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Showing 2 results for Aghamaali
Volume 10, Issue 1 (Winter 2019)
Abstract
The fruit of has a lot of acidic proteases and its extract has been used in cheese manufacturing. However, there are few studies about purification and characterization of this enzyme. must be satisfied for the enzyme to be used in industry: 1- stability of enzymes against metal ions and 2- Ability to sustain proper function and stability in the absence of metal ion. Accordingly, in this investigation, the effect of various ions different concentrations activity, stability and somewhat on structural properties of the purified protease were studied. Based on the results, it was shown that the enzyme was relatively stable against NaCl and CaCl2, but by increment of these salts, stability and activity of enzyme . Also, the enzyme was stable against low concentration of various metal ions and only Hg2+ reduces enzyme stability and activity. By studying the role of 2+ of , it was found that 2+ have any role in thermal stability of enzyme at 67˚C. Likewise, by observing the effect of metal ions on of it was that all tested ions increased intensity of emission and caused to shift toward lower wave length. In all, of these showed that the purified enzyme from bad is very stable against various metal heavy metals and it is favorable for industrial application.
Volume 15, Issue 3 (6-2024)
Abstract
Magnetic nanoparticles (MNPs) have emerged as contrast agents in magnetic resonance imaging (MRI) and metal-organic frameworks (MOFs) due to their high porosity and adjustable structure, serving as drug carriers and new contrast agents in biomedicine. Designing efficient nanoplatforms that leverage the combined properties of both MNPs and MOFs is of great importance.
In this study, we introduce a simple in-situ synthesis method for a mesopore core-shell nanocomposite structure of MOF@Cu-ferrite. Initially, Cu-ferrite nanoparticles were synthesized using a hydrothermal method. Subsequently, the addition of fumaric acid to the Cu-ferrite nanoparticles activated the F0 component, inducing MOF nucleation. As a result, the Cu-ferrite core was gradually covered with a crystalline MOF shell, forming the MOF@Cu-ferrite structure. The MOF@Cu-ferrite nanocomposite is characterized by high porosity, numerous accessible surface functional sites, good crystalline stability, low toxicity of copper, excellent water dispersion, high magnetic properties, and cost-effectiveness. This study investigates the effect of the MOF@Cu-ferrite nanocomposite on the MRI signal intensity. T2-weighted images were obtained using MRI scanner at various iron concentrations of the magnetic nanocomposite, showing a significant change in signal intensity with increasing iron concentration. The transverse relaxivity rate (r2) for different iron concentrations was found to be 504.7 mM-1s-1. The results showed that Cu-ferrite magnetic nanoparticles coated with MOF have significant potential as negative contrast agents in MRI, reducing T2 relaxation time and improve contrast intensity in MR images.
