The Concentration Cell

2019 ◽  
pp. 89-161
Keyword(s):  
Concentration Cell

scholarly journals Apoptosis-like cell death upon kinetoplastid induction by compounds isolated from the brown algae Dictyota spiralis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Olfa Chiboub ◽  
Ines Sifaoui ◽  
Manef Abderrabba ◽  
Mondher Mejri ◽  
José J. Fernández ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Mitochondrial Membrane ◽  
Brown Seaweed ◽  
Cell Permeability ◽  
Oxygen Species ◽  
Potential Drug ◽  
Concentration Cell ◽  
Drug Candidates

Abstract Background The in vitro activity of the brown seaweed Dictyota spiralis against both Leishmania amazonensis and Trypanosoma cruzi was evaluated in a previous study. Processing by bio-guided fractionation resulted in the isolation of three active compounds, classified as diterpenes. In the present study, we performed several assays to detect clinical features associated to cell death in L. amazonensis and T. cruzi with the aim to elucidate the mechanism of action of these compounds on parasitic cells. Methods The aims of the experiments were to detect and evaluate specific events involved in apoptosis-like cell death in the kinetoplastid, including DNA condensation, accumulation of reactive oxygen species and changes in ATP concentration, cell permeability and mitochondrial membrane potential, respectively, in treated cells. Results The results demonstrated that the three isolated diterpenes could inhibit the tested parasites by inducing an apoptosis-like cell death. Conclusions These results encourage further investigation on the isolated compounds as potential drug candidates against both L. amazonensis and T. cruzi. Graphic abstract

scholarly journals Nephrotoxicity Of Polymyxin B: Experimental Study In Cells And Implications For Nursing Practice

2014 ◽  
Vol 48 (2) ◽  
pp. 272-277 ◽  
Author(s):  
Luciana Barros de Moura Neiva ◽  
Fernanda Teixeira Borges ◽  
Mirian Watanabe ◽  
Edson de Andrade Pessoa ◽  
Dulce Aparecida Barbosa ◽  
...  
Keyword(s):  
Fluorescent Dyes ◽  
Cell Damage ◽  
Kidney Injury ◽  
In Vitro Study ◽  
Polymyxin B ◽  
Concentration Cell ◽  
Tubular Cells ◽  
Risk Patients ◽  
Proximal Tubular

The aim of the study was to characterize the cell damage mechanisms involved in the pathophysiology of cytotoxicity of polymyxin B in proximal tubular cells (LLC - PK1) and discuss about the nurses interventions to identify at risk patients and consider prevention or treatment of nephrotoxicity acute kidney injury. This is a quantitative experimental in vitro study, in which the cells were exposed to 375μM polymyxin B sulfate concentration. Cell viability was determined by exclusion of fluorescent dyes and morphological method with visualization of apoptotic bodies for fluorescence microscopy. Cells exposed to polymyxin B showed reduced viability, increased number of apoptotic cells and a higher concentration of the enzyme lactate dehydrogenase. The administration of polymyxin B in vitro showed the need for actions to minimize adverse effects such as nephrotoxicity.


scholarly journals Propagation of radiosonde pressure sensor errors to ozonesonde measurements

2014 ◽  
Vol 7 (1) ◽  
pp. 65-79 ◽  
Author(s):  
R. M. Stauffer ◽  
G. A. Morris ◽  
A. M. Thompson ◽  
E. Joseph ◽  
G. J. R. Coetzee ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Atmospheric Pressure ◽  
Pressure Profile ◽  
Mixing Ratio ◽  
Concentration Cell ◽  
Pressure Profiles ◽  
Dependent Variables ◽  
Sensor Errors ◽  
Subsequent Addition ◽  
Total Column

Abstract. Several previous studies highlight pressure (or equivalently, pressure altitude) discrepancies between the radiosonde pressure sensor and that derived from a GPS flown with the radiosonde. The offsets vary during the ascent both in absolute and percent pressure differences. To investigate this problem further, a total of 731 radiosonde/ozonesonde launches from the Southern Hemisphere subtropics to northern mid-latitudes are considered, with launches between 2005 and 2013 from both longer term and campaign-based intensive stations. Five series of radiosondes from two manufacturers (International Met Systems: iMet, iMet-P, iMet-S, and Vaisala: RS80-15N and RS92-SGP) are analyzed to determine the magnitude of the pressure offset. Additionally, electrochemical concentration cell (ECC) ozonesondes from three manufacturers (Science Pump Corporation; SPC and ENSCI/Droplet Measurement Technologies; DMT) are analyzed to quantify the effects these offsets have on the calculation of ECC ozone (O3) mixing ratio profiles (O3MR) from the ozonesonde-measured partial pressure. Approximately half of all offsets are > ±0.6 hPa in the free troposphere, with nearly a third > ±1.0 hPa at 26 km, where the 1.0 hPa error represents ~ 5% of the total atmospheric pressure. Pressure offsets have negligible effects on O3MR below 20 km (96% of launches lie within ±5% O3MR error at 20 km). Ozone mixing ratio errors above 10 hPa (~ 30 km), can approach greater than ±10% (> 25% of launches that reach 30 km exceed this threshold). These errors cause disagreement between the integrated ozonesonde-only column O3 from the GPS and radiosonde pressure profile by an average of +6.5 DU. Comparisons of total column O3 between the GPS and radiosonde pressure profiles yield average differences of +1.1 DU when the O3 is integrated to burst with addition of the McPeters and Labow (2012) above-burst O3 column climatology. Total column differences are reduced to an average of −0.5 DU when the O3 profile is integrated to 10 hPa with subsequent addition of the O3 climatology above 10 hPa. The RS92 radiosondes are superior in performance compared to other radiosondes, with average 26 km errors of −0.12 hPa or +0.61% O3MR error. iMet-P radiosondes had average 26 km errors of −1.95 hPa or +8.75 % O3MR error. Based on our analysis, we suggest that ozonesondes always be coupled with a GPS-enabled radiosonde and that pressure-dependent variables, such as O3MR, be recalculated/reprocessed using the GPS-measured altitude, especially when 26 km pressure offsets exceed ±1.0 hPa/±5%.

An Aluminum Acid‐Base Concentration Cell Using Room Temperature Chloroaluminate Ionic Liquids

1984 ◽  
Vol 131 (12) ◽  
pp. 2887-2892 ◽  
Author(s):  
C. J. Dymek ◽  
J. L. Williams ◽  
D. J. Groeger ◽  
J. J. Auborn
Keyword(s):  
Ionic Liquids ◽  
Room Temperature ◽  
Acid Base ◽  
Concentration Cell

Diffusion in Materials with Ionic and Electronic Disorder

1990 ◽  
Vol 210 ◽  
Author(s):  
Joachim Maier
Keyword(s):  
Ionic Conduction ◽  
Diffusion Theory ◽  
Local Equilibrium ◽  
Transport Coefficients ◽  
Electrochemical Techniques ◽  
Chemical Diffusion ◽  
Tracer Diffusion ◽  
Internal Defect ◽  
Concentration Cell ◽  
The Individual

AbstractBesides some necessary reviewing of conventional diffusion theory, this paper deals with the modification of the mass and charge transport equations originating from the occurence of internal defect-chemical reactions (especially valence changes of the defects) which can be considered to be in local equilibrium. It is shown how the phenomenological transport coefficients for chemical diffusion, tracer diffusion and ionic conduction depend on the individual defect diffusivities under such general conditions. Moreover, the evaluation formulae of well-known electrochemical techniques such as Wagner-Hebb polarization and concentration cell experiments have to be modified. Application is made to the influence of trapping effects in doped SrTi03, to the valence changes in YBa2Cu3O6+x as well as to the mixed conduction in orthorhombic PbO.

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