Nanoisozymes: Crystal‐Facet‐Dependent Enzyme‐Mimetic Activity of V2O5 Nanomaterials

Nanomaterials with enzyme‐like activity (nanozymes) attract significant interest owing to their applications in biomedical research. Particularly, redox nanozymes that exhibit glutathione peroxidase (GPx)‐like activity play important roles in cellular signaling by controlling the hydrogen peroxide (H₂O₂) level. Herein we report, for the first time, that the redox properties and GPx‐like activity of V₂O₅ nanozyme depends not only on the size and morphology, but also on the crystal facets exposed on the surface within the same crystal system of the nanomaterials. These results suggest that the surface of the nanomaterials can be engineered to fine‐tune their redox properties to act as “nanoisozymes” for specific biological applications.     

Anomalies in quantitative measurement of 40K in natural samples

Journal of Radioanalytical and Nuclear Chemistry - Efficiency calibration by standard materials of known activity is usual protocol for γ-ray spectrometry. In general, 40K activity is measured...     

Estimation of radiological indices in Indian Sundarbans: a mangrove habitat

Stereoscopic porous microspheres based gellan gum (GG–Ca) were successfully prepared by sol–gel method using ethyl acetate as porogen and glutaraldehyde as crosslinker. The obtained GG–Ca microspheres were mainly of mesoporous with the average pore diameter was about 4 nm. It displayed a higher ability for uranium removal. In addition, the uranium adsorption process was endothermic and spontaneous following a pseudo-second-order and the adsorption isotherm was the best fit with the Freundlich model with maximum uranium capacity of 202.26 mg g⁻¹. The UO²⁺ adsorption mechanism is ion-exchange with Ca²⁺ based on SEM, EDX and XPS data analysis.

     

Quantitative estimation of total potassium and 40K in surface soil samples of Indian Sundarbans

The present study attempts to quantitatively estimate total potassium content in soil samples collected from different areas of Indian Sundarbans by gamma-spectrometry, exploiting the radiogenic properties of potassium and by wavelength dispersive X-ray fluorescence technique. The elemental K concentration varied in between 2.08 ± 0.05 and 3.46 ± 0.06% in the soil samples. Besides estimation of total potassium, the activity of ⁴⁰K was also estimated in the same soil samples and found to be in the range of 532 ± 8.9 to 1043 ± 13.2 Bq kg⁻¹.