Variations in electrical impedance and phase angle among seedlings of Pinus densata and parental species in Pinus tabuliformis habitat environment

We evaluated a novel and non-destructive method of the electrical impedance spectroscopy (EIS) to elucidatethe genetic and evolutionary relationship of homoploid hybrid conifer of Pinus densata (P.d) and its parental species Pinus tabuliformis (P.t) and Pinus yunnanensis(P.y), as well as the artificial hybrids of the P.t and P.y. Field common garden tests of96 trees sampled from 760 seedlings and 480 EIS records of 1,440 needles assessed the interspecific variation of the P.d, P.t, P.y and the artificial hybrids. We found that (1) EIS at different frequencies diverged significantly among germplasms; P.ywasthe highest, P.t was the lowest, and their artificial hybrids were within the range of P.t and P.y; (2) maternal species effect of EIS magnitudes inthe hybrids and P.d was stronger than the paternal species characteristics; (3)EIS of the artificial hybrid confirmed the mid-parent and partial maternal species characteristics;(4) unified exponential modelof EIS for the interspecific and hybrids canbe constructedas; (5) cluster analysis for species and hybrid combinationsin total corroborated with the previous hybrid model ofPinus densata. Our non-destructive EIS method complemented the previous finding that Pinus densata was originated from P.t and P.y. We conclude that the impedance would be a viable indicator to investigate the interspecific genetic variations of conifers.

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Impedance-Based Monitoring of Mesenchymal Stromal Cell Three-Dimensional Proliferation Using Aerosol Jet Printed Sensors: A Tissue Engineering Application

Materials ◽

10.3390/ma13102231 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2231 ◽

Cited By ~ 4

Author(s):

Sarah Tonello ◽

Andrea Bianchetti ◽

Simona Braga ◽

Camillo Almici ◽

Mirella Marini ◽

...

Keyword(s):

Cell Proliferation ◽

Phase Angle ◽

Electrical Impedance ◽

Three Dimensional ◽

Model Parameters ◽

Tissue Engineering Application ◽

Hybrid Hydrogel ◽

Invasive Approach ◽

Non Invasive ◽

Aerosol Jet Printing

One of the main hurdles to improving scaffolds for regenerative medicine is the development of non-invasive methods to monitor cell proliferation within three-dimensional environments. Recently, an electrical impedance-based approach has been identified as promising for three-dimensional proliferation assays. A low-cost impedance-based solution, easily integrable with multi-well plates, is here presented. Sensors were developed using biocompatible carbon-based ink on foldable polyimide substrates by means of a novel aerosol jet printing technique. The setup was tested to monitor the proliferation of human mesenchymal stromal cells into previously validated gelatin-chitosan hybrid hydrogel scaffolds. Reliability of the methodology was assessed comparing variations of the electrical impedance parameters with the outcomes of enzymatic proliferation assay. Results obtained showed a magnitude increase and a phase angle decrease at 4 kHz (maximum of 2.5 kΩ and −9 degrees) and an exponential increase of the modeled resistance and capacitance components due to the cell proliferation (maximum of 1.5 kΩ and 200 nF). A statistically significant relationship with enzymatic assay outcomes could be detected for both phase angle and electric model parameters. Overall, these findings support the potentiality of this non-invasive approach for continuous monitoring of scaffold-based cultures, being also promising in the perspective of optimizing the scaffold-culture system.

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Electrical impedance tomography identifies a distinct change in regional phase angle delay pattern in ventilation filling immediately prior to a spontaneous pneumothorax

Journal of Applied Physiology ◽

10.1152/japplphysiol.00973.2018 ◽

2019 ◽

Vol 127 (3) ◽

pp. 707-712

Author(s):

Martijn Miedema ◽

Andy Adler ◽

Karen E. McCall ◽

Elizabeth J. Perkins ◽

Anton H. van Kaam ◽

...

Keyword(s):

Electrical Impedance Tomography ◽

Preterm Infants ◽

Phase Angle ◽

High Frequency ◽

Electrical Impedance ◽

High Frequency Oscillatory Ventilation ◽

Impedance Tomography ◽

Oscillatory Ventilation ◽

Filling Characteristics ◽

High Frequency Oscillatory

Pneumothoraxes are common in preterm infants and are a major cause of morbidity. Early detection and treatment of pneumothoraxes are vital to minimize further respiratory compromise. Electrical impedance tomography (EIT) has been suggested as a method of rapidly detecting pneumothoraxes at the bedside. Our objective was to define the EIT-derived regional phase angle differences in filling characteristics before and during spontaneous pneumothoraxes in preterm lambs. Preterm lambs (124–127-day gestation) were ventilated with high-frequency oscillatory ventilation for 120 min. EIT data and cardiorespiratory parameters were monitored continuously and recorded for 3 min every 15 min. Six animals spontaneously developed a pneumothorax within a gravity-nondependent quadrant of the lung and were included for this analysis. Changes in end-expiratory lung impedance (EELI), ventilation, and phase angle delay were calculated in the four lung quadrants at the onset of the pneumothorax and 15 and 30 min prior. At the onset of the pneumothorax, all animals showed a clear increase in EELI in the affected lung quadrant. Fifteen and thirty minutes before the pneumothorax there was a significant phase angle delay between the nondependent and dependent lung. At 1 min before pneumothorax this phase angle delay was isolated just to the affected quadrant (nondependent). These findings are the first description of the events within the lung at initiation of a pneumothorax, demonstrating distinct predictive changes in air-filling characteristics before the occurrence of pneumothorax. This suggests that EIT may be able to accurately identify the onset of a pneumothorax. NEW & NOTEWORTHY In this article we describe for the first time predictive changes in electrical impedance tomography-based regional filling characteristics of the lung before the onset of a one-sided pneumothorax in six preterm lambs ventilated with high-frequency oscillatory ventilation. This can give clinicians bedside information to change treatment of preterm infants and prevent pneumothorax as life-threatening event from happening.

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Electrical impedance phase angle as an indicator of plant root stress

Biosystems Engineering ◽

10.1016/j.biosystemseng.2018.03.004 ◽

2018 ◽

Vol 169 ◽

pp. 226-232 ◽

Cited By ~ 7

Author(s):

Imre Cseresnyés ◽

Kálmán Rajkai ◽

Tünde Takács ◽

Eszter Vozáry

Keyword(s):

Phase Angle ◽

Electrical Impedance ◽

Plant Root ◽

Root Stress

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Role of phase angle measurement in electrical impedance spectroscopy

International Agrophysics ◽

10.2478/intag-2013-0007 ◽

2013 ◽

Vol 27 (4) ◽

pp. 377-383 ◽

Cited By ~ 13

Author(s):

I. Cseresnyés ◽

K. Rajkai ◽

E. Vozáry

Keyword(s):

Energy Dissipation ◽

Impedance Spectroscopy ◽

Phase Angle ◽

Characteristic Frequency ◽

Electrical Impedance ◽

Angle Measurement ◽

Electrical Impedance Spectroscopy ◽

Impedance Method ◽

Soil System ◽

Current Frequency

Abstract Importance of phase angle measurement during the application of electrical impedance spectroscopy was studied by executing pot experiments with maize. Electrical impedance, phase angle (strength of capacitive character), and dissipation factor in the plant-soil system were scanned between 100 and 10 000 Hz current frequency. The frequency-dependent change in the phase angle could be described by optimum curves culminating within 920-3 650 Hz. Since the rate of energy dissipation is independent of root extent, the higher phase angle and lower energy dissipation were associated with the higher coefficient of determination achieved for the root electrical impedance - root system size (root dry mass and root surface area) regressions. The characteristic frequency selected on the basis of phase angle spectra provided a higher significance level at statistical comparison of plant groups subjected to stress conditions influencing root development. Due to the physicochemical changes observable in aging root tissue, the apex of phase angle spectra, thus the characteristic frequency, shifted continuously toward the higher frequencies over time. Consequently, the regularly repeated phase angle measurement is advisable in time-course studies for effective application of the electrical impedance method, and the systematic operation at the same frequency without determination of phase angle spectra should be avoided.

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The Value of Phase Angle in Electrical Impedance Tomography Breath Detection

2018 Progress in Electromagnetics Research Symposium (PIERS-Toyama) ◽

10.23919/piers.2018.8597702 ◽

2018 ◽

Author(s):

Davood Khodadad ◽

Sven Nordebo ◽

Nima Seifnaraghi ◽

Rebecca Yerworth ◽

Andreas D. Waldmann ◽

...

Keyword(s):

Electrical Impedance Tomography ◽

Phase Angle ◽

Electrical Impedance ◽

Impedance Tomography ◽

Breath Detection

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Study of stilbene and resin acid content of Scots pine heartwood by electrical impedance spectroscopy (EIS)

Holzforschung ◽

10.1515/hf.2011.111 ◽

2011 ◽

Vol 65 (5) ◽

Cited By ~ 7

Author(s):

Laura Tomppo ◽

Markku Tiitta ◽

Tapio Laakso ◽

Anni Harju ◽

Martti Venäläinen ◽

...

Keyword(s):

Impedance Spectroscopy ◽

Phase Angle ◽

Scots Pine ◽

Acid Content ◽

Electrical Impedance ◽

Resin Acid ◽

Complex Impedance ◽

Electrical Impedance Spectroscopy ◽

Model Parameters ◽

Frequency Range

Abstract Scots pine (Pinus sylvestris L.) heartwood samples were measured with electrical impedance spectroscopy (EIS) at frequency range 1 Hz–10 MHz in green and relative humidity (RH) 65% conditioned moisture content (MC) after oven-drying. Complex impedance parameters were studied in relation to the density, moisture, resin acid and stilbene contents. The measurements were conducted in tangential (T) and longitudinal (L) directions with 36 samples in each analysis. For green MC, there were significant correlations between impedance phase angle and contents of stilbenes and resin acids at frequencies below 400 Hz. For the resin acid content, the strongest correlation with phase-angleT was -0.45 (P<0.01) at 100 Hz. Impedance magnitude correlated significantly with MC throughout the frequency range, e.g., at 10 kHz, r was -0.71 (P<0.001) for L-direction. In moisture conditioned state, the correlation between stilbenes and T-measured phase angle was strongest at 250 Hz, (r=-0.56, P<0.001). Equivalent circuit model of two ZARC-Cole elements in series was fitted for the measurements in green MC. Several model parameters correlated with MC (e.g., R1, L r=-0.64, P<0.001), but only one parameter correlated weakly with stilbene content (R2, T r=0.35, P<0.05). The study shows that EIS has a potential for independent determination of resin acid or stilbene contents and MC for green pine heartwood.

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Microelectrical Impedance Spectroscopy for the Differentiation between Normal and Cancerous Human Urothelial Cell Lines: Real-Time Electrical Impedance Measurement at an Optimal Frequency

BioMed Research International ◽

10.1155/2016/8748023 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 11

Author(s):

Yangkyu Park ◽

Hyeon Woo Kim ◽

Joho Yun ◽

Seungwan Seo ◽

Chang-Ju Park ◽

...

Keyword(s):

Impedance Spectroscopy ◽

Real Time ◽

Cell Lines ◽

Phase Angle ◽

Electrical Impedance ◽

Impedance Measurement ◽

Urothelial Cell ◽

Optimal Frequency ◽

Electrical Impedance Measurement ◽

Human Urothelial Cell

Purpose. To distinguish between normal (SV-HUC-1) and cancerous (TCCSUP) human urothelial cell lines using microelectrical impedance spectroscopy (μEIS). Materials and Methods. Two types of μEIS devices were designed and used in combination to measure the impedance of SV-HUC-1 and TCCSUP cells flowing through the channels of the devices. The first device (μEIS-OF) was designed to determine the optimal frequency at which the impedance of two cell lines is most distinguishable. The μEIS-OF trapped the flowing cells and measured their impedance at a frequency ranging from 5 kHz to 1 MHz. The second device (μEIS-RT) was designed for real-time impedance measurement of the cells at the optimal frequency. The impedance was measured instantaneously as the cells passed the sensing electrodes of μEIS-RT. Results. The optimal frequency, which maximized the average difference of the amplitude and phase angle between the two cell lines (p<0.001), was determined to be 119 kHz. The real-time impedance of the cell lines was measured at 119 kHz; the two cell lines differed significantly in terms of amplitude and phase angle (p<0.001). Conclusion. The μEIS-RT can discriminate SV-HUC-1 and TCCSUP cells by measuring the impedance at the optimal frequency determined by the μEIS-OF.

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