Kinetic and Computational Study of Degradation of Two Azo Dyes, Metanil Yellow and Orange II, by Iron Oxide Nanoparticles Synthesized Using Hylocereus undatus.

Wastewater treatment is an unavoidable necessity and requires immediate action with the aim of saving future generations from water crises and ensuring the sustainability of clean and drinkable water. In the present work, green synthesis of iron oxide nanoparticles (IONPs) was carried out from fruit extract of Hylocereus undatus to observe its photocatalytic activity towards two azo dyes, namely, Metanil yellow and Orange II dye. IONPs served as an efficient photocatalyst for the degradation of Metanil yellow dye, and the reaction followed pseudo-first-order kinetics. The effect of the initial dye concentration, amount of photocatalyst added, and effect of pH on photocatalytic degradation of Metanil yellow and Orange II dye using IONPs was studied. The results were compiled to reveal the most effective conditions for degradation to occur. A computational study of two dyes using DFT (Density Functional Theory) calculations were also performed to calculate thermodynamic properties such as the free energy, dipole moment, HOMO-LUMO energy gap, chemical potential, global hardness, softness, global electrophilicity index, ionization potential, electron affinity, etc. These parameters were used to describe the reactivity of dye toward the active photocatalytic species responsible for the degradation of dye. Natural population analysis was also performed, and Fukui indices were also calculated to explain the possible attacking sites of dyes by active photocatalytic species.

Multi-use of single use unims: Does economic burden outweigh contamination risk?

Aim: To assess if residual drops of unims can be used after single use to cut down economic load. Setting: Laboratory setting. Materials and Methods: This study was done to determine the possibility of multi-use of such unims. Ten unims of Acuvail (ketorolac tromethamine 0.45%) were opened simultaneously to culture a single drop from each unim daily for 7 days and growth was studied at 24 h (group 1); a similar study was done taking extra aseptic precautions (group 2), and with another set of 10 unims, with one drop twice a day for 3 days (group 3). Results: 20% unims showed growth on the 1st day and 60% on the 6th day. The growth consisted of Staphylococcus aureus. No growth was found in the second part of the study. Two drops per day arm showed incremental growth from the 3 rd dose (2 nd day). Conclusion: Even though unims contain more than one drop, patients should be strictly instructed for single use of such vials because there is potential risk of transmitting pathogens and a serious threat to post-cataract surgery patients.

Eumycetoma versus actinomycetoma: Diagnosis on cytology.

Eumycetoma is a chronic cutaneous and subcutaneous infection caused by various genera of fungi producing specific colored granules known as grains. A 45-year-old farmer presented clinically with a left foot mass with multiple discharging sinuses existing for last 3 years. Clinical and radiological findings suggested a diagnosis of chronic osteomyelitis with suspicion of tuberculosis. Imprints plus fine needle aspiration cytology (FNAC) smears exhibited distinct brown-black colonies of a fungus having branching and septate hyphae embedded in matrix like material against a mixed inflammatory background. Periodic acid Schiff (PAS) stain gave positive staining and subsequent fungal culture confirmed the cytological diagnosis and aided in species identification as Madurella mycetomatis. Thus, eumycetoma can precisely be diagnosed and confidently differentiated from similar conditions such as actinomycetoma by simple and inexpensive cytological techniques such as FNAC and imprint smears, employing routine May-Grünwald-Giemsa, Papanicolaou and simple PAS stains on cytological specimen, thus leading to rapid diagnosis for institution of correct treatment.