Enhancement of current density by dc electric concentrator.
Ontology highlight
ABSTRACT:
SUBMITTER: Jiang WX
PROVIDER: S-EPMC3518816 | biostudies-other | 2012
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The control of cellular processes by direct electronic interface will facilitate the development of biosensors, synthetic biology, and nanobiotechnology by providing the means to pass information from synthetic to living elements of hybrid systems. To investigate the potential of manipulating cellular gene expression by means of electric current, Escherichia coli cultures were screened for electric current inducible genes using global gene expression profiling. Cells in stationary phase were subjected to a DC current density of 2.5 mA/cm2 for 2 min after which the cells were lysed and the total RNA extracted. Of the 4290 expressed genes in E. coli , 432 genes were found to be significantly differentially expressed at an effective alpha value of 5.8 X 10-6. Of these, 333 genes were induced and 99 repressed. Several genes were verified as differentially expressed by quantitative real-time RT-PCR. The set of differentially expressed genes were examined for the presence of regulatory factors, subsidiary regulon genes, and biological function, particularly redox functions. Transcripts for the regulatory proteins fnr, sspB, soxS, oxyR, creB and yeiL were found to be up-regulated, and crp was down regulated. While soxS and oxyR were up-regulated, the downstream genes controlled by these regulatory proteins were not differentially expressed, suggesting that the oxidative stress level of low-current electric exposure is small. Genes controlled by FNR and CRP, many of which have redox function, were found to be differentially expressed suggesting modulation by direct reduction that can only be partially explained as a response to the reducing environment created by the electrolytic generation of H2 at the cathode. Genes associated with phosphate metabolism and membrane proteins were also differentially expressed. Keywords: electric current induced gene expression
2008-02-12 | GSE5192 | GEO
Project description:The control of cellular processes by direct electronic interface will facilitate the development of biosensors, synthetic biology, and nanobiotechnology by providing the means to pass information from synthetic to living elements of hybrid systems. To investigate the potential of manipulating cellular gene expression by means of electric current, Escherichia coli cultures were screened for electric current inducible genes using global gene expression profiling. Cells in stationary phase were subjected to a DC current density of 2.5 mA/cm2 for 2 min after which the cells were lysed and the total RNA extracted. Of the 4290 expressed genes in E. coli , 432 genes were found to be significantly differentially expressed at an effective alpha value of 5.8 X 10-6. Of these, 333 genes were induced and 99 repressed. Several genes were verified as differentially expressed by quantitative real-time RT-PCR. The set of differentially expressed genes were examined for the presence of regulatory factors, subsidiary regulon genes, and biological function, particularly redox functions. Transcripts for the regulatory proteins fnr, sspB, soxS, oxyR, creB and yeiL were found to be up-regulated, and crp was down regulated. While soxS and oxyR were up-regulated, the downstream genes controlled by these regulatory proteins were not differentially expressed, suggesting that the oxidative stress level of low-current electric exposure is small. Genes controlled by FNR and CRP, many of which have redox function, were found to be differentially expressed suggesting modulation by direct reduction that can only be partially explained as a response to the reducing environment created by the electrolytic generation of H2 at the cathode. Genes associated with phosphate metabolism and membrane proteins were also differentially expressed. Three biological replicates were exposed to electric current along with three biological replicate controls.
2010-06-25 | E-GEOD-5192 | biostudies-arrayexpress
Project description:In 1963 Ridley postulated that under certain bias conditions circuit elements exhibiting a current- or voltage-controlled negative differential resistance will separate into coexisting domains with different current densities or electric fields, respectively, in a process similar to spinodal decomposition of a homogeneous liquid or disproportionation of a metastable chemical compound. The ensuing debate, however, failed to agree on the existence or causes of such electronic decomposition. Using thermal and chemical spectro-microscopy, we directly imaged signatures of current-density and electric-field domains in several metal oxides. The concept of local activity successfully predicts initiation and occurrence of spontaneous electronic decomposition, accompanied by a reduction in internal energy, despite unchanged power input and heat output. This reveals a thermodynamic constraint required to properly model nonlinear circuit elements. Our results explain the electroforming process that initiates information storage via resistance switching in metal oxides and has significant implications for improving neuromorphic computing based on nonlinear dynamical devices.
| S-EPMC5966426 | biostudies-literature
Project description:We grew MDA-MB231 cells in a media that had been reconstituted with water that was treated by the Bio-Electric Field Enhancement device generated direct current dielectrophoretic electromagnetic field (Treated group) and cells that were grown in media that was reconstituted with water that was not treated by the BEFE device dc DEP EMF. They were grown for 3 days in each of these media and then analyzed with Affymetrix 2.0 Microarrary Analyses. It was an experimental controlled design.
2017-03-30 | GSE92320 | GEO
Project description:Naturally-occurring, endogenous electric fields (EFs) have been detected at skin wounds, damaged tissue sites and vasculature. Applied EFs guide migration of many types of cells, including endothelial cells to migrate directionally. Homing of endothelial progenitor cells (EPCs) to an injury site is important for repair of vasculature and also for angiogenesis. However, it has not been reported whether EPCs respond to applied EFs. Aiming to explore the possibility to use electric stimulation to regulate the progenitor cells and angiogenesis, we tested the effects of direct-current (DC) EFs on EPCs. We first used immunofluorescence to confirm the expression of endothelial progenitor markers in three lines of EPCs. We then cultured the progenitor cells in EFs. Using time-lapse video microscopy, we demonstrated that an applied DC EF directs migration of the EPCs toward the cathode. The progenitor cells also align and elongate in an EF. Inhibition of vascular endothelial growth factor (VEGF) receptor signaling completely abolished the EF-induced directional migration of the progenitor cells. We conclude that EFs are an effective signal that guides EPC migration through VEGF receptor signaling in vitro. Applied EFs may be used to control behaviors of EPCs in tissue engineering, in homing of EPCs to wounds and to an injury site in the vasculature.
| S-EPMC3238468 | biostudies-literature
Project description:BackgroundThe formation of acetylcholine receptor (AChR) cluster is a key event during the development of the neuromuscular junction. It is induced through the activation of muscle-specific kinase (MuSK) by the heparan-sulfate proteoglycan agrin released from the motor axon. On the other hand, DC electric field, a non-neuronal stimulus, is also highly effective in causing AChRs to cluster along the cathode-facing edge of muscle cells.Methodology/principal findingsTo understand its molecular mechanism, quantum dots (QDs) were used to follow the movement of AChRs as they became clustered under the influence of electric field. From analyses of trajectories of AChR movement in the membrane, it was concluded that diffuse receptors underwent Brownian motion until they were immobilized at sites of cluster formation. This supports the diffusion-mediated trapping model in explaining AChR clustering under the influence of this stimulus. Disrupting F-actin cytoskeleton assembly and interfering with rapsyn-AChR interaction suppressed this phenomenon, suggesting that these are integral components of the trapping mechanism induced by the electric field. Consistent with the idea that signaling pathways are activated by this stimulus, the localization of tyrosine-phosphorylated forms of AChR β-subunit and Src was observed at cathodal AChR clusters. Furthermore, disrupting MuSK activity through the expression of a kinase-dead form of this enzyme abolished electric field-induced AChR clustering.ConclusionsThese results suggest that DC electric field as a physical stimulus elicits molecular reactions in muscle cells in the form of cathodal MuSK activation in a ligand-free manner to trigger a signaling pathway that leads to cytoskeletal assembly and AChR clustering.
| S-EPMC3201969 | biostudies-literature
Project description:In this work, the electro-coalescence process of three nanodroplets under a constant DC electric field is investigated via molecular dynamics simulations (MD), aiming to explore the electric manipulation of multiple droplets coalescence on the molecular level. The symmetrical and asymmetrical dynamic evolutions of electrocoalescence process can be observed. Our MD simulations show that there are two types of critical electric fields to induce the special dynamics. The chain configuration can be formed, when one of the critical electric field is exceeded, referred to as Ecc. On the other hand, there is another critical electric field to change the coalescence pattern from complete coalescence to partial coalescence, the so-called Ecn. Finally, we find that the use of the pulsed DC electric field can overcome the drawbacks of the constant DC electric field in the crude oil industry, and the mechanisms behind the suppressed effect of the water chain or non-coalescence are further revealed.
| S-EPMC11003697 | biostudies-literature
Project description:DC railways are characterized by particularly intense arcing caused by pantograph detachment, due to the large current intensity and the general implementation of onboard resonant filters, whose transient response is triggered by electric transients including electric arcs. Electric arc depends on the train speed (the relative speed between the sliding contact over the pantograph and the hot spot on the catenary system), the intensity of the collected pantograph current and the line voltage level. Electric arcs are broadband in nature and can trigger the system transient response dominated by the resonant filter, besides interfering with the operation of onboard equipment (such as for energy conversion and metering).
| S-EPMC7378579 | biostudies-literature
Project description:The circRNA, lncRNA, miRNA, and mRNA levels of both the direct-current electric field and control groups of adipose-derived stem cells were obtained by RNA sequencing.
2020-11-23 | GSE149888 | GEO
Project description:We investigated the transport characteristics of a square shape superconducting Ta thin film under DC electrical current bias along the diagonal direction. The resistance parallel (R∥) and perpendicular (R⊥) to the DC current, IDC, is measured with various magnetic fields. R∥ and R⊥ show contrasting dependence on IDC. First, the critical current of R∥ is smaller than that of R⊥. Second, R⊥ shows an unexpected reduction at current bias where R∥ shows a rapid increase near the transition from a flux flow state to a normal state. The intriguing anisotropic transport characteristics can be understood by the inhomogeneous current density profile over the square sample. Diagonal DC current induces an anisotropic current density profile where the current density is high near the biasing electrode and low at the center of the sample. Accordingly, the electrical transport in the perpendicular direction could remain less affected even near the critical current of R∥, which leads to the higher critical current in R⊥. Complicated conduction profile may also allow the anomalous reduction in the R⊥ before finally shifting to the normal state.
| S-EPMC7546633 | biostudies-literature