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Results 401 - 450 of 1668
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Wang Lei - - 2008
Cell migration is crucial in many physiological and pathological processes including embryonic development, immune response and cancer metastasis. Traditional methods for cell migration detection such as wound healing assay usually involve physical scraping of a cell monolayer followed by an optical observation of cell movement. However, these methods require hand-operation ...
Novikova N S - - 2008
Studies of the pattern of activation of hypothalamic cells in conditions of electrical pain stimulation demonstrated an increase in the proportion of c-Fos-positive cells (to 72.02-98.95%), predominantly affecting cells of size 10-50 microm2. UHF irradiation of the skin activated hypothalamic cells of size 10-70 microm2 in the paraventricular and dorsomedial ...
Galland Marie-Annick - - 2008
Hybrid passiveactive cells previously developed at the LMFA have proved their efficiency for global noise reduction. A hybrid cell combines passive absorbent properties of a porous layer and active control at its rear face. Active control is mainly used to increase absorption at low frequencies by cancelling the imaginary part ...
Galindo Federico Gómez - - 2008
The effect of the application of pulsed electric fields to potato tissue on the diffusion of the fluorescent dye FM1-43 through the cell wall was studied. Potato tissue was subjected to field strengths ranging from 30 to 500 V/cm, with one 1 ms rectangular pulse, before application of FM1-43 and ...
Choi D S - - 2008
We describe a method to induce hyperthermia in cells, in-vitro, by remotely heating Ni nanowires (NWs) with radio frequency (RF) electromagnetic fields. Ni NWs were internalized by human embryonic kidney cells (HEK-293). Only cells proximal to NWs or with internalized NWs changed shape on exposure to RF fields indicative of ...
Pavicic Ivan - - 2008
The aim of this study was to evaluate whether low-level, ultra high frequency (UHF) irradiation of 935 MHz influences the cell structure and growth of V79 cells. UHF field was generated inside a Gigahertz Transversal Electromagnetic Mode cell (GTEM-cell) with a Hewlett-Packard signal generator. The electric field strength was 8.2+/-0.3 ...
Bhattarai Shanta Raj - - 2008
We developed hexanoyl chloride-modified chitosan (Nac-6) stabilized iron oxide nanoparticles (Nac-6-IOPs) as magnetic nanoparticles for viral gene (Ad/LacZ) delivery via magnetofection. This vector, Nac-6-IOPs/Ad/LacZ, binds to K562 cells in the presence of external magnetic fields and results in enhanced expression of the transgene in those cells that do not exhibit ...
Guignet Emmanuel G - - 2008
We present a high-throughput method that enables efficient delivery of biomolecules into cells. The device consists of an array of 96 suspended electrode pairs, where small sample volumes are top-loaded, electroporated and bottom-ejected into 96-well plates. We demonstrate the use of this suspended-drop electroporation (SDE) device to effectively introduce fluorescent ...
Seriburi Pahnit - - 2008
This work presents an electrical technique called electric cell-substrate impedance sensing to measure the cell-substrate separation and the projected area of an individual adherent cell. Cell adhesion and cell spreading are fundamental processes of adherent cells. By recording changes in the cell-substrate separation, the projected area, or both properties with ...
Xiao Xilin - - 2008
A wireless sensing device was developed for the in-situ monitoring of the growth of human breast cancer cells (MCF-7) and evaluation of the cytotoxicity of the anticancer drugs fluorouracil and cisplatin. The sensor is fabricated by coating a magnetoelastic ribbon-like sensor with a layer of polyurethane that protects the iron-rich ...
Chen Guo-Wei - - 2008
Instead of the utilization of artificial redox mediators or other catalysts, a biocathode has been applied in a two-chamber microbial fuel cell in this study, and the cell performance and microbial community were analyzed. After a 2-month startup, the microorganisms of each compartment in microbial fuel cell were well developed, ...
Cogle Christopher R - - 2008
The nascent field of regenerative medicine has taken root in cardiovascular disease. Preclinical data demonstrating hemangioblast potential of marrow cells and cardioprotective effects of growth factors served as the basis for numerous early phase clinical trials. With the first wave of safety and efficacy trials complete, much is still unknown ...
Kang Yuejun - - 2008
DC-Dielectrophoresis (DC-DEP), the induced motion of the dielectric particles in a spatially non-uniform DC electric field, is applied to separate biological cells by size. The locally non-uniform electric field is generated by an insulating hurdle fabricated within a PDMS microchannel. The cells experience a negative DEP (accordingly a repulsive) force ...
Busalmen Juan Pablo - - 2008
The mechanism(s) by which electricity-producing microorganisms interact with an electrode is poorly understood. Outer membrane cytochromes and conductive pili are being considered as possible players, but the available information does not concur to a consensus mechanism yet. In this work we demonstrate that Geobacter sulfurreducens cells are able to change ...
Tryfona Theodora - - 2008
The permeability barrier of the microbial cell envelope for substrates and products often causes very low reaction rates of whole cells. Therefore, it is of interest to develop an effective method to reduce this permeability barrier in order to increase product yields. Utilisation of pulse electric fields may improve amino ...
Le Duc Vinh - - 2008
We present a coupled immersed interface method-boundary element method (IIM-BEM) numerical technique that predicts the behaviour of deformable cells under the effect of both hydrodynamic and electrical forces. This technique is applied to the study of a hybrid electrical-mechanical trap for single-cell trapping. We report on the effect of different ...
Ron Amit - - 2008
Dielectric spectroscopy (DS) of living biological cells is based on the analysis of the complex dielectric permittivity of cells suspended in a physiological medium. It provides knowledge on the polarization-relaxation response of cells to external electric field as function of the excitation frequency. This response is strongly affected by both ...
Marc Paul J - - 2008
Electrically addressable cell traps were integrated with capillary electrophoresis for the analysis of the contents of single adherent cells. Electrodes composed of indium tin oxide were patterned on a glass surface followed by formation of topographical cell traps using 1002F photoresist. Single cells trapped in the holes could be lysed ...
Yasukawa Tomoyuki - - 2008
A novel microfluidic device with an array of analytical chambers was developed in order to perform single-cell-based gene-function analysis. A series of analytical processes was carried out using the device, including electrophoretic manipulation of single cells and electrochemical measurement of gene function. A poly(dimethylsiloxane) microstructure with a microfluidic channel (150 ...
Bao Ning - - 2008
Microfluidics offers an ideal platform to integrate cell-based assays with electric measurements. The technological advances in microfluidics, microelectronics, electrochemistry, and electrophysiology have greatly inspired the development of microfluidic/electric devices that work with a low number of cells or single cells. The applications of these microfluidic systems range from the detecting ...
Urdaneta Mario - - 2008
This paper presents a method of using multiple frequencies to counteract electric field distortions that interfere with the dielectrophoretic (DEP) manipulation of particles or cells. To demonstrate the technique, simulations were performed for a scenario in which cells were to be loaded into a cage whose walls created parasitic trapping ...
Zhu He - - 2008
The development of integrated microsystems capable of interrogation, characterization and sorting of mammalian cells is highly significant for further advancement of point-of-care diagnostics and drug discovery fields. The present study sought to design a novel strategy for releasing antibody-bound cells through electrochemical disruption of the underlying antibody (Ab) layer. A ...
Kjeang Erik - - 2008
A microfluidic fuel cell architecture incorporating flow-through porous electrodes is demonstrated. The design is based on cross-flow of aqueous vanadium redox species through the electrodes into an orthogonally arranged co-laminar exit channel, where the waste solutions provide ionic charge transfer in a membraneless configuration. This flow-through architecture enables improved utilization ...
Cricenti A - - 2008
Human HaCaT cells, exposed for 24 h to a 1 mT (rms) 50 Hz sinusoidal magnetic field in a temperature-regulated solenoid, suffer detectable changes in their biochemical properties and shapes. By using infrared wavelength-selective scanning near-field optical microscopy, we observed changes in the distribution of the inner chemical functional groups ...
Fukuda Nobuo - - 2008
Magnetic separation provides a relatively quick and easy-to-use method for cell isolation and protein purification. We have developed a rapid and efficient procedure to isolate yeast cells displaying a target polypeptide, namely, the Staphylococcus aureus ZZ domain, which serves as s model for protein interactions and can bind immunoglobulin G ...
Santagata Scott - - 2008
Despite the embryological and anatomical disparities present among lophotrochozoan phyla, there are morphological similarities in the cellular arrangements of ciliated cells used for propulsion among the nonfeeding larval forms of kamptozoans, nemerteans, annelids, mollusks, and bryozoans. Evaluating whether these similarities are the result of convergent selective pressures or a shared ...
Dobson Jon - - 2008
By binding magnetic nanoparticles to the surface of cells, it is possible to manipulate and control cell function with an external magnetic field. The technique of activating cells with magnetic nanoparticles offers a means to isolate and explore cellular mechanics and ion channel activation to gain better understanding of these ...
Matthie James R - - 2008
Bioimpedance spectroscopy represents one of the largest emerging medical device technologies. The method is generally known as impedance spectroscopy and is an inexpensive, yet extremely powerful, analytical technique for studying the electrical properties of materials. Much of what we know about biological cells and tissues comes from use of this ...
Pavicic I - - 2008
The aim of this study was to evaluate and compare the influence of 864 MHz and 935 MHz radiofrequency/microwave (RF/MW) fields on the growth, colony-forming ability, and viability of V79 cells (continuous line). Cell samples with 1 x 10(4) V79 cells each, were exposed to continuous wave frequencies of 864 ...
Auinger Barbara M - - 2008
Here we introduce a method for quantitative analysis of planktonic protists and microalgae from preserved field samples combining morphological and small-subunit (SSU) rRNA gene sequence analysis. We linked a microscopic screening with PCR of single cells using field samples preserved with Lugol's iodine solution. Cells possessing a rigid cell wall ...
Davis, Frank
In 2006, the journal Biosensors and Bioelectronics published a special issue devoted exclusively to biofuel cells, including several research papers and an extensive review of the field [Bullen, R.A., Arnot, T.C., Lakeman, J.B., Walsh, F.C., 2006. Biosens. Bioelectron.]. Within this review a brief description will firstly be given of the ...
Martino Carlos F - - 2008
Although pulsed electromagnetic fields (PEMFs) have been used for treatments of nonunion bone fracture healing for more than three decades, the underlying cellular mechanism of bone formation promoted by PEMFs is still unclear. It has been observed that a series of parameters such as pulse shape and frequency should be ...
Ionescu-Zanetti Cristian - - 2008
Single-cell electroporation, in which a focused electric field is applied to permeabilize an individual target cell using relatively low applied voltages, has demonstrated improved cell viability and transfection rates over conventional bulk electroporation set-ups. Here, we introduce a new strategy, in conjunction with single-cell electroporation, to enhance exogenous transport efficiency: ...
Tolmachev Aleksey V - - 2008
The trapped-ion cell is a key component critical for optimal performance in Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS). To extend the performance of FT-ICR MS, we have developed a new cell design that is capable of generating a DC trapping potential which closely approaches that of an ...
Wasz, Margot
The traditional T30 Teflon emulsion used in nickel-hydrogen battery cells is being phased due to EPA concerns with two of its minority components. This presentation reviews work done to date by The Aerospace Corporation to better understand the relationship between the properties of the hydrogen electrode affected by the Teflon ...
Doh, Il
We present a high-throughput continuous cell separation chip using hydrodynamic dielectrophoresis (DEP) process. The continuous cell separation chip uses three planar electrodes in a separation channel, where the positive DEP cells are moved away from the central streamline while the negative DEP cells remain in the central streamline. In the ...
MacQueen Luke A - - 2008
We report the use of dielectrophoresis (DEP) to position U-937 monocytes within a non-uniform electric field, prior to electroporation (EP) for gene delivery. DEP positioning and EP pulsing were both accomplished using a common set of inert planar electrodes, micro-fabricated on a glass substrate. A single-shell model of the cell's ...
Zhou Yun - - 2008
Sonoporation has been exploited as a promising nonviral strategy for intracellular delivery of drugs and genes. The technique utilizes ultrasound application, often facilitated by the presence of microbubbles, to generate transient, nonspecific pores on the cell membrane. However, due to the complexity and transient nature of ultrasound-mediated bubble interaction with ...
Manohar Aswin K - - 2008
Electrochemical impedance spectroscopy (EIS) has been used to determine several electrochemical properties of the anode and cathode of a mediator-less microbial fuel cell (MFC) under different operational conditions. These operational conditions included a system with and without the bacterial catalyst and EIS measurements at the open-circuit potential of the anode ...
Kress, Moshe
We consider two types of non-reactive aerial sensors, which are subject to false-positive and false-negative errors. The sensors search for threat objects such as ballistic missile launchers or improvised explosive devices. The objects are located in a certain area of interest, which is divided into a grid of area-cells. The ...
Hadipour, A.
A generalized methodology is developed to obtain the current–voltage characteristic of polymer tandem solar cells by knowing the electrical performance of both sub cells. We demonstrate that the electrical characteristics of polymer tandem solar cells are correctly predicted for both the series and parallel connection of the sub cells. The ...
Loghavi, Laleh
The effect of frequency and electric field strength on diffusion enhancement from cells and impedimetric signature were of considerable interest. The objectives were: to investigate the effects of moderate electric field (MEF, an electric field from 1-1000 V/cm) at different frequencies and stages of growth, on growth kinetics and metabolic ...
Popescu, Lacramioara Mihaela
The direct conversion of the sunlight into electricity is the most elegant process to generate environmentally-friendly renewable energy. Plastic solar cells offer the prospect of flexible, lightweight, lower cost of manufacturing, and hopefully an efficient way to produce electricity from sunlight. Since the discovery of photo induced charge transfer from ...
Ly, Mai Thanh, Graduate ...
Problem investigated: Chronic wounds are not only a major burden to the patient arising from general pain and discomfort but also generate economic costs to both these individuals and the health care system. Various electrical stimulation regimes have been employed to study the effects of electrical stimulation on wound healing ...
Cho, S.
Non-invasive single cell analyses are increasingly required for the medical diagnostics of test substances or the development of drugs and therapies on the single cell level. For the non-invasive characterisation of cells, impedance spectroscopy which provides the frequency dependent electrical properties has been used. Recently, microfludic systems have been investigated ...
Maercker, C.
A big demand exists for high-throughput functional in vitro assays which can measure cellular phenotypes by molecular methods and therefore improve the resources of primary cells for cell therapy, tissue engineering and high-content screenings in drug development. This approach focuses on cellular adhesion which is an important differentiation process during ...
Jäger, M.
In parallel to recent progress of high-content analysis in cell biology, negative dielectrophoresis (nDEP) has continuously evolved as a potent tool for contact-free manipulation and investigation of single cells. As such, it can be especially beneficial for the handling of rare and valuable cells, e. g. in stem cell research, ...
Kellner, M.
Since the 1990s KERAFOL - Keramische Folien GmbH is developing zirconia based ceramic tapes and sintered substrates for Electrolyte Supported Cells (ESC). Together with Fraunhofer Institute for Ceramic Technologies and Systems (IKTS) in Dresden investigations and developments had taken place to improve the properties of the ESC. The result of ...
Diethelm, Stefan
Planar SOFC stack technology based on a unique concept (SOFConnex™) uses structured gas distribution layers between unprofiled metal sheet interconnects and thin Ni-YSZ anode supported electrolyte cells. The layers are flexible both in material and designand allow to implement new configurations relatively simply; manifolding can be internal, external, or combined. ...
Demierre, Nicolas
This thesis reports on the integration of continuous-flow cell separation method for lab-on-a-chip applications. Cell separation methods are widely used in biology to prepare samples prior to analysis. There is a need for a highly sensitive separation method that is capable to quickly isolate a particular cell type in a ...
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