scholarly journals Electrical impedance measurement system to assess in-situ experiments on epithelia under ELF magnetic fields exposure

2021 ◽  
Vol 19 (3) ◽  
pp. 217-226
Author(s):  
G. Domínguez ◽  
E. Cardiel ◽  
J.L Reyes ◽  
E. Sánchez ◽  
P.R. Hernández
Keyword(s):  
Impedance Spectroscopy ◽  
Magnetic Fields ◽  
Cell Cultures ◽  
Electrical Impedance ◽  
Controlled Environment ◽  
Spectroscopy Technique ◽  
In Situ Experiments ◽  
Impedance Spectroscopy Technique

Purpose: The development of an electric impedance meter based on the impedance spectroscopy technique, for in vitro and in situ experimentation, with cellular epithelia submitted to extremely low frequency magnetic fields in a controlled environment. Unlike other reported systems, a strength of the one presented here is that it avoids the influence of external factors on the experiment. Materials and methods: The designed system employs the electrical impedance values obtained by the impedance spectroscopy technique to determine the parameters of the simple equivalent electrical model of a cellular monolayer. The Madin-Darby Canine Kidney (MDCK) cell cultures were used as subjects of study in the experimental protocol. Results: The validation was carried out by comparing the transepithelial electrical impedance data of the cell cultures obtained with the developed system and those of the Cellzscope® commercial system used as the standard. Non-significant differences were obtained. Conclusion: It was confirmed that the developed system provides reliable values of transepithelial electrical impedance to experiment with cell cultures and take advantage of the controlled environment to reduce the effects of experimental management.

Measurement of Solids Concentration in Slurries Using Electrical Impedance Spectroscopy Technique (Keynote)

2003 ◽  
Author(s):  
Shenggen Hu ◽  
Bruce Firth
Keyword(s):  
Liquid Phase ◽  
Impedance Spectroscopy ◽  
Electrical Impedance ◽  
Research Work ◽  
Impedance Spectrum ◽  
Phase Changes ◽  
Electrical Impedance Spectroscopy ◽  
Spectroscopy Technique ◽  
Solids Concentration ◽  
Impedance Spectroscopy Technique

In this research work, an electrical impedance spectroscopy technique has been developed to measure the solids concentration of slurry mixtures. This new measurement technique is based on the fact that the AC frequency responses of solids are distinct from those for the liquid phase. In this technique, the electrical impedance spectrum of slurry mixtures is measured over the frequency range of 0.1 Hz to 1 MHz. Changes in the frequency response at different excitation signal amplitudes reflect changes in the slurry composition and the electrical conductivity of the liquid phase, and by analyzing the spectra using artificial intelligence data analysis techniques, such as Multiplayer Perceptron Artificial Neural Network, one can determine the volumetric fraction of the solids phase. The technique has been successfully tested for various slurries under different conductivities of liquid phase and temperatures. In contrast with previous techniques based on conductivity or capacitance, this new technique can be used for on-line measurement of solids concentration in slurry streams even when the conductivity of the liquid phase changes substantially with time.

ANG II modifies cardiomyocyte function via extracardiac and intracardiac neurons: in situ and in vitro studies

1997 ◽  
Vol 272 (3) ◽  
pp. R766-R775 ◽  
Author(s):  
M. Horackova ◽  
J. A. Armour
Keyword(s):  
Guinea Pig ◽  
Receptor Antagonist ◽  
Neuronal Activity ◽  
Ang Ii ◽  
Arterial Blood ◽  
Cardiac Ganglia ◽  
In Situ Experiments ◽  
Anesthetized Dogs

To determine whether angiotensin II (ANG II) affects cardiac performance via neurons in intrathoracic cardiac ganglia, studies were performed on anesthetized dogs. To exclude possible vascular regulatory effects of ANG II, experiments were also performed using long-term cultures of adult guinea pig ventricular cardiomyocytes with or without intrathoracic neurons. 1) In in situ experiments in 10 anesthetized dogs, cardiac augmentation occurred when ANG II (10 microl or 0.1 ml; 10-100 microM) was administered into limited loci within acutely decentralized stellate or middle cervical ganglia that were neurally connected to, but not those disconnected from, the heart. In another 18 dogs, ANG II increased intrinsic cardiac neuronal activity when administered adjacent to such neurons or into their local arterial blood supply. Ventricular ionotropic effects elicited by ANG II were eliminated by timolol, whereas increases in intrinsic cardiac neuronal activity were not affected. Effects elicited by ANG II were eliminated by administration of a selective AT1 receptor antagonist (losartan) but not by a selective AT2 receptor antagonist (PD-123319). 2) In in vitro experiments, ANG II (100 nM) induced positive chronotropic effects on cultured adult guinea pig cardiomyocytes innervated with adult extrinsic or intrinsic cardiac neurons, but not those cultured without neurons. The frequency of calcium inward current (Ca(i)) transients (recorded by fura 2 fluorescence) increased in innervated cocultures but not in the noninnervated cardiomyocyte cultures; however, the amplitude of Ca(i) transients was not affected by ANG II in cultures or in freshly isolated adult guinea pig cardiomyocytes. ANG II-induced effects in cocultures were blocked by losartan but not PD-123319 or timolol. Thus 1) ANG II-sensitive neurons exist in intrathoracic extracardiac and intrinsic cardiac ganglia; 2) these neurons possess AT1 receptors; and 3) these neurons appear to act directly and indirectly via adrenergic neurons to enhance cardiomyocyte function.

scholarly journals Agrobiological Interactions of Essential Oils of Two Menthol Mints: Mentha piperita and Mentha arvensis

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 59 ◽  
Author(s):  
Danuta Kalemba ◽  
Agnieszka Synowiec
Keyword(s):  
Biological Activities ◽  
Review Article ◽  
Mentha Piperita ◽  
Agricultural Pest ◽  
Mentha Arvensis ◽  
Botanical Pesticides ◽  
New Methods ◽  
In Situ Experiments

This review article discusses the active constituents and potential of two menthol mint oils, Mentha piperita (MPEO) and Mentha arvensis (MAEO), as natural sources for botanical pesticides. The biological activities of these menthol mint oils, which can be useful in agriculture, have been broadly researched, especially toward phytotoxic microorganisms. To a lesser extent, the insecticidal and herbicidal activities of mint EOs have also been studied. It is apparent that the prospect of using menthol mint oils in agriculture is increasing in popularity. A number of investigations showed that the in vitro efficacy of MPEO and MAEO, as well as that of their main constituent, menthol, is pronounced. The results of in vitro research are useful for choosing EOs for further investigations. However, it is clear that in situ experiments are crucial and should be more extensively developed. At the same time, known techniques are to be applied to this area and new methods should be worked out, aiming at the improvement of EOs’ pesticidal efficacy and cost-effectiveness, for future implementation in agricultural pest control.

Electric–dielectric properties and complex impedance analysis of La0.5Ca0.5−xAgxMnO3 manganites

RSC Advances ◽  
2015 ◽  
Vol 5 (3) ◽  
pp. 2177-2184 ◽  
Author(s):  
M. Smari ◽  
H. Rahmouni ◽  
N. Elghoul ◽  
I. Walha ◽  
E. Dhahri ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Impedance Analysis ◽  
Spectroscopy Technique ◽  
Complex Impedance Analysis ◽  
Impedance Spectroscopy Technique

The electric and dielectric properties of La0.5Ca0.5−xAgxMnO3 (LCMO–Ag with x = 0 and x = 0.4) were investigated using the impedance spectroscopy technique.

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