scholarly journals Infection-generated electric field in gut epithelium drives bidirectional migration of macrophages

2018 ◽  
Author(s):  
Yaohui Sun ◽  
Brian Reid ◽  
Fernando Ferreira ◽  
Guillaume Luxardi ◽  
Li Ma ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Ricinus Communis ◽  
Pathogenicity Island ◽  
Sialic Acids ◽  
Directional Migration ◽  
Primary Mouse ◽  
Follicle Associated Epithelium ◽  
Migration Of Macrophages

AbstractMany bacterial pathogens hijack macrophages to egress from the port of entry to the lymphatic/blood-stream, causing dissemination of life-threatening infections. However, the underlying mechanisms are not well understood. Here, we report thatSalmonellainfection generates directional electric fields (EF) in the follicle-associated epithelium of mouse cecum.In vitroapplication of an EF, mimicking the infection-generated electric field (IGEF), induces directional migration of primary mouse macrophages to the anode, which is reversed to the cathode uponSalmonellainfection. This infection-dependent directional switch is independent of theSalmonellapathogenicity island 1 (SPI-1) type III secretion system. The switch is accompanied by a reduction of sialic acids on glycosylated surface components during phagocytosis of bacteria, which is absent in macrophages challenged by microspheres. Moreover, enzymatic cleavage of terminally exposed sialic acids reduces macrophage surface negativity and severely impairs directional migration of macrophages in response to EF. Based on these findings, we propose that macrophages are attracted to the site of infection by a combination of chemotaxis and galvanotaxis; after phagocytosis of bacteria, surface electrical properties of the macrophage change, and galvanotaxis directs the cells away from the site of infection.AbbreviationsCFU, colony-forming unit; Con A, Concanavalin A; EF, electric field; FAE, follicle-associated epithelium; GNL, Galanthus Nivalis lectin; IGEF, infection-generated electric field; Ji, electric current density; MAL-2, Maackia Amurensis lectin II; MLN, mesenteric lymph node; MOI, multiplicity of infection; nMFI, normalized mean fluorescence intensity; RCA-1, Ricinus Communis Agglutinin I; SNA, Sambucus Nigra lectin;S. Typhimurium,Salmonella entericaserotype Typhimurium; SPI-1,Salmonellapathogenicity island 1; PDMS, polydimethylsiloxane; TEP, trans-epithelial potential difference; TLR, Toll-like receptors; WGEF, wound-generated electric field

scholarly journals Understanding the Properties of Starch in Potatoes (Solanum tuberosum var. Agria) after Being Treated with Pulsed Electric Field Processing

Foods ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 159 ◽  
Author(s):  
Setya B.M. Abduh ◽  
Sze Ying Leong ◽  
Dominic Agyei ◽  
Indrawati Oey
Keyword(s):  
Solanum Tuberosum ◽  
Electric Field ◽  
Light Microscopy ◽  
Electric Fields ◽  
Potato Starch ◽  
Potato Tissue ◽  
Scanning Calorimetry ◽  
Starch Properties ◽  
Polarised Light

The purpose of this study was to investigate the properties of starch in potatoes (Solanum tuberosum cv. Agria) after being treated with pulsed electric fields (PEF). Potatoes were treated at 50 and 150 kJ/kg specific energies with various electric field strengths of 0, 0.5, 0.7, 0.9 and 1.1 kV/cm. Distilled water was used as the processing medium. Starches were isolated from potato tissue and from the PEF processing medium. To assess the starch properties, various methods were used, i.e., the birefringence capability using a polarised light microscopy, gelatinisation behaviour using hot-stage light microscopy and differential scanning calorimetry (DSC), thermal stability using thermogravimetry (TGA), enzyme susceptibility towards α-amylase and the extent of starch hydrolysis under in vitro simulated human digestion conditions. The findings showed that PEF did not change the properties of starch inside the potatoes, but it narrowed the temperature range of gelatinisation and reduced the digestibility of starch collected in the processing medium. Therefore, this study confirms that, when used as a processing aid for potato, PEF does not result in detrimental effects on the properties of potato starch.

Dynamic Control of Sliding Directions of Kinesin-Driven Microtubules With Rotating Electric Fields

2008 ◽  
Author(s):  
Shukei Sugita ◽  
Naoya Sakamoto ◽  
Toshiro Ohashi ◽  
Masaaki Sato
Keyword(s):  
Angular Velocity ◽  
Electric Field ◽  
Electric Fields ◽  
Dynamic Control ◽  
Rate Of Change ◽  
Precise Control ◽  
Biomolecular Motors ◽  
Random Direction

Kinesins, biomolecular motors that move along microtubules (MTs) can potentially be utilized as an actuator in nanoscale transporting systems. Recent studies have reported inverted geometry in vitro, in which MTs randomly moved on kinesins fixed to substrates. To develop the transporting systems, one of key elements includes precise control of the direction of sliding MTs. One possible method is to utilize electric field (EF) to direct the MTs because MTs are negatively charged in neutral solutions [1,2]. For example, MTs have been shown to orient to the direction of uniaxially or biaxially applied EFs [3,4]. However, for a reliable transporting system, further studies are still required to control the direction of sliding MTs dynamically and effectively. In our previous study [5], we applied EF to MTs in random direction and showed that the rate of change in angle (angular velocity) was proportional to the sin of the angle between the directions of MTs and the generated electrophoretic force. The result indicates that it is most efficient to continuously apply EF perpendicular to the direction of MTs. In this study, the direction of sliding MTs was dynamically controlled with EF, particularly demonstrating a circular movement of MTs.

scholarly journals Electric field stimulation for tissue engineering applications

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Christina N. M. Ryan ◽  
Meletios N. Doulgkeroglou ◽  
Dimitrios I. Zeugolis
Keyword(s):  
Tissue Engineering ◽  
Wound Healing ◽  
Electric Field ◽  
Electric Fields ◽  
Cell Types ◽  
Field Stimulation ◽  
Electric Field Stimulation ◽  
Physiological Processes ◽  
Different Cell Types

AbstractElectric fields are involved in numerous physiological processes, including directional embryonic development and wound healing following injury. To study these processes in vitro and/or to harness electric field stimulation as a biophysical environmental cue for organised tissue engineering strategies various electric field stimulation systems have been developed. These systems are overall similar in design and have been shown to influence morphology, orientation, migration and phenotype of several different cell types. This review discusses different electric field stimulation setups and their effect on cell response.

Application of direct current electric fields to cells and tissues in vitro and modulation of wound electric field in vivo

2007 ◽  
Vol 2 (6) ◽  
pp. 1479-1489 ◽  
Author(s):  
Bing Song ◽  
Yu Gu ◽  
Jin Pu ◽  
Brian Reid ◽  
Zhiqiang Zhao ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Direct Current

Tuning the Electric Field Response of MOFs by Rotatable Dipolar Linkers

2019 ◽  
Author(s):  
Johannes P. Dürholt ◽  
Babak Farhadi Jahromi ◽  
Rochus Schmid
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Structural Changes ◽  
Dielectric Behavior ◽  
Two Dimensions ◽  
Dielectric Constants ◽  
Electric Response ◽  
Dipole Strength ◽  
Metal Organic ◽  
Dynamics Simulations

Recently the possibility of using electric fields as a further stimulus to trigger structural changes in metal-organic frameworks (MOFs) has been investigated. In general, rotatable groups or other types of mechanical motion can be driven by electric fields. In this study we demonstrate how the electric response of MOFs can be tuned by adding rotatable dipolar linkers, generating a material that exhibits paralectric behavior in two dimensions and dielectric behavior in one dimension. The suitability of four different methods to compute the relative permittivity κ by means of molecular dynamics simulations was validated. The dependency of the permittivity on temperature T and dipole strength μ was determined. It was found that the herein investigated systems exhibit a high degree of tunability and substantially larger dielectric constants as expected for MOFs in general. The temperature dependency of κ obeys the Curie-Weiss law. In addition, the influence of dipolar linkers on the electric field induced breathing behavior was investigated. With increasing dipole moment, lower field strength are required to trigger the contraction. These investigations set the stage for an application of such systems as dielectric sensors, order-disorder ferroelectrics or any scenario where movable dipolar fragments respond to external electric fields.

In-Vitro Effects of Ricinus Communis Seed Kernel Extract On Some Antioxidant And Hydrolytic Enzymes In Nymph And Adult Zonocerus Variegatus (Grasshopper)

2019 ◽  
Vol 3 (1) ◽  
pp. 129-137
Author(s):  
Gbadebo E . Adeleke ◽  
Olaniyi T. Adedosu ◽  
Rachael O. Adeyi ◽  
John O. Fatoki
Keyword(s):  
Ricinus Communis ◽  
Hydrolytic Enzymes ◽  
Crude Enzyme ◽  
Economic Losses ◽  
Seed Kernel ◽  
Zonocerus Variegatus ◽  
Sod Activity ◽  
Enzyme Preparations ◽  
In Vitro Effects

Background: Many plants have been identified for their insecticidal properties as alternatives to synthetic ones, which are toxic to untargeted organisms and environment. Ricinus communis (Castor) has been re-ported to exhibit insecticidal properties against insect pests. Zonocerus variegatus (Grasshopper) is a notable pest of several crops, and has been linked with great economic losses to farmers. The present study investigates the in-vitro toxicity of R. communis seed kernel extract (RCSKE) on the activities of selected antioxidant and hydrolytic enzymes in nymph and adult Zonocerus variegatus (Grasshopper), using cypermethrin (CYPER-M) and chlorpyrifos (CPF) as standard conventional pesticides. Methods: Seed kernel of Ricinus communis (Castor) was subjected to acidified aqueous extraction to obtain the extract (RCSKE). Crude enzyme preparations were obtained from nymph and adult Z. variegatus grass-hoppers. The in-vitro effects of different concentrations (15, 30, 45, 60, 75, 90 and 105μg/ml) each of RCSKE, CYPER-M and CPF on the activities of superoxide dismutase (SOD), catalase (CAT), acetylcholinesterase (AChE) and carboxylesterase (CES) in crude enzyme preparations were estimated spectrophotometrically. The level of statistical significance was 0.05. Results: The RCSKE significantly reduced the in-vitro SOD activity (p < 0.05) in nymph Z. variegatus at all the concentrations, whereas both CYPER-M and CPF significantly reduced the activity only at certain concentrations. The CAT activity in the nymph was significantly decreased by RCSKE and CPF at all the concentrations, but CYPER-M decreased it only at certain concentrations. In adult Z. variegatus, SOD activity was not significantly affected (p > 0.05), while CAT activity was significantly increased (p < 0.05) by the three agents at all the concentrations. The AChE and CES activities in the nymph were significantly reduced by RCSKE, CYPER-M and CPF at all the concentrations. The RCSKE and CPF significantly increased the CES activity, while CYPER-M caused a significant decrease in the activity in adult Z. variegatus. Conclusion: The seed kernel extract of Ricinus communis is an effective pesticidal agent and hence, it could be a source of biopesticide alternative with greater potential than cypermethrin and chlorpyrifos. In addition, the antioxidant, acetylcholinesterase and carboxylesterase enzymes in the nymphs of Z. variegatus grasshoppers are more susceptible to the effect of the extract than in the adult grasshoppers.

Establishment of in Vitro regeneration system for Ricinus communis

2014 ◽  
Vol 39 (5) ◽  
pp. 484-488
Author(s):  
Chao XING ◽  
Lu JIN ◽  
Peng LIU ◽  
Ying RUAN ◽  
Chun-lin LIU
Keyword(s):  
Ricinus Communis ◽  
Regeneration System

scholarly journals Meta-Deflectors Made of Dielectric Nanohole Arrays with Anti-Damage Potential

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 107
Author(s):  
Haichao Yu ◽  
Feng Tang ◽  
Jingjun Wu ◽  
Zao Yi ◽  
Xin Ye ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Laser Cutting ◽  
High Complexity ◽  
Damage Potential ◽  
Optical Components ◽  
Nanohole Arrays ◽  
Intense Light ◽  
Polarization Of Light ◽  
Air Hole

In intense-light systems, the traditional discrete optical components lead to high complexity and high cost. Metasurfaces, which have received increasing attention due to the ability to locally manipulate the amplitude, phase, and polarization of light, are promising for addressing this issue. In the study, a metasurface-based reflective deflector is investigated which is composed of silicon nanohole arrays that confine the strongest electric field in the air zone. Subsequently, the in-air electric field does not interact with the silicon material directly, attenuating the optothermal effect that causes laser damage. The highest reflectance of nanoholes can be above 99% while the strongest electric fields are tuned into the air zone. One presentative deflector is designed based on these nanoholes with in-air-hole field confinement and anti-damage potential. The 1st order of the meta-deflector has the highest reflectance of 55.74%, and the reflectance sum of all the orders of the meta-deflector is 92.38%. The optothermal simulations show that the meta-deflector can theoretically handle a maximum laser density of 0.24 W/µm2. The study provides an approach to improving the anti-damage property of the reflective phase-control metasurfaces for intense-light systems, which can be exploited in many applications, such as laser scalpels, laser cutting devices, etc.

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