani, Liana; Nasr-Esfahani, Mohammad-Hossein

    2016-05-01

    Super magnetic nanoparticle NiFe2O4 with high magnetization, physical and chemical stability was introduced as a core particle which exhibits high thermal stability (>97%) during the harsh coating process. Instead of multi-stage process for coating, the magnetic nanoparticles was mineralized via one step coating by a cheap, safe, stable and recyclable alumina sol-gel lattice (from bohemite source) saturated by nickel ions. The TEM, SEM, VSM and XRD imaging and BET analysis confirmed the structural potential of NiFe2O4@NiAl2O4 core-shell magnetic nanoparticles for selective and sensitive purification of His-tagged protein, in one step. The functionality and validity of the nickel magnetic nanoparticles were attested by purification of three different bioactive His-tagged recombinant fusion proteins including hIGF-1, GM-CSF and bFGF. The bonding capacity of the nickel magnetics nanoparticles was studied by Bradford assay and was equal to 250 ± 84 μg Protein/mg MNP base on protein size. Since the metal ion leakage is the most toxicity source for purification by nickel magnetic nanoparticles, therefor the nickel leakage in purified final protein was determined by atomic absorption spectroscopy and biological activity of final purified protein was confirmed in comparison with reference. Also, in vitro cytotoxicity of nickel magnetic nanoparticles and trace metal ions were investigated by MTS assay analysis. The results confirmed that the synthesized nickel magnetic nanoparticles did not show metal ion toxicity and not affected on protein folding. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Synthesis and applications of magnetic nanoparticles for biorecognition and point of care medical diagnostics

    International Nuclear Information System (INIS)

    Sandhu, Adarsh; Handa, Hiroshi; Abe, Masanori

    2010-01-01

    Functionalized magnetic nanoparticles are important components in biorecognition and medical diagnostics. Here, we present a review of our contribution to this interdisciplinary research field. We start by describing a simple one-step process for the synthesis of highly uniform ferrite nanoparticles (d = 20-200 nm) and their functionalization with amino acids via carboxyl groups. For real-world applications, we used admicellar polymerization to produce 200 nm diameter 'FG beads', consisting of several 40 nm diameter ferrite nanoparticles encapsulated in a co-polymer of styrene and glycidyl methacrylate for high throughput molecular screening. The highly dispersive FG beads were functionalized with an ethylene glycol diglycidyl ether spacer and used for affinity purification of methotrexate-an anti-cancer agent. We synthesized sub-100 nm diameter magnetic nanocapsules by exploiting the self-assembly of viral capsid protein pentamers, where single 8, 20, and 27 nm nanoparticles were encapsulated with VP1 pentamers for applications including MRI contrast agents. The FG beads are now commercially available for use in fully automated bio-screening systems. We also incorporated europium complexes inside a polymer matrix to produce 140 nm diameter fluorescent-ferrite beads (FF beads), which emit at 618 nm. These FF beads were used for immunofluorescent staining for diagnosis of cancer metastases to lymph nodes during cancer resection surgery by labeling tumor cell epidermal growth factor receptor (EGFRs), and for the detection of brain natriuretic peptide (BNP)-a hormone secreted in excess amounts by the heart when stressed-to a level of 2.0 pg ml -1 . We also describe our work on Hall biosensors made using InSb and GaAs/InGaAs/AlGaAs 2DEG heterostructures integrated with gold current strips to reduce measurement times. Our approach for the detection of sub-200 nm magnetic bead is also described: we exploit the magnetically induced capture of micrometer sized 'probe beads

  3. Synthesis and applications of magnetic nanoparticles for biorecognition and point of care medical diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Sandhu, Adarsh [Electronics-Inspired Interdisciplinary Research Institute (EIIRIS), Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi 441-8580 (Japan); Handa, Hiroshi [Integrated Research Institute, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Abe, Masanori [Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2010-11-05

    Functionalized magnetic nanoparticles are important components in biorecognition and medical diagnostics. Here, we present a review of our contribution to this interdisciplinary research field. We start by describing a simple one-step process for the synthesis of highly uniform ferrite nanoparticles (d = 20-200 nm) and their functionalization with amino acids via carboxyl groups. For real-world applications, we used admicellar polymerization to produce 200 nm diameter 'FG beads', consisting of several 40 nm diameter ferrite nanoparticles encapsulated in a co-polymer of styrene and glycidyl methacrylate for high throughput molecular screening. The highly dispersive FG beads were functionalized with an ethylene glycol diglycidyl ether spacer and used for affinity purification of methotrexate-an anti-cancer agent. We synthesized sub-100 nm diameter magnetic nanocapsules by exploiting the self-assembly of viral capsid protein pentamers, where single 8, 20, and 27 nm nanoparticles were encapsulated with VP1 pentamers for applications including MRI contrast agents. The FG beads are now commercially available for use in fully automated bio-screening systems. We also incorporated europium complexes inside a polymer matrix to produce 140 nm diameter fluorescent-ferrite beads (FF beads), which emit at 618 nm. These FF beads were used for immunofluorescent staining for diagnosis of cancer metastases to lymph nodes during cancer resection surgery by labeling tumor cell epidermal growth factor receptor (EGFRs), and for the detection of brain natriuretic peptide (BNP)-a hormone secreted in excess amounts by the heart when stressed-to a level of 2.0 pg ml{sup -1}. We also describe our work on Hall biosensors made using InSb and GaAs/InGaAs/AlGaAs 2DEG heterostructures integrated with gold current strips to reduce measurement times. Our approach for the detection of sub-200 nm magnetic bead is also described: we exploit the magnetically induced capture of micrometer

  4. Hierarchical Fe_3O_4@MoS_2/Ag_3PO_4 magnetic nanocomposites: Enhanced and stable photocatalytic performance for water purification under visible light irradiation

    International Nuclear Information System (INIS)

    Guo, Na; Li, Haiyan; Xu, Xingjian; Yu, Hongwen

    2016-01-01

    Highlights: • The FM/A-6% possesses a large specific surface area: 76.56 m"2/g. • The FM/A-6% displays high photocatalytic stability. • The FM/A-6% can be collected easily from the water by magnetic field. - Abstract: Novel hierarchical Fe_3O_4@MoS_2/Ag_3PO_4 magnetic nanophotocatalyst with remarkable photocatalytic capability were prepared by simply depositing the Ag_3PO_4 onto the surface of crumpled Fe_3O_4@MoS_2 nanosphere. The nanocomposites were characterized by XRD, TEM, HRTEM, XPS, BET, and UV–vis DRS. The outcome of the photocatalytic experiments demonstrated that Fe_3O_4@MoS_2/Ag_3PO_4 with 6 wt% content of Ag_3PO_4 (FM/A-6%) showed the highest photocatalytic activity upon the degradation Congo red (CR) and Rhodamine B (RhB) under both visible light and simulated sunlight irradiation. In addition, FM/A-6% possessed larger specific surface area (76.56 m"2/g) and excellent optical property. The possible Z-scheme charge carriers transfer mechanism for the enhanced photocatalytic properties of the FM/A-6% was also discussed. The Z-scheme charge carriers transfer mechanism established between MoS_2 and Ag_3PO_4 facilitate the charge separation efficiency. Moreover, FM/A-6% can be separated and collected easily by external magnetic field and maintain high activity after five times photoreaction cycles. Given the remarkable photocatalytic performance and high stability of FM/A-6% nanocomposite, it is looking forward to exhibit great potential for applications in water purification.

  5. Single-Step Incubation Determination of miRNAs in Cancer Cells Using an Amperometric Biosensor Based on Competitive Hybridization onto Magnetic Beads

    Directory of Open Access Journals (Sweden)

    Eva Vargas

    2018-03-01

    Full Text Available This work reports an amperometric biosensor for the determination of miRNA-21, a relevant oncogene. The methodology involves a competitive DNA-target miRNA hybridization assay performed on the surface of magnetic microbeads (MBs and amperometric transduction at screen-printed carbon electrodes (SPCEs. The target miRNA competes with a synthetic fluorescein isothiocyanate (FITC-modified miRNA with an identical sequence for hybridization with a biotinylated and complementary DNA probe (b-Cp immobilized on the surface of streptavidin-modified MBs (b-Cp-MBs. Upon labeling, the FITC-modified miRNA attached to the MBs with horseradish peroxidase (HRP-conjugated anti-FITC Fab fragments and magnetic capturing of the MBs onto the working electrode surface of SPCEs. The cathodic current measured at −0.20 V (versus the Ag pseudo-reference electrode was demonstrated to be inversely proportional to the concentration of the target miRNA. This convenient biosensing method provided a linear range between 0.7 and 10.0 nM and a limit of detection (LOD of 0.2 nM (5 fmol in 25 μL of sample for the synthetic target miRNA without any amplification step. An acceptable selectivity towards single-base mismatched oligonucleotides, a high storage stability of the b-Cp-MBs, and usefulness for the accurate determination of miRNA-21 in raw total RNA (RNAt extracted from breast cancer cells (MCF-7 were demonstrated.

  6. Magnetic bead based immuno-detection of Listeria monocytogenes and Listeria ivanovii from infant formula and leafy green vegetables using the Bio-Plex suspension array system.

    Science.gov (United States)

    Day, J B; Basavanna, U

    2015-04-01

    Listeriosis, a disease contracted via the consumption of foods contaminated with pathogenic Listeria species, can produce severe symptoms and high mortality in susceptible people and animals. The development of molecular methods and immuno-based techniques for detection of pathogenic Listeria in foods has been challenging due to the presence of assay inhibiting food components. In this study, we utilize a macrophage cell culture system for the isolation and enrichment of Listeria monocytogenes and Listeria ivanovii from infant formula and leafy green vegetables for subsequent identification using the Luminex xMAP technique. Macrophage monolayers were exposed to infant formula, lettuce and celery contaminated with L. monocytogenes or L. ivanovii. Magnetic microspheres conjugated to Listeria specific antibody were used to capture Listeria from infected macrophages and then analyzed using the Bio-Plex 200 analyzer. As few as 10 CFU/mL or g of L. monocytogenes was detected in all foods tested. The detection limit for L. ivanovii was 10 CFU/mL in infant formula and 100 CFU/g in leafy greens. Microsphere bound Listeria obtained from infected macrophage lysates could also be isolated on selective media for subsequent confirmatory identification. This method presumptively identifies L. monocytogenes and L. ivanovii from infant formula, lettuce and celery in less than 28 h with confirmatory identifications completed in less than 48 h. Published by Elsevier Ltd.

  7. Potential uses of high gradient magnetic filtration for high-temperature water purification in boiling water reactors

    International Nuclear Information System (INIS)

    Elliott, H.H.; Holloway, J.H.; Abbott, D.G.

    1979-01-01

    Studies of various high-temperature filter devices indicate a potentially positive impact for high gradient magnetic filtration on boiling water reactor radiation level reduction. Test results on in-plant water composition and impurity crystallography are presented for several typical boiling water reactors (BWRs) on plant streams where high-temperature filtration may be particularly beneficial. An experimental model on the removal of red iron oxide (hematite) from simulated reactor water with a high gradient magnetic filter is presented, as well as the scale-up parameters used to predict the filtration efficiency on various high temperature, in-plant streams. Numerical examples are given to illustrate the crud removal potential of high gradient magnetic filters installed at alternative stream locations under typical, steady-state, plant operating conditions

  8. Demonstration of a strategy for product purification by high-gradient magnetic fishing: Recovery of superoxide dismutase from unconditioned whey

    DEFF Research Database (Denmark)

    Meyer, A.; Hansen, D.B.; Goncalves Gomes, Claudia Sofia

    2005-01-01

    and solids; (iv) elution of the target protein; and (v) recovery of the eluted supports from the HGMF rig. Efficient recovery of SOD was demonstrated at similar to50-fold increased scale (cf. magnetic rack studies) in three separate HGMF experiments, and in the best of these (run 3) an SOD yield of >85...

  9. Removal of Congo Red by magnetic mesoporous titanium dioxide-graphene oxide core-shell microspheres for water purification.

    Science.gov (United States)

    Li, Leilei; Li, Xiangjun; Duan, Huimin; Wang, Xiaojiao; Luo, Chuannan

    2014-06-14

    Magnetic mesoporous titanium dioxide-graphene oxide (Fe3O4@mTiO2@GO) with a large surface area and a good magnetic responsiveness was synthesized by immobilizing a mesoporous titanium dioxide (mTiO2) shell on the surface of magnetic Fe3O4 nanoparticles prior to binding with graphene oxide (GO). It showed a tunable pore structure and surface properties, and was mechanically strong. The characteristic results of a Fourier transform infrared spectrometer (FTIR), a scanning electron microscope (SEM), a vibrating sample magnetometer (VSM) and X-ray diffraction (XRD) indicated that Fe3O4@mTiO2@GO has been prepared. Fe3O4@mTiO2@GO was used as an adsorbent for the removal of Congo Red (CR) from simulated wastewater with a fast solid-liquid separation in the presence of an external magnetic field. Batch adsorption experiments were performed to evaluate the adsorption conditions and reusability. The results showed that the maximum adsorption capacity was 89.95 mg g(-1), which is much higher than the previously reported values of other absorbent materials. Moreover, the Fe3O4@mTiO2@GO could be repeatedly used via simple treatment without any obvious structure and performance degradation. The adsorption kinetic data were best described by a pseudo-second-order model and the equilibrium adsorptions were well-described by the Freundlich isotherm model. The Fe3O4@mTiO2@GO may be suitable materials for use in CR pollution cleanup if synthesized on a large scale and at a low price in the near future.

  10. Hydrothermal assisted synthesis of iron oxide-based magnetic silica spheres and their performance in magnetophoretic water purification

    Energy Technology Data Exchange (ETDEWEB)

    Caparros, C., E-mail: ccaparros@fisica.uminho.pt [Centro de Fisica, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Benelmekki, M.; Martins, P.M. [Centro de Fisica, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Xuriguera, E. [Facultat de Quimica, Universitat de Barcelona, 08028 Barcelona (Spain); Silva, C.J.R. [Departamento de Quimica, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Martinez, Ll.M. [Sepmag Technologies, Parc Tecnologic del Valles, 08290 Barcelona (Spain); Lanceros-Mendez, S. [Centro de Fisica, Universidade do Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2012-08-15

    Porous Magnetic Silica (PMS) spheres of about 400 nm diameter were synthesised by one-pot process using the classical Stber method combined with hydrothermal treatment. Maghemite nanoparticles ({gamma}-Fe{sub 2}O{sub 3}) were used as fillers and cetyltrimethylammonium bromide (CTAB) was used as templating agent. The application of the hydrothermal process (120 Degree-Sign C during 48 h) before the calcination leads to the formation of homogeneous and narrow size distribution PMS spheres. X-ray diffraction patterns (XRD), Infrared measurements (FTIR) and Transmission Electron microscopy (TEM) methods were used to determine the composition and morphology of the obtained PMS spheres. The results show a homogeneous distribution of the {gamma}-Fe{sub 2}O{sub 3} nanoparticles in the silica matrix with a 'hollow-like' morphology. Magnetophoresis measurements at 60 T m{sup -1} show a total separation time of the PMS spheres suspension of about 16 min. By using this synthesis method, the limitation of the formation of silica spheres without incorporation of magnetic nanoparticles is overcome. These achievements make this procedure interesting for industrial up scaling. The obtained PMS spheres were evaluated as adsorbents for Ni{sup 2+} in aqueous solution. Their adsorption capacity was compared with the adsorption capacity of magnetic silica spheres obtained without hydrothermal treatment before calcination process. PMS spheres show an increase of the adsorption capacity of about 15% of the initial dissolution of Ni{sup 2+} without the need to functionalize the silica surface. Highlights: Black-Right-Pointing-Pointer Homogeneous and controlled size porous magnetic silica spheres were obtained. Black-Right-Pointing-Pointer Magnetophoretic removing of Ni{sup 2+} processes was successfully preformed at HLGMF. Black-Right-Pointing-Pointer PMS show higher Ni{sup 2+} removing capacity than spheres without hydrothermal treatment. Black-Right-Pointing-Pointer PMS can be

  11. Fluorescent detection of C-reactive protein using polyamide beads

    Science.gov (United States)

    Jagadeesh, Shreesha; Chen, Lu; Aitchison, Stewart

    2016-03-01

    Bacterial infection causes Sepsis which is one of the leading cause of mortality in hospitals. This infection can be quantified from blood plasma using C - reactive protein (CRP). A quick diagnosis at the patient's location through Point-of- Care (POC) testing could give doctors the confidence to prescribe antibiotics. In this paper, the development and testing of a bead-based procedure for CRP quantification is described. The size of the beads enable them to be trapped in wells without the need for magnetic methods of immobilization. Large (1.5 mm diameter) Polyamide nylon beads were used as the substrate for capturing CRP from pure analyte samples. The beads captured CRP either directly through adsorption or indirectly by having specific capture antibodies on their surface. Both methods used fluorescent imaging techniques to quantify the protein. The amount of CRP needed to give a sufficient fluorescent signal through direct capture method was found suitable for identifying bacterial causes of infection. Similarly, viral infections could be quantified by the more sensitive indirect capture method. This bead-based assay can be potentially integrated as a disposable cartridge in a POC device due to its passive nature and the small quantities needed.

  12. Disposal of bead ion exchange resin wastes

    International Nuclear Information System (INIS)

    Gay, R.L.; Granthan, L.F.

    1985-01-01

    Bead ion exchange resin wastes are disposed of by a process which involves spray-drying a bead ion exchange resin waste in order to remove substantially all of the water present in such waste, including the water on the surface of the ion exchange resin beads and the water inside the ion exchange resin beads. The resulting dried ion exchange resin beads can then be solidified in a suitable solid matrix-forming material, such as a polymer, which solidifies to contain the dried ion exchange resin beads in a solid monolith suitable for disposal by burial or other conventional means

  13. Synthesis and purification of some alkyl phenanthrenes and presentation of their infrared, ultraviolet, nuclear magnetic resonance and mass spectra

    International Nuclear Information System (INIS)

    Persaud, K.

    1965-01-01

    We have carried out the synthesis of: - phenanthrene - its five monomethyl derivatives - three dimethyl derivatives - two trimethyl derivatives. We have then purified these products as well as a certain number of others obtained from various sources. We have been able to obtain in the majority of cases, a purity of 99.5 per cent or over, these figures being obtained by low voltage mass spectrometry. Finally we have recorded the infrared, ultraviolet, nuclear magnetic resonance and mass spectra of these products for which an atlas has been drawn up. (author) [fr

  14. A Magnetic Sensor System for Biological Detection

    KAUST Repository

    Li, Fuquan

    2015-05-01

    Magnetic biosensors detect biological targets through sensing the stray field of magnetic beads which label the targets. Commonly, magnetic biosensors employ the “sandwich” method to immobilize biological targets, i.e., the targets are sandwiched between a bio-functionalized sensor surface and bio-functionalized magnetic beads. This method has been used very successfully in different application, but its execution requires a rather elaborate procedure including several washing and incubation steps. This dissertation investigates a new magnetic biosensor concept, which enables a simple and effective detection of biological targets. The biosensor takes advantage of the size difference between bare magnetic beads and compounds of magnetic beads and biological targets. First, the detection of super-paramagnetic beads via magnetic tunnel junction (MTJ) sensors is implemented. Frequency modulation is used to enhance the signal-to-noise ratio, enabling the detection of a single magnetic bead. Second, the concept of the magnetic biosensor is investigated theoretically. The biosensor consists of an MTJ sensor, which detects the stray field of magnetic beads inside of a trap on top of the MTJ. A microwire between the trap and the MTJ is used to attract magnetic beads to the trapping well by applying a current to it. The MTJ sensor’s output depends on the number of beads inside the trap. If biological targets are in the sample solution, the beads will form bead compounds consisting of beads linked to the biological targets. Since bead compounds are larger than bare beads, the number of beads inside the trapping well will depend on the presence of biological targets. Hence, the output of the MTJ sensor will depend on the biological targets. The dependences of sensor signals on the sizes of the MTJ sensor, magnetic beads and biological targets are studied to find the optimum constellations for the detection of specific biological targets. The optimization is demonstrated

  15. Immobilization of Aspergillus niger F7-02 Lipase in Polysaccharide Hydrogel Beads of Irvingia gabonensis Matrix

    Directory of Open Access Journals (Sweden)

    Safaradeen Olateju Kareem

    2014-01-01

    Full Text Available The potential of polysaccharide Irvingia gabonensis matrix as enzyme immobilization support was investigated. Lipase of Aspergillus niger F7-02 was immobilized by entrapment using glutaraldehyde as the cross-linking agent and stabilized in ethanolic-formaldehyde solution. The pH and temperature stability and activity yield of the immobilized enzyme were determined. Such parameters as enzyme load, bead size, number of beads, and bead reusability were also optimized. Adequate gel strength to form stabilized beads was achieved at 15.52% (w/v Irvingia gabonensis powder, 15% (v/v partially purified lipase, 2.5% (v/v glutaraldehyde, and 3 : 1 (v/v ethanolic-formaldehyde solution. There was 3.93-fold purification when the crude enzyme was partially purified in two-step purification using Imarsil and activated charcoal. Optimum lipase activity 75.3 Ug−1 was achieved in 50 mL test solution containing 15 beads of 7 mm bead size. Relative activity 80% was retained at eight repeated cycles. The immobilization process gave activity yield of 59.1% with specific activity of 12.3 Umg−1 and stabilized at optimum pH 4.5 and temperature 55°C. Thus the effectiveness and cost-efficiency of I. gabonensis as a polymer matrix for lipase immobilization have been established.

  16. Calibration beads containing luminescent lanthanide ion complexes

    Science.gov (United States)

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  17. Three-bead steering microswimmers

    Science.gov (United States)

    Rizvi, Mohd Suhail; Farutin, Alexander; Misbah, Chaouqi

    2018-02-01

    The self-propelled microswimmers have recently attracted considerable attention as model systems for biological cell migration as well as artificial micromachines. A simple and well-studied microswimmer model consists of three identical spherical beads joined by two springs in a linear fashion with active oscillatory forces being applied on the beads to generate self-propulsion. We have extended this linear microswimmer configuration to a triangular geometry where the three beads are connected by three identical springs in an equilateral triangular manner. The active forces acting on each spring can lead to autonomous steering motion; i.e., allowing the swimmer to move along arbitrary paths. We explore the microswimmer dynamics analytically and pinpoint its rich character depending on the nature of the active forces. The microswimmers can translate along a straight trajectory, rotate at a fixed location, as well as perform a simultaneous translation and rotation resulting in complex curved trajectories. The sinusoidal active forces on the three springs of the microswimmer contain naturally four operating parameters which are more than required for the steering motion. We identify the minimal operating parameters which are essential for the motion of the microswimmer along any given arbitrary trajectory. Therefore, along with providing insights into the mechanics of the complex motion of the natural and artificial microswimmers, the triangular three-bead microswimmer can be utilized as a model for targeted drug delivery systems and autonomous underwater vehicles where intricate trajectories are involved.

  18. Molecular diagnostics using magnetic nanobeads

    International Nuclear Information System (INIS)

    Zardan Gomez de la Torre, Teresa; Stroemberg, Mattias; Goeransson, Jenny; Stroemme, Maria; Gunnarsson, Klas; Svedlindh, Peter; Nilsson, Mats

    2010-01-01

    In this paper, we investigate the volume-amplified magnetic nanobead detection assay with respect to bead size, bead concentration and bead oligonucleotide surface coverage in order to improve the understanding of the underlying microscopic mechanisms. It has been shown that: (i) the immobilization efficiency of the beads depends on the surface coverage of oligonucleotides, (ii) by using lower amounts of probe-tagged beads, detection sensitivity can be improved and (iii) using small enough beads enables both turn-off and turn-on detection. Finally, biplex detection was demonstrated.

  19. Fundamentals of magnet-actuated droplet manipulation on an open hydrophobic surface†

    Science.gov (United States)

    Long, Zhicheng; Shetty, Abhishek M.; Solomon, Michael J.; Larson, Ronald G.

    2010-01-01

    We systematically investigate droplet movement, coalescence, and splitting on an open hydrophobic surface. These processes are actuated by magnetic beads internalized in an oil-coated aqueous droplet using an external magnet. Results are organized into an ‘operating diagram’ that describes regions of droplet stable motion, breakage, and release from the magnet. The results are explained theoretically with a simple model that balances magnetic, friction, and capillary-induced drag forces and includes the effects of particle type, droplet size, surrounding oil layer, surface tension, and viscosity. Finally, we discuss the implications of the results for the design of magnet-actuated droplet systems for applications such as nucleic acid purification, immunoassay and drug delivery. PMID:19458864

  20. Microstructural Study on Oxygen Permeated Arc Beads

    Directory of Open Access Journals (Sweden)

    Kuan-Heng Liu

    2015-01-01

    Full Text Available We simulated short circuit of loaded copper wire at ambient atmosphere and successfully identified various phases of the arc bead. A cuprous oxide flake was formed on the surface of the arc bead in the rapid solidification process, and there were two microstructural constituents, namely, Cu-κ eutectic structure and solutal dendrites. Due to the arc bead formed at atmosphere during the local equilibrium solidification process, the phase of arc bead has segregated to the cuprous oxide flake, Cu-κ eutectic, and Cu phase solutal dendrites, which are the fingerprints of the arc bead permeated by oxygen.

  1. Identification of phosphorylated butyrylcholinesterase in human plasma using immunoaffinity purification and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Aryal, Uma K.; Lin, Chiann Tso; Kim, Jong Seo; Heibeck, Tyler H.; Wang, Jun; Qian, Weijun; Lin, Yuehe

    2012-04-20

    Paraoxon (diethyl 4-nitrophenyl phosphate) is an active metabolite of the common insecticide parathion and is acutely toxic due to the inhibition of cholinesterase (ChE) activity in the nervous systems. The Inhibition of butyrylcholinesterase (BChE) activity by paraoxon is due to the formation of phosphorylated BChE adduct, and the detection of the phosphorylated BChE adduct in human plasma can serve as an exposure biomarker of organophosphate pesticides and nerve agents. In this study, we performed immunoaffinity purification and liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis for identifying phosphorylated BChE in human plasma treated by paraoxon. BChE was captured by biotinylated anti-BChE polyclonal antibodies conjugated to streptavidin magnetic beads. Western blot analysis showed that the antibody was effective to recognize both native and modified BChE with high specificity. The exact phosphorylation site of BChE was confirmed on Serine 198 by MS/MS with a 108 Da modification mass and accurately measured parent ion masses. The phosphorylated BChE peptide was also successfully detected in the immunoaffinity purified sample from paraoxon treated human plasma. Thus, immunoaffinity purification combined with mass spectrometry represents a viable approach for the detection of paraoxon-modified BChE and other forms of modified BChE as exposure biomarkers of organophosphates and nerve agents.

  2. Selective extraction of plutonium from nitric acid medium by bifunctional polyethersulfone beads for quantification with thermal ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Paul, Sumana; Aggarwal, S.K.; Pandey, A.K.

    2015-01-01

    Polyethersulfone (PES) magnetic beads were prepared by phase inversion technique. The beads were grafted with two monomers, viz. 2-hydroxyethylmethacrylate phosphoric acid (HEMP) and (3-acrylamidopropyl)trimethyl ammonium chloride (AMAC), by photo-induced free radical polymerization. Effect of different HNO 3 concentrations on the sorption profiles of Am(III) and Pu(IV) was studied using the grafted PES beads. The beads were found to extract plutonium quantitatively from high nitric acid medium (3-8 M). The effect of presence of competing actinide, e.g. U(VI), on the sorption of Pu(IV) was also studied. (author)

  3. Direct friction measurement in draw bead testing

    DEFF Research Database (Denmark)

    Olsson, David Dam; Bay, Niels; Andreasen, Jan Lasson

    2005-01-01

    The application of draw beads in sheet metal stamping ensures controlled drawing-in of flange parts. Lubrication conditions in draw beads are severe due to sliding under simultaneous bending. Based on the original draw bead test design by Nine [1] comprehensive studies of friction in draw beads...... have been reported in literature. A major drawback in all these studies is that friction is not directly measured, but requires repeated measurements of the drawing force with and without relative sliding between the draw beads and the sheet material. This implies two tests with a fixed draw bead tool...... and a freely rotating tool respectively, an approach, which inevitably implies large uncertainties due to scatter in the experimental conditions. In order to avoid this problem a new draw bead test is proposed by the authors measuring the friction force acting on the tool radius directly by a build...

  4. Developement of Spherical Polyurethane Beads

    Institute of Scientific and Technical Information of China (English)

    K. Maeda; H. Ohmori; H. Gyotoku

    2005-01-01

    @@ 1Results and Discussion We established a new method to produce the spherical polyurethane beads which have narrower distribution of particle size. This narrower distribution was achieved by the polyurethane prepolymer which contains ketimine as a blocked chain-extending agent. Firstly, the prepolymer is dispersed into the aqueous solution containing surfactant. Secondaly, water comes into the inside of prepolymer as oil phase. Thirdly, ketimine is hydrolyzed to amine, and amine reacts with prepolymer immediately to be polyurethane.Our spherical polyurethane beads are very suitable for automotive interior parts especially for instrument panel cover sheet producing under the slush molding method, because of good process ability, excellent durability to the sunlight and mechanical properties at low temperature. See Fig. 1 ,Fig. 2 and Fig. 3 (Page 820).

  5. Sequential mass spectrometric analysis of uranium and plutonium employing resin bead technique

    International Nuclear Information System (INIS)

    Ramakumar, K.L.; Aggarwal, S.K.; Chitambar, S.A.; Jain, H.C.

    1985-01-01

    Sequential mass spectrometric analysis of uranium and plutonium employing anion exchange resin bead technique is reported using a high sensitive single stage magnetic analyser instrument, the routinely employed rhenium double filament assembly and 0.5M HNO 3 as a wetting agent for loading the resin beads. A precision of bettter than 0.3per cent (2sigma) is obtained on the isotopic ratio measurements. However, extreme care has to be exercised to carry the resin bead experiments under ultra clean conditions so as to avoid pick up of contamination. (author)

  6. Electrochemical Detection of E. coli O157:H7 in Water after Electrocatalytic and Ultraviolet Treatments Using a Polyguanine-Labeled Secondary Bead Sensor

    Directory of Open Access Journals (Sweden)

    Michael G. Beeman

    2018-05-01

    Full Text Available The availability of clean drinking water is a significant problem worldwide. Many technologies exist for purifying drinking water, however, many of these methods require chemicals or use simple methods, such as boiling and filtering, which may or may not be effective in removing waterborne pathogens. Present methods for detecting pathogens in point-of-use (POU sterilized water are typically time prohibitive or have limited ability differentiating between active and inactive cells. This work describes a rapid electrochemical sensor to differentially detect the presence of active Escherichia coli (E. coli O157:H7 in samples that have been partially or completely sterilized using a new POU electrocatalytic water purification technology based on superradicals generated by defect laden titania (TiO2 nanotubes. The sensor was also used to detect pathogens sterilized by UV-C radiation for a comparison of different modes of cell death. The sensor utilizes immunomagnetic bead separation to isolate active bacteria by forming a sandwich assay comprised of antibody functionalized secondary magnetic beads, E. coli O157:H7, and polyguanine (polyG oligonucleotide functionalized secondary polystyrene beads as an electrochemical tag. The assay is formed by the attachment of antibodies to active receptors on the membrane of E. coli, allowing the sensor to differentially detect viable cells. Ultravioloet (UV-C radiation and an electrocatalytic reactor (ER with integrated defect-laden titania nanotubes were used to examine the sensors’ performance in detecting sterilized cells under different modes of cell death. Plate counts and flow cytometry were used to quantify disinfection efficacy and cell damage. It was found that the ER treatments shredded the bacteria into multiple fragments, while UV-C treatments inactivated the bacteria but left the cell membrane mostly intact.

  7. Electrochemical Detection of E. coli O157:H7 in Water after Electrocatalytic and Ultraviolet Treatments Using a Polyguanine-Labeled Secondary Bead Sensor.

    Science.gov (United States)

    Beeman, Michael G; Nze, Ugochukwu C; Sant, Himanshu J; Malik, Hammad; Mohanty, Swomitra; Gale, Bruce K; Carlson, Krista

    2018-05-10

    The availability of clean drinking water is a significant problem worldwide. Many technologies exist for purifying drinking water, however, many of these methods require chemicals or use simple methods, such as boiling and filtering, which may or may not be effective in removing waterborne pathogens. Present methods for detecting pathogens in point-of-use (POU) sterilized water are typically time prohibitive or have limited ability differentiating between active and inactive cells. This work describes a rapid electrochemical sensor to differentially detect the presence of active Escherichia coli (E. coli) O157:H7 in samples that have been partially or completely sterilized using a new POU electrocatalytic water purification technology based on superradicals generated by defect laden titania (TiO₂) nanotubes. The sensor was also used to detect pathogens sterilized by UV-C radiation for a comparison of different modes of cell death. The sensor utilizes immunomagnetic bead separation to isolate active bacteria by forming a sandwich assay comprised of antibody functionalized secondary magnetic beads, E. coli O157:H7, and polyguanine (polyG) oligonucleotide functionalized secondary polystyrene beads as an electrochemical tag. The assay is formed by the attachment of antibodies to active receptors on the membrane of E. coli , allowing the sensor to differentially detect viable cells. Ultravioloet (UV)-C radiation and an electrocatalytic reactor (ER) with integrated defect-laden titania nanotubes were used to examine the sensors’ performance in detecting sterilized cells under different modes of cell death. Plate counts and flow cytometry were used to quantify disinfection efficacy and cell damage. It was found that the ER treatments shredded the bacteria into multiple fragments, while UV-C treatments inactivated the bacteria but left the cell membrane mostly intact.

  8. Bead Injection Extraction Chromatography using High-capacity Lab-on-Valve as a Front End to Inductively Coupled Plasma Mass Spectrometry for Rapid Urine Radiobioassay

    DEFF Research Database (Denmark)

    Qiao, Jixin; Hou, Xiaolin; Roos, Per

    2013-01-01

    A novel bead injection (BI) extraction chromatographic microflow system exploiting high-capacity lab-on-valve (LOV) platform coupled with inductively coupled plasma mass spectrometric detection is developed for rapid and automated determination of plutonium in human urine. A microconduit (1 m......L) incorporated within the LOV processing unit is loaded on-line with a metered amount of disposable extraction chromatographic resin (up to 330 mg of TEVA) through programmable beads transport. Selective capture and purification of plutonium onto the resin beads is then performed by pressure driven flow after...

  9. Purification and Characterization of Lipase from Aspergillus flavus ...

    African Journals Online (AJOL)

    USER

    Abstract. Lipase from Aspergillus flavus was purified in a single step purification using MnFeO4 magnetic nano particles to achieve a 20.53- fold purification with specific activity of. 11.29 U/mg and a 59% recovery yield. SDS-PAGE of lipase showed a single pure band with corresponding molecular weight of 35 kDa.

  10. A Mössbauer study of the chemical stability of iron oxide nanoparticles in PMMA and PVB beads

    DEFF Research Database (Denmark)

    Chen, Wei; Mørup, Steen; Hansen, Mikkel Fougt

    2008-01-01

    We have prepared magnetic beads consisting of iron oxide nanoparticles in a polymethyl methacrylate (PMMA) and a polyvinyl butyral (PVB) matrix. High-field Mossbauer studies show that the particles have an almost perfect collinear spin structure and magnetization measurements show that they are s...... transformed to maghemite. The PVB beads are hydrophilic and biocompatible and are therefore well suited for applications in medicine and biology....

  11. Structure and superparamagnetic behaviour of magnetite nanoparticles in cellulose beads

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Jose R., E-mail: correa@fq.uh.cu [Department of General Chemistry, Faculty of Chemistry, University of Havana, Zapata and G, Havana City 10400 (Cuba); Bordallo, Eduardo [Sugar Cane-Cellulose Research Center, Cuba-9, Quivican (Cuba); Canetti, Dora [Department of Inorganic Chemistry, Faculty of Chemistry, University of Havana, Zapata and G, Havana City 10400 (Cuba); Leon, Vivian [Sugar Cane-Cellulose Research Center, Cuba-9, Quivican (Cuba); Otero-Diaz, Luis C. [Department of Inorganic Chemistry-1, Complutense University of Madrid, Madrid 28040 (Spain); Electron Microscopy Center, Complutense University of Madrid, Madrid 28040 (Spain); Negro, Carlos [Chemical Engineering Department, Complutense University of Madrid, Madrid 28040 (Spain); Gomez, Adrian [Electron Microscopy Center, Complutense University of Madrid, Madrid 28040 (Spain); Saez-Puche, Regino [Department of Inorganic Chemistry-1, Complutense University of Madrid, Madrid 28040 (Spain)

    2010-08-15

    Superparamagnetic magnetite nanoparticles were obtained starting from a mixture of iron(II) and iron(III) solutions in a preset total iron concentration from 0.04 to 0.8 mol l{sup -1} with ammonia at 25 and 70 {sup o}C. The regeneration of cellulose from viscose produces micrometrical spherical cellulose beads in which synthetic magnetite were embedded. The characterization of cellulose-magnetite beads by X-ray diffraction, Scanning and Transmission Electron Microscopy and magnetic measurement is reported. X-ray diffraction patterns indicate that the higher is the total iron concentration and temperature the higher is the crystal size of the magnetite obtained. Transmission Electron Microscopy studies of cellulose-magnetite beads revealed the distribution of magnetite nanoparticles inside pores of hundred nanometers. Magnetite as well as the cellulose-magnetite composites exhibit superparamagnetic characteristics. Field cooling and zero field cooling magnetic susceptibility measurements confirm the superparamagnetic behaviour and the blocking temperature for the magnetite with a mean size of 12.5 nm, which is 200 K.

  12. Beautiful Beads: A Lesson in Making Beads with Friendly Clay. AMACO[R] Lesson.

    Science.gov (United States)

    Gamble, Harriet; Gamble, David

    This lesson resource includes a brief summary of the history of bead making and historic fascination with beads as adornment. A focus on design elements, color theory, craftsmanship, and technical skill in bead making is encouraged. The plan includes lesson goals and objectives; background preparation; a glossary of terms; a list of supplies; and…

  13. Homologous high-throughput expression and purification of highly conserved E coli proteins

    Directory of Open Access Journals (Sweden)

    Duchmann Rainer

    2007-06-01

    Full Text Available Abstract Background Genetic factors and a dysregulated immune response towards commensal bacteria contribute to the pathogenesis of Inflammatory Bowel Disease (IBD. Animal models demonstrated that the normal intestinal flora is crucial for the development of intestinal inflammation. However, due to the complexity of the intestinal flora, it has been difficult to design experiments for detection of proinflammatory bacterial antigen(s involved in the pathogenesis of the disease. Several studies indicated a potential association of E. coli with IBD. In addition, T cell clones of IBD patients were shown to cross react towards antigens from different enteric bacterial species and thus likely responded to conserved bacterial antigens. We therefore chose highly conserved E. coli proteins as candidate antigens for abnormal T cell responses in IBD and used high-throughput techniques for cloning, expression and purification under native conditions of a set of 271 conserved E. coli proteins for downstream immunologic studies. Results As a standardized procedure, genes were PCR amplified and cloned into the expression vector pQTEV2 in order to express proteins N-terminally fused to a seven-histidine-tag. Initial small-scale expression and purification under native conditions by metal chelate affinity chromatography indicated that the vast majority of target proteins were purified in high yields. Targets that revealed low yields after purification probably due to weak solubility were shuttled into Gateway (Invitrogen destination vectors in order to enhance solubility by N-terminal fusion of maltose binding protein (MBP, N-utilizing substance A (NusA, or glutathione S-transferase (GST to the target protein. In addition, recombinant proteins were treated with polymyxin B coated magnetic beads in order to remove lipopolysaccharide (LPS. Thus, 73% of the targeted proteins could be expressed and purified in large-scale to give soluble proteins in the range of 500

  14. Adsorption of ochratoxin A from grape juice by yeast cells immobilised in calcium alginate beads.

    Science.gov (United States)

    Farbo, Maria Grazia; Urgeghe, Pietro Paolo; Fiori, Stefano; Marceddu, Salvatore; Jaoua, Samir; Migheli, Quirico

    2016-01-18

    Grape juice can be easily contaminated with ochratoxin A (OTA), one of the known mycotoxins with the greatest public health significance. Among the different approaches to decontaminate juice from this mycotoxin, microbiological methods proved efficient, inexpensive and safe, particularly the use of yeast or yeast products. To ascertain whether immobilisation of the yeast biomass would lead to successful decontamination, alginate beads encapsulating Candida intermedia yeast cells were used in our experiments to evaluate their OTA-biosorption efficacy. Magnetic calcium alginate beads were also prepared by adding magnetite in the formulation to allow fast removal from the aqueous solution with a magnet. Calcium alginate beads were added to commercial grape juice spiked with 20 μg/kg OTA and after 48 h of incubation a significant reduction (>80%), of the total OTA content was achieved, while in the subsequent phases (72-120 h) OTA was slowly released into the grape juice by alginate beads. Biosorption properties of alginate-yeast beads were tested in a prototype bioreactor consisting in a glass chromatography column packed with beads, where juice amended with OTA was slowly flowed downstream. The adoption of an interconnected scaled-up bioreactor as an efficient and safe tool to remove traces of OTA from liquid matrices is discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Magnetic polymeric microspheres for protein adsorption

    International Nuclear Information System (INIS)

    Felinto, M.C.F.C.; Parra, D.F.; Lugao, A.B.; Batista, M.P.; Higa, O.Z.; Yamaura, M.; Camilo, R.L.; Ribela, M.T.C.P.; Sampaio, L.C.

    2005-01-01

    Magnetic beads consisting of polymer-coated manganese ferrite nanoparticles were prepared by the precipitation reaction of manganese ferrite into the channels of methyl methacrylate polymer beads by sodium hydroxide, resulting in MnMagBead. MnMagBead was characterized by infrared spectra (FTIR), thermogravimetric analysis of TGA/DTG and indicates the presence of -CO (carbonyl) groups and the MnFe 2 O 4 on the beads. Magnetization measurements were obtained at room temperature in magnetic fields up to 10 KOe using a vibrating sample magnetometer. Introductory Protein adsorption biological tests were processed using labeled I-125 albumin (BSA), and the activity was measured in a gamma counting spectrometer. These superparamagnetic beads exhibit the capacity to bind biological molecules such as proteins like albumin, with a good capability (5 x 10 -6 ) μg/100 mg of beads as compared with other magnetic resins studied in our group

  16. Fused Bead Analysis of Diogenite Meteorites

    Science.gov (United States)

    Mittlefehldt, D.W.; Beck, B.W.; McSween, H.Y.; Lee, C.T. A.

    2009-01-01

    Bulk rock chemistry is an essential dataset in meteoritics and planetary science [1]. A common method used to obtain the bulk chemistry of meteorites is ICP-MS. While the accuracy, precision and low detection limits of this process are advantageous [2], the sample size used for analysis (approx.70 mg) can be a problem in a field where small and finite samples are the norm. Fused bead analysis is another bulk rock analytical technique that has been used in meteoritics [3]. This technique involves forming a glass bead from 10 mg of sample and measuring its chemistry using a defocused beam on a microprobe. Though the ICP-MS has lower detection limits than the microprobe, the fused bead method destroys a much smaller sample of the meteorite. Fused bead analysis was initially designed for samples with near-eutectic compositions and low viscosities. Melts generated of this type homogenize at relatively low temperatures and produce primary melts near the sample s bulk composition [3]. The application of fused bead analysis to samples with noneutectic melt compositions has not been validated. The purpose of this study is to test if fused bead analysis can accurately determine the bulk rock chemistry of non-eutectic melt composition meteorites. To determine this, we conduct two examinations of the fused bead. First, we compare ICP-MS and fused bead results of the same samples using statistical analysis. Secondly, we inspect the beads for the presence of crystals and chemical heterogeneity. The presence of either of these would indicate incomplete melting and quenching of the bead.

  17. A Magnetic Sensor System for Biological Detection

    KAUST Repository

    Li, Fuquan

    2015-01-01

    Magnetic biosensors detect biological targets through sensing the stray field of magnetic beads which label the targets. Commonly, magnetic biosensors employ the “sandwich” method to immobilize biological targets, i.e., the targets are sandwiched

  18. Microfluidic magnetic separator using an array of soft magnetic elements

    DEFF Research Database (Denmark)

    Smistrup, Kristian; Lund-Olesen, Torsten; Hansen, Mikkel Fougt

    2006-01-01

    We present the design, fabrication, characterization, and demonstration of a new passive magnetic bead separator. The device operates in an effective state when magnetized by an external magnetic field of only 50 mT, which is available from a tabletop electromagnet. We demonstrate the complete...... capture of 1.0 mu m fluorescent magnetic beads from a 7.5 mu L sample volume traveling at an average linear fluid velocity of 5 mm/s....

  19. Development and optimization of water treatment reactors using TiO2-modified polymer beads with a refractive index identical to that of water

    Science.gov (United States)

    Myoga, Arata; Iwashita, Ryutaro; Unno, Noriyuki; Satake, Shin-ichi; Taniguchi, Jun; Yuki, Kazuhisa; Seki, Yohji

    2018-06-01

    Various water purification reactors were constructed using beads of TiO2-coated MEXFLON, which is a fluoropolymer exhibiting a refractive index identical to that of water. The performance of these reactors was evaluated in a recirculation experiment utilizing an aqueous solution of methylene blue. Reactor pipes (length = 150 mm, internal diameter = 10 mm) were made of a fluorinated ethylene polymer with a refractive index of 1.338 and contained 206-bead clusters. A UV lamp was used to irradiate eight reactor pipes surrounding it. The above-mentioned eight bead-packed pipes were connected both in series and in parallel, and the performances of these two reactor types were compared. A pseudo-first-order rate constant of 0.70 h- 1 was obtained for the series connection, whereas the corresponding value for the parallel connection was 1.5 times smaller, confirming the effectiveness of increasing the reaction surface by employing a larger number of beads.

  20. Development and optimization of water treatment reactors using TiO2-modified polymer beads with a refractive index identical to that of water

    Science.gov (United States)

    Myoga, Arata; Iwashita, Ryutaro; Unno, Noriyuki; Satake, Shin-ichi; Taniguchi, Jun; Yuki, Kazuhisa; Seki, Yohji

    2018-03-01

    Various water purification reactors were constructed using beads of TiO2-coated MEXFLON, which is a fluoropolymer exhibiting a refractive index identical to that of water. The performance of these reactors was evaluated in a recirculation experiment utilizing an aqueous solution of methylene blue. Reactor pipes (length = 150 mm, internal diameter = 10 mm) were made of a fluorinated ethylene polymer with a refractive index of 1.338 and contained 206-bead clusters. A UV lamp was used to irradiate eight reactor pipes surrounding it. The above-mentioned eight bead-packed pipes were connected both in series and in parallel, and the performances of these two reactor types were compared. A pseudo-first-order rate constant of 0.70 h- 1 was obtained for the series connection, whereas the corresponding value for the parallel connection was 1.5 times smaller, confirming the effectiveness of increasing the reaction surface by employing a larger number of beads.

  1. Rapid Detection of Enterobacter Sakazakii in milk Powder using amino modified chitosan immunomagnetic beads.

    Science.gov (United States)

    Zhu, Yinglian; Wang, Dongfeng

    2016-12-01

    Chitosan immunomagnetic beads (CIBs) were first prepared through converting hydroxyl groups of natural polymer material-chitosan into amino groups using epichlorohydrin and ethylenediamine as modification agent and then coupling with polyclonal antibodies of Enterobacter sakazakii using glutaraldehyde as cross-linking agent. The beads before coupling with antibodies were characterized by magnetic property measurement, FTIR, SEM and XRD technologies. In the assay a natural polysaccharide-chitosan, which has good biological and chemical properties such as non-toxicity, biocompatibility and high chemical reactivity was first used for synthesis of immunomagnetic beads. The detection method first established in this paper that combined the beads with chromogenic medium together to rapid detect E. sakazakii in milk powder could greatly improve the detection specificity and working efficiency. The beads exhibited a maximum capturing capacity of 1×10 6 cfu/g with the detection sensitivity of 4cfu/g. The results demonstrate that the assay is a straightforward, specific and sensitive alternative for rapid detection of E.sakazakii in food matrix. The total analysis time was as little as about 25h, which greatly shorten the detection time. The method can provides new ideas not only to preparation technique of immunomagnetic beads but to imunne detection technique in food safety. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Evaluation and optimization of DNA extraction and purification procedures for soil and sediment samples.

    Science.gov (United States)

    Miller, D N; Bryant, J E; Madsen, E L; Ghiorse, W C

    1999-11-01

    We compared and statistically evaluated the effectiveness of nine DNA extraction procedures by using frozen and dried samples of two silt loam soils and a silt loam wetland sediment with different organic matter contents. The effects of different chemical extractants (sodium dodecyl sulfate [SDS], chloroform, phenol, Chelex 100, and guanadinium isothiocyanate), different physical disruption methods (bead mill homogenization and freeze-thaw lysis), and lysozyme digestion were evaluated based on the yield and molecular size of the recovered DNA. Pairwise comparisons of the nine extraction procedures revealed that bead mill homogenization with SDS combined with either chloroform or phenol optimized both the amount of DNA extracted and the molecular size of the DNA (maximum size, 16 to 20 kb). Neither lysozyme digestion before SDS treatment nor guanidine isothiocyanate treatment nor addition of Chelex 100 resin improved the DNA yields. Bead mill homogenization in a lysis mixture containing chloroform, SDS, NaCl, and phosphate-Tris buffer (pH 8) was found to be the best physical lysis technique when DNA yield and cell lysis efficiency were used as criteria. The bead mill homogenization conditions were also optimized for speed and duration with two different homogenizers. Recovery of high-molecular-weight DNA was greatest when we used lower speeds and shorter times (30 to 120 s). We evaluated four different DNA purification methods (silica-based DNA binding, agarose gel electrophoresis, ammonium acetate precipitation, and Sephadex G-200 gel filtration) for DNA recovery and removal of PCR inhibitors from crude extracts. Sephadex G-200 spin column purification was found to be the best method for removing PCR-inhibiting substances while minimizing DNA loss during purification. Our results indicate that for these types of samples, optimum DNA recovery requires brief, low-speed bead mill homogenization in the presence of a phosphate-buffered SDS-chloroform mixture, followed

  3. Magnetic separation in microfluidic systems

    DEFF Research Database (Denmark)

    Smistrup, Kristian

    2007-01-01

    to facilitate real-time monitoring of the experiments. The set-up and experimental protocol are described in detail. Results are presented for ’active’ magnetic bead separators, where on-chip microfabricated electromagnets supply the magnetic field and field gradients necessary for magnetic bead separation....... It is shown conceptually how such a system can be applied for parallel biochemical processing in a microfluidic system. ’Passive’ magnetic separators are presented, where on-chip soft magnetic elements are magnetized by an external magnetic field and create strong magnetic fields and gradients inside...

  4. Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads

    Directory of Open Access Journals (Sweden)

    Igor Rocha

    2018-03-01

    Full Text Available Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels, coagulation activation (thrombin-antithrombin (TAT levels and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

  5. Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads.

    Science.gov (United States)

    Rocha, Igor; Lindh, Jonas; Hong, Jaan; Strømme, Maria; Mihranyan, Albert; Ferraz, Natalia

    2018-03-07

    Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels), coagulation activation (thrombin-antithrombin (TAT) levels) and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

  6. Magnetic Solid-phase Extraction with Fe3O4/Molecularly Imprinted Polymers Modified by Deep Eutectic Solvents and Ionic Liquids for the Rapid Purification of Alkaloid Isomers (Theobromine and Theophylline from Green Tea

    Directory of Open Access Journals (Sweden)

    Guizhen Li

    2017-06-01

    Full Text Available Different kinds of deep eutectic solvents (DES based on choline chloride (ChCl and ionic liquids (ILs based on 1-methylimidazole were used to modify Fe3O4/molecularly imprinted polymers (Fe3O4/MIPs, and the resulting materials were applied for the rapid purification of alkaloid isomers (theobromine and theophylline from green tea with magnetic solid-phase extraction (M-SPE. The M-SPE procedure was optimized using the response surface methodology (RSM to analyze the maximum conditions. The materials were characterized by Fourier transform infrared spectroscopy (FI-IR and field emission scanning electron microscopy (FE-SEM. Compared to the ILs-Fe3O4/MIPs, the DESs-Fe3O4/MIPs were developed for the stronger recognition and higher recoveries of the isomers (theophylline and theobromine from green tea, particularly DES-7-Fe3O4/MIPs. With RSM, the optimal recovery condition for theobromine and theophylline in the M-SPE were observed with ratio of methanol (80% as the washing solution, methanol/acetic acid (HAc (8:2 as the eluent at pH 3, and an eluent volume of 4 mL. The practical recoveries of theobromine and theophylline in green tea were 92.27% and 87.51%, respectively, with a corresponding actual extraction amount of 4.87 mg•g−1 and 5.07 mg•g−1. Overall, the proposed approach with the high affinity of Fe3O4/MIPs might offer a novel method for the purification of complex isomer samples.

  7. Magnetic Solid-phase Extraction with Fe₃O₄/Molecularly Imprinted Polymers Modified by Deep Eutectic Solvents and Ionic Liquids for the Rapid Purification of Alkaloid Isomers (Theobromine and Theophylline) from Green Tea.

    Science.gov (United States)

    Li, Guizhen; Wang, Xiaoqin; Row, Kyung Ho

    2017-06-25

    Different kinds of deep eutectic solvents (DES) based on choline chloride (ChCl) and ionic liquids (ILs) based on 1-methylimidazole were used to modify Fe3O4/molecularly imprinted polymers (Fe3O4/MIPs), and the resulting materials were applied for the rapid purification of alkaloid isomers (theobromine and theophylline) from green tea with magnetic solid-phase extraction (M-SPE). The M-SPE procedure was optimized using the response surface methodology (RSM) to analyze the maximum conditions. The materials were characterized by Fourier transform infrared spectroscopy (FI-IR) and field emission scanning electron microscopy (FE-SEM). Compared to the ILs-Fe3O4/MIPs, the DESs-Fe3O4/MIPs were developed for the stronger recognition and higher recoveries of the isomers (theophylline and theobromine) from green tea, particularly DES-7-Fe3O4/MIPs. With RSM, the optimal recovery condition for theobromine and theophylline in the M-SPE were observed with ratio of methanol (80%) as the washing solution, methanol/acetic acid (HAc) (8:2) as the eluent at pH 3, and an eluent volume of 4 mL. The practical recoveries of theobromine and theophylline in green tea were 92.27% and 87.51%, respectively, with a corresponding actual extraction amount of 4.87 mg•g-1 and 5.07 mg•g-1. Overall, the proposed approach with the high affinity of Fe3O4/MIPs might offer a novel method for the purification of complex isomer samples.

  8. Preparation and Characterization of Super-paramagnetic Nano-beads for DNA Isolation

    Institute of Scientific and Technical Information of China (English)

    Xin XIE; Xu ZHANG; Bing Bin YU; wei Yang FE

    2004-01-01

    Unique coupling reagent, bis-(2-hydroxyethyl methacrylate) phosphate was used to prepare coated and functionalized superparamagnetic nanobeads, leading to a simple, effective method for coating the nanobeads. With this method, the thickness of the coating layer and the functional group contents on the nano-beads could be controlled by changing the quantity of the coated monomers. The nanobeads were characterized by means of transmission electron microscopy (TEM) and Fourier transformation infrared spectroscopy (FTIR). The carboxyl-modified magnetic nano-beads were employed to streamline the protocol of isolation of genomic DNA from the human whole blood.

  9. The Beads of Translation: Using Beads to Translate mRNA into a Polypeptide Bracelet

    Science.gov (United States)

    Dunlap, Dacey; Patrick, Patricia

    2012-01-01

    During this activity, by making beaded bracelets that represent the steps of translation, students simulate the creation of an amino acid chain. They are given an mRNA sequence that they translate into a corresponding polypeptide chain (beads). This activity focuses on the events and sites of translation. The activity provides students with a…

  10. Laboratory of minerals purification

    International Nuclear Information System (INIS)

    2002-01-01

    The laboratory of minerals purification was organized in 1962 where with application of modern physical and chemical methods were investigated the mechanism of flotation reagents interaction with minerals' surface, was elaborated technologies on rising complexity of using of republic's minerals

  11. Construction and characterisation of a modular microfluidic system: coupling magnetic capture and electrochemical detection

    DEFF Research Database (Denmark)

    Godino, N.; Snakenborg, Detlef; Kutter, Jörg Peter

    2010-01-01

    , and a polycarbonate base where permanent magnets are hosted; these parts are designed to fit so that wire bonding and encapsulation are avoided. This system can perform bioassays over the surface of magnetic beads and uses only 50 mu L of bead suspension per assay. Following detection, captured beads are released...

  12. Purification and Characterization of Lipase from Aspergillus flavus ...

    African Journals Online (AJOL)

    Lipase from Aspergillus flavus was purified in a single step purification using MnFeO4 magnetic nano particles to achieve a 20.53- fold purification with specific activity of 11.29 U/mg and a 59% recovery yield. SDS-PAGE of lipase showed a single pure band with corresponding molecular weight of 35 kDa. The optimal ...

  13. Hierarchical Fe{sub 3}O{sub 4}@MoS{sub 2}/Ag{sub 3}PO{sub 4} magnetic nanocomposites: Enhanced and stable photocatalytic performance for water purification under visible light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Na [Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Li, Haiyan; Xu, Xingjian [Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102 (China); Yu, Hongwen, E-mail: yuhw@neigae.ac.cn [Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102 (China)

    2016-12-15

    Highlights: • The FM/A-6% possesses a large specific surface area: 76.56 m{sup 2}/g. • The FM/A-6% displays high photocatalytic stability. • The FM/A-6% can be collected easily from the water by magnetic field. - Abstract: Novel hierarchical Fe{sub 3}O{sub 4}@MoS{sub 2}/Ag{sub 3}PO{sub 4} magnetic nanophotocatalyst with remarkable photocatalytic capability were prepared by simply depositing the Ag{sub 3}PO{sub 4} onto the surface of crumpled Fe{sub 3}O{sub 4}@MoS{sub 2} nanosphere. The nanocomposites were characterized by XRD, TEM, HRTEM, XPS, BET, and UV–vis DRS. The outcome of the photocatalytic experiments demonstrated that Fe{sub 3}O{sub 4}@MoS{sub 2}/Ag{sub 3}PO{sub 4} with 6 wt% content of Ag{sub 3}PO{sub 4} (FM/A-6%) showed the highest photocatalytic activity upon the degradation Congo red (CR) and Rhodamine B (RhB) under both visible light and simulated sunlight irradiation. In addition, FM/A-6% possessed larger specific surface area (76.56 m{sup 2}/g) and excellent optical property. The possible Z-scheme charge carriers transfer mechanism for the enhanced photocatalytic properties of the FM/A-6% was also discussed. The Z-scheme charge carriers transfer mechanism established between MoS{sub 2} and Ag{sub 3}PO{sub 4} facilitate the charge separation efficiency. Moreover, FM/A-6% can be separated and collected easily by external magnetic field and maintain high activity after five times photoreaction cycles. Given the remarkable photocatalytic performance and high stability of FM/A-6% nanocomposite, it is looking forward to exhibit great potential for applications in water purification.

  14. ADSORPTION AND RELEASING PROPERTIES OF BEAD CELLULOSE

    Institute of Scientific and Technical Information of China (English)

    A. Morales; E. Bordallo; V. Leon; J. Rieumont

    2004-01-01

    The adsorption of some dyes on samples of bead cellulose obtained in the Unit of Research-Production "Cuba 9"was studied. Methylene blue, alizarin red and congo red fitted the adsorption isotherm of Langmuir. Adsorption kinetics at pH = 6 was linear with the square root of time indicating the diffusion is the controlling step. At pH = 12 a non-Fickian trend was observed and adsorption was higher for the first two dyes. Experiments carried out to release the methylene blue occluded in the cellulose beads gave a kinetic behavior of zero order. The study of cytochrome C adsorption was included to test a proteinic material. Crosslinking of bead cellulose was performed with epichlorohydrin decreasing its adsorption capacity in acidic or alkaline solution.

  15. Cooling Rates of Lunar Volcanic Glass Beads

    Science.gov (United States)

    Hui, Hejiu; Hess, Kai-Uwe; Zhang, Youxue; Peslier, Anne; Lange, Rebecca; Dingwell, Donald; Neal, Clive

    2016-01-01

    It is widely accepted that the Apollo 15 green and Apollo 17 orange glass beads are of volcanic origin. The diffusion profiles of volatiles in these glass beads are believed to be due to degassing during eruption (Saal et al., 2008). The degree of degassing depends on the initial temperature and cooling rate. Therefore, the estimations of volatiles in parental magmas of lunar pyroclastic deposits depend on melt cooling rates. Furthermore, lunar glass beads may have cooled in volcanic environments on the moon. Therefore, the cooling rates may be used to assess the atmospheric condition in an early moon, when volcanic activities were common. The cooling rates of glasses can be inferred from direct heat capacity measurements on the glasses themselves (Wilding et al., 1995, 1996a,b). This method does not require knowledge of glass cooling environments and has been applied to calculate the cooling rates of natural silicate glasses formed in different terrestrial environments. We have carried out heat capacity measurements on hand-picked lunar glass beads using a Netzsch DSC 404C Pegasus differential scanning calorimeter at University of Munich. Our preliminary results suggest that the cooling rate of Apollo 17 orange glass beads may be 12 K/min, based on the correlation between temperature of the heat capacity curve peak in the glass transition range and glass cooling rate. The results imply that the parental magmas of lunar pyroclastic deposits may have contained more water initially than the early estimations (Saal et al., 2008), which used higher cooling rates, 60-180 K/min in the modeling. Furthermore, lunar volcanic glass beads could have been cooled in a hot gaseous medium released from volcanic eruptions, not during free flight. Therefore, our results may shed light on atmospheric condition in an early moon.

  16. Beads from Inhumation Rite Burials of Gnezdovo Burial Mound

    Directory of Open Access Journals (Sweden)

    Dobrova Olga P.

    2017-12-01

    Full Text Available The beads from 33 inhumation burials at Gnezdovo burial mound are examined in the article. The beads (total 367 were crafted from stretched tube (258, stretched stick (3, winding (45, press molding (2 pcs., welding (2 pcs., and mosaic beads (9 pcs.. The burial mound contains virtually no broken beads, including the settlement's most common yellow glass beads. Besides glass beads, cornelian, crystal, amber and faience beads have been registered among the burial mound material, as well as beads crafted with metal. Apart from beads, grave inventories contained a series of pendants with a bead strung on a wire ring. The considered complexes contain five pendants of this type. Besides Gnezdovo, similar pendants have been discovered in Kiev, Timerev, Pskov and Vladimir barrows. A comparison between bead sets from Gnezdovo and Kiev burial mounds allows to conclude that the general composition and occurrence frequency of beads is identical for these burials. At the same time, beads crafted with rock crystal, cornelian and metal are more frequently discovered in Kiev inhumations.

  17. High-throughput multipesticides residue analysis in earthworms by the improvement of purification method: Development and application of magnetic Fe3 O4 -SiO2 nanoparticles based dispersive solid-phase extraction.

    Science.gov (United States)

    Sun, Yuhan; Qi, Peipei; Cang, Tao; Wang, Zhiwei; Wang, Xiangyun; Yang, Xuewei; Wang, Lidong; Xu, Xiahong; Wang, Qiang; Wang, Xinquan; Zhao, Changshan

    2018-06-01

    As a key representative organism, earthworms can directly illustrate the influence of pesticides on environmental organisms in soil ecosystems. The present work aimed to develop a high-throughput multipesticides residue analytical method for earthworms using solid-liquid extraction with acetonitrile as the solvent and magnetic material-based dispersive solid-phase extraction for purification. Magnetic Fe 3 O 4 nanoparticles were modified with a thin silica layer to form Fe 3 O 4 -SiO 2 nanoparticles, which were fully characterized by field-emission scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffractometry, and vibrating sample magnetometry. The Fe 3 O 4 -SiO 2 nanoparticles were used as the separation media in dispersive solid-phase extraction with primary secondary amine and ZrO 2 as the cleanup adsorbents to eliminate matrix interferences. The amounts of nanoparticles and adsorbents were optimized for the simultaneous determination of 44 pesticides and six metabolites in earthworms by liquid chromatography with tandem mass spectrometry. The method performance was systematically validated with satisfactory results. The limits of quantification were 20 μg/kg for all analytes studied, while the recoveries of the target analytes ranged from 65.1 to 127% with relative standard deviation values lower than 15.0%. The developed method was subsequently utilized to explore the bioaccumulation of bitertanol in earthworms exposed to contaminated soil, verifying its feasibility for real sample analysis. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. exploring traditional glass bead making techniques in jewellery

    African Journals Online (AJOL)

    User

    Glass bead making techniques and their mass production will help the individual ... communicate cultural values in a symbolic lan- guage which ..... Surface of most of the new beads were rough ... tourism potential to be developed further to.

  19. Fungal cultivation on glass-beads

    DEFF Research Database (Denmark)

    Droce, Aida; Sørensen, Jens Laurids; Giese, Henriette

    Transcription of various bioactive compounds and enzymes are dependent on fungal cultivation method. In this study we cultivate Fusarium graminearum and Fusarium solani on glass-beads with liquid media in petri dishes as an easy and inexpensive cultivation method, that resembles in secondary...... metabolite production to agar-cultivation but with an easier and more pure RNA-extraction of total fungal mycelia....

  20. Study on the etched carnelian beads unearthed in China

    Institute of Scientific and Technical Information of China (English)

    Deyun Zhao

    2014-01-01

    Etched carnelian beads originated in the Indus Civilization;this kind of ornaments and its manufacturing techniques were spread to the whole Eurasia Continent.The etched carnelian beads unearthed in China can be classified into four types,the comparisons of which to their foreign counterparts may reveal their different sources and diffusion routes.The etched carnelian beads and their glass imitations unearthed in China had influences to the making of the glass "eye beads" in

  1. Water purification in Borexino

    Energy Technology Data Exchange (ETDEWEB)

    Giammarchi, M. [Infn Milano (Italy); Balata, M.; Ioannucci, L.; Nisi, S. [Laboratori Nazionali del Gran Sasso (Italy); Goretti, A.; Ianni, A. [Princeton University (United States); Miramonti, L. [Dip. di Fisica dell' Università di Milano e Infn (Italy)

    2013-08-08

    Astroparticle Physics and Underground experiments searching for rare nuclear events, need high purity materials to act as detectors or detector shielding. Water has the advantage of being cheap, dense and easily available. Most of all, water can be purified to the goal of obatining a high level of radiopurity. Water Purification can be achieved by means of a combination of processes, including filtration, reverse osmosis, deionization and gas stripping. The Water Purification System for the Borexino experiment, will be described together with its main performances.

  2. Metal-Containing Polystyrene Beads as Standards for Mass Cytometry.

    Science.gov (United States)

    Abdelrahman, Ahmed I; Ornatsky, Olga; Bandura, Dmitry; Baranov, Vladimir; Kinach, Robert; Dai, Sheng; Thickett, Stuart C; Tanner, Scott; Winnik, Mitchell A

    2010-01-01

    We examine the suitability of metal-containing polystyrene beads for the calibration of a mass cytometer instrument, a single particle analyser based on an inductively coupled plasma ion source and a time of flight mass spectrometer. These metal-containing beads are also verified for their use as internal standards for this instrument. These beads were synthesized by multiple-stage dispersion polymerization with acrylic acid as a comonomer. Acrylic acid acts as a ligand to anchor the metal ions within the interior of the beads. Mass cytometry enabled the bead-by-bead measurement of the metal-content and determination of the metal-content distribution. Beads synthesized by dispersion polymerization that involved three stages were shown to have narrower bead-to-bead variation in their lanthanide content than beads synthesized by 2-stage dispersion polymerization. The beads exhibited insignificant release of their lanthanide content to aqueous solutions of different pHs over a period of six months. When mixed with KG1a or U937 cell lines, metal-containing polymer beads were shown not to affect the mass cytometry response to the metal content of element-tagged antibodies specifically attached to these cells.

  3. A Controlled Drug-Delivery Experiment Using Alginate Beads

    Science.gov (United States)

    Farrell, Stephanie; Vernengo, Jennifer

    2012-01-01

    This paper describes a simple, cost-effective experiment which introduces students to drug delivery and modeling using alginate beads. Students produce calcium alginate beads loaded with drug and measure the rate of release from the beads for systems having different stir rates, geometries, extents of cross-linking, and drug molecular weight.…

  4. Assessment of the Problems of Manual Automobile Tyre Bead ...

    African Journals Online (AJOL)

    The tyre-rim bead bond must be broken to carry out repairs on a failed automobile tyre. The use of the locally fabricated manual bead breaking equipment as it is being practiced today by commercial tyre repair artisans in Nigeria is characterized by drudgery. This article reports a study of the local manual bead breaking ...

  5. New Nanoparticles Dispersing Beads Mill with Ultra Small Beads and its Application

    International Nuclear Information System (INIS)

    Inkyo, M; Tahara, T; Imajyo, Y

    2011-01-01

    Two of the major problems related to nanoparticle dispersion with a conventional beads mill are re-agglomeration and damage to the crystalline structure of the particles. The Ultra Apex Mill was developed to solve these problems by enabling the use of ultra-small beads with a diameter of less than 0.1mm. The core of this breakthrough development is centrifugation technology which allows the use of beads as small as 0.015mm. When dispersing agglomerated nanoparticles the impulse of the small beads is very low which means there is little influence on the particles. The surface energy of the nanoparticles remains low so the properties are not likely to change. As a result, stable nanoparticle dispersions can be achieved without re-cohesion. The Ultra Apex Mill is superior to conventional beads mills that are limited to much larger bead sizes. The technology of the Ultra Apex Mill has pioneered practical applications for nanoparticles in various fields: composition materials for LCD screens, ink-jet printing, ceramic condensers and cosmetics.

  6. Friction of N-bead macromolecules in solution: Effects of the bead-solvent interaction

    International Nuclear Information System (INIS)

    Uvarov, Alexander; Fritzsche, Stephan

    2006-01-01

    The role of the bead-solvent interaction has been studied for its influence on the dynamics of an N-bead macromolecule which is immersed into a solution. Using a Fokker-Planck equation for the phase-space distribution function of the macromolecule, we show that all the effects of the solution can be treated entirely in terms of the friction tensors which are assigned to each pair of interacting beads in the chain. For the high-density as well as for the critical solvent, the properties of these tensors are discussed in detail and are calculated by using several (realistic) choices of the bead-solvent potential. From the friction tensors, moreover, an expression for the center-of-mass friction coefficient of a (N-bead) chain macromolecule is derived. Numerical data for this coefficient for 'truncated' Lennard-Jones bead-solvent potential are compared with results from molecular dynamic simulations and from the phenomenological theoretical data as found in the literature

  7. Resin bead-thermal ionization mass spectrometry for determination of plutonium concentration in irradiated fuel dissolver solution

    International Nuclear Information System (INIS)

    Paul, Sumana; Shah, R.V.; Aggarwal, S.K.; Pandey, A.K.

    2015-01-01

    Determination of isotopic composition (IC) and concentration of plutonium (Pu) is necessary at various stages of nuclear fuel cycle which involves analysis of complex matrices like dissolver solution of irradiated fuel, nuclear waste stream etc. Mass spectrometry, e.g. thermal ionization mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICP-MS) are commonly used for determination of IC and concentration of plutonium. However, to circumvent matrix interferences, efficient separation as well as preconcentration of Pu is required prior to mass spectrometric analysis. Purification steps employing ion-exchange resins are widely used for the separation of Pu from dissolver solution or from mixture of other actinides e.g. U, Am. However, an alternative way is to selectively preconcentrate Pu on a resin bead, followed by direct loading of the bead on the filament of thermal ionization mass spectrometer

  8. Superparamagnetic microbead transport induced by a magnetic field on large-area magnetic antidot arrays

    Science.gov (United States)

    Ouk, Minae; Beach, Geoffrey S. D.

    2017-12-01

    A method is presented for directed transport of superparamagnetic microbeads (SPBs) on magnetic antidot patterned substrates by applying a rotating elliptical magnetic field. We find a critical frequency for transport, beyond which the bead dynamics transitions from stepwise locomotion to local oscillation. We also find that the out-of-plane (HOOP) and in-plane (HIP) field magnitudes play crucial roles in triggering bead motion. Namely, we find threshold values in HOOP and HIP that depend on bead size, which can be used to independently and remotely address specific bead populations in a multi-bead mixture. These behaviors are explained in terms of the dynamic potential energy lansdscapes computed from micromagnetic simulations of the substrate magnetization configuration. Finally, we show that large-area magnetic patterns suitable for particle transport and sorting can be fabricated through a self-assembly lithography technique, which provides a simple, cost-effective means to integrate magnetic actuation into microfluidic systems.

  9. Magnetic biosensor system to detect biological targets

    KAUST Repository

    Li, Fuquan

    2012-09-01

    Magneto-resistive sensors in combination with magnetic beads provide sensing platforms, which are small in size and highly sensitive. These platforms can be fully integrated with microchannels and electronics to enable devices capable of performing complex tasks. Commonly, a sandwich method is used that requires a specific coating of the sensor\\'s surface to immobilize magnetic beads and biological targets on top of the sensor. This paper concerns a micro device to detect biological targets using magnetic concentration, magnetic as well as mechanical trapping and magnetic sensing. Target detection is based on the size difference between bare magnetic beads and magnetic beads with targets attached. This method remedies the need for a coating layer and reduces the number of steps required to run an experiment. © 2012 IEEE.

  10. Sodium purification in Rapsodie

    International Nuclear Information System (INIS)

    Giraud, B.

    1968-01-01

    This report is one of a series of publications presenting the main results of tests carried out during the start-up of the first french fast neutron reactor: Rapsodie. The article presents the sodium purification techniques used in the reactor cooling circuits both from the constructional point of view and with respect to results obtained during the first years working. (author) [fr

  11. Bead-bead interaction parameters in dissipative particle dynamics: Relation to bead-size, solubility parameter, and surface tension

    Science.gov (United States)

    Maiti, Amitesh; McGrother, Simon

    2004-01-01

    Dissipative particle dynamics (DPD) is a mesoscale modeling method for simulating equilibrium and dynamical properties of polymers in solution. The basic idea has been around for several decades in the form of bead-spring models. A few years ago, Groot and Warren [J. Chem. Phys. 107, 4423 (1997)] established an important link between DPD and the Flory-Huggins χ-parameter theory for polymer solutions. We revisit the Groot-Warren theory and investigate the DPD interaction parameters as a function of bead size. In particular, we show a consistent scheme of computing the interfacial tension in a segregated binary mixture. Results for three systems chosen for illustration are in excellent agreement with experimental results. This opens the door for determining DPD interactions using interfacial tension as a fitting parameter.

  12. A magnetic biosensor system for detection of E. coli

    KAUST Repository

    Li, Fuquan

    2013-07-01

    This work describes a device for detecting E. coli bacteria by manipulating superparamagnetic beads to a sensing area and immobilizing them in a trapping well. The trapping well replaces the biochemical immobilization layer, which is commonly used in magnetic biosensor systems. A concept exploiting the volume difference between bare magnetic beads and magnetic bead-bioanalyte compounds is utilized to detect E. coli bacteria. Trapped beads are detected by the help of a tunnel magneto-resistive sensor. Frequency modulation is employed, in order to increase the signal-to-noise ratio, enabling the detection of individual superparamagnetic beads of 2.8 μm in diameter. Replacing the biochemical immobilization layer by the trapping well greatly simplifies the detection process. After applying the mixture of E. coli and magnetic beads to the biosensor system, bacteria detection is achieved in a single step, within a few minutes. © 2013 IEEE.

  13. Imaging based agglutination measurement of magnetic micro-particles on a lab-on-a-disk platform

    DEFF Research Database (Denmark)

    Wantiya, P.; Burger, Robert; Alstrøm, Tommy Sonne

    2014-01-01

    In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution.......In this work we present a magnetic micro beads based agglutination assay on a centrifugal microfluidic platform. An imaging based method is used to quantify bead agglutination and measure the concentration of antibodies or C-reactive protein in solution....

  14. Magnets

    International Nuclear Information System (INIS)

    Young, I.R.

    1984-01-01

    A magnet pole piece for an NMR imaging magnet is made of a plurality of magnetic wires with one end of each wire held in a non-magnetic spacer, the other ends of the wires being brought to a pinch, and connected to a magnetic core. The wires may be embedded in a synthetic resin and the magnetisation and uniformity thereof can be varied by adjusting the density of the wires at the spacer which forms the pole piece. (author)

  15. The control of beads diameter of bead-on-string electrospun nanofibers and the corresponding release behaviors of embedded drugs

    Energy Technology Data Exchange (ETDEWEB)

    Li, Tingxiao [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education of China, Shanghai 201620 (China); College of Textiles, Donghua University, Shanghai 201620 (China); Ding, Xin, E-mail: xding@dhu.edu.cn [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education of China, Shanghai 201620 (China); College of Textiles, Donghua University, Shanghai 201620 (China); Tian, Lingling, E-mail: lingling_tian@nus.edu.sg [Center of Nanofibers & Nanotechnology, Department of Mechanical Engineering, National University of Singapore, 117576 (Singapore); Hu, Jiyong; Yang, Xudong [Key Laboratory of Textile Science and Technology (Donghua University), Ministry of Education of China, Shanghai 201620 (China); College of Textiles, Donghua University, Shanghai 201620 (China); Ramakrishna, Seeram [Center of Nanofibers & Nanotechnology, Department of Mechanical Engineering, National University of Singapore, 117576 (Singapore); Guangdong-Hongkong-Macau Institute of CNS Regeneration (GHMICR), Jinan University, Guangzhou 510632 (China)

    2017-05-01

    Bead-on-string nanofibers, with appropriate control of the beads diameter, are potential fibrous structures for efficient encapsulation of particle drugs in micron scales and could achieve controlled drug release for tissue engineering applications. In this study, the beads diameter of electrospun bead-on-string nanofibers was controlled by adjusting the concentration of spinning polymer, poly (lactic-co-glycolic acid) (PLGA), and the solvent ratio of chloroform to acetone. The images of the scanning electron microscopy (SEM) suggested that bead-on-string nanofibers could be successfully obtained only with a certain range of PLGA solution concentration. Moreover, with the decrease in the solvent ratio of chloroform to acetone, the range was left-shifted towards a smaller concentration. In addition, increase in the PLGA solution concentration within the range the beads diameter became greater and the shape of the beads changed from oval to slender when increasing the PLGA concentration within the range. The bead-on-string nanofibers with different beads diameter were further used to load micro-particle drugs of tetracycline hydrochloride, as a model drug, to examine the release behavior of nanofibers scaffold. The release profiles of drug loaded bead-on-string nanofibers demonstrated the possibility to alleviate the burst drug release by means of beads diameter control. - Highlights: • Bead diameter of bead-on-string electrospun nanofibers was controlled by varying solvent ratio and polymer concentration. • The effect of the addition of particle drugs on BD of bead-on-string electrospun nanofibers was studied. • The corresponding release behaviors of nanofibers with different BD loading micro-particle drugs were investigated. • Bead-on-string nanofibers with bigger BD could alleviate the initial burst release.

  16. The control of beads diameter of bead-on-string electrospun nanofibers and the corresponding release behaviors of embedded drugs

    International Nuclear Information System (INIS)

    Li, Tingxiao; Ding, Xin; Tian, Lingling; Hu, Jiyong; Yang, Xudong; Ramakrishna, Seeram

    2017-01-01

    Bead-on-string nanofibers, with appropriate control of the beads diameter, are potential fibrous structures for efficient encapsulation of particle drugs in micron scales and could achieve controlled drug release for tissue engineering applications. In this study, the beads diameter of electrospun bead-on-string nanofibers was controlled by adjusting the concentration of spinning polymer, poly (lactic-co-glycolic acid) (PLGA), and the solvent ratio of chloroform to acetone. The images of the scanning electron microscopy (SEM) suggested that bead-on-string nanofibers could be successfully obtained only with a certain range of PLGA solution concentration. Moreover, with the decrease in the solvent ratio of chloroform to acetone, the range was left-shifted towards a smaller concentration. In addition, increase in the PLGA solution concentration within the range the beads diameter became greater and the shape of the beads changed from oval to slender when increasing the PLGA concentration within the range. The bead-on-string nanofibers with different beads diameter were further used to load micro-particle drugs of tetracycline hydrochloride, as a model drug, to examine the release behavior of nanofibers scaffold. The release profiles of drug loaded bead-on-string nanofibers demonstrated the possibility to alleviate the burst drug release by means of beads diameter control. - Highlights: • Bead diameter of bead-on-string electrospun nanofibers was controlled by varying solvent ratio and polymer concentration. • The effect of the addition of particle drugs on BD of bead-on-string electrospun nanofibers was studied. • The corresponding release behaviors of nanofibers with different BD loading micro-particle drugs were investigated. • Bead-on-string nanofibers with bigger BD could alleviate the initial burst release.

  17. Adsorption of arsenic by activated carbon, calcium alginate and their composite beads

    Czech Academy of Sciences Publication Activity Database

    Hassan, A F.; Abdel-Mohsen, A. M.; Elhadidy, Hassan

    2014-01-01

    Roč. 68, JUL (2014), s. 125-130 ISSN 0141-8130 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA MŠk(CZ) EE2.3.20.0214 Institutional support: RVO:68081723 Keywords : Apricot stone * Alginate beads * Composite * Arsenic * Adsorption Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.858, year: 2014

  18. Biosorption of americium by alginate beads

    International Nuclear Information System (INIS)

    Borba, Tania Regina de; Marumo, Julio Takehiro; Goes, Marcos Maciel de; Ferreira, Rafael Vicente de Padua; Sakata, Solange Kazumi

    2009-01-01

    The use of biotechnology to remove heavy metals from wastes plays great potential in treatment of radioactive wastes and therefore the aim of this study was to evaluate the biosorption of americium by alginate beads. Biosorption has been defined as the property of certain biomolecules to bind and remove selected ions or other molecules from aqueous solutions. The calcium alginate beads as biosorbent were prepared and analyzed for americium uptaking. The experiments were performed in different solution activity concentrations, pH and exposure time. The results suggest that biosorption process is more efficient at pH 4 and for 75, 150, 300 Bq/mL and 120 minutes were necessary to remove almost 100% of the americium-241 from the solution. (author)

  19. RF Bead Pull Measurements of the DQW

    CERN Document Server

    Jaume, Guillaume

    2015-01-01

    This report was written within the framework of the CERN Summer Student Program. It is focused on the Radio Frequency study of the Double Quarter Wave Crab Cavity [1] considered for the crab-crossing scheme of the LHC Luminosity upgrade [2]. HFSS simulation [3] and Bead-Pull Measurements technique were used for the characterization of the higher-order terms of the main deflecting mode.

  20. Magnetic Bead—Magic Bullet

    Directory of Open Access Journals (Sweden)

    Christine Ruffert

    2016-01-01

    Full Text Available Microfluidics is assumed to be one of the leading and most promising areas of research since the early 1990s. In microfluidic systems, small spherical magnetic particles with superparamagnetic properties, called magnetic beads, play an important role in the design of innovative methods and tools, especially in bioanalysis and medical sciences. The intention of this review paper is to address main aspects from the state-of-the-art in the area of magnetic bead research, while demonstrating the broad variety of applications and the huge potential to solve fundamental biological and medical problems in the fields of diagnostics and therapy. Basic issues and demands related to the fabrication of magnetic particles and physical properties of nanosize magnets are discussed in Section 2. Of main interest are the control and adjustment of the nanoparticles’ properties and the availability of adequate approaches for particle detection via their magnetic field. Section 3 presents an overview of magnetic bead applications in nanomedicine. In Section 4, practical aspects of sample manipulation and separation employing magnetic beads are described. Finally, the benefits related to the use of magnetic bead-based microfluidic systems are summarized, illustrating ongoing questions and open tasks to be solved on the way to an approaching microfluidic age.

  1. Spray drying of bead resins: feasibility tests

    International Nuclear Information System (INIS)

    Gay, R.L.; Grantham, L.F.; Jones, L.J.

    1984-01-01

    Rockwell International has developed a volume reduction system for low-level reactor wastes based on drying the wastes in a heated-air spray dryer. The drying of slurries of sodium sulfate, boric acid, and powdered ion exchange resins was demonstrated in previous tests. The drying of bead ion exchange resins can be especially difficult due to the relatively large size of bead resins (about 500 to 800 microns) and their natural affinity for water. This water becomes part of the pore structure of the resins and normally comprises 50 t 60 wt % of the resin weight. A 76-cm-diameter spray dryer was used for feasibility tests of spray drying of cation and anion bead resins. These resins were fed to the dryer in the as-received form (similar to dewatered resins) and as slurries. A dry, free-flowing product was produced in all the tests. The volume of the spray-dried product was one-half to one-third the volume of the as-received material. An economic analysis was made of the potential cost savings that can be achieved using the Rockwel spray dryer system. In-plant costs, transportation costs, and burial costs of spray-dried resins were compared to similar costs for disposal of dewatered resins. A typical utility producing 170 m 3 (6,000 ft 3 ) per year of dewatered resins can save $600,000 to $700,000 per year using this volume reduction system

  2. Demonstrations of the Action and Reaction Law and the Energy Conservation Law Using Fine Spherical Plastic Beads

    Science.gov (United States)

    Khumaeni, A.; Tanaka, S.; Kobayashi, A.; Lee, Y. I.; Kurniawan, K. H.; Ishii, K.; Kagawa, K.

    2008-01-01

    Equipment for demonstrating Newton's third law and the energy conservation law in mechanics have successfully been constructed utilizing fine spherical plastic beads in place of metal ball bearings. To demonstrate Newton's third law, special magnetized Petri dishes were employed as objects, while to examine the energy conservation law, a…

  3. Lab-on-a-Chip Magneto-Immunoassays: How to Ensure Contact between Superparamagnetic Beads and the Sensor Surface

    Directory of Open Access Journals (Sweden)

    Andreas Hütten

    2013-09-01

    Full Text Available Lab-on-a-chip immuno assays utilizing superparamagnetic beads as labels suffer from the fact that the majority of beads pass the sensing area without contacting the sensor surface. Different solutions, employing magnetic forces, ultrasonic standing waves, or hydrodynamic effects have been found over the past decades. The first category uses magnetic forces, created by on-chip conducting lines to attract beads towards the sensor surface. Modifications of the magnetic landscape allow for additional transport and separation of different bead species. The hydrodynamic approach uses changes in the channel geometry to enhance the capture volume. In acoustofluidics, ultrasonic standing waves force µm-sized particles onto a surface through radiation forces. As these approaches have their disadvantages, a new sensor concept that circumvents these problems is suggested. This concept is based on the granular giant magnetoresistance (GMR effect that can be found in gels containing magnetic nanoparticles. The proposed design could be realized in the shape of paper-based test strips printed with gel-based GMR sensors.

  4. Peptide nucleic acid probe for protein affinity purification based on biotin-streptavidin interaction and peptide nucleic acid strand hybridization.

    Science.gov (United States)

    Tse, Jenny; Wang, Yuanyuan; Zengeya, Thomas; Rozners, Eriks; Tan-Wilson, Anna

    2015-02-01

    We describe a new method for protein affinity purification that capitalizes on the high affinity of streptavidin for biotin but does not require dissociation of the biotin-streptavidin complex for protein retrieval. Conventional reagents place both the selectively reacting group (the "warhead") and the biotin on the same molecule. We place the warhead and the biotin on separate molecules, each linked to a short strand of peptide nucleic acid (PNA), synthetic polymers that use the same bases as DNA but attached to a backbone that is resistant to attack by proteases and nucleases. As in DNA, PNA strands with complementary base sequences hybridize. In conditions that favor PNA duplex formation, the warhead strand (carrying the tagged protein) and the biotin strand form a complex that is held onto immobilized streptavidin. As in DNA, the PNA duplex dissociates at moderately elevated temperature; therefore, retrieval of the tagged protein is accomplished by a brief exposure to heat. Using iodoacetate as the warhead, 8-base PNA strands, biotin, and streptavidin-coated magnetic beads, we demonstrate retrieval of the cysteine protease papain. We were also able to use our iodoacetyl-PNA:PNA-biotin probe for retrieval and identification of a thiol reductase and a glutathione transferase from soybean seedling cotyledons. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Uranium hexafluoride purification

    International Nuclear Information System (INIS)

    Araujo, Eneas F. de

    1986-01-01

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF 6 -HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF 6 -HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  6. Electron beam silicon purification

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Anatoly [SIA ' ' KEPP EU' ' , Riga (Latvia); Kravtsov, Alexey [' ' KEPP-service' ' Ltd., Moscow (Russian Federation)

    2014-11-15

    Purification of heavily doped electronic grade silicon by evaporation of N-type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150-300 kg) and yield solar grade silicon. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Discrete dipole approximation simulation of bead enhanced diffraction grating biosensor

    International Nuclear Information System (INIS)

    Arif, Khalid Mahmood

    2016-01-01

    We present the discrete dipole approximation simulation of light scattering from bead enhanced diffraction biosensor and report the effect of bead material, number of beads forming the grating and spatial randomness on the diffraction intensities of 1st and 0th orders. The dipole models of gratings are formed by volume slicing and image processing while the spatial locations of the beads on the substrate surface are randomly computed using discrete probability distribution. The effect of beads reduction on far-field scattering of 632.8 nm incident field, from fully occupied gratings to very coarse gratings, is studied for various bead materials. Our findings give insight into many difficult or experimentally impossible aspects of this genre of biosensors and establish that bead enhanced grating may be used for rapid and precise detection of small amounts of biomolecules. The results of simulations also show excellent qualitative similarities with experimental observations. - Highlights: • DDA was used to study the relationship between the number of beads forming gratings and ratio of first and zeroth order diffraction intensities. • A very flexible modeling program was developed to design complicated objects for DDA. • Material and spatial effects of bead distribution on surfaces were studied. • It has been shown that bead enhanced grating biosensor can be useful for fast detection of small amounts of biomolecules. • Experimental results qualitatively support the simulations and thus open a way to optimize the grating biosensors.

  8. Theoretical analysis of ferromagnetic microparticles in streaming liquid under the influence of external magnetic forces

    International Nuclear Information System (INIS)

    Brandl, Martin; Mayer, Michael; Hartmann, Jens; Posnicek, Thomas; Fabian, Christian; Falkenhagen, Dieter

    2010-01-01

    The microsphere based detoxification system (MDS) is designed for high specific toxin removal in extracorporeal blood purification using functionalized microparticles. A thin wall hollow fiber membrane filter separates the microparticle-plasma suspension from the bloodstream. For patient safety, it is necessary to have a safety system to detect membrane ruptures that could lead to the release of microparticles into the bloodstream. A non-invasive optical detection system including a magnetic trap is developed to monitor the extracorporeal venous bloodstream for the presence of released microparticles. For detection, fluorescence-labeled ferromagnetic beads are suspended together with adsorbent particles in the MDS circuit. In case of a membrane rupture, the labeled particles would be released into the venous bloodstream and partly captured by the magnetic trap of the detector. A physical model based on fluidic, gravitational and magnetic forces was developed to simulate the motion and sedimentation of ferromagnetic particles in a magnetic trap. In detailed simulation runs, the concentrations of accumulated particles under different applied magnetic fields within the magnetic trap are shown. The simulation results are qualitatively compared with laboratory experiments and show excellent accordance. Additionally, the sensitivity of the particle detection system is proofed in a MDS laboratory experiment by simulation of a membrane rupture.

  9. Magnetic microbead detection using the planar Hall effect

    International Nuclear Information System (INIS)

    Ejsing, Louise; Hansen, Mikkel F.; Menon, Aric K.; Ferreira, Hugo A.; Graham, Daniel L.; Freitas, Paulo P.

    2005-01-01

    Magnetic sensors based on the planar Hall effect of exchanged-biased permalloy have been fabricated and characterized. It is demonstrated that the sensors are feasible for detecting just a few commercial 2.0 μm magnetic beads commonly used for bioseparation (Micromer-M, Micromod, Germany) and that the sensor sense current is sufficient to generate a signal from the beads

  10. HPMA and HEMA copolymer bead interactions with eukaryotic cells

    Directory of Open Access Journals (Sweden)

    Cristina D. Vianna-Soares

    2004-09-01

    Full Text Available Two different hydrophilic acrylate beads were prepared via aqueous suspension polymerization. Beads produced of a hydroxypropyl methacrylate (HPMA and ethyleneglycol methacrylate (EDMA copolymer were obtained using a polyvinyl alcohol suspending medium. Copolymers of 2hydroxyethyl methacrylate (HEMA, methyl methacrylate (MMA and ethyleneglycol methacrylate (EDMA beads were obtained using magnesium hydroxide as the suspending agent. Following characterization by scanning electron microscopy (SEM, nitrogen sorption analysis (NSA and mercury intrusion porosimetry (MIP, the beads were cultured with monkey fibroblasts (COS7 to evaluate their ability to support cell growth, attachment and adhesion. Cell growth behavior onto small HPMA/EDMA copolymer beads and large HEMA/MMA/EDMA copolymer beads is evaluated regarding their hidrophilicity/hidrophobicity and surface roughness.

  11. Microarray of DNA probes on carboxylate functional beads surface

    Institute of Scientific and Technical Information of China (English)

    黄承志; 李原芳; 黄新华; 范美坤

    2000-01-01

    The microarray of DNA probes with 5’ -NH2 and 5’ -Tex/3’ -NH2 modified terminus on 10 um carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) is characterized in the preseni paper. it was found that the microarray capacity of DNA probes on the beads surface depends on the pH of the aqueous solution, the concentra-tion of DNA probe and the total surface area of the beads. On optimal conditions, the minimum distance of 20 mer single-stranded DNA probe microarrayed on beads surface is about 14 nm, while that of 20 mer double-stranded DNA probes is about 27 nm. If the probe length increases from 20 mer to 35 mer, its microarray density decreases correspondingly. Mechanism study shows that the binding mode of DNA probes on the beads surface is nearly parallel to the beads surface.

  12. Microarray of DNA probes on carboxylate functional beads surface

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The microarray of DNA probes with 5′-NH2 and 5′-Tex/3′-NH2 modified terminus on 10 m m carboxylate functional beads surface in the presence of 1-ethyl-3-(3-dimethylaminopropyl)- carbodiimide (EDC) is characterized in the present paper. It was found that the microarray capacity of DNA probes on the beads surface depends on the pH of the aqueous solution, the concentration of DNA probe and the total surface area of the beads. On optimal conditions, the minimum distance of 20 mer single-stranded DNA probe microarrayed on beads surface is about 14 nm, while that of 20 mer double-stranded DNA probes is about 27 nm. If the probe length increases from 20 mer to 35 mer, its microarray density decreases correspondingly. Mechanism study shows that the binding mode of DNA probes on the beads surface is nearly parallel to the beads surface.

  13. Detection of ''beading faults'' in welded tubes

    International Nuclear Information System (INIS)

    Mondot, J.

    In the steel tube industry the word ''beading'' refers to a highly localised leak affecting the welded zone. During the pneumatic test its flow rate is generally very low no more than a few thousandths of a mm 3 /second. Detection of such a fault by this test is consequently slow, and those which are choked or at the limit of leakage may escape detection. For greater safety, the tube technician is now using non-destructive testing methods such as eddy-currents and ultrasonics [fr

  14. A magnetic method to concentrate and trap biological targets

    KAUST Repository

    Li, Fuquan

    2012-11-01

    Magnetoresistive sensors in combination with magnetic particles have been used in biological applications due to, e.g., their small size and high sensitivity. A growing interest is to integrate magnetoresistive sensors with microchannels and electronics to fabricate devices that can perform complex analyses. A major task in such systems is to immobilize magnetic particles on top of the sensor surface, which is required to detect the particles\\' stray field. In the presented work, a bead concentrator, consisting of gold microstructures, at the bottom of a microchannel, is used to attract and move magnetic particles into a trap. The trap is made of a chamber with a gold microstructure underneath and is used to attract and immobilize a defined number of magnetic beads. In order to detect targets, two kinds of solutions were prepared; one containing only superparamagnetic particles, the other one containing beads with the protein Bovine serum albumin as the target and fluorescent markers. Due to the size difference between bare beads and beads with target, less magnetic beads were immobilized inside the volume chamber in case of magnetic beads with target as compared to bare magnetic beads. © 1965-2012 IEEE.

  15. Creating nanoshell on the surface of titanium hydride bead

    Directory of Open Access Journals (Sweden)

    PAVLENKO Vyacheslav Ivanovich

    2016-12-01

    Full Text Available The article presents data on the modification of titanium hydride bead by creating titanium nanoshell on its surface by ion-plasma vacuum magnetron sputtering. To apply titanium nanoshell on the titanium hydride bead vacuum coating plant of multifunctional nanocomposite coatings QVADRA 500 located in the center of high technology was used. Analysis of the micrographs of the original surface of titanium hydride bead showed that the microstructure of the surface is flat, smooth, in addition the analysis of the microstructure of material surface showed the presence of small porosity, roughness, mainly cavities, as well as shallow longitudinal cracks. The presence of oxide film in titanium hydride prevents the free release of hydrogen and fills some micro-cracks on the surface. Differential thermal analysis of both samples was conducted to determine the thermal stability of the initial titanium hydride bead and bead with applied titanium nanoshell. Hydrogen thermal desorption spectra of the samples of the initial titanium hydride bead and bead with applied titanium nanoshell show different thermal stability of compared materials in the temperature range from 550 to 860о C. Titanium nanoshells applied in this way allows increasing the heat resistance of titanium hydride bead – the temperature of starting decomposition is 695о C and temperature when decomposition finishes is more than 1000о C. Modified in this way titanium hydride bead can be used as a filler in the radiation protective materials used in the construction or upgrading biological protection of nuclear power plants.

  16. Study on Surface Modification of Glass Bead by a Block Copolymer Coupling Agent

    Institute of Scientific and Technical Information of China (English)

    LI Yin; ZHANG Bing; ZHOU Xiao-dong

    2008-01-01

    A tri-block copolymer coupling agent polystyrene biock-poly(n-butyl-acrylate)-block-poly(r-methacryloxypro pylt rimethoxysilane)(PS-b-PnBA-b-PMPS)was synthesized by atom transfer radical polymerization(ATRP),and its molecular structure was characterized by fourier-transform infrared spectra,hydrogen nuclear magnetic resonance and gel permeation chromatography.The glass bead was treated with the block copolymer coupling agent,and then studied by transmission electron microscopy.The result showed that strong interaction was formed between the block copolymer coupling agent and the surface of glass bead,and then the block of poly(n-butylacrylate)formed a layer of film on the surface.

  17. Magnetic manipulation and sensing of beads for bioapplications

    DEFF Research Database (Denmark)

    Henriksen, Anders Dahl

    Point-of-care diagnostics is predicted to revolutionize the way of healthcare and advance the field of personalized medicine. Point-of-care diagnostics opens the possibility of doing complex molecular biochemical analysis at the patient's home or at the doctor's office, instead of sending samples...

  18. Enzyme-linked electrochemical DNA ligation assay using magnetic beads

    Czech Academy of Sciences Publication Activity Database

    Stejskalová, Eva; Horáková Brázdilová, Petra; Vacek, J.; Bowater, R. P.; Fojta, Miroslav

    2014-01-01

    Roč. 406, č. 17 (2014), s. 4129-4136 ISSN 1618-2642 R&D Projects: GA ČR(CZ) GPP206/11/P739; GA ČR(CZ) GAP206/11/1638; GA AV ČR(CZ) IAA400040901 Institutional support: RVO:68081707 Keywords : Electrochemistry * Enzyme labeling * DNA ligase Subject RIV: BO - Biophysics Impact factor: 3.436, year: 2014

  19. Air/Water Purification

    Science.gov (United States)

    1992-01-01

    After 18 years of research into air/water pollution at Stennis Space Center, Dr. B. C. Wolverton formed his own company, Wolverton Environmental Services, Inc., to provide technology and consultation in air and water treatment. Common houseplants are used to absorb potentially harmful materials from bathrooms and kitchens. The plants are fertilized, air is purified, and wastewater is converted to clean water. More than 100 U.S. communities have adopted Wolverton's earlier water hyacinth and artificial marsh applications. Catfish farmers are currently evaluating the artificial marsh technology as a purification system.

  20. Water Purification Product

    Science.gov (United States)

    2004-01-01

    Ecomaster, an affiliate of BioServe Space Technologies, this PentaPure technology has been used to purify water for our nation's Space Shuttle missions since 1981. WTC-Ecomaster of Mirneapolis, Minnesota manufactures water purification systems under the brand name PentaPure (TM). BioServe researcher Dr. George Marchin, of Kansas State University, first demonstrated the superiority of this technology and licensed it to WTC. Marchin continues to perform microgravity research in the development of new technologies for the benefit of life on Earth.

  1. Gas purification project

    International Nuclear Information System (INIS)

    Broothaerts, J.; Claes, J.; Collard, G.; Goossens, W.; Harnie, R.; Heylen, P.; Vaesen, J.; Beukelaer, R. de; Dubois, G.; Glibert, R.; Mestrez, J.; Zahlen, A.

    1975-06-01

    Conceptual and experimental studies on LMFBR reprocessing and reactor off-gas purification systems are summarized. Iodine sorption on zeolites, low-temperature adsorption of noble gases on charcoal and catalytic oxidation of hydrogen, simulating tritium, are being studied in laboratory set-ups. A pilot loop with 25 m 3 h -1 throughput has been constructed. Results are quoted from the first phase of the iodine removal programme by scrubbing systems. Further extension of the test loop, comprising off-gases conditioning to removal of krypton in a cryodistillation unit, has been prepared. Delay-bed studies on 133 Xe extraction from LWR off-gases are reported. (author)

  2. Identifying specific protein interaction partners using quantitative mass spectrometry and bead proteomes

    Science.gov (United States)

    Trinkle-Mulcahy, Laura; Boulon, Séverine; Lam, Yun Wah; Urcia, Roby; Boisvert, François-Michel; Vandermoere, Franck; Morrice, Nick A.; Swift, Sam; Rothbauer, Ulrich; Leonhardt, Heinrich; Lamond, Angus

    2008-01-01

    The identification of interaction partners in protein complexes is a major goal in cell biology. Here we present a reliable affinity purification strategy to identify specific interactors that combines quantitative SILAC-based mass spectrometry with characterization of common contaminants binding to affinity matrices (bead proteomes). This strategy can be applied to affinity purification of either tagged fusion protein complexes or endogenous protein complexes, illustrated here using the well-characterized SMN complex as a model. GFP is used as the tag of choice because it shows minimal nonspecific binding to mammalian cell proteins, can be quantitatively depleted from cell extracts, and allows the integration of biochemical protein interaction data with in vivo measurements using fluorescence microscopy. Proteins binding nonspecifically to the most commonly used affinity matrices were determined using quantitative mass spectrometry, revealing important differences that affect experimental design. These data provide a specificity filter to distinguish specific protein binding partners in both quantitative and nonquantitative pull-down and immunoprecipitation experiments. PMID:18936248

  3. MAGNET

    CERN Multimedia

    by B. Curé

    2011-01-01

    The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...

  4. TiO2 beads and TiO2-chitosan beads for urease immobilization

    International Nuclear Information System (INIS)

    Ispirli Doğaç, Yasemin; Deveci, İlyas; Teke, Mustafa; Mercimek, Bedrettin

    2014-01-01

    The aim of the present study is to synthesize TiO 2 beads for urease immobilization. Two different strategies were used to immobilize the urease on TiO 2 beads. In the first method (A), urease enzyme was immobilized onto TiO 2 beads by adsorption and then crosslinking. In the second method (B), TiO 2 beads were coated with chitosan-urease mixture. To determine optimum conditions of immobilization, different parameters were investigated. The parameters of optimization were initial enzyme concentration (0.5; 1; 1.5; 2 mg/ml), alginate concentration (1; 2; 3%), glutaraldehyde concentration (1; 2; 3% v/v) and chitosan concentration (2; 3; 4 mg/ml). The optimum enzyme concentrations were determined as 1.5 mg/ml for A and 1.0 mg/ml for B. The other optimum conditions were found 2.0% (w/v) for alginate concentration (both A and B); 3.0 mg/ml for chitosan concentration (B) and 2.0% (v/v) for glutaraldehyde concentration (A). The optimum temperature (20-60 °C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4–70 °C), pH stability (4.0-9.0), operational stability (0-230 min) and reusability (20 times) were investigated for characterization. The optimum temperatures were 30 °C (A), 40 °C (B) and 35 °C (soluble). The temperature profiles of the immobilized ureases were spread over a large area. The optimum pH values for the soluble urease and immobilized urease prepared by using methods (A) and (B) were found to be 7.5, 7.0, 7.0, respectively. The thermal stabilities of immobilized enzyme sets were studied and they maintained 50% activity at 65 °C. However, at this temperature free urease protected only 15% activity. - Highlights: • TiO 2 and TiO 2 -chitosan beads for urease immobilization have been prepared and characterized. • The beads used in this work are good matrices for the immobilization of urease. • The immobilized urease was shown to have good properties and stabilities (pH and thermal stability, operational stability). • The 50

  5. Bead Collage: An Arts-Based Research Method

    Science.gov (United States)

    Kay, Lisa

    2013-01-01

    In this paper, "bead collage," an arts-based research method that invites participants to reflect, communicate and construct their experience through the manipulation of beads and found objects is explained. Emphasizing the significance of one's personal biography and experiences as a researcher, I discuss how my background as an…

  6. Growth and morphology of thermophilic dairy starters in alginate beads.

    Science.gov (United States)

    Lamboley, Laurence; St-Gelais, Daniel; Champagne, Claude P; Lamoureux, Maryse

    2003-06-01

    The aim of this research was to produce concentrated biomasses of thermophilic lactic starters using immobilized cell technology (ICT). Fermentations were carried out in milk using pH control with cells microentrapped in alginate beads. In the ICT fermentations, beads represented 17% of the weight. Some assays were carried out with free cells without pH control, in order to compare the ICT populations with those of classical starters. With Streptococcus thermophilus, overall populations in the fermentor were similar, but maximum bead population for (8.2 x 10(9) cfu/g beads) was 13 times higher than that obtained in a traditional starter (4.9 x 10(8) cfu/ml). For both Lactobacillus helveticus strains studied, immobilized-cell populations were about 3 x 10(9) cfu/g beads. Production of immobilized Lb. bulgaricus 210R strain was not possible, since no increases in viable counts occurred in beads. Therefore, production of concentrated cell suspension in alginate beads was more effective for S. thermophilus. Photomicrographs of cells in alginate beads demonstrated that, while the morphology of S. thermophilus remained unchanged during the ICT fermentation, immobilized cells of Lb. helveticus appeared wider. In addition, cells of Lb. bulgaricus were curved and elongated. These morphological changes would also impair the growth of immobilized lactobacilli.

  7. Towards Hypoxia-responsive Drug-eluting Embolization Beads.

    Science.gov (United States)

    Ashrafi, Koorosh; Heaysman, Clare L; Phillips, Gary J; Lloyd, Andrew W; Lewis, Andrew L

    2017-05-30

    Drug release from chemoembolization microspheres stimulated by the presence of a chemically reducing environment may provide benefits for targeting drug resistant and metastatic hypoxic tumours. A water-soluble disulfide-based bifunctional cross-linker bis(acryloyl)-(l)-cystine (BALC) was synthesised, characterised and incorporated into a modified poly(vinyl) alcohol (PVA) hydrogel beads at varying concentrations using reverse suspension polymerisation. The beads were characterised to confirm the amount of cross-linker within each formulation and its effects on the bead properties. Elemental and UV/visible spectroscopic analysis confirmed the incorporation of BALC within the beads and sizing studies showed that in the presence of a reducing agent, all bead formulations increased in mean diameter. The BALC beads could be loaded with doxorubicin hydrochloride and amounts in excess of 300mg of drug per mL of hydrated beads could be achieved but required conversion of the carboxylic acid groups of the BALC to their sodium carboxylate salt forms. Elution of doxorubicin from the beads demonstrated a controlled release via ionic exchange. Some formulations exhibited an increase in size and release of drug in the presence of a reducing agent, and therefore demonstrated the ability to respond to an in vitro reducing environment. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Concepts for increasing gentamicin release from handmade bone cement beads

    NARCIS (Netherlands)

    Rasyid, Hermawan N; van der Mei, Henny C; Frijlink, Henderik W; Soegijoko, Soegijardjo; Van Horn, Jim R; Busscher, Hendrik; Neut, Daniëlle

    2009-01-01

    BACKGROUND AND PURPOSE: Commercial gentamicin-loaded bone cement beads (Septopal) constitute an effective delivery system for local antibiotic therapy. These beads are not available in all parts of the world, and are too expensive for frequent use in others. Thus, orthopedic surgeons worldwide make

  9. Beaded Fiber Mats of PVA Containing Unsaturated Heteropoly Salt

    Institute of Scientific and Technical Information of China (English)

    Guo Cheng YANG; Yan PAN; Jian GONG; Chang Lu SHAO; Shang Bin WEN; Chen SHAO; Lun Yu QU

    2004-01-01

    Poly(vinyl alcohol) (PVA) fiber mats containing unsaturated heteropoly salt was prepared for the first time. IR, X-ray diffraction and SEM photographs characterized the beaded fiber mats.The viscoelasticity and the conductivity of the solution were the key factors that influence the formation of the beaded fiber mats.

  10. Optimization of weld bead geometry of MS plate

    Indian Academy of Sciences (India)

    The considered specimen was checked to harmonize the optimum setting between input factors, for example, welding current, open circuit voltage, and thickness of plate, with respect to obtaining prosperous weld strength as well as bead geometry quality characteristics, for example, tensile strength, bead width, ...

  11. SparseBeads data: benchmarking sparsity-regularized computed tomography

    DEFF Research Database (Denmark)

    Jørgensen, Jakob Sauer; Coban, Sophia B.; Lionheart, William R. B.

    2017-01-01

    -regularized reconstruction. A collection of 48 x-ray CT datasets called SparseBeads was designed for benchmarking SR reconstruction algorithms. Beadpacks comprising glass beads of five different sizes as well as mixtures were scanned in a micro-CT scanner to provide structured datasets with variable image sparsity levels...

  12. Effect of charcoal on water purification

    OpenAIRE

    Suzuki, Hirotaka; Kawahigashi, Tatsuo

    2014-01-01

    [Abstract] A natural basin system purifies water through self-purification, but the water pollution load of a river might exceed its self-purification capacity. Charcoal, which is used for other uses aside from heating, such as air purification, was evaluated experimentally for water quality purification. The experiment described herein is based on simple water quality measurements. Some experimentally obtained results are discussed.

  13. Statistical and Judgmental Criteria for Scale Purification

    DEFF Research Database (Denmark)

    Wieland, Andreas; Durach, Christian F.; Kembro, Joakim

    2017-01-01

    of scale purification, to critically analyze the current state of scale purification in supply chain management (SCM) research and to provide suggestions for advancing the scale-purification process. Design/methodology/approach A framework for making scale-purification decisions is developed and used...

  14. Entrapment of laurel lipase in chitosan hydrogel beads.

    Science.gov (United States)

    Yagar, Hulya; Balkan, Ugur

    2017-08-01

    Laurel seed lipase was entrapped within chitosan beads with ionotropic gelatin method using tripolyphosphate (TPP) as multivalent covalent counter ion. Immobilization yield was 78%. First, optimum immobilization conditions were determined, and morphology of chitosan beads was characterized by scanning electron microscopy. Optimum pH and temperature were evaluated as 6.0 and 40 °C, respectively. The immobilized beads saved about 55% of its activities at 60° while saved about 32% at 70 °C for 30 min. V max /K m values were determined as 31.75 and 2.87 using olive oil as substrate for immobilized beads and free enzyme, respectively. Immobilized beads showed the activities during 30 days at +4 °C.

  15. A NOVEL APPROACH TO SYNTHESIZE CHITOSAN BEADS CROSSLINKED BY EPICHLOROHYDRIN

    Institute of Scientific and Technical Information of China (English)

    WANG Yongjian; BAI Shu; SUN Yan

    2001-01-01

    The present investigation describes a novel method for preparing spherical chitosan particles based on crosslinking with epichlorohydrin. Certain amount of pre-crosslinking agent was added to form chitosan gels by traditional inverse phase suspension polymerization. Then the gels were crosslinked by epichlorohydrin at basic condition to obtain chitosan beads. The effects of reaction conditions, such as crosslinking time, the amount of crosslinking agent and the NaOtt concentration,on the physical properties of the chitosan beads were investigated. The beads were found to have more amino groups in the polymer chains than the beads crosslinked by glutaraldehyde. The capacity for copper ions is as high as 40mg/g. The beads have good mechanical strength and can be reused.

  16. A NOVEL APPROACH TO SYNTHESIZE CHITOSAN BEADS CROSSLINKED BY EPICHLOROHYDRIN

    Institute of Scientific and Technical Information of China (English)

    WANGYongjina; BAIShu; 等

    2001-01-01

    The present investigation describes a novel method for preparing spherical chitosan particles based on crosslinking with epichlorohydrin.Certain amount of pre-crosslinking agent was added to form chitosan gels by traditional inverse phase suspension polymerization.Then the gels were crosslinked by epichlorohydrin at basic condition to obtain chitosan beads.The effects of reaction conditions,such as crosslinking time,the amount of crosslinking agent and the NaOH concentration,on the physical properties of the chitosan beads were investigated.The beads were found to have more amino groups in the polymer chains than the beads crosslinked by glutaraldehyde.The capacity for copper ions in as high as 40mg/g,The beads have good mechanical strength and can be reused.

  17. Oxytetracycline removal from water by novel microbial embedding gel beads

    Science.gov (United States)

    Wu, Nan; Pan, Peng; Zeng, Ming; Wang, Wei; Xu, Chenshan; Zhang, Zongpeng; Liu, Xinyuan; Wang, Yichao

    2018-01-01

    As a common antibiotic in aquatic environment, excessive oxytetracycline (OTC) is urgent to be removed due to its great biological toxicity. Compared with the traditional activated sludge, microbial embedding can enhance the treating efficiency. In this study, novel microbial embedding gel beads were produced with the additional agent of cyclodextrin (CD). Results show that CD could increase the mass transfer of OTC into gel beads, possibly because of its strong affinity for organic matters. In terms of OTC biodegradation, gel beads with CD were comparable to gel beads without CD, while the former’s sucrose removal efficiency was higher than the latter. The biodegradation of OTC only occurred in the presence of sucrose. The respiration test also confirmed these findings. Overall, the produced novel gel beads modified with CD could improve the removal performance of OTC.

  18. Design of systems for handling radioactive ion exchange resin beads

    International Nuclear Information System (INIS)

    Shapiro, S.A.; Story, G.L.

    1979-01-01

    The flow of slurries in pipes is a complex phenomenon. There are little slurry data available on which to base the design of systems for radioactive ion exchange resin beads and, as a result, the designs vary markedly in operating plants. With several plants on-line, the opportunity now exists to evaluate the designs of systems handling high activity spent resin beads. Results of testing at Robbins and Meyers Pump Division to quantify the behavior of resin bead slurries are presented. These tests evaluated the following slurry parameters; resin slurry velocity, pressure drop, bead degradation, and slurry concentration effects. A discussion of the general characteristics of resin bead slurries is presented along with a correlation to enable the designer to establish the proper flowrate for a given slurry composition and flow regime as a function of line size. Guidelines to follow in designing a resin handling system are presented

  19. Metallic gold beads in hyaluronic acid

    DEFF Research Database (Denmark)

    Pedersen, Dan Sonne; Tran, Thao Phuong; Smidt, Kamille

    2013-01-01

    . In conclusion, our findings support that bio-liberation of gold from metallic gold surfaces have anti-inflammatory properties similar to classic gold compounds, warranting further studies into the pharmacological potential of this novel gold-treatment and the possible synergistic effects of hyaluronic acid....... by exploiting macrophage-induced liberation of gold ions (dissolucytosis) from gold surfaces. Injecting gold beads in hyaluronic acid (HA) as a vehicle into the cavities of the brain can delay clinical signs of disease progression in the MS model, experimental autoimmune encephalitis (EAE). This study...... investigates the anti-inflammatory properties of metallic gold/HA on the gene expression of tumor necrosis factor (Tnf-α), Interleukin (Il)-1β, Il-6, Il-10, Colony-stimulating factor (Csf)-v2, Metallothionein (Mt)-1/2, Bcl-2 associated X protein (Bax) and B cell lymphoma (Bcl)-2 in cultured J774 macrophages...

  20. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65°C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...

  1. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...

  2. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...

  3. Inhibitive Effect of antibiotic-loaded beads to cure chronic osteomyelitis in developing country : Hand-made vs commercial beads

    NARCIS (Netherlands)

    Rasyid, Hcrmawan N.; Van Horn, Jim R.; Van der Mei, Henny C.; Soegijoko, Sooegijardjo; Busscher, Henk J.; Neut, Danielle; Ibrahim, F; Osman, NAA; Usman, J; Kadri, NA

    2007-01-01

    Local antibiotic-loaded beads have been approved for standard treatment of orthopaedic pathogens, especially chronic osteomyelitis. Septopal (R), the only commercial local antibiotic bead available on the market, is expensive and contains only gentamicin. This study aimed to compare the in vitro

  4. Manipulation of Superparamagnetic Beads on Patterned Exchange-Bias Layer Systems for Biosensing Applications.

    Science.gov (United States)

    Ehresmann, Arno; Koch, Iris; Holzinger, Dennis

    2015-11-13

    A technology platform based on a remotely controlled and stepwise transport of an array arrangement of superparamagnetic beads (SPB) for efficient molecular uptake, delivery and accumulation in the context of highly specific and sensitive analyte molecule detection for the application in lab-on-a-chip devices is presented. The near-surface transport of SPBs is realized via the dynamic transformation of the SPBs' magnetic potential energy landscape above a magnetically stripe patterned Exchange-Bias (EB) thin film layer systems due to the application of sub-mT external magnetic field pulses. In this concept, the SPB velocity is dramatically influenced by the magnitude and gradient of the magnetic field landscape (MFL) above the magnetically stripe patterned EB substrate, the SPB to substrate distance, the magnetic properties of both the SPBs and the EB layer system, respectively, as well as by the properties of the external magnetic field pulses and the surrounding fluid. The focus of this review is laid on the specific MFL design in EB layer systems via light-ion bombardment induced magnetic patterning (IBMP). A numerical approach is introduced for the theoretical description of the MFL in comparison to experimental characterization via scanning Hall probe microscopy. The SPB transport mechanism will be outlined in terms of the dynamic interplay between the EB substrate's MFL and the pulse scheme of the external magnetic field.

  5. Manipulation of Superparamagnetic Beads on Patterned Exchange-Bias Layer Systems for Biosensing Applications

    Directory of Open Access Journals (Sweden)

    Arno Ehresmann

    2015-11-01

    Full Text Available A technology platform based on a remotely controlled and stepwise transport of an array arrangement of superparamagnetic beads (SPB for efficient molecular uptake, delivery and accumulation in the context of highly specific and sensitive analyte molecule detection for the application in lab-on-a-chip devices is presented. The near-surface transport of SPBs is realized via the dynamic transformation of the SPBs’ magnetic potential energy landscape above a magnetically stripe patterned Exchange-Bias (EB thin film layer systems due to the application of sub-mT external magnetic field pulses. In this concept, the SPB velocity is dramatically influenced by the magnitude and gradient of the magnetic field landscape (MFL above the magnetically stripe patterned EB substrate, the SPB to substrate distance, the magnetic properties of both the SPBs and the EB layer system, respectively, as well as by the properties of the external magnetic field pulses and the surrounding fluid. The focus of this review is laid on the specific MFL design in EB layer systems via light-ion bombardment induced magnetic patterning (IBMP. A numerical approach is introduced for the theoretical description of the MFL in comparison to experimental characterization via scanning Hall probe microscopy. The SPB transport mechanism will be outlined in terms of the dynamic interplay between the EB substrate’s MFL and the pulse scheme of the external magnetic field.

  6. Self-assembled magnetic filter for highly efficient immunomagnetic separation.

    Science.gov (United States)

    Issadore, David; Shao, Huilin; Chung, Jaehoon; Newton, Andita; Pittet, Mikael; Weissleder, Ralph; Lee, Hakho

    2011-01-07

    We have developed a compact and inexpensive microfluidic chip, the self-assembled magnetic filter, to efficiently remove magnetically tagged cells from suspension. The self-assembled magnetic filter consists of a microfluidic channel built directly above a self-assembled NdFeB magnet. Micrometre-sized grains of NdFeB assemble to form alternating magnetic dipoles, creating a magnetic field with a very strong magnitude B (from the material) and field gradient ▽B (from the configuration) in the microfluidic channel. The magnetic force imparted on magnetic beads is measured to be comparable to state-of-the-art microfabricated magnets, allowing for efficient separations to be performed in a compact, simple device. The efficiency of the magnetic filter is characterized by sorting non-magnetic (polystyrene) beads from magnetic beads (iron oxide). The filter enriches the population of non-magnetic beads to magnetic beads by a factor of >10(5) with a recovery rate of 90% at 1 mL h(-1). The utility of the magnetic filter is demonstrated with a microfluidic device that sorts tumor cells from leukocytes using negative immunomagnetic selection, and concentrates the tumor cells on an integrated membrane filter for optical detection.

  7. Future of antibody purification.

    Science.gov (United States)

    Low, Duncan; O'Leary, Rhona; Pujar, Narahari S

    2007-03-15

    Antibody purification seems to be safely ensconced in a platform, now well-established by way of multiple commercialized antibody processes. However, natural evolution compels us to peer into the future. This is driven not only by a large, projected increase in the number of antibody therapies, but also by dramatic improvements in upstream productivity, and process economics. Although disruptive technologies have yet escaped downstream processes, evolution of the so-called platform is already evident in antibody processes in late-stage development. Here we perform a wide survey of technologies that are competing to be part of that platform, and provide our [inherently dangerous] assessment of those that have the most promise.

  8. Energy efficient bead milling of microalgae: Effect of bead size on disintegration and release of proteins and carbohydrates.

    Science.gov (United States)

    Postma, P R; Suarez-Garcia, E; Safi, C; Yonathan, K; Olivieri, G; Barbosa, M J; Wijffels, R H; Eppink, M H M

    2017-01-01

    The disintegration of three industry relevant algae (Chlorella vulgaris, Neochloris oleoabundans and Tetraselmis suecica) was studied in a lab scale bead mill at different bead sizes (0.3-1mm). Cell disintegration, proteins and carbohydrates released into the water phase followed a first order kinetics. The process is selective towards proteins over carbohydrates during early stages of milling. In general, smaller beads led to higher kinetic rates, with a minimum specific energy consumption of ⩽0.47kWhkg DW -1 for 0.3mm beads. After analysis of the stress parameters (stress number and stress intensity), it appears that optimal disintegration and energy usage for all strains occurs in the 0.3-0.4mm range. During the course of bead milling, the native structure of the marker protein Rubisco was retained, confirming the mildness of the disruption process. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, D; Bradley Pickenheim, B

    2008-11-24

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  10. DWPF GLASS BEADS AND GLASS FRIT TRANSPORT DEMONSTRATION

    International Nuclear Information System (INIS)

    Adamson, D.; Pickenheim, Bradley

    2008-01-01

    DWPF is considering replacing irregularly shaped glass frit with spherical glass beads in the Slurry Mix Evaporator (SME) process to decrease the yield stress of the melter feed (a non-Newtonian Bingham Plastic). Pilot-scale testing was conducted on spherical glass beads and glass frit to determine how well the glass beads would transfer when compared to the glass frit. Process Engineering Development designed and constructed the test apparatus to aid in the understanding and impacts that spherical glass beads may have on the existing DWPF Frit Transfer System. Testing was conducted to determine if the lines would plug with the glass beads and the glass frit slurry and what is required to unplug the lines. The flow loop consisted of vertical and horizontal runs of clear PVC piping, similar in geometry to the existing system. Two different batches of glass slurry were tested: a batch of 50 wt% spherical glass beads and a batch of 50 wt% glass frit in process water. No chemicals such as formic acid was used in slurry, only water and glass formers. The glass beads used for this testing were commercially available borosilicate glass of mesh size -100+200. The glass frit was Frit 418 obtained from DWPF and is nominally -45+200 mesh. The spherical glass beads did not have a negative impact on the frit transfer system. The transferring of the spherical glass beads was much easier than the glass frit. It was difficult to create a plug with glass bead slurry in the pilot transfer system. When a small plug occurred from setting overnight with the spherical glass beads, the plug was easy to displace using only the pump. In the case of creating a man made plug in a vertical line, by filling the line with spherical glass beads and allowing the slurry to settle for days, the plug was easy to remove by using flush water. The glass frit proved to be much more difficult to transfer when compared to the spherical glass beads. The glass frit impacted the transfer system to the point

  11. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

      The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...

  12. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

      The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...

  13. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...

  14. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...

  15. Recovery and purification of ethylene

    Science.gov (United States)

    Reyneke, Rian [Katy, TX; Foral, Michael J [Aurora, IL; Lee, Guang-Chung [Houston, TX; Eng, Wayne W. Y. [League City, TX; Sinclair, Iain [Warrington, GB; Lodgson, Jeffery S [Naperville, IL

    2008-10-21

    A process for the recovery and purification of ethylene and optionally propylene from a stream containing lighter and heavier components that employs an ethylene distributor column and a partially thermally coupled distributed distillation system.

  16. Preparation of magnetic nanoparticles embedded in polystyrene microspheres

    International Nuclear Information System (INIS)

    Nguyen Hoang Hai; Nguyen Hoang Luong; Nguyen Chau; Ngo Quy Tai

    2009-01-01

    Superparamagnetic particles are widely used for biological applications such as cell separation. The size of the particles is normally in the range of 10 - 20 nm which is much smaller than the size of a cell. Therefore small particles create small force which is not strong enough to separate the cells from solution. Superparamagnetic nanoparticles embedded in Polystyrene microspheres (magnetic beads) are very useful for cell separation. Magnetic beads have been prepared by solvent evaporation of an emulsion. The beads with size of 0.2 μm - 1.0 μm have a saturation magnetization of 10 - 25 emu/g. The change of the amount of surfactants, volatile solvent, magnetic particles resulted to the change of size, magnetic properties of the magnetic beads.

  17. Fiscal 1999 industrial science and technology R and D (industrial-academic) project report. R and D on technologies for creating bioaffinity molecules using submicron beads (Development of practical technologies for energy saving); 1999 nendo biryushi riyogata seimeitai ketsugo busshitsu nado sosei gijutsu no kenkyu kaihatsu seika hokokusho. Energy shiyo gorika kankei gijutsu jitsuyoka kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This report summarizes the fiscal 1999 R and D result on technologies for creating bioaffinity molecules using submicron beads. By improving particle production, favorable SGNEGDE particles for drug fixation were produced on a scale 10 times as large as previous one. Various functional groups were obtained for particles immobilizing ligands. Magnetic purification was attempted by using new magnetic polymer particles. Synthesis of particle unsusceptible to non- specific bonds, and analysis of its modified surface properties were attempted. Reversible attachable-detachable surface coat was obtained by immobilizing boric acid to glycol group on affinity latex SG particles. The experiment result on affinity latex for detecting one-point mismatched DNAs showed the dependence of DNA hybridization on shearing resistance. To construct the library of new substances reacting with bio-receptors, solid phase synthesis of anti- tumor heterocyclic compounds was analyzed. The library of the pharmacology of new lead compound such as sugar moiety was also constructed. Study was made on attachment of alkaloid to a solid phase, synthetic reaction on a solid phase and library construction. (NEDO)

  18. Calcium Pectinate Beads Formation: Shape and Size Analysis

    Directory of Open Access Journals (Sweden)

    Boon-Beng Lee

    2014-04-01

    Full Text Available The aim of this study was to investigate the inter-relationship between process variables and the size and shape of pectin solution droplets upon detachment from a dripping tip as well as Ca-pectinate beads formed after gelation via image analysis. The sphericity factor (SF of the droplets was generally smaller than 0.05. There was no specific trend between the SF of the droplets and the pectin concentration or the dripping tip radius. The SF the beads formed from high-concentration pectin solutions and a small dripping tip was smaller than 0.05. The results show that the Reynolds number and Ohnesorge number of the droplets fall within the operating region for forming spherical beads in the shape diagram, with the exception to the lower boundary. The lower boundary of the operating region has to be revised to Oh = 2.3. This is because the critical viscosity for Ca-pectinate bead formation is higher than that of Ca-alginate beads. On the other hand, the radius of the droplets and beads increased as the dripping tip radius increased. The bead radius can easily be predicted by Tate’s law equation.

  19. Ecohydraulics of Strings and Beads in Bedrock Rivers

    Science.gov (United States)

    Wohl, E.

    2016-12-01

    Twenty years ago, Jack Stanford and others described rivers in bedrock canyons as resembling beads on a string when viewed in planform. The beads are relatively wide, low gradient river segments with floodplains, whereas the strings are the intervening steep, narrow river segments with minimal floodplain development. This pattern of longitudinal variations in channel and valley morphology along bedrock canyon rivers is very common, from small channels to major rivers such as the Colorado. Basic understanding of river ecosystems, as well as limited studies, indicates that the beads are more retentive and biologically productive. Although both strings and beads can provide habitat for diverse organisms, strings are more likely to serve as migration corridors, whereas beads provide spawning and nursery habitat, facilitate lateral (channel-floodplain) and vertical (channel-hyporheic) exchanges and associated habitat diversity, and retain dissolved and particulate organic matter. Recognition of the different characteristics and functions of strings and beads can be used to identify their spatial distribution along a river or within a river network and the hydraulically driven processes that sustain channel form, water quality, and biota within strings and beads. Diverse modeling approaches can then be used to quantify the fluxes of water and sediment needed to maintain these hydraulically driven processes. This conceptual framework is illustrated using examples from mountain streams in the Southern Rockies and canyon rivers in the southwestern United States.

  20. A novel multiplex bead-based platform highlights the diversity of extracellular vesicles.

    Science.gov (United States)

    Koliha, Nina; Wiencek, Yvonne; Heider, Ute; Jüngst, Christian; Kladt, Nikolay; Krauthäuser, Susanne; Johnston, Ian C D; Bosio, Andreas; Schauss, Astrid; Wild, Stefan

    2016-01-01

    The surface protein composition of extracellular vesicles (EVs) is related to the originating cell and may play a role in vesicle function. Knowledge of the protein content of individual EVs is still limited because of the technical challenges to analyse small vesicles. Here, we introduce a novel multiplex bead-based platform to investigate up to 39 different surface markers in one sample. The combination of capture antibody beads with fluorescently labelled detection antibodies allows the analysis of EVs that carry surface markers recognized by both antibodies. This new method enables an easy screening of surface markers on populations of EVs. By combining different capture and detection antibodies, additional information on relative expression levels and potential vesicle subpopulations is gained. We also established a protocol to visualize individual EVs by stimulated emission depletion (STED) microscopy. Thereby, markers on single EVs can be detected by fluorophore-conjugated antibodies. We used the multiplex platform and STED microscopy to show for the first time that NK cell-derived EVs and platelet-derived EVs are devoid of CD9 or CD81, respectively, and that EVs isolated from activated B cells comprise different EV subpopulations. We speculate that, according to our STED data, tetraspanins might not be homogenously distributed but may mostly appear as clusters on EV subpopulations. Finally, we demonstrate that EV mixtures can be separated by magnetic beads and analysed subsequently with the multiplex platform. Both the multiplex bead-based platform and STED microscopy revealed subpopulations of EVs that have been indistinguishable by most analysis tools used so far. We expect that an in-depth view on EV heterogeneity will contribute to our understanding of different EVs and functions.

  1. Detection of Escherichia coli O157:H7 and Salmonella in ground beef by a bead-free quantum dot-facilitated isolation method.

    Science.gov (United States)

    Wang, Luxin; Wu, Chung-Shieh; Fan, Xudong; Mustapha, Azlin

    2012-05-01

    The aims of this study were to introduce a new immunological bead-free cell detection method using quantum dots (QDs) as reporter markers for foodborne pathogen detection. QDs are nanosized particles with long-term photostability, high quantum yield, broad absorption spectra, and narrow, symmetric emission and high signal-to-noise ratio. The chemical compound [(1-ethyl-3-3-dimethylaminopropyl) carbodiimide hydrochloride] (EDC) and protein A were used as crosslinkers for manufacturing QD-antibody conjugates. To minimize the inhibition of QD fluorescence by the magnetic beads, the beads were removed after the primary pathogen isolation and before fluorescence measurement. Detection signals were increased four-fold after employing the bead-free isolation method. With a 24-h enrichment, the bead-free QD-facilitated detection method was able to detect 10 CFU/g Escherichia coli O157:H7 and Salmonella from artificially contaminated ground beef. To our knowledge, this detection method is the first research that combined a new EDC-protein A QD-labeling technique and bead-free fluorescence measurement to detect E. coli O157:H7 and Salmonella in ground beef. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Random glycopeptide bead libraries for seromic biomarker discovery

    DEFF Research Database (Denmark)

    Kracun, Stjepan Kresimir; Cló, Emiliano; Clausen, Henrik

    2010-01-01

    have developed a random glycopeptide bead library screening platform for detection of autoantibodies and other binding proteins. Libraries were build on biocompatible PEGA beads including a safety-catch C-terminal amide linker (SCAL) that allowed mild cleavage conditions (I(2)/NaBH(4) and TFA...... to other tumor glycoforms by on-bead enzymatic glycosylation reactions with recombinant glycosyltransferases. Hence, we have developed a high-throughput flexible platform for rapid discovery of O-glycopeptide biomarkers and the method has applicability in other types of assays such as lectin...

  3. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

    The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....

  4. A two-channel detection method for autofluorescence correction and efficient on-bead screening of one-bead one-compound combinatorial libraries using the COPAS fluorescence activated bead sorting system

    International Nuclear Information System (INIS)

    Hintersteiner, Martin; Auer, Manfred

    2013-01-01

    One-bead one-compound combinatorial library beads exhibit varying levels of autofluorescence after solid phase combinatorial synthesis. Very often this causes significant problems for automated on-bead screening using TentaGel beads and fluorescently labeled target proteins. Herein, we present a method to overcome this limitation when fluorescence activated bead sorting is used as the screening method. We have equipped the COPAS bead sorting instrument with a high-speed profiling unit and developed a spectral autofluorescence correction method. The correction method is based on a simple algebraic operation using the fluorescence data from two detection channels and is applied on-the-fly in order to reliably identify hit beads by COPAS bead sorting. Our method provides a practical tool for the fast and efficient isolation of hit beads from one-bead one-compound library screens using either fluorescently labeled target proteins or biotinylated target proteins. This method makes hit bead identification easier and more reliable. It reduces false positives and eliminates the need for time-consuming pre-sorting of library beads in order to remove autofluorescent beads. (technical note)

  5. Method for regenerating magnetic polyamine-epichlorohydrin resin

    Science.gov (United States)

    Kochen, Robert L.; Navratil, James D.

    1997-07-29

    Magnetic polymer resins capable of efficient removal of actinides and heavy metals from contaminated water are disclosed together with methods for making, using, and regenerating them. The resins comprise polyamine-epichlorohydrin resin beads with ferrites attached to the surfaces of the beads. Markedly improved water decontamination is demonstrated using these magnetic polymer resins of the invention in the presence of a magnetic field, as compared with water decontamination methods employing ordinary ion exchange resins or ferrites taken separately.

  6. K Basin sludge/resin bead separation test report

    International Nuclear Information System (INIS)

    Squier, D.M.

    1998-01-01

    The K Basin sludge is an accumulation of fuel element corrosion products, organic and inorganic ion exchange materials, canister gasket materials, iron and aluminum corrosion products, sand, dirt and minor amounts of other organic material. The sludge will be collected and treated for storage and eventual disposal. This process will remove the large solid materials by a 1/4 inch screen. The screened material will be subjected to nitric acid in a chemical treatment process. The organic ion exchange resin beads produce undesirable chemical reactions with the nitric acid. The resin beads must be removed from the bulk material and treated by another process. An effective bead separation method must extract 95% of the resin bead mass without entraining more than 5% of the other sludge component mass. The test plan I-INF-2729, ''Organic Ion Exchange Resin Separation Methods Evaluation,'' proposed the evaluation of air lift, hydro cyclone, agitated slurry and elutriation resin bead separation methods. This follows the testing strategy outlined in section 4.1 of BNF-2574, ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process''. Engineering study BNF-3128, ''Separation of Organic Ion Exchange Resins from Sludge,'' Rev. 0, focused the evaluation tests on a method that removed the fine sludge particles by a sieve and then extracted the beads by means of a elutriation column. Ninety-nine percent of the resin beads are larger than 125 microns and 98.5 percent are 300 microns and larger. Particles smaller than 125 microns make up the largest portion of sludge in the K Basins. Eliminating a large part of the sludge's non-bead component will reduce the quantity that is lifted with the resin beads in the elutriation column. Resin bead particle size distribution measurements are given in Appendix A The Engineering Testing Laboratory conducted measurements of a elutriation column's ability to extract resin beads from a sieved, non-radioactive sludge

  7. Force measurements of a magnetic micro actuator proposed for a microvalve array

    International Nuclear Information System (INIS)

    Chang, Pauline J; Chang, Frank W; Yuen, Michelle C; Horsley, David A; Otillar, Robert

    2014-01-01

    Low-cost, easily-fabricated and power-efficient microvalves are necessary for many microfluidic lab-on-a-chip applications. In this study, we present a simple, low-power, scalable, CMOS-compatible magnetic actuator for microvalve applications composed of a paramagnetic bead as the ball valve over a picoliter reaction well etched into a silicon substrate. The paramagnetic bead, composed of either pure FeSi or magnetite in a SiO 2  matrix, is actuated by the local magnetic field gradient generated by a microcoil in an aqueous environment, and the reaction well is situated at the microcoil center. A permanent magnet beneath the microvalve device provides an external magnetic biasing field that magnetizes the bead, enabling bidirectional actuation and reducing the current required to actuate the bead to a level below 10 mA. The vertical and radial magnetic forces exerted on the bead by the microcoil were measured for both pure FeSi and composite beads and agree well with the predictions of 2D axisymmetric finite element method models. Vertical forces were within a range of 13–80 nN, and radial forces were 11–60 nN depending on the bead type. The threshold current required to initiate bead actuation was measured as a function of bead diameter and is found to scale inversely with volume for small beads, as expected based on the magnetic force model. To provide an estimate of the stiction force acting between the bead and the passivation layer on the substrate, repeated actuation trials were used to study the bead throw distance for substrates coated with silicon dioxide, Parylene-C, and photoresist. The stiction observed was lowest for a photoresist-coated substrate, while silicon dioxide and Parylene-C coated substrates exhibited similar levels of stiction. (paper)

  8. Online Oxide Contamination Measurement and Purification Demonstration

    Science.gov (United States)

    Bradley, D. E.; Godfroy, T. J.; Webster, K. L.; Garber, A. E.; Polzin, K. A.; Childers, D. J.

    2011-01-01

    Liquid metal sodium-potassium (NaK) has advantageous thermodynamic properties indicating its use as a fission reactor coolant for a surface (lunar, martian) power system. A major area of concern for fission reactor cooling systems is system corrosion due to oxygen contaminants at the high operating temperatures experienced. A small-scale, approximately 4-L capacity, simulated fission reactor cooling system employing NaK as a coolant was fabricated and tested with the goal of demonstrating a noninvasive oxygen detection and purification system. In order to generate prototypical conditions in the simulated cooling system, several system components were designed, fabricated, and tested. These major components were a fully-sealed, magnetically-coupled mechanical NaK pump, a graphite element heated reservoir, a plugging indicator system, and a cold trap. All system components were successfully demonstrated at a maximum system flow rate of approximately 150 cc/s at temperatures up to 550 C. Coolant purification was accomplished using a cold trap before and after plugging operations which showed a relative reduction in oxygen content.

  9. Intracellular manipulation of chromatin using magnetic nanoparticles

    NARCIS (Netherlands)

    Kanger, Johannes S.; Subramaniam, Vinod; van Driel, Roel

    2008-01-01

    Magnetic tweezers are widely used for manipulating small magnetic beads inside the cell cytoplasm in order to gain insight into the structural and mechanical properties of the cytoskeleton. Here we discuss the use of magnetic tweezers for the study of nuclear architecture and the mechanical

  10. Water Purification Systems

    Science.gov (United States)

    1994-01-01

    Clearwater Pool Technologies employs NASA-developed silver/copper ionization to purify turtle and dolphin tanks, cooling towers, spas, water recycling systems, etc. The pool purifier consists of a microcomputer to monitor water conditions, a pair of metallic electrodes, and a rheostat controller. Ions are generated by passing a low voltage current through the electrodes; the silver ions kill the bacteria, and the copper ions kill algae. This technology has found broad application because it offers an alternative to chemical disinfectants. It was originally developed to purify water on Apollo spacecraft. Caribbean Clear has been using NASA's silver ionization technology for water purification for more than a decade. Two new products incorporate advancements of the basic technology. One is the AquaKing, a system designed for areas with no source of acceptable drinking water. Another is the Caribbean Clear Controller, designed for commercial pool and water park applications where sanitizing is combined with feedback control of pH and an oxidizer, chlorine or bromine. The technology was originally developed to purify water on Apollo spacecraft.

  11. Liquid metal purification device

    International Nuclear Information System (INIS)

    Sakai, Takao; Shimoyashiki, Shigehiro.

    1992-01-01

    The device of the present invention concerns a liquid metal purification device for removing and purifying impuries in liquid metal sodium used as coolants of an FBR type reactor. A vessel having a group of pipes made of hydrogen permeable metal at the inside thereof is disposed to the inlet pipeline of a cold trap. The group of hydrogen permeable metal pipes is connected to an exhaust pipe and a vacuum pump, so that the inside of the pipes is exhausted. Liquid metal sodium branched from the main pipeline of a coolant system passes through the outer side of the group of the hydrogen permeable metal pipes. In this cae, hydrogen contained as impurities in the liquid metal sodium diffuses and permeates the hydrogen permeation metal pipes and enters into the pipe group and is discharged out of the system by the vacuum pump. This can mitigate the hydrogen removing burden of the cold trap, to extend the device life time. (I.N.)

  12. Efficient functionalization of poly(styrene) beads immobilized metal ...

    Indian Academy of Sciences (India)

    Three types of new bead-shaped heterogeneous nanoparticle (NP) catalysts were synthesized by sim- plified procedures .... and Ag+-doped titanium. Therefore, removal ..... References. 1. Storhoff J J, Elghanian R, Mucic R C, Mirkin C A and.

  13. Standard specification for beaded process glass pipe and fittings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This specification covers chemically resistant, low expansion Type-I borosilicate glass, Class A, (see Specification E 438) used to manufacture beaded end flanged-glass pipe and fittings for pressure and vacuum applications.

  14. Influence of recycled polystyrene beads on cement paste properties

    Directory of Open Access Journals (Sweden)

    Maaroufi Maroua

    2018-01-01

    Full Text Available In order to keep up with the requirements of sustainable development, there is a growing interest towards reducing the energy consumption in the construction and rehabilitation of buildings and the promotion of recycling waste in building materials. The use of recycled polystyrene beads in cement-based materials composition constitutes a solution to improve the insulation in buildings. This allows also limiting landfill by reusing the polystyrene waste. The aim of this study is to compare some properties and performances of a cement paste containing polystyrene beads to a reference paste designed with only the same cement. An experimental campaign was conducted and the obtained results showed that adding recycled polystyrene beads to a cement paste improves its hygro-thermal properties. Further studies are however necessary to better understand the real role of the polystyrene beads in the heat and mass transfers.

  15. TiO₂ beads and TiO₂-chitosan beads for urease immobilization.

    Science.gov (United States)

    Ispirli Doğaç, Yasemin; Deveci, Ilyas; Teke, Mustafa; Mercimek, Bedrettin

    2014-09-01

    The aim of the present study is to synthesize TiO2 beads for urease immobilization. Two different strategies were used to immobilize the urease on TiO2 beads. In the first method (A), urease enzyme was immobilized onto TiO2 beads by adsorption and then crosslinking. In the second method (B), TiO2 beads were coated with chitosan-urease mixture. To determine optimum conditions of immobilization, different parameters were investigated. The parameters of optimization were initial enzyme concentration (0.5; 1; 1.5; 2mg/ml), alginate concentration (1; 2; 3%), glutaraldehyde concentration (1; 2; 3% v/v) and chitosan concentration (2; 3; 4 mg/ml). The optimum enzyme concentrations were determined as 1.5mg/ml for A and 1.0mg/ml for B. The other optimum conditions were found 2.0% (w/v) for alginate concentration (both A and B); 3.0mg/ml for chitosan concentration (B) and 2.0% (v/v) for glutaraldehyde concentration (A). The optimum temperature (20-60°C), optimum pH (3.0-10.0), kinetic parameters, thermal stability (4-70°C), pH stability (4.0-9.0), operational stability (0-230 min) and reusability (20 times) were investigated for characterization. The optimum temperatures were 30°C (A), 40°C (B) and 35°C (soluble). The temperature profiles of the immobilized ureases were spread over a large area. The optimum pH values for the soluble urease and immobilized urease prepared by using methods (A) and (B) were found to be 7.5, 7.0, 7.0, respectively. The thermal stabilities of immobilized enzyme sets were studied and they maintained 50% activity at 65°C. However, at this temperature free urease protected only 15% activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

    The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...

  17. MAGNET

    CERN Multimedia

    B. Curé

    MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...

  18. MAGNET

    CERN Multimedia

    Benoit Curé.

    The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...

  19. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

    The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...

  20. Sensitive detection of nucleic acids by PNA hybridization directed co-localization of fluorescent beads

    DEFF Research Database (Denmark)

    Shiraishi, Takehiko; Deborggraeve, Stijn; Büscher, Philippe

    2011-01-01

    )avidin-coated fluorescent beads, differing in size and color [green beads (1 µm) and red beads (5.9 µm)], thereby allowing distinct detection of each PNA probe by conventional fluorescence microscopy. These two PNA beads showed easily detectable co-localization when simultaneously hybridizing to a target nucleic acid...

  1. Magnetic susceptibility characterisation of superparamagnetic microspheres

    Science.gov (United States)

    Grob, David Tim; Wise, Naomi; Oduwole, Olayinka; Sheard, Steve

    2018-04-01

    The separation of magnetic materials in microsystems using magnetophoresis has increased in popularity. The wide variety and availability of magnetic beads has fuelled this drive. It is important to know the magnetic characteristics of the microspheres in order to accurately use them in separation processes integrated on a lab-on-a-chip device. To investigate the magnetic susceptibility of magnetic microspheres, the magnetic responsiveness of three types of Dynabeads microspheres were tested using two different approaches. The magnetophoretic mobility of individual microspheres is studied using a particle tracking system and the magnetization of each type of Dynabeads microsphere is measured using SQUID relaxometry. The magnetic beads' susceptibility is obtained at four different applied magnetic fields in the range of 38-70 mT for both the mobility and SQUID measurements. The susceptibility values in both approaches show a consistent magnetic field dependence.

  2. Preparation of Bio-beads and Their Atrazine Degradation Characteristics

    Institute of Scientific and Technical Information of China (English)

    BI Hai-tao; ZHANG Lan-ying; LIU Na; ZHU Bo-lin

    2011-01-01

    Screened atrazine-mineralizing bacterium-Pseudomonas W4 was embedded inside an improved PVAH3BO3 embedment matrix to make bio-beads to degrade atrazine. The atrazine degradation characteristics were studied. The preparation procedure of bio-beads was as follows: (1) preparing a mixture of 100, 12.5, 10, 1.5 and 1 g/L PVA, bentonite(Ca), activated carbon powder, sodium alginate and centrifuged Pseudomonas W4 bacterium, respectively; (2) the mixture was dropped into a gently stirred cross linker solution(pH=6.7) and cured at 10 ℃ for 24 h.The optimal atrazine degradation conditions by bio-beads were as follows: pH=7, the auxiliary carbon source was glucose, and the concentration of glucose was greater than 325 mg/L. The bio-beads demonstrated stronger tolerance ability than the free microorganism to the increase of PCBs, hydrogen ion and hydroxide ion. SEM images show the uniform distribution of the microorganism inside bio-beads and the porous cross-linked structure of bio-beads which provides excellent mass transfer capacity.

  3. On-bead fluorescent DNA nanoprobes to analyze base excision repair activities

    Energy Technology Data Exchange (ETDEWEB)

    Gines, Guillaume; Saint-Pierre, Christine; Gasparutto, Didier, E-mail: didier.gasparutto@cea.fr

    2014-02-17

    Graphical abstract: -- Highlights: •On magnetic beads fluorescent enzymatic assays. •Simple, easy, non-radioactive and electrophoresis-free functional assay. •Lesion-containing hairpin DNA probes are selective for repair enzymes. •The biosensing platform allows the measurement of DNA repair activities from purified enzymes or within cell free extracts. -- Abstract: DNA integrity is constantly threatened by endogenous and exogenous agents that can modify its physical and chemical structure. Changes in DNA sequence can cause mutations sparked by some genetic diseases or cancers. Organisms have developed efficient defense mechanisms able to specifically repair each kind of lesion (alkylation, oxidation, single or double strand break, mismatch, etc). Here we report the adjustment of an original assay to detect enzymes’ activity of base excision repair (BER), that supports a set of lesions including abasic sites, alkylation, oxidation or deamination products of bases. The biosensor is characterized by a set of fluorescent hairpin-shaped nucleic acid probes supported on magnetic beads, each containing a selective lesion targeting a specific BER enzyme. We have studied the DNA glycosylase alkyl-adenine glycosylase (AAG) and the human AP-endonuclease (APE1) by incorporating within the DNA probe a hypoxanthine lesion or an abasic site analog (tetrahydrofuran), respectively. Enzymatic repair activity induces the formation of a nick in the damaged strand, leading to probe's break, that is detected in the supernatant by fluorescence. The functional assay allows the measurement of DNA repair activities from purified enzymes or in cell-free extracts in a fast, specific, quantitative and sensitive way, using only 1 pmol of probe for a test. We recorded a detection limit of 1 μg mL{sup −1} and 50 μg mL{sup −1} of HeLa nuclear extracts for APE1 and AAG enzymes, respectively. Finally, the on-bead assay should be useful to screen inhibitors of DNA repair

  4. On-bead fluorescent DNA nanoprobes to analyze base excision repair activities

    International Nuclear Information System (INIS)

    Gines, Guillaume; Saint-Pierre, Christine; Gasparutto, Didier

    2014-01-01

    Graphical abstract: -- Highlights: •On magnetic beads fluorescent enzymatic assays. •Simple, easy, non-radioactive and electrophoresis-free functional assay. •Lesion-containing hairpin DNA probes are selective for repair enzymes. •The biosensing platform allows the measurement of DNA repair activities from purified enzymes or within cell free extracts. -- Abstract: DNA integrity is constantly threatened by endogenous and exogenous agents that can modify its physical and chemical structure. Changes in DNA sequence can cause mutations sparked by some genetic diseases or cancers. Organisms have developed efficient defense mechanisms able to specifically repair each kind of lesion (alkylation, oxidation, single or double strand break, mismatch, etc). Here we report the adjustment of an original assay to detect enzymes’ activity of base excision repair (BER), that supports a set of lesions including abasic sites, alkylation, oxidation or deamination products of bases. The biosensor is characterized by a set of fluorescent hairpin-shaped nucleic acid probes supported on magnetic beads, each containing a selective lesion targeting a specific BER enzyme. We have studied the DNA glycosylase alkyl-adenine glycosylase (AAG) and the human AP-endonuclease (APE1) by incorporating within the DNA probe a hypoxanthine lesion or an abasic site analog (tetrahydrofuran), respectively. Enzymatic repair activity induces the formation of a nick in the damaged strand, leading to probe's break, that is detected in the supernatant by fluorescence. The functional assay allows the measurement of DNA repair activities from purified enzymes or in cell-free extracts in a fast, specific, quantitative and sensitive way, using only 1 pmol of probe for a test. We recorded a detection limit of 1 μg mL −1 and 50 μg mL −1 of HeLa nuclear extracts for APE1 and AAG enzymes, respectively. Finally, the on-bead assay should be useful to screen inhibitors of DNA repair activities

  5. Rapid purification of recombinant histones.

    Science.gov (United States)

    Klinker, Henrike; Haas, Caroline; Harrer, Nadine; Becker, Peter B; Mueller-Planitz, Felix

    2014-01-01

    The development of methods to assemble nucleosomes from recombinant histones decades ago has transformed chromatin research. Nevertheless, nucleosome reconstitution remains time consuming to this day, not least because the four individual histones must be purified first. Here, we present a streamlined purification protocol of recombinant histones from bacteria. We termed this method "rapid histone purification" (RHP) as it circumvents isolation of inclusion bodies and thereby cuts out the most time-consuming step of traditional purification protocols. Instead of inclusion body isolation, whole cell extracts are prepared under strongly denaturing conditions that directly solubilize inclusion bodies. By ion exchange chromatography, the histones are purified from the extracts. The protocol has been successfully applied to all four canonical Drosophila and human histones. RHP histones and histones that were purified from isolated inclusion bodies had similar purities. The different purification strategies also did not impact the quality of octamers reconstituted from these histones. We expect that the RHP protocol can be readily applied to the purification of canonical histones from other species as well as the numerous histone variants.

  6. RELIGION AND PURIFICATION OF SOUL

    Directory of Open Access Journals (Sweden)

    Azam Khodashenas Pelko

    2010-11-01

    Full Text Available The Jainism emphasizes three major teachings about the purification of the soul (jiva, Ahimsa, Aparigrapha and anekantwad. Jainism, The focus of this religion has been purification of the soul by means of right conduct, right faith and right knowledge. The ultimate goal of Hinduism is Moksha or liberation (total freedom. In Hinduism, purification of the soul is a goal that one must work to attain. The Buddhism is the science of pursuing the aim of making the human mind perfect, and of purifying the human soul. The knowledge of purifying of the soul and softening of the hearts is as essential for human. They having the correct motivations means purifying our souls from hypocrisy, caprice, and heedlessness. The primary goal of Taoism may be described as the mystical intuition of the Tao, which is the way, the undivided unity, and the ultimate Reality. According to the Christianity access to truth cannot be conceived without purity of the soul

  7. Antimicrobial Peptide Production and Purification.

    Science.gov (United States)

    Suda, Srinivas; Field, Des; Barron, Niall

    2017-01-01

    Antimicrobial peptides (AMPs) are natural defense compounds which are synthesized as ribosomal gene-encoded pre-peptides and produced by all living organisms. AMPs are small peptides, usually cationic and typically have hydrophobic residues which interact with cell membranes and have either a narrow or broad spectrum of biological activity. AMPs are isolated from the natural host or heterologously expressed in other hosts such as Escherichia coli. The proto-typical lantibiotic Nisin is a widely used AMP that is produced by the food-grade organism Lactococcus lactis. Although AMP production and purification procedures require optimization for individual AMPs, the Nisin production and purification protocol outlined in this chapter can be easily applied with minor modifications for the production and purification of other lantibiotics or AMPs. While Nisin is produced and secreted into the supernatant, steps to recover Nisin from both cell-free supernatant and cell pellet are outlined in detail.

  8. MAGNET

    CERN Multimedia

    Benoit Curé

    The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...

  9. MAGNET

    CERN Multimedia

    B. Curé

    During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...

  10. Effects of agitation rate on aggregation during beads-to-beads subcultivation of microcarrier culture of human mesenchymal stem cells.

    Science.gov (United States)

    Takahashi, Iori; Sato, Keigo; Mera, Hisashi; Wakitani, Shigeyuki; Takagi, Mutsumi

    2017-06-01

    With the aim to utilize human mesenchymal stem cells (hMSCs) grown in large scale for regenerative medicine, effects of agitation rate on aggregation during beads-to-beads subcultivation of microcarrier culture of hMSCs were studied. hMSCs could attach and grew on surface-type microcarriers of Cytodex 1, whereas almost no cell elongation and growth were observed on porous type microcarriers of Cytopores. The percentages of aggregated Cytodex 1 microcarriers at an agitation rate of 60 and 90 rpm were lower than that at 30 rpm, which was the lowest agitation rate necessary for the suspension of Cytodex 1 microcarriers, and the cells grew fastest at 60 rpm. hMSC could be subcultivated on Cytodex 1 by the beads-to-beads method at both 30 and 60 rpm without trypsinization. However, agitation at 60 rpm resulted in a markedly lower percentage of aggregated microcarriers not only before but also after subcultivation. The percentages of CD90- and CD166-positive cells among cells grown on Cytodex 1 at 60 rpm (91.5 and 87.6 %) were comparable to those of cells grown in the pre-culture on dishes. In conclusion, hMSCs could be subcultivated on Cytodex 1 by beads-to-beads method maintaining the expressions of the cell surface antigens CD90 and CD166, while adjusting agitation rate could decrease the microcarrier aggregation.

  11. The various sodium purification techniques

    International Nuclear Information System (INIS)

    Courouau, J.L.; Masse, F.; Rodriguez, G.; Latge, C.; Redon, B.

    1997-01-01

    In the framework of sodium waste treatment, the sodium purification phase plays an essential role in the chain of operations leading to the transformation of the active sodium, considered as waste, into a stable sodium salt. The objectives of the purification operations are: To keep a low impurity level, particularly a low concentration in oxygen and hydrogen, in order to allow its transfer to a processing plant, and in order to avoid risks of plugging and/or corrosion in sodium facilities; To reduce the sodium activity in order to limit the dose rate close to the facilities, and in order to reduce the activity of the liquid and gaseous effluents. After a recall of the different kind of impurities that can be present in sodium, and of the different purification methods that could be associated with, the following points are highlighted: (i) Oxygen and hydrogen purification needs, and presentation of some selection criteria for a purification unit adapted to a sodium processing plant, as well as 2 cold trap concepts that are in accordance with these criteria: PSICHOS and PIRAMIDE. (ii) Tritium reduction in a bulk of liquid sodium by swamping, isotopic exchange, or permeation throughout a membrane. (iii) Caesium trapping on carbonaceous matrix. The main matrices used at present are R.V.C. (Reticulated Vitreous Carbon) and Actitex/Pica products. Tests in the laboratory and on an experimental device have demonstrated the performances of these materials, which are able to reduce sodium activity in Cs 134 and Cs 137 to very low values. The sodium purification processes as regards to the hydrogen, oxygen and caesium, that are aimed at facilitating the subsequent treatment of sodium, are therefore mastered operations. Regarding the operations associated with the reduction of the tritium activity, the methods are in the process of being qualified, or to be qualified. (author)

  12. Partial Purification and Characterization of Extracellular Protease ...

    African Journals Online (AJOL)

    Nigerian Journal of Basic and Applied Sciences ... Purification of the enzyme by gel filtration chromatography on Sephadex G75 following ammonium sulphate precipitation gave 2.26 fold increase in purification with specific activity of 46.13 units/mg protein while purification on Sephadex CM50 resulted in reduced ...

  13. Purification of Water by Aquatic Plants

    OpenAIRE

    Morimitsu, Katsuhito; Kawahigashi, Tatsuo

    2013-01-01

    [Abstract] Water quality purification of many water systems including those occurring in rivers depends to a great degree on water quality purification activities of aquatic plants and microbes. This paper presents a discussion of results, based on laboratory experiments, of purification by aquatic plants.

  14. Dual-mode fluorophore-doped nickel nitrilotriacetic acid-modified silica nanoparticles combine histidine-tagged protein purification with site-specific fluorophore labeling.

    Science.gov (United States)

    Kim, Sung Hoon; Jeyakumar, M; Katzenellenbogen, John A

    2007-10-31

    We present the first example of a fluorophore-doped nickel chelate surface-modified silica nanoparticle that functions in a dual mode, combining histidine-tagged protein purification with site-specific fluorophore labeling. Tetramethylrhodamine (TMR)-doped silica nanoparticles, estimated to contain 700-900 TMRs per ca. 23 nm particle, were surface modified with nitrilotriacetic acid (NTA), producing TMR-SiO2-NTA-Ni2+. Silica-embedded TMR retains very high quantum yield, is resistant to quenching by buffer components, and is modestly quenched and only to a certain depth (ca. 2 nm) by surface-attached Ni2+. When exposed to a bacterial lysate containing estrogen receptor alpha ligand binding domain (ERalpha) as a minor component, these beads showed very high specificity binding, enabling protein purification in one step. The capacity and specificity of these beads for binding a his-tagged protein were characterized by electrophoresis, radiometric counting, and MALDI-TOF MS. ERalpha, bound to TMR-SiO2-NTA-Ni++ beads in a site-specific manner, exhibited good activity for ligand binding and for ligand-induced binding to coactivators in solution FRET experiments and protein microarray fluorometric and FRET assays. This dual-mode type TMR-SiO2-NTA-Ni2+ system represents a powerful combination of one-step histidine-tagged protein purification and site-specific labeling with multiple fluorophore species.

  15. Materials for Molybdenum 99 purification

    International Nuclear Information System (INIS)

    Wilkinson, M. Victoria; Mondino, Angel V.; Manzini, Alberto C.

    2003-01-01

    The National Atomic Energy Commission (CNEA) produces fission Mo 99, an isotope of wide use in nuclear medicine. In order to simplify the current Mo 99 production process, to shorten its duration and reduce impurities in the final product, alternative methods for purification steps were looked for. In this work a variety of new materials for the purification columns were designed, all of them with carbon. These materials were studied and a material which contribute with the best results for molybdenum retention, was selected. The preparation procedure and the working conditions were determined. (author)

  16. Hydrogen purification by periodic adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Barg, Christian; Secchi, Argimiro R.; Trierweiler, Jorge O. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica]. E-mail: cbarg@enq.ufrgs.br; arge@enq.ufrgs.br; jorge@enq.ufrgs.br

    2000-07-01

    The periodic adsorption processes have been widely used for industrial applications, mainly because it spends less energy than the usual gas separation processes, like the cryogenic distillation. The largest commercial application of periodic adsorption processes is the pressure swing adsorption (PSA) applied to hydrogen purification. Although its wide use in the chemical and petrochemical industry, there are no reports in the open literature about complete modeling studies of a complex commercial unit, with multiple adsorbents and multiple beds and several feed components. This study has as objective the modeling, optimization and dynamical analysis of an industrial PSA unit for hydrogen purification. (author)

  17. Use of antibiotic beads to salvage infected breast implants.

    Science.gov (United States)

    Sherif, Rami D; Ingargiola, Michael; Sanati-Mehrizy, Paymon; Torina, Philip J; Harmaty, Marco A

    2017-10-01

    When an implant becomes infected, implant salvage is often performed where the implant is removed, capsulectomy is performed, and a new implant is inserted. The patient is discharged with a PICC line and 6-8 weeks of intravenous (IV) antibiotics. This method has variable success and subjects the patient to long-term systemic antibiotics. In the 1960s, the use of antibiotic-impregnated beads for the treatment of chronic osteomyelitis was described. These beads deliver antibiotic directly to the site of the infection, thereby eliminating the complications of systemic IV antibiotics. This study aimed to present a case series illustrating the use of STIMULAN calcium sulfate beads loaded with vancomycin and tobramycin to increase the rate of salvage of the infected implant and forgo IV antibiotics. A retrospective analysis was performed of patients who were treated at Mount Sinai Hospital for implant infection with salvage and antibiotic beads. Twelve patients were identified, 10 of whom had breast cancer. Comorbidities included hypertension, smoking, and immunocompromised status. Infections were noted anywhere from 5 days to 8 years postoperatively. Salvage was successful in 9 out of the 12 infected implants using antibiotic bead therapy without home IV antibiotics. The use of antibiotic beads is promising for salvaging infected breast implants without IV antibiotics. Seventy-five percent of the implants were successfully salvaged. Of the three patients who had unsalvageable implants, one was infected with antibiotic-resistant Rhodococcus that was refractory to bead therapy and one was noncompliant with postoperative instructions. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Two Contrasting Failure Modes of Enteric Coated Beads.

    Science.gov (United States)

    Shi, Galen H; Dong, Xia; Lytle, Michelle; Kemp, Craig A J; Behme, Robert J; Hinds, Jeremy; Xiao, Zhicheng

    2018-04-09

    This study aimed to elucidate the mechanisms and kinetics of coating failure for enteric coated beads exposed to high-humidity conditions at different storage temperatures. Enteric coated beads were placed on high-humidity conditions (75 to 98% relative humidity (RH)) in the temperature range of 5 to 40°C. These stability samples of beads were tested for acid dissolution and water activity and also analyzed with SEM, X-ray CT, and DMA. Exposure of enteric coated beads to high humidity led to increased gastric release of drug which eventually failed the dissolution specification. SEM showed visible cracks on the surface of beads exposed to 5°C/high humidity and fusion of enteric beads into agglomerates at 40°C/high humidity. In a non-destructive time elapse study, X-ray CT demonstrated swelling of microcrystalline cellulose cores, crack initiation, and propagation through the API layer within days under 5°C/98% RH storage conditions and ultimately fracture through the enteric coating. DMA data showed a marked reduction in T g of the enteric coating materials after exposure to humidity. At 5°C/high humidity, the hygroscopic microcrystalline cellulose core absorbed moisture leading to core swelling and consequent fracture through the brittle API and enteric layers. At 40°C (high humidity) which is above the T g of the enteric polymer, enteric coated beads coalesced into agglomerates due to melt flow of the enteric coating. We believe it is the first report on two distinct failure models of enteric coated dosage forms.

  19. On-chip immunomagnetic separation of bacteria by in-flow dynamic manipulation of paramagnetic beads

    Science.gov (United States)

    Ahmed, Shakil; Noh, Jong Wook; Hoyland, James; de Oliveira Hansen, Roana; Erdmann, Helmut; Rubahn, Horst-Günter

    2016-11-01

    Every year, millions of people all over the world fall ill due to the consumption of unsafe food, where consumption of contaminated and spoiled animal origin product is the main cause for diseases due to bacterial growth. This leads to an intense need for efficient methods for detection of food-related bacteria. In this work, we present a method for integration of immunomagnetic separation of bacteria into microfluidic technology by applying an alternating magnetic field, which manipulates the paramagnetic beads into a sinusoidal path across the whole microchannel, increasing the probability for bacteria capture. The optimum channel geometry, flow rate and alternating magnetic field frequency were investigated, resulting in a capture efficiency of 68 %.

  20. Lipid vesicle-mediated affinity chromatography using magnetic activated cell sorting (LIMACS): a novel method to analyze protein-lipid interaction.

    Science.gov (United States)

    Bieberich, Erhard

    2011-04-26

    The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification procedures. As an alternative, lipids can be coated on flat surfaces as used for lipid ELISA and Plasmon resonance spectroscopy. However, surface coating lipids do not form microdomain structures, which may be important for the lipid binding properties. Further, these methods do not allow for the purification of larger amounts of proteins binding to their target lipids. To overcome these limitations of testing lipid protein interaction and to purify lipid binding proteins we developed a novel method termed lipid vesicle-mediated affinity chromatography using magnetic-activated cell sorting (LIMACS). In this method, lipid vesicles are prepared with the target lipid and phosphatidylserine as the anchor lipid for Annexin V MACS. Phosphatidylserine is a ubiquitous cell membrane phospholipid that shows high affinity to the protein Annexin V. Using magnetic beads conjugated to Annexin V the phosphatidylserine-containing lipid vesicles will bind to the magnetic beads. When the lipid vesicles are incubated with a cell lysate the protein binding to the target lipid will also be bound to the beads and can be co-purified using MACS. This method can also be used to test if recombinant proteins reconstitute a protein complex binding to the target lipid. We have used this method to show the interaction of atypical PKC (aPKC) with the sphingolipid ceramide and to co-purify prostate apoptosis response 4 (PAR-4), a protein binding to ceramide-associated aPKC. We have also used this method for the reconstitution of a ceramide-associated complex of recombinant aPKC with the cell polarity-related proteins Par6 and Cdc42. Since lipid vesicles can be prepared with a variety of sphingo- or phospholipids, LIMACS offers a versatile test for lipid-protein interaction in a lipid environment that resembles closely that of the cell membrane

  1. Confocal nanoscanning, bead picking (CONA): PickoScreen microscopes for automated and quantitative screening of one-bead one-compound libraries.

    Science.gov (United States)

    Hintersteiner, Martin; Buehler, Christof; Uhl, Volker; Schmied, Mario; Müller, Jürgen; Kottig, Karsten; Auer, Manfred

    2009-01-01

    Solid phase combinatorial chemistry provides fast and cost-effective access to large bead based libraries with compound numbers easily exceeding tens of thousands of compounds. Incubating one-bead one-compound library beads with fluorescently labeled target proteins and identifying and isolating the beads which contain a bound target protein, potentially represents one of the most powerful generic primary high throughput screening formats. On-bead screening (OBS) based on this detection principle can be carried out with limited automation. Often hit bead detection, i.e. recognizing beads with a fluorescently labeled protein bound to the compound on the bead, relies on eye-inspection under a wide-field microscope. Using low resolution detection techniques, the identification of hit beads and their ranking is limited by a low fluorescence signal intensity and varying levels of the library beads' autofluorescence. To exploit the full potential of an OBS process, reliable methods for both automated quantitative detection of hit beads and their subsequent isolation are needed. In a joint collaborative effort with Evotec Technologies (now Perkin-Elmer Cellular Technologies Germany GmbH), we have built two confocal bead scanner and picker platforms PS02 and a high-speed variant PS04 dedicated to automated high resolution OBS. The PS0X instruments combine fully automated confocal large area scanning of a bead monolayer at the bottom of standard MTP plates with semiautomated isolation of individual hit beads via hydraulic-driven picker capillaries. The quantification of fluorescence intensities with high spatial resolution in the equatorial plane of each bead allows for a reliable discrimination between entirely bright autofluorescent beads and real hit beads which exhibit an increased fluorescence signal at the outer few micrometers of the bead. The achieved screening speed of up to 200,000 bead assayed in less than 7 h and the picking time of approximately 1 bead

  2. Processes Leading to Beaded Channels Formation in Central Yakutia

    Science.gov (United States)

    Tarbeeva, A. M.; Lebedeva, L.; Efremov, V. S.; Krylenko, I. V.; Surkov, V. V.

    2017-12-01

    Beaded channels, consisting of deepened and widened pools and connecting narrow runs, are common fluvial forms in permafrost regions. Recent studies have shown that beaded channels are very important for connecting alluvial rivers with headwater lakes allowing fish passage and foraging habitats, as well as regulating river runoff. Beaded channels are known as typical thermokarst landforms; however, there is no evidence of their origin and formative processes. Geomorphological analyzes of beaded channels have been completed in several permafrost regions including field observations of Shestakovka River in Central Yakutia. The study aims to recognize the modern exogenic processes and formative mechanisms of beaded river channels. We show that beaded channel of Shestakovka River form in the perennially frozen sand with low ice content, leading us to hypothesize that thermokarst is not the main process of formation. Due to the significant volume of water, the pools don't freeze over entirely during winters, even under harsh climatic conditions. As a result, lenses of pressurized water remain under surface ice underlain by perennially thawed sediments. The presence of thawed sediments under the pools and frozen sediments under the runs leads to uneven thermoerosion of the riverbed during floods, providing the beaded form of the channel. In addition, freezing of pools during winter leads to pressure increasing under ice cover and formation of ice mounds, which crack several times during winter leading to disturbance of riverbanks. Many 1st to 3rd order streams have a specific transitional meandering-to-beaded form resembling the shape of unconfined meandering rivers, but consisting of pools and runs. However, such channels exhibit no evidences of present-day erosion of concave banks and sediment accumulation at the convex banks as typically being observed in normally meandering rivers. Such forms of channels indicates that their formation occurred by the greater channel

  3. Transarterial chemoembolization with drug-eluting beads in hepatocellular carcinoma

    Science.gov (United States)

    Nam, Hee Chul; Jang, Bohyun; Song, Myeong Jun

    2016-01-01

    Transarterial chemoembolization (TACE) is a widely used standard treatment for patients with hepatocellular carcinoma (HCC) who are not suitable candidates for curative treatments. The rationale for TACE is that intra-arterial chemotherapy using lipiodol and chemotherapeutic agents, followed by selective vascular embolization, results in a strong cytotoxic effect as well as ischemia (conventional TACE). Recently, drug-eluting beads (DC Beads®) have been developed for transcatheter treatment of HCC to deliver higher doses of the chemotherapeutic agent and to prolong contact time with the tumor. DC Beads® can actively sequester doxorubicin hydrochloride from solution and release it in a controlled sustained fashion. Treatment with DC Beads® substantially reduced the amount of chemotherapeutic agent that reached the systemic circulation compared with conventional, lipiodol-based regimens, significantly reducing drug-related adverse events. In this article, we describe the treatment response, survival, and safety of TACE used with drug-eluting beads for the treatment of HCC and discuss future therapeutic possibilities. PMID:27833376

  4. Surface imprinted beads for the recognition of human serum albumin.

    Science.gov (United States)

    Bonini, Francesca; Piletsky, Sergey; Turner, Anthony P F; Speghini, Adolfo; Bossi, Alessandra

    2007-04-15

    The synthesis of poly-aminophenylboronic acid (ABPA) imprinted beads for the recognition of the protein human serum albumin (HSA) is reported. In order to create homogeneous recognition sites, covalent immobilisation of the template HSA was exploited. The resulting imprinted beads were selective for HSA. The indirect imprinting factor (IF) calculated from supernatant was 1.6 and the direct IF, evaluated from the protein recovered from the beads, was 1.9. The binding capacity was 1.4 mg/g, which is comparable to commercially available affinity materials. The specificity of the HSA recognition was evaluated with competitive experiments, indicating a molar ratio 4.5/1 of competitor was necessary to displace half of the bound HSA. The recognition and binding of the imprinted beads was also tested with a complex sample, human serum and targeted removal of HSA without a loss of the other protein components was demonstrated. The easy preparation protocol of derivatised beads and a good protein recognition properties make the approach an attractive solution to analytical and bio-analytical problems in the field of biotechnology.

  5. Removal of Uranium from Aqueous Solution by Alginate Beads

    Directory of Open Access Journals (Sweden)

    Jing Yu

    2017-04-01

    Full Text Available The adsorption of uranium (VI by calcium alginate beads was examined by batch experiments. The effects of environmental conditions on U (VI adsorption were studied, including contact time, pH, initial concentration of U (VI, and temperature. The alginate beads were characterized by using scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Fourier transform infrared spectra indicated that hydroxyl and alkoxy groups are present at the surface of the beads. The experimental results showed that the adsorption of U (VI by alginate beads was strongly dependent on pH, the adsorption increased at pH 3∼7, then decreased at pH 7∼9. The adsorption reached equilibrium within 2 minutes. The adsorption kinetics of U (VI onto alginate beads can be described by a pseudo first-order kinetic model. The adsorption isotherm can be described by the Redlich-Peterson model, and the maximum adsorption capacity was 237.15 mg/g. The sorption process is spontaneous and has an exothermic reaction.

  6. Removal of uranium from aqueous solution by aliginate beads

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Jing; Wang, Jian Long [Collaborative Innovation Center for Advanced Nuclear Energy Technology, INET, Tsinghua University, Beijing (China); Jiang, Yizhou [Northwest Institute of Nuclear Technology, Xian (China)

    2017-04-15

    The adsorption of uranium (VI) by calcium alginate beads was examined by batch experiments. The effects of environmental conditions on U (VI) adsorption were studied, including contact time, pH, initial concentration of U (VI), and temperature. The alginate beads were characterized by using scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Fourier transform infrared spectra indicated that hydroxyl and alkoxy groups are present at the surface of the beads. The experimental results showed that the adsorption of U (VI) by alginate beads was strongly dependent on pH, the adsorption increased at pH 3∼7, then decreased at pH 7∼9. The adsorption reached equilibrium within 2 minutes. The adsorption kinetics of U (VI) onto alginate beads can be described by a pseudo first-order kinetic model. The adsorption isotherm can be described by the Redlich-Peterson model, and the maximum adsorption capacity was 237.15 mg/g. The sorption process is spontaneous and has an exothermic reaction.

  7. Controlled antiseptic release by alginate polymer films and beads.

    Science.gov (United States)

    Liakos, Ioannis; Rizzello, Loris; Bayer, Ilker S; Pompa, Pier Paolo; Cingolani, Roberto; Athanassiou, Athanassia

    2013-01-30

    Biodegradable polymeric materials based on blending aqueous dispersions of natural polymer sodium alginate (NaAlg) and povidone iodine (PVPI) complex, which allow controlled antiseptic release, are presented. The developed materials are either free standing NaAlg films or Ca(2+)-cross-linked alginate beads, which properly combined with PVPI demonstrate antibacterial and antifungal activity, suitable for therapeutic applications, such as wound dressing. Glycerol was used as the plasticizing agent. Film morphology was studied by optical and atomic force microscopy. It was found that PVPI complex forms well dispersed circular micro-domains within the NaAlg matrix. The beads were fabricated by drop-wise immersion of NaAlg/PVPI/glycerol solutions into aqueous calcium chloride solutions to form calcium alginate beads encapsulating PVPI solution (CaAlg/PVPI). Controlled release of PVPI was possible when the composite films and beads were brought into direct contact with water or with moist media. Bactericidal and fungicidal properties of the materials were tested against Escherichia coli bacteria and Candida albicans fungi. The results indicated very efficient antibacterial and antifungal activity within 48 h. Controlled release of PVPI into open wounds is highly desired in clinical applications to avoid toxic doses of iodine absorption by the wound. A wide variety of applications are envisioned such as external and internal wound dressings with controlled antiseptic release, hygienic and protective packaging films for medical devices, and polymer beads as water disinfectants. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Bioinspired Materials for Water Purification

    Directory of Open Access Journals (Sweden)

    Alfredo Gonzalez-Perez

    2016-06-01

    Full Text Available Water scarcity issues associated with inadequate access to clean water and sanitation is a ubiquitous problem occurring globally. Addressing future challenges will require a combination of new technological development in water purification and environmental remediation technology with suitable conservation policies. In this scenario, new bioinspired materials will play a pivotal role in the development of more efficient and environmentally friendly solutions. The role of amphiphilic self-assembly on the fabrication of new biomimetic membranes for membrane separation like reverse osmosis is emphasized. Mesoporous support materials for semiconductor growth in the photocatalytic degradation of pollutants and new carriers for immobilization of bacteria in bioreactors are used in the removal and processing of different kind of water pollutants like heavy metals. Obstacles to improve and optimize the fabrication as well as a better understanding of their performance in small-scale and pilot purification systems need to be addressed. However, it is expected that these new biomimetic materials will find their way into the current water purification technologies to improve their purification/removal performance in a cost-effective and environmentally friendly way.

  9. Magnetic

    Science.gov (United States)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  10. MAGNET

    CERN Multimedia

    Benoit Curé

    The cooling down to the nominal temperature of 4.5 K was achieved at the beginning of August, in conjunction with the completion of the installation work of the connection between the power lines and the coil current leads. The temperature gradient on the first exchanger of the cold box is now kept within the nominal range. A leak of lubricant on a gasket of the helium compressor station installed at the surface was observed and several corrective actions were necessary to bring the situation back to normal. The compressor had to be refilled with lubricant and a regeneration of the filters and adsorbers was necessary. The coil cool down was resumed successfully, and the cryogenics is running since then with all parameters being nominal. Preliminary tests of the 20kA coil power supply were done earlier at full current through the discharge lines into the dump resistors, and with the powering busbars from USC5 to UXC5 without the magnet connected. On Monday evening August 25th, at 8pm, the final commissionin...

  11. MAGNET

    CERN Document Server

    B. Curé

    The first phase of the commissioning ended in August by a triggered fast dump at 3T. All parameters were nominal, and the temperature recovery down to 4.5K was carried out in two days by the cryogenics. In September, series of ramps were achieved up to 3 and finally 3.8T, while checking thoroughly the detectors in the forward region, measuring any movement of and around the HF. After the incident of the LHC accelerator on September 19th, corrective actions could be undertaken in the forward region. When all these displacements were fully characterized and repetitive, with no sign of increments in displacement at each field ramp, it was possible to start the CRAFT, Cosmic Run at Four Tesla (which was in fact at 3.8T). The magnet was ramped up to 18.16kA and the 3 week run went smoothly, with only 4 interruptions: due to the VIP visits on 21st October during the LHC inauguration day; a water leak on the cooling demineralized water circuit, about 1 l/min, that triggered a stop of the cooling pumps, and resulte...

  12. MAGNET

    CERN Multimedia

    Benoit Curé

    2013-01-01

    Maintenance work and consolidation activities on the magnet cryogenics and its power distribution are progressing according to the schedules. The manufacturing of the two new helium compressor frame units has started. The frame units support the valves, all the sensors and the compressors with their motors. This activity is subcontracted. The final installation and the commissioning at CERN are scheduled for March–April 2014. The overhauls of existing cryogenics equipment (compressors, motors) are in progress. The reassembly of the components shall start in early 2014. The helium drier, to be installed on the high-pressure helium piping, has been ordered and will be delivered in the first trimester of 2014. The power distribution for the helium compressors in SH5 on the 3.3kV network is progressing. The 3.3kV switches, between each compressor and its hot spare compressor, are being installed, together with the power cables for the new compressors. The 3.3kV electrical switchboards in SE5 will ...

  13. A Pneumatic Actuated Microfluidic Beads-Trapping Device

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-20

    The development of a polydimethylsiloxane (PDMS) microfluidic microbeads trapping device is reported in this paper. Besides fluid channels, the proposed device includes a pneumatic control chamber and a beads-trapping chamber with a filter array structure. The pneumatic flow control chamber and the beads-trapping chamber are vertically stacked and separated by a thin membrane. By adjusting the pressure in the pneumatic control chamber, the membrane can either be pushed against the filter array to set the device in trapping mode or be released to set the device in releasing mode. In this paper, a computational fluid dynamics simulation was conducted to optimize the geometry design of the filter array structure; the device fabrication was also carried out. The prototype device was tested and the preliminary experimental results showed that it can be used as a beads-trapping unit for various biochemistry and analytical chemistry applications, especially for flow injection analysis systems.

  14. Bead-based screening in chemical biology and drug discovery

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Nielsen, Thomas Eiland; Qvortrup, Katrine

    2018-01-01

    libraries for early drug discovery. Among the various library forms, the one-bead-one-compound (OBOC) library, where each bead carries many copies of a single compound, holds the greatest potential for the rapid identification of novel hits against emerging drug targets. However, this potential has not yet...... been fully realized due to a number of technical obstacles. In this feature article, we review the progress that has been made towards bead-based library screening and applications to the discovery of bioactive compounds. We identify the key challenges of this approach and highlight key steps needed......High-throughput screening is an important component of the drug discovery process. The screening of libraries containing hundreds of thousands of compounds requires assays amanable to miniaturisation and automization. Combinatorial chemistry holds a unique promise to deliver structural diverse...

  15. The dispersion of fine chitosan particles by beads-milling

    Science.gov (United States)

    Rochima, Emma; Utami, Safira; Hamdani, Herman; Azhary, Sundoro Yoga; Praseptiangga, Danar; Joni, I. Made; Panatarani, Camellia

    2018-02-01

    This research aimed to produce fine chitosan particles from a crab shell waste by beads-milling method by two different concentration of PEG as dispersing agent (150 and 300 wt. %). The characterization was performed to obtain the size and size distribution, the characteristics of functional groups and the degree of deacetylation. The results showed that the chitosan fine particles was obtained with a milling time 120 minutes with the best concentration of PEG 400 150 wt. %. The average particle size of the as-prepared suspension is 584 nm after addition of acetic acid solution (1%, v/v). Beads milling process did not change the glucosamine and N-acetylglucosamine content on chitosan structure which is indicated by degree of deacetylation higher than 70%. It was concluded that beads milling process can be applied to prepare chitosan fineparticles by proper adjustment in the milling time, pH and dosage of dispersing agent.

  16. Development of multifunctional chitosan beads for fluoride removal

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Natrayasamy [Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamilnadu (India); Sairam Sundaram, C. [Department of Science and Humanities, Karaikal Polytechnic College, Karaikal 609 609, Puducherry (India); Meenakshi, S., E-mail: drs_meena@rediffmail.com [Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamilnadu (India)

    2009-08-15

    Chitosan beads (CB) which have negligible defluoridation capacity (DC) have been chemically modified by introducing multifunctional groups, viz., NH{sub 3}{sup +} and COOH groups by means of protonation and carboxylation in order to utilize both amine and hydroxyl groups for fluoride removal. The protonated cum carboxylated chitosan beads (PCCB) showed a maximum DC of 1800 mg F{sup -}/kg whereas raw chitosan beads displayed only 52 mg F{sup -}/kg. Sorption process was found to be independent of pH and slightly influenced in the presence of other common anions. The fluoride sorption on modified forms was reasonably explained by Freundlich and Langmuir isotherms. The sorbents were characterised by FTIR and SEM with EDAX analysis. The sorption process follows pseudo-second-order and intraparticle diffusion kinetic models. The suitability of PCCB has been tested with field sample collected from a nearby fluoride endemic area.

  17. The Surface Imprinted Polystyrene Beads Prepared via Emulsion Templates

    Institute of Scientific and Technical Information of China (English)

    Guo Xiang CHENG; Guang Ling PEI; Ling Gang ZENG; Li Yong ZHANG; Chao LIU

    2004-01-01

    In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788), the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer, cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.

  18. Corrosion of ancient glass beads found in Southern Thailand

    International Nuclear Information System (INIS)

    Won-in, K; Thongkam, Y; Intarasiri, S; Kamwanna, T; Dararutana, P

    2012-01-01

    Glass has been used as ornaments and decorations in Thailand for several hundred years. The archaeological resources suggested that the ancient glass beads excavated in southern Thailand were made more than 1300 years ago. Initial findings revealed that there were number of difference in shade between the glass beads of difference colors. Energy dispersive X-ray spectrometer (EDS) system attached with scanning electron microscope (SEM) and particle-induced X-ray emission spectroscopy (PIXE) were firstly used to study the surface corrosion of the samples. SEM micrographs showed more corroded and flaked microstructure. These were contributed to the interaction of both the ground water and its dissolved chemical compounds.

  19. Sodium purification in Rapsodie; La purification du sodium a Rapsodie

    Energy Technology Data Exchange (ETDEWEB)

    Giraud, B [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Cadarache (France). Centre d' Etudes Nucleaires

    1968-07-01

    This report is one of a series of publications presenting the main results of tests carried out during the start-up of the first french fast neutron reactor: Rapsodie. The article presents the sodium purification techniques used in the reactor cooling circuits both from the constructional point of view and with respect to results obtained during the first years working. (author) [French] Ce rapport fait partie d'une serie de publications presentant l'essentiel des resultats des essais effectues a l'occasion du demarrage du premier reacteur francais a neutrons rapides: RAPSODIE. Cet article expose les techniques de la purification du sodium utilise dans les circuits de refroidissement du reacteur tant au point de vue de leur realisation technologique, que des resultats obtenus pendant la premiere annee de fonctionnement. (auteur)

  20. Residual gentamicin-release from antibiotic-loaded polymethylmethacrylate beads after 5 years of implantation

    NARCIS (Netherlands)

    Neut, D; van de Belt, H; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    In infected joint arthroplasty, high local levels of antibiotics are achieved through temporary implantation of non-biodegradable gentamicin-loaded polymethylmethacrylate beads. Despite their antibiotic release, these beads act as a biomaterial surface to which bacteria preferentially adhere, grow

  1. Water purification using organic salts

    Science.gov (United States)

    Currier, Robert P.

    2004-11-23

    Water purification using organic salts. Feed water is mixed with at least one organic salt at a temperature sufficiently low to form organic salt hydrate crystals and brine. The crystals are separated from the brine, rinsed, and melted to form an aqueous solution of organic salt. Some of the water is removed from the aqueous organic salt solution. The purified water is collected, and the remaining more concentrated aqueous organic salt solution is reused.

  2. The bubble method of water purification

    Science.gov (United States)

    Smirnov, B. M.; Babaeva, N. Yu.; Naidis, G. V.; Panov, V. A.; Saveliev, A. S.; Son, E. E.; Tereshonok, D. V.

    2018-02-01

    The processes of water purification from admixture molecules are analyzed. The purification rate is limited due to a low diffusion coefficient of the admixture molecules in water. At non-small concentrations of the admixture molecules, the water purication can proceed through association of molecules in condensed nanoparticles which fall on the bottom of the water volume. The rate of association may be increased in an external electric field, but in reality this cannot change significantly the rate of the purification process. The bubble method of water purification is considered, where air bubbles formed at the bottom of the water volume, transfer admixture molecules to the interface. This method allows one to clean small water volumes fast. This mechanism of water purification is realized experimentally and exhibits the promises of the bubble purification method.

  3. Exploring Traditional Glass Bead Making Techniques in Jewellery ...

    African Journals Online (AJOL)

    Exploring traditional glass bead making techniques in jewellery in some prominent areas in Ghana is a means to exposing the area for metal and ceramic artists and other related fields of discipline such as aesthetics and criticism to complement their form of ... Keywords: livelihood, vitreous, glass bottles, furnace, threading ...

  4. Glass bead transformation method for gram-positive bacteria

    OpenAIRE

    Rattanachaikunsopon, Pongsak; Phumkhachorn, Parichat

    2009-01-01

    A simple, inexpensive and reproducible transformation method was developed for Gram-positive bacteria. It was based on agitation of bacterial protoplasts with glass beads in the presence of DNA and polyethylene glycol. By using this method, introduction of pGK12 into protoplasts of several strains of Gram-positive bacteria was achieved.

  5. Collection Development: From Beads to Bangles (Jewelry Making)

    Science.gov (United States)

    Hanrahan, Katie

    2010-01-01

    Jewelry making began exploding as a hobby about ten years ago, largely because the flush economy gave individuals more leisure time and disposable income. Jewelry classes, bead stores, and special events have multiplied like craft shows at Christmas time. While the recent economic downturn has slowed the growth of the hobby, it is still as popular…

  6. Evaluation of double drop beads pavement edge lines.

    Science.gov (United States)

    2009-08-01

    This report presents an evaluation of Double Drop Bead (DDB) edge lines used on ALDOT-maintained highways. It compares DDB to three other pavement marking types in terms of service lives, life-cycle costs, and both dry-night retroreflectivity and wet...

  7. StoryBeads: Preserving indigenous knowledge through tangible interaction design

    CSIR Research Space (South Africa)

    Reitsma, L

    2013-09-01

    Full Text Available in technology adoption. The study resulted in a recording device that fits the target group’s oral tradition and is based on a concept in which oral stories are recorded and associated with tangible beads that can be incorporated into traditional beadwork...

  8. Continuous removal and recovery of lead by alginate beads, free ...

    African Journals Online (AJOL)

    This study examines the possibility of using Chlorella vulgaris cells in repeated lead adsorption/desorption cycles. Alginate beads and immobilized with algal cells were more effective and suitable than free cells. Consistently high lead removal (>90%) and recovery (about 100%) were achieved. Lead adsorption was mainly ...

  9. 485 assessment of the problems of manual automobile tyre bead

    African Journals Online (AJOL)

    eobe

    rim bead bond must be broken to carry out repairs on a failed automobile tyre. ... engine will not be transformed into the motion of the vehicle. It provides the only point of contact between ..... Popular Mechanic 162 (6): 62. http://books.google.

  10. Technological assumptions for biogas purification.

    Science.gov (United States)

    Makareviciene, Violeta; Sendzikiene, Egle

    2015-01-01

    Biogas can be used in the engines of transport vehicles and blended into natural gas networks, but it also requires the removal of carbon dioxide, hydrogen sulphide, and moisture. Biogas purification process flow diagrams have been developed for a process enabling the use of a dolomite suspension, as well as for solutions obtained by the filtration of the suspension, to obtain biogas free of hydrogen sulphide and with a carbon dioxide content that does not exceed 2%. The cost of biogas purification was evaluated on the basis of data on biogas production capacity and biogas production cost obtained from local water treatment facilities. It has been found that, with the use of dolomite suspension, the cost of biogas purification is approximately six times lower than that in the case of using a chemical sorbent such as monoethanolamine. The results showed travelling costs using biogas purified by dolomite suspension are nearly 1.5 time lower than travelling costs using gasoline and slightly lower than travelling costs using mineral diesel fuel.

  11. Low-cost commercial glass beads as dosimeters in radiotherapy

    International Nuclear Information System (INIS)

    Jafari, S.M.; Bradley, D.A.; Gouldstone, C.A.; Sharpe, P.H.G.; Alalawi, A.; Jordan, T.J.; Clark, C.H.; Nisbet, A.; Spyrou, N.M.

    2014-01-01

    Recent developments in advanced radiotherapy techniques using small field photon beams, require small detectors to determine the delivered dose in steep dose gradient fields. Commercially available glass jewellery beads exhibit thermoluminescent properties and have the potential to be used as dosimeters in radiotherapy due to their small size ( 60 Co gamma rays over doses ranging from 1 to 2500 cGy. A thermoluminescence (TL) system and an electron paramagnetic resonance (EPR) system were employed for read out. Both the TL and EPR studies demonstrated a radiation-induced signal, the sensitivity of which varied with bead colour. White coloured beads proved to be the most sensitive for both systems. The smallest and therefore least sensitive bead sizes allowed measurement of doses of 1 cGy using the TL system while that for the EPR system was approximately 1000 cGy. The fading rate was found to be 10% 30 days after irradiation with both readout systems. The dose response is linear with measured dose over the dose range 1 to 2500 cGy, with an R 2 correlation coefficient of greater than 0.999. The batch-to-batch reproducibility of a set of dosimeters after a single irradiation was found to be 3% (1 SD). The reproducibility of individual dosimeters was found to be 1.7%. No measurable angular dependence was found (results agreed within 1%). Dose rate response was found to agree within 1% for dose rates of 100 to 600 cGy/min. These results demonstrate the potential use of glass beads as TL dosimeters over the dose range commonly applied in radiotherapy. - Highlights: • We examined the dosimetric properties of a low cost commercially produced glass seed beads. • Glass beads are available in small size of 1–3 mm, suitable for dosimetry of small radiation fields. • The results demonstrate a mean reproducibility of 0.23% (2 SD), batch homogeneity of within 5%. • Dose response was linear over wide dose range tested for 1 cGy to kGy. • Improved fading effect of 10

  12. 49 CFR 173.221 - Polymeric beads, expandable and Plastic molding compound.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Polymeric beads, expandable and Plastic molding... Than Class 1 and Class 7 § 173.221 Polymeric beads, expandable and Plastic molding compound. (a) Non-bulk shipments of Polymeric beads (or granules), expandable, evolving flammable vapor and Plastic...

  13. Ionically crosslinked alginate–carboxymethyl cellulose beads for the delivery of protein therapeutics

    International Nuclear Information System (INIS)

    Kim, Min Sup; Park, Sang Jun; Gu, Bon Kang; Kim, Chun-Ho

    2012-01-01

    Highlights: ► We prepared Fe 3+ crosslinked alginate–carboxymethyl cellulose (AC) beads. ► Different surface and inner morphology of AC beads were observed on volume of CMC. ► AC beads showed minimum swelling degree in acidic condition. ► Protein release from AC beads was to control in gastrointestinal condition. - Abstract: We developed Fe 3+ -crosslinked alginate–carboxymethyl cellulose (AC) beads in various volume ratios by dropping an AC solution into a ferric chloride solution to form protein therapeutic carrier beads. Scanning electron microscopy revealed that the roughness and pore size of the crosslinked beads increased with the volume ratio of the carboxymethyl cellulose. Fourier transform-infrared analysis revealed the formation of a three-dimensional bonding structure between the anionic polymeric chains of AC and the Fe 3+ ions. The degree of swelling and the release profile of albumin from the beads were investigated under simulated gastrointestinal conditions (pH 1.2, 4.5, and 7.4). The Fe 3+ -crosslinked AC beads displayed different degrees of swelling and albumin release for the various AC volume ratios and under various pH conditions. An in vitro release test was used to monitor the controlled release of albumin from the AC beads under simulated gastrointestinal conditions over 24 h. The Fe 3+ -crosslinked AC beads protected and controlled the release of protein, demonstrating that such beads present a promising protein therapeutic carrier for the oral delivery.

  14. Flow Cytometry-Based Bead-Binding Assay for Measuring Receptor Ligand Specificity

    NARCIS (Netherlands)

    Sprokholt, Joris K.; Hertoghs, Nina; Geijtenbeek, Teunis B. H.

    2016-01-01

    In this chapter we describe a fluorescent bead-binding assay, which is an efficient and feasible method to measure interaction between ligands and receptors on cells. In principle, any ligand can be coated on fluorescent beads either directly or via antibodies. Binding between ligand-coated beads

  15. DTDGA impregnated XAD-16 beads for separation and recovery of palladium from acidic wastes

    International Nuclear Information System (INIS)

    Singh, Krishan Kant; Kanagare, Anant B.; Bairwa, K.K.; Manmohan Kumar; Bajaj, Parma N.; Ruhela, Ritesh; Singh, Ajoy K.; Hubli, Rajendra C.

    2014-01-01

    In the present study DTDGA extractant impregnated XAD16 polymeric beads (DTDGA- XAD16) were synthesized by wet chemical method and the beads were characterized by various techniques viz. FT-IR, Optical microscopy, SEM and TGA. The DTDGA-XAD 16 beads were evaluated for separation and recovery of palladium from high level waste solutions (HLW)

  16. Rapid, highly sensitive detection of herpes simplex virus-1 using multiple antigenic peptide-coated superparamagnetic beads.

    Science.gov (United States)

    Ran, Ying-Fen; Fields, Conor; Muzard, Julien; Liauchuk, Viktoryia; Carr, Michael; Hall, William; Lee, Gil U

    2014-12-07

    A sensitive, rapid, and label free magnetic bead aggregation (MBA) assay has been developed that employs superparamagnetic (SPM) beads to capture, purify, and detect model proteins and the herpes simplex virus (HSV). The MBA assay is based on monitoring the aggregation state of a population of SPM beads using light scattering of individual aggregates. A biotin-streptavidin MBA assay had a femtomolar (fM) level sensitivity for analysis times less than 10 minutes, but the response of the assay becomes nonlinear at high analyte concentrations. A MBA assay for the detection of HSV-1 based on a novel peptide probe resulted in the selective detection of the virus at concentrations as low as 200 viral particles (vp) per mL in less than 30 min. We define the parameters that determine the sensitivity and response of the MBA assay, and the mechanism of enhanced sensitivity of the assay for HSV. The speed, relatively low cost, and ease of application of the MBA assay promise to make it useful for the identification of viral load in resource-limited and point-of-care settings where molecular diagnostics cannot be easily implemented.

  17. Semi-Automated Hydrophobic Interaction Chromatography Column Scouting Used in the Two-Step Purification of Recombinant Green Fluorescent Protein

    Science.gov (United States)

    Murphy, Patrick J. M.

    2014-01-01

    Background Hydrophobic interaction chromatography (HIC) most commonly requires experimental determination (i.e., scouting) in order to select an optimal chromatographic medium for purifying a given target protein. Neither a two-step purification of untagged green fluorescent protein (GFP) from crude bacterial lysate using sequential HIC and size exclusion chromatography (SEC), nor HIC column scouting elution profiles of GFP, have been previously reported. Methods and Results Bacterial lysate expressing recombinant GFP was sequentially adsorbed to commercially available HIC columns containing butyl, octyl, and phenyl-based HIC ligands coupled to matrices of varying bead size. The lysate was fractionated using a linear ammonium phosphate salt gradient at constant pH. Collected HIC eluate fractions containing retained GFP were then pooled and further purified using high-resolution preparative SEC. Significant differences in presumptive GFP elution profiles were observed using in-line absorption spectrophotometry (A395) and post-run fluorimetry. SDS-PAGE and western blot demonstrated that fluorometric detection was the more accurate indicator of GFP elution in both HIC and SEC purification steps. Comparison of composite HIC column scouting data indicated that a phenyl ligand coupled to a 34 µm matrix produced the highest degree of target protein capture and separation. Conclusions Conducting two-step protein purification using the preferred HIC medium followed by SEC resulted in a final, concentrated product with >98% protein purity. In-line absorbance spectrophotometry was not as precise of an indicator of GFP elution as post-run fluorimetry. These findings demonstrate the importance of utilizing a combination of detection methods when evaluating purification strategies. GFP is a well-characterized model protein, used heavily in educational settings and by researchers with limited protein purification experience, and the data and strategies presented here may aid in

  18. Process and device for fabrication of ice beads and application to abrasive blasting with ice beads for surface treatments

    International Nuclear Information System (INIS)

    Barnier, M.; Manificat, A.; Perroud, P.

    1989-01-01

    A device is described for cleaning and decontamination by abrasive blasting with ice beads. It comprises a water injector, with many holes, at the top of a column feeded with cold gas where solidification of water droplets begins, solidification is completed in a cooling liquids, ice is extracted by a screw and pushed to the projection nozzle with cold gas [fr

  19. Comparing Russian and Finnish standards of water purification

    OpenAIRE

    Maria, Pupkova

    2012-01-01

    The subject of this thesis is water purification. The first aim of this thesis is to consider different ways of water purification. The second aim is to compare Finnish and Russian standards of water purification. The third one is to show water purification methods on the pattern of Mikkeli water purification plan. Water purification methods of water intended for human consumption will be described.Combined tables will be done according to the quality requirement of drinking water of both,...

  20. Strategies for enumeration of circulating microvesicles on a conventional flow cytometer: Counting beads and scatter parameters.

    Science.gov (United States)

    Alkhatatbeh, Mohammad J; Enjeti, Anoop K; Baqar, Sara; Ekinci, Elif I; Liu, Dorothy; Thorne, Rick F; Lincz, Lisa F

    2018-01-01

    Enumeration of circulating microvesicles (MVs) by conventional flow cytometry is accomplished by the addition of a known amount of counting beads and calculated from the formula: MV/μl = (MV count/bead count) × final bead concentration. We sought to optimize each variable in the equation by determining the best parameters for detecting 'MV count' and examining the effects of different bead preparations and concentrations on the final calculation. Three commercially available bead preparations (TruCount, Flow-Count and CountBright) were tested, and MV detection on a BD FACSCanto was optimized for gating by either forward scatter (FSC) or side scatter (SSC); the results were compared by calculating different subsets of MV on a series of 74 typical patient plasma samples. The relationship between the number of beads added to each test and the number of beads counted by flow cytometry remained linear over a wide range of bead concentrations ( R 2 ≥ 0.997). However, TruCount beads produced the most consistent (concentration variation = 3.8%) calculated numbers of plasma CD41 + /Annexin V + MV, which were significantly higher from that calculated using either Flow-Count or CountBright ( p beads by FSC and 0.16 μm beads by SSC, but there were significantly more background events using SSC compared with FSC (3113 vs. 470; p = 0.008). In general, sample analysis by SSC resulted in significantly higher numbers of MV ( p beads provided linear results at concentrations ranging from 6 beads/μl to 100 beads/μl, but TruCount was the most consistent. Using SSC to gate MV events produced high background which negatively affected counting bead enumeration and overall MV calculations. Strategies to reduce SSC background should be employed in order to reliably use this technique.

  1. Stability of alginate-titanium dioxide based photocatalyst beads for water treatment application under UV irradiation

    OpenAIRE

    WENG HOONG LAM

    2017-01-01

    Immobilizing TiO2 photocatalyst in alginate beads has been considered to be a green approach for the separation and recycling of the photocatalyst in UV water treatment. However, the feasibility of using alginate beads in industry is largely dependent on their photo-stability during operation. This study aimed to provide a better understanding on the degradation of alginate/TiO2 beads under UV irradiation and to improve beads stability. The beads stability can be improved by increasing the al...

  2. Compositional characterization of sintered (U,Th)O2 pellets by EDXRF using fused bead specimens

    International Nuclear Information System (INIS)

    Sanjay Kumar, S.; Dhara, Sangita; Misra, N.L.; Aggarwal, S.K.

    2015-01-01

    Fused bead specimens were used for analyzing sintered (U,Th)O 2 pellets by Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry. The bead specimens of calibration mixtures U 3 O 8 and ThO 2 were made by fusing them in Lithium Tetraborate/Metaborate fusion mixtures using a fusion bead machine. The EDXRF spectra of these beads were used for making calibration plot for U% determination in (U+Th) amounts. Using these calibration plots and EDXRF spectra of bead of sintered (U,Th)O 2 pellets, U% in these pellets was successfully determined. (author)

  3. Ion exchange purification of scandium

    Science.gov (United States)

    Herchenroeder, Laurie A.; Burkholder, Harvey R.

    1990-10-23

    An improvement in purification of scandium through ion exchange chromatography is disclosed in which the oxidation potential of the eluting solution is altered by the addition of potassium chlorate or ammonium chloride so that removal of contaminants is encouraged. The temperature, pH and concentration of the eluent HEDTA are controlled in order to maintain the scandium in the column while minimizing dilution of the scandium band. Recovery of scandium is improved by pumping dilute scandium over the column prior to stripping the scandium and precipitation. This eliminates the HEDTA ion and other monovalent cations contaminating the scandium band. This method maximizes recovery of scandium while maintaining purity.

  4. Improvement of removal characteristics for uranium by immobilization of diphosil powder into alginate bead

    International Nuclear Information System (INIS)

    Kim, K. J.; Kang, I. S.; Lee, Y. H.; Son, J. S.; Hong, K. P.

    2003-01-01

    Chemical wastes containing small amounts of uranium can not be disposed of them as industrial wastes. Especially for the removal of uranium, In this study, the method of immobilizing Diphosil powder within alginate beads is adopted to make a bead from powdered resin. Sodium alginate bead itself showed a capability to uptake uranium to above 60%, but the value was decreased to below 30% after equilibrium. The rate of uranium adsorption increased with increasing content of Diphosil in sodium alginate bead. Diphosil resin itself showed very fast uptake of uranium from early stages, and then the rates were leveled off. Diphosil bead showed a improved capability to uptake uranium considering Diphosil content in the bead, and a considerable potential for further applications of a continuous process by using a bead form of Diphosil

  5. Separation of yttrium using carbon nanotube doped polymeric beads impregnated with D2EHPA

    International Nuclear Information System (INIS)

    Dasgupta, Kinshuk; Yadav, Kartikey K.; Singh, D.K.; Anitha, M.; Singh, H.

    2013-01-01

    Di-2-ethylhexyl phosphoric acid impregnated polyethersulfone based composite beads in combination with additives such as polyvinyl alcohol (PVA) and multiwalled carbon nanotube (MWCNT) has been prepared by non-solvent phase inversion method. The synthesized beads were characterized by scanning electron microscopy, thermogravimetry and infra-red spectroscopy. Effect of additives on bead morphology, solvent impregnation capacity, extractability and stability has been examined to compare their suitability for yttrium recovery from acidic medium. Microstructural investigation as well as experimental findings confirmed the role of additives in modifying the pore structures in beads, responsible for varied degree of yttrium extraction. Further the role of metal ion concentration in aqueous phase on its recovery by polymeric beads was also evaluated. Among the tested beads PES/D2EHPA/MWCNT/PVA beads were found to be superior for Y(Ill) extraction. (author)

  6. On the occurrence of ‘bead lightning’ phenomena in long laboratory sparks

    Energy Technology Data Exchange (ETDEWEB)

    Vayanganie, S.P.A., E-mail: amilavayanganie@gmail.com [Atmospheric Physics and Lightning Research Group, University of Colombo, Colombo 03 (Sri Lanka); Cooray, V.; Rahman, Mahbubur; Hettiarachchi, Pasan; Diaz, Oscar [Lightning Research Group, The Ångström Laboratory Division of Electricity, Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Fernando, M. [Atmospheric Physics and Lightning Research Group, University of Colombo, Colombo 03 (Sri Lanka)

    2016-02-22

    The formation of bead lightning, where the lightning channel appears to break up into luminous fragments, is still an object of speculation. Here we report similar observations in laboratory discharges. Analysis of time resolved photographs shows that the discharge channel exhibits a ‘bead pattern’ in the decaying stage of the discharge and the occurrence of loops in the channel sections where the bead pattern is observed. This result presents the first evidence that the rapid cooling of non-uniform channel sections could lead to the formation of beads. It is suggested that periodically occurring non-uniform channel sections could explain the bead pattern of lightning discharges. - Highlights: • For the first time, the occurrence of bead patterns in the channel of laboratory sparks was reported. • Depending on the geometry some regions of the channel decays faster than the other sections. • A possible mechanism for the occurrence of beads in decaying states of lightning flashes is proposed.

  7. Lysine purification with cation exchange resin

    International Nuclear Information System (INIS)

    Khayati, GH.; Mottaghi Talab, M.; Hamooni Hagheeghat, M.; Fatemi, M.

    2003-01-01

    L-lysine is an essential amino acid for the growth most of animal species and the number one limiting amino acid for poultry. After production and biomass removal by filtration and centrifugation, the essential next step is the lysine purification and recovery. There are different methods for lysine purification. The ion exchange process is one of the most commonly used purification methods. Lysine recovery was done from broth by ion exchange resin in three different ways: repeated passing, resin soaking and the usual method. Impurities were isolated from the column by repeated wash with distilled water. Recovery and purification was done with NH 4 OH and different alcohol volumes respectively. The results showed that repeated passing is the best method for lysine absorption (maximum range 86.21 %). Washing with alkali solution revealed that most of lysine is obtained in the first step of washing. The highest degree of lysine purification was achieved with the use of 4 volumes of alcohol

  8. On the chemical variability of Middelburg glass beads and rods

    International Nuclear Information System (INIS)

    Karklins, K.; Kottman, J.; Hancock, R.G.V.; Sempowski, M.L.; Nohe, A.W.; Moreau, J.-F.; Aufreiter, S.; Kenyon, I.

    2001-01-01

    Forty-three glass samples from a late 16th-early 17th century, glass beadmaking house in Middelburg, the Netherlands, were selected for maximum colouring variability, including plain and multi-coloured varieties. The glass chemistries were quite diverse, within each colour grouping. For each single colour of glass, anticipated colouring elements (copper for turquoise blue, cobalt for dark blue, manganese for rose, and tin for white) were used, with the exception of two beads that were opacified wih antimony rather than with tin. Multi-coloured glass glasses (chevron beads) produced chemistries that match the mixing of the different coloured glasses. In some cases, low relative amounts of some inter-mixed glasses were not detectable against the composition of the major glass component. (author). 16 refs., 3 tabs

  9. Frictionless Demonstration Using Fine Plastic Beads For Teaching Mechanics

    International Nuclear Information System (INIS)

    Ishii, K.; Kagawa, K.; Khumaeni, A.; Kurniawan, K. H.

    2010-01-01

    New equipment for demonstrating laws of mechanics have successfully been constructed utilizing fine sphere plastic beads (0.3 mm in diameter). Fine plastic beads function as ball bearings to reduce the friction between the object and the plate surface. By this method, a quantitative measurement of energy conservation law has successfully been carried out with a small error of less 3%. The strong advantage of this frictionless method is that we can always use the same objects like Petri dishes for demonstrating many kinds of mechanics laws, such as the first, second, and the third laws of motion, momentum conservation law, and energy conservation law. This demonstration method surely has a beneficial effect for students, who can then understand mechanics laws systematically with a unified concept and no confusion.

  10. Methodological Study of Cell Separation with Domestic Immunomagnetic Beads

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To establish the method of cell separation with domestic immuomagnetic beads, three methods were investigated. Direct method, SPA method and Biotin-Avidin method were applied to separate cell strain Hut-78 and CD4 positive cells. Separation rate of strain Hut-78 was more than 90 % in direct method. Detachment rate with papain was over 95 %. Cell activity was well retained. SPA method and Biotin-Avidin methods were also effective, but the direct method was superior to the other two techniques. Before separated by the direct method, CD4 positive cells constituted 46.4 %±6.4 % of mononuclear cells (MNC), but in eliminated suspension there was only 6.2 %±2.3 % CD4 positive cells left. In the separated part, 80.6 %±7.2 % of the cells combined with the beads. It is concluded that the direct method in separating cells had high sensitivity and specificity.

  11. Bead perturbation measurement for the KEK linac cavity

    International Nuclear Information System (INIS)

    Okumura, Shoji; Swenson, D.A.

    1975-03-01

    The axial electric field in the KEK linac cavity is measured by a bead perturbation method. The beat signal of around 1 kHz is generated with the rf signals from the cavity in self-excitation and from a signal generator whose output frequency is fixed. The period of the beat signal is measured by a counter in order to detect the small change in the resonant frequency of the cavity due to a bead perturbation. The counting data are transferred to a mini-computer after each period of the beat signal. The average fields of each gap are calculated in the computer and they are displayed on a storage oscilloscope. It takes about 50 seconds to complete the whole process of the measurement. The measuring system and the results obtained are described in this paper. (auth.)

  12. Plasticity of an Amorphous Assembly of Elastic Gel Beads

    Science.gov (United States)

    Grosshans, D.; Knaebel, A.; Lequeux, F.

    1995-01-01

    We have studied the rheological properties of an assembly of swollen gel beads in a lack of solvent. The system is an amorphous assembly of packed soft spheres in a given volume. We have studied the plastic behavior of the system, and interpreted it in terms of bead rearrangements within the assembly. Nous avons étudié les propriétés rhéologiques d'un assemblage de billes de gel gonflées en défaut de solvant. Le système est donc une assemblée amorphe de sphères molles écrasées à volume total constant. Nous avons étudié divers aspects du comportement plastique et nous l'avons interprété en termes de réorganisations de billes dans l'assemblage.

  13. Molecularly Imprinted Polymer Beads-Synthesis, Evaluation and Applications

    OpenAIRE

    Zhou, Tongchang

    2016-01-01

    Molecularly imprinted polymers (MIPs) are artificial receptors designed for the selective recognition of template molecules. These polymers have been applied in analytical separations, as chemical sensors and in drug delivery system due to their low cost and high stability. In recent years MIP beads, especially those with good selectivity in aqueous solution, have become attractive as they can be potentially used as selective adsorbents for the solid phase extraction (SPE) and chromatographic...

  14. Hot wire TIG temper bead welding for nuclear repairs

    International Nuclear Information System (INIS)

    Lambert, J.A.; Gilston, P.F.

    1989-08-01

    A preliminary assessment has been carried out to determine the suitability of the hot wire tungsten inert gas (TIG) welding process for the repair of thick section, ferritic steel nuclear pressure vessels. The objective has been to identify a hot wire TIG temper bead procedure, suitable for repairs without post weld heat treatment. This procedure involves depositing two weld layers with carefully selected welding parameters such that overlapping thermal cycles produce a refined and tempered heat affected zone, HAZ, microstructure. (author)

  15. HOM identification by bead pulling in the Brookhaven ERL cavity

    CERN Document Server

    Hahn, H; Jain, Puneet; Johnson, Elliott C; Xu, Wencan

    2014-01-01

    Exploratory measurements of the Brookhaven Energy Recovery Linac (ERL) cavity at superconducting temperature produced a long list of high order modes (HOMs). The niobium 5-cell cavity is terminated at each end with HOM ferrite dampers that successfully reduce the Q-factors to levels required to avoid beam break up (BBU) instabilities. However, a number of un-damped resonances with Q≥106 were found at 4 K and their mode identification forms the focus of this paper. The approach taken here consists of bead pulling on a copper (Cu) replica of the ERL cavity with dampers involving various network analyzer measurements. Several different S21 transmission measurements are used, including those taken from the fundamental input coupler to the pick-up probe across the cavity, others between beam-position monitor probes in the beam tubes, and also between probes placed into the cells. The bead pull technique suitable for HOM identification with a metallic needle or dielectric bead is detailed. This paper presents the...

  16. Chitosan and chemically modified chitosan beads for acid dyes sorption

    Institute of Scientific and Technical Information of China (English)

    AZLAN Kamari; WAN SAIME Wan Ngah; LAI KEN Liew

    2009-01-01

    The capabilities of chitosan and chitosan-EGDE (ethylene glycol diglycidyl ether) beads for removing Acid Red 37 (AR 37) and Acid Blue 25 (AB 25) from aqueous solution were examined. Chitosan beads were cross-linked with EGDE to enhance its chemical resistance and mechanical strength. Experiments were performed as a function of pH, agitation period and concentration of AR 37 and AB 25. It was shown that the adsorption capacities of chitosan were comparatively higher than chitosan-EGDE for both acid dyes. This is mainly because cross-linking using EGDE reduces the major adsorption sites -NH3+ on chitosan. Langmuir isotherm model showed best conformity compared to Freundlich and BET. The kinetic experimental data agreed very well to the pseudo second-order kinetic model. The desorption study revealed that after three cycles of adsorption and desorption by NaOH and HCl, both adsorbents retained their promising adsorption abilities. FT-IR analysis proved that the adsorption of acid dyes onto chitosan-based adsorbents was a physical adsorption. Results also showed that chitosan and chitosan-EGDE beads were favourable adsorbers and could be employed as low-cost alternatives for the removal of acid dyes in wastewater treatment.

  17. Magnetic ghosts and monopoles

    International Nuclear Information System (INIS)

    Vandewalle, N; Dorbolo, S

    2014-01-01

    While the physics of equilibrium systems composed of many particles is well known, the interplay between small-scale physics and global properties is still a mystery for athermal systems. Non-trivial patterns and metastable states are often reached in those systems. We explored the various arrangements adopted by magnetic beads along chains and rings. Here, we show that it is possible to create mechanically stable defects in dipole arrangements keeping the memory of dipole frustration. Such defects, nicknamed ‘ghost junctions’, seem to act as macroscopic magnetic monopoles, in a way reminiscent of spin ice systems. (paper)

  18. Microfluidic high gradient magnetic cell separation

    Science.gov (United States)

    Inglis, David W.; Riehn, Robert; Sturm, James C.; Austin, Robert H.

    2006-04-01

    Separation of blood cells by native susceptibility and by the selective attachment of magnetic beads has recently been demonstrated on microfluidic devices. We discuss the basic principles of how forces are generated via the magnetic susceptibility of an object and how microfluidics can be combined with micron-scale magnetic field gradients to greatly enhance in principle the fractionating power of magnetic fields. We discuss our efforts and those of others to build practical microfluidic devices for the magnetic separation of blood cells. We also discuss our attempts to integrate magnetic separation with other microfluidic features for developing handheld medical diagnostic tools.

  19. Investigations on the magnetization behavior of magnetic composite particles

    Energy Technology Data Exchange (ETDEWEB)

    Eichholz, Christian [Process Research and Chemical Engineering, BASF SE, Ludwigshafen (Germany); Knoll, Johannes, E-mail: johannes.knoll@kit.edu [Institute of Mechanical Engineering and Mechanics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Lerche, Dietmar [L.U.M. GmbH, Berlin (Germany); Nirschl, Hermann [Institute of Mechanical Engineering and Mechanics, Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2014-11-15

    In life sciences the application of surface functionalized magnetic composite particles is establishing in diagnostics and in downstream processing of modern biotechnology. These magnetic composite particles consist of non-magnetic material, e.g. polystyrene, which serves as a matrix for the second magnetic component, usually colloidal magnetite. Because of the multitude of magnetic cores these magnetic beads show a complex magnetization behavior which cannot be described with the available approaches for homogeneous magnetic material. Therefore, in this work a new model for the magnetization behavior of magnetic composite particles is developed. By introducing an effective magnetization and considering an overall demagnetization factor the deviation of the demagnetization of homogeneously magnetized particles is taken into account. Calculated and experimental results show a good agreement which allows for the verification of the adapted model of particle magnetization. Besides, a newly developed magnetic analyzing centrifuge is used for the characterization of magnetic composite particle systems. The experimental results, also used for the model verification, give both, information about the magnetic properties and the interaction behavior of particle systems. By adding further components to the particle solution, such as salts or proteins, industrial relevant systems can be reconstructed. The analyzing tool can be used to adapt industrial processes without time-consuming preliminary tests with large samples in the process equipments. - Highlights: • New model for magnetizability calculation of magnetic composite particles. • New method for particle bulk characterization relating to their magnetizability. • Model verification due to experimental data.

  20. Investigations on the magnetization behavior of magnetic composite particles

    International Nuclear Information System (INIS)

    Eichholz, Christian; Knoll, Johannes; Lerche, Dietmar; Nirschl, Hermann

    2014-01-01

    In life sciences the application of surface functionalized magnetic composite particles is establishing in diagnostics and in downstream processing of modern biotechnology. These magnetic composite particles consist of non-magnetic material, e.g. polystyrene, which serves as a matrix for the second magnetic component, usually colloidal magnetite. Because of the multitude of magnetic cores these magnetic beads show a complex magnetization behavior which cannot be described with the available approaches for homogeneous magnetic material. Therefore, in this work a new model for the magnetization behavior of magnetic composite particles is developed. By introducing an effective magnetization and considering an overall demagnetization factor the deviation of the demagnetization of homogeneously magnetized particles is taken into account. Calculated and experimental results show a good agreement which allows for the verification of the adapted model of particle magnetization. Besides, a newly developed magnetic analyzing centrifuge is used for the characterization of magnetic composite particle systems. The experimental results, also used for the model verification, give both, information about the magnetic properties and the interaction behavior of particle systems. By adding further components to the particle solution, such as salts or proteins, industrial relevant systems can be reconstructed. The analyzing tool can be used to adapt industrial processes without time-consuming preliminary tests with large samples in the process equipments. - Highlights: • New model for magnetizability calculation of magnetic composite particles. • New method for particle bulk characterization relating to their magnetizability. • Model verification due to experimental data