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Results 351 - 400 of 1688
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Joye Neil N Microelectronic Systems Laboratroy, Swiss Federal Institute of Technology (EPFL), 1015 Lausanne, Switzerland. - - 2009
A cell-electrode interface noise model is developed which is dedicated to enable the co-simulation of the cell-electrode electrical characteristics, along with the electronics of novel CMOS-based MEA. The electrode noise is investigated for Pt and Pt black electrodes. It is shown that the electrode noise can be the dominant noise ...
Braeken Dries D Interuniversity MicroElectronics Center (IMEC), Kapeldreef 75, 3001 Leuven, Belgium. - - 2009
In this paper, we describe the localized and selective electrical stimulation of single cells using a three-dimensional electrode array. The chip consisted of 84 nail-like electrodes with a stimulation surface of 0.8 microm(2) and interelectrode distances as small as 3 microm. N2A cells were used to compare bipolar stimulation between ...
Karshafian Raffi - - 2009
This work investigates the effect of ultrasound exposure parameters on the sonoporation of KHT-C cells in suspension by perflutren microbubbles. Variations in insonating acoustic pressure (0.05 to 3.5 MPa), pulse frequency (0.5 to 5.0 MHz), pulse repetition frequency (10 to 3000 Hz), pulse duration (4 to 32 micros) and insonation ...
Manceur Aziza P - - 2009
The use of cell-penetrating peptides as transduction vectors is a promising approach to deliver peptides and proteins into cells. However, the uptake and bioavailability of trans-activating transcriptor (TAT)-conjugated molecules vary depending on the cell type and the cargo. This study aimed to determine whether a low-voltage electrical pulse can enhance ...
Groene, Grant Anthony
Drought is the single most limiting factor in crop production. This study was conducted to investigate if a cell viability assay could serve as an effective, efficient screen to determine post-anthesis drought tolerance in sorghum (Sorghum bicolor [L.] Moench) and maize (Zea mays [L]). The assay measured decline in chlorophyll ...
Lin Cheng Ming - - 2008
This paper presents hydrodynamic trapping of bioparticles in a microfluidic device. An in-plane oscillatory microplate, driven via Lorentz law, generates two counter-rotating microvortices, trapping the bioparticles within the confines of the microvortices. The force required to trap bioparticles is quantified by tuning the background flow and the microplate's excitation voltage. ...
Hu Ling - - 2008
AIM: Efforts are underway to establish a preparation method for the phycoerythrin subunit (PE-sub) liposome, and enhance the cellular uptake and photodynamic therapy (PDT) effect on cancer cells. METHODS: A film dispersion method was used to prepare the PE-sub liposome, an orthogonal analysis was conducted to optimize the PE-sub liposome ...
Tang Y B - - 2008
Vertically aligned Mg-doped GaN nanorods have been epitaxially grown on n-type Si substrate to form a heterostructure for fabricating p-n heterojunction photovoltaic cells. The p-type GaN nanorod/n-Si heterojunction cell shows a well-defined rectifying behavior with a rectification ratio larger than 10(4) in dark. The cell has a high short-circuit photocurrent ...
Techaumnat B - - 2008
The authors present the use of electric-field constriction created by a microfabricated structure to realise high-yield electrofusion of biological cells. The method uses an orifice on an electrically insulating wall (orifice plate) whose diameter is as small as that of the cells. Owing to the field constriction created by the ...
Kaasgaard Thomas - - 2009
Two lipophilic methotrexate analogues have been synthesized and evaluated for cytotoxicity against KATO III and HT-29 human colon cancer cells. Both analogues contained a C16-alkyl chain attached to the gamma-carboxylic acid and one of the analogues had an additional benzyl group attached to the alpha-carboxylic acid. The cytotoxicity of the ...
Adams Jonathan D - - 2008
Magnetic selection allows high-throughput sorting of target cells based on surface markers, and it is extensively used in biotechnology for a wide range of applications from in vitro diagnostics to cell-based therapies. However, existing methods can only perform separation based on a single parameter (i.e., the presence or absence of ...
Smithmaitrie Pruittikorn - - 2008
PURPOSE: The objective of this research is to investigate dynamic responses of the piezoelectric Braille cell when it is subjected to both electrical signal and touching force. METHOD: Physical behavior of the piezoelectric actuator inside the piezoelectric Braille cell is analyzed. The mathematical model of the piezoelectric Braille system is ...
de Oliveira Pedro Xavier - - 2008
Defibrillator-type shocks may cause electric and contractile dysfunction. In this study, we determined the relationship between probability of lethal injury and electric field intensity (E in isolated rat ventricular myocytes, with emphasis on field orientation and stimulus waveform. This relationship was sigmoidal with irreversible injury for E > 50 V/cm ...
Van Meerbergen, Bart
Neuro-electronic hybrid devices are cell based biosensors using neuronal cells. The electrical activity of these cells allows integration with electrical read-out sensors and stimulation electrodes. The electrical coupling between the neurons and the sensor is critical element in order to obtain high signal to noise ratio recordings and controlled stimulation.<br/> ...
Rahman Abdur Rub Abdur - - 2009
We report on the electrical impedance spectroscopy characterization of OVCA429 ovarian cancer cells. A commercially available eight-well cell culture impedance array (ECIS-8W1E), commonly used in electrical cell-substrate impedance sensing (ECIS), was used for OVCA429 characterization. Impedances of ECIS-8W1E array were recorded with cell culture medium (without cells) and with OVCA429 ...
Lin Cheng Ming - - 2008
This paper presents hydrodynamic trapping of bioparticles in a microfluidic device. An in-plane oscillatory microplate, driven via Lorentz law, generates two counter-rotating microvortices, trapping the bioparticles within the confines of the microvortices. The force required to trap bioparticles is quantified by tuning the background flow and the microplate's excitation voltage. ...
Tang Y B - - 2008
Vertically aligned Mg-doped GaN nanorods have been epitaxially grown on n-type Si substrate to form a heterostructure for fabricating p-n heterojunction photovoltaic cells. The p-type GaN nanorod/n-Si heterojunction cell shows a well-defined rectifying behavior with a rectification ratio larger than 10 (4) in dark. The cell has a high short-circuit ...
Hu Zhen - - 2008
An efficient numerical method based on the Dirichlet-to-Neumann (DtN) maps of the unit cells is developed for accurate simulations of two-dimensional photonic crystal (PhC) devices in the frequency domain. The DtN map of a unit cell is an operator that maps the wave field on the boundary of the cell ...
Fujimoto Hiroyuki - - 2008
This paper describes the fabrication of microarrays that enable the parallel electroporation of small interfering RNAs (siRNAs) into mammalian cells. To optimize the conditions of microarray preparation and electric pulsing, a self-assembled monolayer was formed on a gold electrode, and a cationic polymer was adsorbed by the entire surface of ...
Cho Sungbo - - 2009
Pesticides used to control unwanted insects are potentially toxic to humans. In assessing the risk involved in exposure to pesticides or complex chemical mixtures, an in vitro cell-based test can provide useful information regarding danger to human health. Cell differentiation is a biological process of fundamental importance in developing and ...
Kim Unyoung U Department of Mechanical Engineering, University of California, Santa Barbara, California 93106, - - 2008
The ability to rapidly and efficiently isolate specific viruses, bacteria, or mammalian cells from complex mixtures lies at the heart of biomedical applications ranging from in vitro diagnostics to cell transplantation therapies. Unfortunately, many current selection methods for cell separation, such as magnetic activated cell sorting (MACS), only allow the ...
Sato Kae - - 2009
Microchip technology has matured over the years into an important field in which novel technologies are being constantly invented, and down-sizing and incorporation of already existing methodologies into the microscale is increasing assay performance and bearing the promise of future total integration for simple, widespread use. One rapidly growing sub-discipline ...
Varshney Madhukar - - 2009
Impedance spectroscopy is a sensitive technique to characterize the chemical and physical properties of solid, liquid, and gas phase materials. In recent years this technique has gained widespread use in developing biosensors for monitoring the catalyzed reaction of enzymes; the bio-molecular recognition events of specific proteins, nucleic acids, whole cells, ...
Sandholt, P. E.
We document the activation of transient polar arcs emanating from the cusp within a 15 min long intermediate phase during the transition from a standard two-cell convection pattern, representative of a strongly southward interplanetary magnetic field (IMF), to a "reverse" two-cell pattern, representative of strongly northward IMF conditions. During the ...
Templer Richard H - - 2008
For this special issue of J. R. Soc. Interface we present an overview of the driving forces behind technological advances in the field of single-cell analysis. These range from increasing our understanding of cellular heterogeneity through to the study of rare cells, areas of research that cannot be tackled effectively ...
Brown Robert B - - 2008
Owing to the small quantities of analytes and small volumes involved in single-cell analysis techniques, manipulation strategies must be chosen carefully. The lysis of single cells for downstream chemical analysis in capillaries and lab-on-a-chip devices can be achieved by optical, acoustic, mechanical, electrical or chemical means, each having their respective ...
Sedgwick H - - 2008
Lab-on-a-chip systems offer a versatile environment in which low numbers of cells and molecules can be manipulated, captured, detected and analysed. We describe here a microfluidic device that allows the isolation, electroporation and lysis of single cells. A431 human epithelial carcinoma cells, expressing a green fluorescent protein-labelled actin, were trapped ...
de la Rosa Carlos - - 2008
A miniaturized microfluidic device was developed to facilitate electromanipulation of bacterial respiratory pathogens. The device comprises a microchip with circular aluminum electrodes patterned on glass, which is housed in a microfluidic system fabricated utilizing polydimethylsiloxane. The device provides sample preparation capability by exploiting positive dielectrophoresis (DEP) in conjunction with pulsed ...
Reich Uta - - 2008
Cochlear implants (CIs) can restore hearing in deaf patients by electrical stimulation of the auditory nerve. To optimize the electrical stimulation, the number of independent channels must be increased by reduction of connective tissue growth on the electrode surface and selective neuronal cell contact. The femtosecond laser microstructuring of the ...
Gundersen, Martin A.
Pulsed power for biological investigations newly developed at USC include a fast diode-based systems designed to drive cell suspensions in a microscope slide electrode microchamber for observations of living cells during pulse exposure with pulse durations from 3 ns to 30 ns and electric fields from 1 MV/m to 10 ...
Wang, Manyan
Single-cell electroporation (SCEP) is a recently developing powerful technique for cell analysis and cell manipulation. In the first chapter of this thesis, a review about the theories and techniques is fulfilled, including a detailed description of the factors affecting SCEP, and a discussion about how to optimize SCEP for high ...
Funk Richard H W - - 2009
In this review we compile and discuss the published plethora of cell biological effects which are ascribed to electric fields (EF), magnetic fields (MF) and electromagnetic fields (EMF). In recent years, a change in paradigm took place concerning the endogenously produced static EF of cells and tissues. Here, modern molecular ...
Koklic Tilen - - 2008
We have investigated interaction of alkyphospholipid (APL) liposomes consisting of 1,1-dimethylpiperidin-1-ium-4-yl) octadecyl phosphate (OPP) and different concentrations of cholesterol (CH) with human MT-3 breast-cancer cells using electron paramagnetic resonance method (EPR) with advanced characterization of EPR spectra of spin labeled liposome membranes. After incubation of OPP liposomes with MT-3 cells, ...
Theodossiou Theodossis A - - 2008
We have developed novel cocktail liposomes bearing doxorubicin in their hydrophilic cores, and amiodarone, a potent multidrug resistance inhibitor, in their lipid bilayers. The efficacy of these liposomes was studied in DU145 human prostate carcinoma cells. Intracellular calcein retention, which is inversely proportional to multidrug resistance activity, significantly increased following ...
Burais, Noël
This work tackles the development of numerical methods in order to study the influence of a nanosecond electrical pulse on the phenomena arising in a biological cell. Formulations employed are presented and applied to the observation of the sensitivity of an eukaryote cell to the orientation of the electric field.
Provan, G.
On the 22 December 2002 the interplanetary magnetic field (IMF) was directed northwards for more than 12h. The Northern and Southern Hemisphere SuperDARN radars were used to study global high-latitude convection during this interval, complemented by data from the ACE and DMSP F13 spacecraft. The relative magnitudes of the IMF ...
Tekle E - - 2008
Cells undergoing apoptosis lose lipid asymmetry that is often manifested by the exposure of phosphatidylserine (PS) to the outer surface of the cell membrane. Macrophages and other cell types recognize externalized PS to signal phagocytosis, thereby eliciting a non-inflammatory response. PS exposure is obligatory in the recognition and clearance of ...
Masiuk Marek - - 2008
PURPOSE: The aim of the study was to analyze the influence of rotating magnetic fields (RMF) on the expression and intranuclear distribution of nucleolin, protein involved in ribosome biosynthesis, in HL-60 (acute promyelocytic leukemia) and K-562 (chronic myelogenous leukemia) established human cell lines. MATERIALS AND METHODS: Cells were exposed to ...
Wong Serena H SH Edward L Ginzton Laboratory, Stanford University, Stanford, CA, USA. - - 2008
Increasing fill factor is one design approach used to increase average output displacement, output pressure, and sensitivity of capacitive micromachined ultrasonic transducers (CMUTs). For rectangular cells, the cell-to-cell spacing and the aspect ratio determine the fill factor. In this paper, we explore the effects of these parameters on performance, in ...
Cai Dong D Department of Biology, Boston College, Chestnut Hill, MA 02467, - - 2008
We show herein that CNT-cell complexes are formed in the presence of a magnetic field. The complexes were analyzed by flow cytometry as a quantitative method for monitoring the physical interactions between CNTs and cells. We observed an increase in side scattering signals, where the amplitude was proportional to the ...
Schiffelers Raymond M - - 2008
Tumor cells have long been the primary target cell type of liposomes for anticancer therapy. At present, it appears that tumor growth and metastasis is facilitated by interactions between tumor cells and supporting cells. These supporting cells consist of adaptive and innate immune cells, endothelial cells, pericytes, fibroblasts, stromal and ...
Weisbrod Chad R - - 2008
A novel FTICR cell called the trapping ring electrode cell (TREC) has been conceived, simulated, developed, and tested. The performance of the TREC is compared to a closed cylindrical cell at different excited cyclotron radii. The TREC permits the ability to maintain coherent ion motion at larger initial excited cyclotron ...
Hiraka Kazue - - 2008
We prepared an anticancer drug based on a pH-sensitive liposome retaining Fe-porphyrin as an SOD mimic. The liposomes contained cationic/anionic lipid combinations and were composed of Fe-porphyrin, 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine, dimethylditetradecylammonium bromide, sodium oleate, and Tween-80. The Fe-porphyrin was released from the liposome at low pH, and the cytotoxicity for cancer cells ...
Kang Hyen-Wook - - 2009
For investigating effects of chemical stressors to cultured cells, we have developed a quartz crystal microbalance (QCM) system with a micro CCD camera that enables microscopic observations simultaneously with the QCM measurements. Human hepatoma cell line (HepG2) cells were cultured on the collagen coated quartz crystal which has indium tin ...
Dittami Gregory M - - 2008
The fabrication and characterization of a microchamber electrode array for electrical and electrochemical studies of individual biological cells are presented. The geometry was tailored specifically for measurements from sensory hair cells isolated from the cochlea of the mammalian inner ear. Conventional microelectromechanical system (MEMS) fabrication techniques were combined with a ...
Caddeo C - - 2008
The possibility of improving the efficacy of resveratrol, a polyphenol with strong antioxidant and free-radical scavenging properties, on cell proliferation and photoprotection by liposomal incorporation was investigated. Oligolamellar vesicles of different lipid compositions, loaded with resveratrol, were prepared and characterized by evaluating size, zeta potential, incorporation efficiency, electron microscopy and ...
Hsiung Lo-Chang - - 2008
Uniform patterning of cells is highly desirable for most cellular studies involving cell-cell interactions but is often difficult in an in vitro environment. This paper presents the development of a collagen-coated planar interdigitated ring electrode (PIRE) array utilizing positive dielectrophoresis to pattern cells uniformly. Key features of the PIRE design ...
Heiskanen Arto R - - 2008
An impedance spectroscopic study of the interaction between thiol-modified Au electrodes and Saccharomyces cerevisiae of strain EBY44 revealed that the cells formed an integral part of the interface, modulating the capacitive properties until a complete monolayer was obtained, whereas the charge transfer resistance ( R ct) to the redox process ...
Lyon Alexander R AR National Heart and Lung Institute, Faculty of Medicine, Imperial College, London, - - 2008
Cardiac cell therapy is an expanding scientific field which is yielding new insights into the pathogenesis of cardiac disease and offers new therapeutic strategies. Inherent to both these areas of research are the electrical properties of individual cells, the electrical interplay between cardiomyocytes, and their roles in arrhythmogenesis. This review ...
S. Lerson, J.L. Lilien, ...
The performance of a 5 kW Solid Oxide Fuel Cell (SOFC) will be studied and described in this paper. This will help to significantly reduce residential Green House Gas (GHG) emission to about 20%, when compared with the actual emissions, based on the high-performance boiler and electricity produced by high-efficiency ...
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