Results 1 - 10 of 9712
Results 1 - 10 of 9712. Search took: 0.044 seconds
|Sort by: date | relevance|
[en] Magnetoliposomes offer new challenges in the field of modern biotechnology and biomedicine. To investigate the important mechanism of interliposomal transfer of encapsulated substances, we investigated in the present work magnetoliposomes and liposomes containing the dye crystal violet. Our study of transmembrane transport showed that the dye transfer from DPPC liposomes to magnetoliposomes was temperature dependent
[en] In the absorption spectrum of solutions containing ions Y3+, La3+, Pr3+, Nd3+, Sm3+ and Gd3+ and methylthymol blue (H6X) at pH 6-8 and with definite component ratios, an absorption band 660-665 nm appears, which corresponds to the formation of complexes of REE with H6X. The conditions are determined of formation of these complexes, their composition (Ln2(H2X)36-) and stability constants. The structure of the complexes is proposed
[en] This paper presents a study on the batch adsorption of crystal violet dye from aqueous solution onto Posidonia oceanica L. fibers in order to explore their potential use as low cost adsorbents for wastewater dye removal. A series of batch tests were conducted and the influence of contact time, initial dye concentration, pH of the solution and adsorbent dosage on crystal violet removal was investigated. FT-IR spectroscopy analysis of the Posidonia oceanica L. fibers before and after dye sorption was also investigated to confirm the mechanism of the removal of crystal violet. Results indicate that crystal violet uptake increased with increased initial dye concentration and decreased with increased pH values. The results showed that the highest dye adsorption capacity (11.75 mg/g) was found at pH = 6, for an adsorbent dosage of 5 g/L, initial dye concentration of 60 mg/L, under a constant temperature of 23±02 degree, and the equilibrium state was reached within 10 min of exposure time. The relatively low cost and high capabilities of Posidonia oceanica L. fibers make them potentially attractive options for dye removal from dilute industrial effluents.
[en] Formation of polynuclear complexes of heavy lanthanides with methylthymol blue has been studied. Conditions necessary for complex formation (pH range, concentration of reagents, their molar ratio, and ionic strength) are determined. The stability constants are reported. They decrease from Tb3+ to Lu3+. The structure of the complex is discussed. (author)
[en] Aqueous solution of crystal violet has been evaluated spectrophotometrically as a gamma-ray chemical dosimeter. The response of the chemical dosimetric system has also been investigated under different environmental conditions, such as light and temperature. In the present study the response has been measured at two wavelengths; 588 nm (λmax of the irradiated solution) and 500 nm. The response of the crystal violet dosimeter was linear in the dose range of 50-550 Gy at pH 5.6 when absorption measurements were made at 588 and 500 nm. The response of the crystal violet dosimeter during post-irradiation storage at room temperature in dark showed slight decrease in absorbance at 588 and 510 nm but the response was almost stable at 460 nm. For higher doses, the change in the response was greater as compared to the low doses. Post-irradiation stability during diffused sunlight showed significant decrease in the response for higher dose at 588 and 510 nm and slower decrease in the response for lower dose at the above mentioned wavelengths. However the response was almost stable up to 97 days at 460 nm for higher and lower doses. At 4 deg C, the decrease in the absorbance was slower at 588 and 510 nm while the response was almost constant at 460 nm. At higher temperatures, such as 40 deg C, the decrease in the absorbance was greater at 588 and 510 nm while at 460 nm the absorbance was almost constant for about 3 months. (author)
[en] Highlights: • A Poly(deep eutectic solvent)@Biomass was prepared as a novel separation medium. • The Poly(DES)@BioMs effectively removed trace DNA toxic compounds. • The removal process was based on multi-physical interactions. • The removal process was investigated using equilibrium/kinetic models. • The removal mechanisms were explored using molecular simulations. DNA toxic compounds (DNA-T-Cs), even in trace amounts, seriously threaten human health and must be completely eliminated. However, the currently used separation media face great challenges in removing trace DNA-T-Cs. Based on the functional advantages of deep eutectic solvents (DESs) and the natural features of biomass (BioM), a series of Poly(DES)@BioMs functioning as adsorbents were prepared for the removal of aromatic/hetero-atomic DNA-T-Cs at the ppm level. After optimisation of experimental conditions, the removal efficiency for DNA-T-Cs ranged from 92.4% to 96.0% with an initial concentration of 20.0 ppm, a temperature of 30 °C, duration of 30 min, and pH of 7.0. The removal processes between the DNA-T-Cs and Poly(DES)@BioMs are well described in the Temkin equilibrium and second-order kinetic adsorption models, and the desorption processes are well shown in the Korsmeryer–Peppas equilibrium and zero-order kinetic models. Molecular simulations revealed that the removal interactions include hydrogen bonding, π–π stacking, and hydrophobic/hydrophilic effects. The removal efficiency for the DNA-T-Cs at 8.0 ppm in industrial sewage ranged from 69.7% to 102%, while the removal efficiency for the DNA-T-Cs standing alone at 20.0 ppm in a methyl violet drug solution was 95.4%, confirming that the Poly(DES)@BioMs effectively removed trace DNA-T-Cs in field samples.