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1.
PLoS One ; 19(5): e0298371, 2024.
Article in English | MEDLINE | ID: mdl-38758738

ABSTRACT

Malathion® is a persistent organophosphate pesticide used against biting and chewing insects on vegetables. It is a difficult-to-remove surface contaminant of vegetables and contaminates surface and ground water and soils. Malathion® is only partially water soluble, but use of detergent carriers makes adhering Malathion® residues difficult to subsequently remove. Magnetically treated water (MTW) successfully removed Malathion® from Chinese Kale (Brassica oleracea L.), meeting Maximum Residue Load (MRL) standards. Samples were soaked in MTW for 30 min prior to detection with GC/MS/MS, 98.5±3.02% of Malathion® was removed after washing by MTW. Removal by simple washing was only ≈42±1.2% which was not nearly sufficient to meet MRL criteria.


Subject(s)
Brassica , Malathion , Brassica/chemistry , Water Pollutants, Chemical/analysis , Water/chemistry , Insecticides/analysis , Pesticide Residues/analysis , Water Purification/methods , Food Contamination/analysis , Gas Chromatography-Mass Spectrometry
2.
PLoS One ; 18(2): e0277044, 2023.
Article in English | MEDLINE | ID: mdl-36821542

ABSTRACT

Cytoplasmic conductivity of human erythrocytes may be significantly disturbed by the composition of the external suspending media. Effects of external NaCl on cytoplasmic conductivity of human erythrocyte (Human Red Blood Cells, HRBC) were investigated in a simple NaCl system. Using thermodynamic theory cytoplasmic conductivities could be calculated from internal [K+], [Na+], [Cl-] and [HCO3-]. Effect of cell volume and cell water changes were introduced and allowed for using the Debye-Hückel-Onsager relation and Walden's rule of viscosity. Cell volume and cell water change of HRBCs were measured in suspending isotonic solutions with conductivities from 0.50 S m-1 up to hypertonic solutions of conductivity of 2.02 S m-1 at selected temperatures of 25°C (standard benchmark temperature) and 37°C (physiological temperature). In isotonic solutions, cytoplasmic conductivity of human erythrocyte decreases with rise in the external media ionic concentration and vice versa for hypertonic solutions. The HRBC is capable of rapidly regulating its volume (and shape) over quite a wide range of osmolality. Specific Absorption Rate (SAR, 900 MHz) values (W kg-1) of electromagnetic radiation are below safe limits at non-physiological 25°C but above legal limits at 37°C [National Council on Radiation Protection and Measurements, NCRP]. However, at 37°C under both hypertonic [Na+] and isotonic but low [Na+], SAR increases further beyond legal limits.


Subject(s)
Sodium Chloride , Sodium , Humans , Sodium Chloride/pharmacology , Erythrocytes , Hypertonic Solutions , Osmolar Concentration , Water , Isotonic Solutions , Electromagnetic Phenomena
3.
Biophys Chem ; 273: 106578, 2021 06.
Article in English | MEDLINE | ID: mdl-33774523

ABSTRACT

The energy absorbed into tissues is known as the specific energy absorption (SAR) which is dependent on conductivity of the tissue. We calculated cytoplasmic conductivity of human red blood cell (HRBC) using the intracellular ionic concentrations and the Debye-Hückel-Onsager relation. The overall concentration is determined by cell volume and cell water content. The calculated HRBC conductivity at 25 o C was σc,25 = 0.5566 ± 0.0146 S m-1, ±SE). It is exponentially related to temperature: Q10 ≈ 1.866. At 37 o C, the calculated SAR value is 1.6 W kg-1 using a linear temperature compensation of conductivity. However, if using a biologically realistic non-linear temperature compensated conductivity, the SAR is ≈ 2.62 ± 0.05 W kg-1. The relationship between SAR and temperature increase is not straightforward. Since there is a wide variance in cellular ionic and water perfusion rates more tissue-specific SAR limits which consider temperature-related factors would be valuable.


Subject(s)
Cytoplasm/chemistry , Erythrocytes/chemistry , Temperature , Electric Conductivity , Humans
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