scholarly journals Estimating Cold Stress in `Beautiful Arcade' Apple Roots using Electrical Impedance Analysis

1996 ◽  
Vol 6 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Jean-Pierre Privé ◽  
M.I.N. Zhang

2,3,5-triphenyl tetrazolium chloride (TTC) staining, electrical conductivity, and electrical impedance (Z) analyses were used to assess freezing injury of `Beautiful Arcade' apple (Malus ×domestica Borkh.) roots taken in late March from either the field or 3C-refrigerated storage (cold-stored). Lethal temperature (LT50) levels using TTC or electrical conductivity occurred at colder temperatures than those found using Z. Techniques varied in their ability to detect changes in cell viability with increasing cold stress. Listed in order of decreasing responsiveness they are electrical impedance (Z), electrical conductivity, and TTC vital staining. With the most sensitive technique, Z, two parameters—extracellular and total tissue electrical resistance—were about five and eight times lower (indicating more injury) for roots from the field than from cold storage. The smaller values obtained from the field roots were probably due to natural in-field freeze-thaw cycling before the controlled cold-stress tests in the laboratory. More importantly, the impedance technique provided more detailed information than TTC or electrical conductivity about how apple roots respond to cold stress and how Z may provide some insight into freeze-thaw history before injury assessment. Although this technique shows potential, future studies are required to render a complete physiological significance to the impedance parameters involved in calculating Z.

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 774F-775
Author(s):  
Jean-Pierre Prive ◽  
M.I.N. Zhang

2,3,5-triphenyltetrazolium chloride (TTC) staining and electrical impedance (?) analyses of apple roots (Malus domestica Borkh. `Beautiful Arcade') taken in late March from either the field or from 3C refrigerated storage (cold-stored). LT50 levels using TTC were much lower than those found using electrical impedance. No loss of viability in the roots was detectable using TTC staining until a freeze–thaw stress of –9C whereas? analysis detected changes in cell viability after a freeze–thaw stress of only –3C. With increasing cold stress, two parameters: extracellular electrical resistance (Ro) and time constant?, decreased linearly for cold-stored roots and exponentially for field roots. Impedance analysis also revealed that the values for both extracellular Ro and total tissue electrical resistance (R?) for the field roots were approximately 5 and 8 times lower, respectively, than in the cold-stored roots. It is believed that the smaller Ro and R? values obtained from the field roots were due to natural in-field freeze–thaw cycling prior to the controlled stress tests in the laboratory. Based on the analyses of winter hardiness using the two methods, the impedance technique? provided the physiological information not only about the hardiness level, but also about freeze–thaw history prior to the hardiness assessment.


1992 ◽  
Vol 70 (11) ◽  
pp. 2254-2258 ◽  
Author(s):  
M. I. N. Zhang ◽  
J. H. M. Willison

Freezing injury of potato tuber tissue was studied by measuring electrical impedance, in the range of 100 Hz to 800 KHz, while the tissue was subjected to a −3 °C environment. It was found that a greater proportion of total impedance was due to electrode polarization in frozen tissues than in nonfrozen tissues. In frozen tissue, electrode impedance could be so great that tissue impedance could not be measured reliably. Analysis of tissue impedance using complex nonlinear least squares revealed some dynamics of the process of tissue freezing. After 1 h of exposure to freezing conditions, extracellular resistance began a sustained decrease. This can be explained by electrolyte leakage to extracellular space, presumably as a result of membrane injury. The capacitances of both plasma membrane and tonoplast also decreased with freezing. Key words: potato (Solanum tuberosum L.) tuber, electrical impedance, freezing injury, membrane capacitance.


2015 ◽  
Vol 107 (2) ◽  
pp. 023701 ◽  
Author(s):  
Tong In Oh ◽  
Hyun Bum Kim ◽  
Woo Chul Jeong ◽  
Saurav Z. K. Sajib ◽  
Eun Jung Kyung ◽  
...  

2020 ◽  
Vol 9 (2) ◽  
pp. 142-152
Author(s):  
Fitria Rahmawati ◽  
◽  
Dwi Aman Nur Romadhona ◽  
Syulfi Faiz ◽  
◽  
...  

Research to prepare NaFePO4 cathode material from iron sand was conducted. The iron sand consists of ilmenite FeTiO3 and hematite Fe2O3. A caustic fusion method used to precipitate iron as Fe(OH)3 and it increased Fe content up to 94.71 %. Phosphate precipitation successfully produced trigonal FePO4 and monoclinic FePO4 comply with ICSD#412736 and ICSD#281079. The prepared-FePO4 was then used as a precursor for Na insertion by applying cyclic voltammetry mode within 2.0 – 4.0 V with 0.05 mVs-1 of the scan rate. It produced orthorhombic olivine NaFePO4 and a secondary phase of orthorhombic Na0.7FePO4. Impedance analysis at 20 Hz – 5 MHz found that the material provided a semicircle at 100 Hz peak point, indicating electrode-bulk interface with a resistance value of 1735W, comparable to the electrical conductivity of 5.36 x 10-6 Scm-1. Even though the conductivity value is quite lower than NaFePO4 prepared from a commercial FePO4 that has been conducted in our previous research, however the electrical conductivity still reliable for cathode.


2018 ◽  
Vol 10 (12) ◽  
pp. 527
Author(s):  
Tássia Fernanda Santos Neri Soares ◽  
Bruno Antônio Lemos de Freitas ◽  
José Geraldo de Araújo Ferreira Filho ◽  
Denise Cunha Fernandes dos Santos Dias ◽  
Camila Andrade Fialho ◽  
...  

Vigor tests are important mainly to identify differences associated to lots performance in field conditions. The objective of this study was to define the most appropriate tests to evaluate the crambe (Crambe abyssinica) seeds vigor. Seven seed lots of crambe were subjected to the standard germination (on the first and last count), germination speed index (GSI), primary root protrusion speed index (PRPSI), seedling length dry and weight seedling, water stress test using PEG 6000 at -0.2 MPa, electrical conductivity and cold test without soil. Crambe lots studied had germination percentages varying from 54 to 80.5%. The GSI, on the first count of water stress and electrical conductivity test ranked lots between two vigor classes The PRPSI, seedling length, seedling dry weight and last count of water stress tests were less sensitive to evaluate vigor for crambe seed. The cold test without soil and the first count of standard germination test were capable to dishtinguish lots more efficiently than the standard germination test on last count by ranking four of the seven seed lots studied.


1994 ◽  
Vol 74 (2) ◽  
pp. 357-358 ◽  
Author(s):  
J. H. M. Willison ◽  
C. H. Cheung ◽  
M. I. N. Zhang ◽  
X. Xiao

Turnip (Brassica rapa L.) root tissue was exposed to freeze-thaw stresses of −7, −9, -−11 and −19 °C. The post-thawed tissues were either subjected to leaching in deionized water for 2 h or left at 100% humidity. Tissue survival was then assayed by vital staining using modified 2,3,5-triphenyltetrazolium chloride (TTC) staining in 0.2 M phosphate buffer. Tissue survival was significantly lower for leached samples than for non-leached samples. It is concluded that freeze-thaw injury in plant tissues is enhanced by post-thaw leaching in water. The 0.05 M phosphate buffer commonly used for TTC staining also damaged freeze-thaw injured tissue. Key words:Brassica rapa L., 2,3,5-triphenyltetrazolium chloride (TTC), freeze-thaw injury, leaching


MRS Advances ◽  
2020 ◽  
Vol 5 (16) ◽  
pp. 847-853
Author(s):  
Rhiannon Morris ◽  
Holly Warren ◽  
Marc in het Panhuis

ABSTRACTPlants produce energy in a sustainable way, they are very effective in converting light energy into a useable form. Utilising certain parts of plants in technology could become an efficient way to enhance energy production and improve sustainability. Integrating plants with technology would offer a ‘green’ way of producing elements for electronic circuits and reduce heavy metal waste. In this paper, we demonstrate that conducting polymers can be incorporated into living system such as celery. Electrical impedance analysis was used to establish the conductivity of celery with a conducting polymer (PEDOT:PSS) into its vascular system. It was demonstrated that electronic celery exhibited conductivity values of up to 0.55 ± 0.03 S/cm. This conductivity value was sufficient to demonstrate the potential of celery electronics where celery stalks are used as electrodes in simple circuits.


Author(s):  
Takashi Yoshimori ◽  
Masaki Fukagawa ◽  
Hiroshi Takamatsu

Cryopreservation of tissues and organs, including artificial organs, could be one of the important steps in the medical service that brings the progress in the tissue engineering to realization. In this case, high viability of cryopreserved cells is critical to recovery after transplantation. In contrast, in the cryosurgery, which is expected to expand its application as a minimally invasive treatment of cancer, malignant cells should be destructed completely to prevent from recurrence. The appropriate freeze-thaw protocol is therefore needed to be established for cryopreservation or cryosurgery depending on specific type of tissues and organs. Although it is determined empirically, the underlying mechanism of cell injury by freezing has been explored for a long time to give a scientific basis of the process. The experiments with a cell suspension showed that the cell injury during slow freezing to a relatively higher sub-zero temperature was attributed to the mechanical stress from the extracellular ice, while the effect of elevated concentration of solutes became more crucial to cell damage at lower temperatures [1]. However, there are some studies that indicates the difference in the freeze tolerance between cell suspensions and attached monolayers, some of which indicated higher susceptibility of monolayers to freezing than cell suspension [2] and the other suggested reverse [3,4]. The goal of our study is thus to validate the difference in freezing injury between isolated cells and tissues that are more important in aforementioned applications and clarify the mechanism. We used cells adhered to a surface as a first simple model of cells in tissues. The cells adhered on a surface at low number density were used to highlight the effect of cell-to-surface interaction without cell-to-cell interactions. In the present study we first demonstrate that the survival of cells adhered on a surface is lower than those in the suspension after a freeze-thaw manipulation. Then the osmotic response to concentration increase was examined to clarify if the extent of dehydration is different between these two types of cells. The cells were observed by a laser confocal scanning microscope that allows real-time 3-D observation.


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