Direct Gate Research Articles

Stimulation-dependent gating of TRPM3 channel in planar lipid bilayers.

The transient receptor potential melastatin (TRPM)-3 channel is critical for various physiologic processes. In somatosensory neurons, TRPM3 has been implicated in temperature perception and inflammatory hyperalgesia, whereas in pancreatic β-cells the channel has been linked to glucose-induced insulin release. As a typical representative of the TRP family, TRPM3 is highly polymodal. In cells, it is activated by heat and chemical agonists, including pregnenolone sulfate (PS) and nifedipine (Nif). To define the nuances of TRPM3 channel activity and its modulators, we succeeded in incorporating the TRPM3 protein into planar lipid bilayers. We found that phosphatidylinositol-4,5-bisphosphate (PIP2) or clotrimazole is necessary for channel opening by PS. Unlike PS, the presence of Nif alone sufficed to induce TRPM3 activity and demonstrated distinct gating behavior. We also performed an extensive thermodynamic analysis of TRPM3 activation and found that TRPM3 exhibited slight temperature sensitivity in the bilayers. In the absence of other agonists TRPM3 channels remained closed upon heat-induced stimulation, but opened in the presence of PIP2, although with only a low open-probability profile. Together, our results elucidate the details peculiar to TRPM3 channel function in an isolated system. We confirmed its direct gating by PS and PIP2, but found a lack of the strong intrinsic temperature sensitivity common to other thermosensitive TRP channels.

Knowledge on Sexuality and Reproductive Health of Malaysian Adolescents – A Short Review

This short review focuses on pressing issue; knowledge of sexuality and reproductive health among Malaysian adolescents. Keeping in view the some steps in order, keyword search was completed by using Google, Science Direct, and research Gate databases. In total 34 peer- reviewed journal articles were selected. After considering the articles within the scope of this paper, 07 most relevant studies were finalized that encompass the years from 2010-2014. Findings of the study exhibit lack of knowledge about sexuality and reproductive health in Malaysian adolescents. As a limitation, bibliographic search and claim of reaching saturation point has not been established.l

Issues and Challenges of Social Media Adoption by Tourism SMEs

Objective - Purpose of this study is to compile a literature review on the issues and challenges of social media adoption by tourism SMEs. The empirical part of this study consists of review from existing literature related to social media adoption by SMEs. Methodology/Technique - A literature review was conducted on related to social media adoption by SMEs published between 2010 to 2015, via Google Scholar and linked to various databases, including Science Direct, Elsevier, Emerald and Research Gate. Snowballing was done on the available references from related articles in the attempt to search for more related materials after which a literature matrix was compiled before the final write up of this article. Findings - Issues and challenges faced by tourism SMEs can be divided to two (2) main categories, which include internal and external challenges. Literature suggests that manpower compatibility issue is the most crucial factor in the adoption of social media by SMEs. This is followed by lack of resources; infrastructures, financial as well as lack of commitment from management. Novelty - This paper contributes to research in the issues and challenges of social media adoption by tourism SMEs. It also provides a source for researchers in discovering research trends in social media adoption literature and will help to stimulate further interest in this area. Type of Paper - Empirical Keywords: SMEs; Social media; Social media adoption; Facebook; Issues and challenges

TU‐PIS‐Exhibit Hall‐5: Use of the Enterprise‐wide Dose Tracking Software Radimetrics In an Academic Medical System

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

TU‐F‐BRB‐02: Motion Artifacts and Suppression in MRI

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

TU‐PIS‐Exhibit Hall‐3: Simultaneous tracking of patient and real time staff dose to optimize interventional workflow

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

TU‐PIS‐Exhibit Hall‐1: Tools for Collecting and Analyzing Patient Dose Index Information from Imaging Equipment

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

TU‐PIS‐Exhibit Hall‐4: How to implement a dose monitoring solution in the real world: a technical perspective

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

TU‐F‐BRB‐03: Clinical Implementation of MR‐Based Motion Management

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

MO‐PIS‐Exhibit Hall‐1: Tools for Collecting and Analyzing Patient Dose Index Information from Imaging Equipment

No Abstract provided

TU‐F‐BRB‐01: Resolving and Characterizing Breathing Motion for Radiotherapy with MRI

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

TU‐F‐BRB‐00: MRI‐Based Motion Management for RT

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

TU‐PIS‐Exhibit Hall‐2: How to Move Beyond Dose Monitoring to Imaging Performance Utilization

The current clinical standard of organ respiratory imaging, 4D‐CT, is fundamentally limited by poor soft‐tissue contrast and imaging dose. These limitations are potential barriers to beneficial “4D” radiotherapy methods which optimize the target and OAR dose‐volume considering breathing motion but rely on a robust motion characterization. Conversely, MRI imparts no known radiation risk and has excellent soft‐tissue contrast. MRI‐based motion management is therefore highly desirable and holds great promise to improve radiotherapy of moving cancers, particularly in the abdomen. Over the past decade, MRI techniques have improved significantly, making MR‐based motion management clinically feasible. For example, cine MRI has high temporal resolution up to 10 f/s and has been used to track and/or characterize tumor motion, study correlation between external and internal motions. New MR technologies, such as 4D‐MRI and MRI hybrid treatment machines (i.e. MR‐linac or MR‐Co60), have been recently developed. These technologies can lead to more accurate target volume determination and more precise radiation dose delivery via direct tumor gating or tracking. Despite all these promises, great challenges exist and the achievable clinical benefit of MRI‐based tumor motion management has yet to be fully explored, much less realized. In this proposal, we will review novel MR‐based motion management methods and technologies, the state‐of‐the‐art concerning MRI development and clinical application and the barriers to more widespread adoption.Learning Objectives: Discuss the need of MR‐based motion management for improving patient care in radiotherapy. Understand MR techniques for motion imaging and tumor motion characterization. Understand the current state of the art and future steps for clinical integration. Henry Ford Health System holds research agreements with Philips Healthcare. Research sponsored in part by a Henry Ford Health System Internal Mentored Grant.

Molecular dynamics simulations of the transport of reactive oxygen species by mammalian and plant aquaporins

BackgroundAquaporins are responsible for water transport across lipid membranes. They are also able to transport reactive oxygen species, playing an important role in redox signaling. Certain plant aquaporins have even the ability to be regulated by oxidative stress. However, the underlying mechanisms are still not fully understood. MethodsHere, molecular dynamics simulations were employed to determine the activation free energies related to the transport of reactive oxygen species through both mammalian and plant aquaporin models. Results and conclusionsBoth aquaporins may transport hydrogen peroxide (H2O2) and the protonated form of superoxide radicals (HO2). The solution-to-pore transfer free energies were low for small oxy-radicals, suggesting that even highly reactive hydroxyl radicals (HO) might have access to the pore interior and oxidize amino acids responsible for channel selectivity. In the plant aquaporin, no significant change in water permeability was observed upon oxidation of the solvent-exposed disulfide bonds at the extracellular region. During the simulated time scale, the existence of a direct oxidative gating mechanism involving these disulfide bonds could not be demonstrated. General significanceSimulation results may improve the understanding of redox signaling mechanisms and help in the interpretation of protein oxidative labeling experiments.

Assessment of subunit-dependent direct gating and allosteric modulatory effects of carisoprodol at GABAA receptors

Carisoprodol is a widely prescribed muscle relaxant, abuse of which has grown considerably in recent years. It directly activates and allosterically modulates α1β2γ2 GABAARs, although the site(s) of action are unknown. To gain insight into the actions of carisoprodol, subunit-dependent effects of this drug were assessed. Whole-cell patch clamp recordings were obtained from HEK293 cells expressing α1β2, α1β3 or αxβzγ2 (where x = 1–6 and z = 1–3) GABAARs, and in receptors incorporating the δ subunit (modeling extrasynaptic receptors). The ability to directly gate and allosterically potentiate GABA-gated currents was observed for all configurations. Presence or absence of the γ2 subunit did not affect the ability of carisoprodol to directly gate or allosterically modulate the receptor. Presence of the β1 subunit conferred highest efficacy for direct activation relative to maximum GABA currents, while presence of the β2 subunit conferred highest efficacy for allosteric modulation of the GABA response. With regard to α subunits, carisoprodol was most efficacious at enhancing the actions of GABA in receptors incorporating the α1 subunit. The ability to directly gate the receptor was generally comparable regardless of the α subunit isoform, although receptors incorporating the α3 subunit showed significantly reduced direct gating efficacy and affinity. In extrasynaptic (α1β3δ and α4β3δ) receptors, carisoprodol had greater efficacy than GABA as a direct gating agonist. In addition, carisoprodol allosterically potentiated both EC20 and saturating GABA concentrations in these receptors. In assessing voltage-dependence, we found direct gating and inhibitory effects were insensitive to membrane voltage, whereas allosteric modulatory effects were affected by membrane voltage. Our findings demonstrate direct and allosteric effects of carisoprodol at synaptic and extrasynpatic GABAARs and that subunit isoform influences these effects.

The amoeboidal Dictyostelium aquaporin AqpB is gated via Tyr216 and aqpB gene deletion affects random cell motility.

Regulation of aquaporin (AQPs) water channels mostly occurs on the transcriptional level or by intracellular trafficking. Direct AQP gating is comparatively rare and is described mainly for fungi and plants. Earlier, we identified a gated water-specific AQP in Dictyostelium discoideum, AqpB, which is opened by truncation of an extended intracellular loop D (AqpB Δ208-219). We show that Tyr216 of loop D is a key residue in the gating mechanism possibly involving phosphorylation. Mutation of Tyr216 to aspartate or glutamate initiated water permeability (Pf =69μm/s) to the same extent as AqpB Δ208-219, whereas neither replacement of Tyr216 by a positive arginine (Y216R) nor introduction of a negative charge in a neighbouring position (T217D) opened the channel. We overexpressed AqpB wildtype and AqpB Δ208-219 as GFP fusion constructs in Dictyostelium amoebae and found that the truncated, permanently open AqpB yielded cells with reduced capability to cope with hypotonic stress. Genetic deletion of aqpB yielded a strain with significantly reduced speed of random motility (4.5μm/min vs. 6.3μm/min of wildtype cells). Yet, chemotaxis towards folate and cAMP was unaffected. In this context, we identified a second, so-far uncharacterised amoeboidal AQP, AqpD, whose role in directed cell locomotion needs to be established. Our data add to the completion of the Dictyostelium model for cell motility and show that knowledge on the expression, permeability properties and localisation of amoeboidal AQPs are crucial for further development of the system.

Erratum: Corrigendum: Direct gating and mechanical integrity of Drosophila auditory transducers require TRPN1

Corrigendum: Direct gating and mechanical integrity of Drosophila auditory transducers require TRPN1

Geometric considerations of polar mesospheric summer echoes in tilted beams using coherent radar imaging

Abstract. We present observations of polar mesospheric summer echoes (PMSE) using the Middle Atmosphere Alomar Radar System in Northern Norway (69.30° N, 16.04° E). The radar is able to resolve PMSE at high spatial and temporal resolution and to perform pulse-to-pulse beam steering. In this experiment, 81 oblique beam directions were used with off-zenith angles up to 25°. For each beam pointing direction and range gate, coherent radar imaging was applied to determine the mean backscatter location. The location of the mean scatterer in the beam volume was calculated by the deviation from the nominal off-zenith angle of the brightest pixel. It shows that in tilted beams with an off-zenith angle greater than 5°, structures appear at the altitudinal edges of the PMSE layer. Our results indicate that the mean influence of the location of the maximum depends on the tilt of the beam and on the observed area of the PMSE layer. At the upper/lower edge of the PMSE layer, the mean backscatter has a greater/smaller off-zenith angle than the nominal off-zenith angle. This effect intensifies with greater off-zenith beam pointing direction, so the beam filling factor plays an important role in the observation of PMSE layers for oblique beams.

The how and why of identifying the hair cell mechano-electrical transduction channel.

Identification of the auditory hair cell mechano-electrical transduction (hcMET) channel has been a major focus in the hearing research field since the 1980s when direct mechanical gating of a transduction channel was proposed (Corey and Hudspeth J Neurosci 3:962-976, 1983). To this day, the molecular identity of this channel remains controversial. However, many of the hcMET channel's properties have been characterized, including pore properties, calcium-dependent ion permeability, rectification, and single channel conductance. At this point, elucidating the molecular identity of the hcMET channel will provide new tools for understanding the mechanotransduction process. This review discusses the significance of identifying the hcMET channel, the difficulties associated with that task, as well as the establishment of clear criteria for this identification. Finally, we discuss potential candidate channels in light of these criteria.

Ion transport and selection through DCGC-based electroosmosis in a conducting nanofluidic channel

Compared to conventional electroosmosis over a non-polarizable insulating surface with fixed surface charge (or zeta potential), induced-charge electroosmosis occurs over an electrically polarizable surface with the ability of surface charge modulation (both magnitude and sign) under externally applied electric fields. Here, for the first time we propose to extend the induced-charge electroosmosis to nanofluidic channels with conducting (ideally polarizable) walls. Furthermore, we present a numerical model to describe the electrokinetic transport in such conducting nanofluidic channels. The analysis of numerical results shows new applications of induced-charge electroosmosis for actively tunable ion selection and flexible flow control in nanofluidics. This is achieved through the direct contact gate control (DCGC) of surface charge in induced-charge electroosmosis by applying very low voltages directly on conducting walls of nanochannels.