Risk assessment of arsenic in ground water of Larkana city

Water is an essential component for the survival of humans and animals. Due to industrialization, water is being contaminated with varying polluting agents, arsenic (As) contamination is one of them. An exclusive study was carried out for the determination of As in groundwater of Larkana city using microwave-assisted digestion followed by atomic absorption spectrometry (AAS). For that purpose, a total of 110 groundwater samples were collected from 10 union councils (UCs) of the city based on global position system (GPS) method. Results revealed that maximum concentration of As was found 17.0 μg/L in UC-6, while in UC-1, UC-2 and UC-10 the concentration of As was found within the permissible limits of WHO. The minimum and maximum mean concentration of As was found 3.59 μg/L and 6.78 μg/L, respectively. Out of 110 ground water samples of Larkana city, 13 samples were found above the permissible limits (~12% of total samples). Hence, water can be used for drinking purpose with caution

Structural dynamics and anti-biofilm screening of novel imidazole derivative to explore their anti-biofilm inhibition mechanism against <i>Pseudomonas Aeruginosa</i>

The biofilm formation is still prevalent mechanism of developing the drug resistance in the Pseudomonas aeruginosa, gram-negative bacteria, known for its major role in nosocomial, ventilator-associated pneumonia (VAP), lung infections and catheter-associated urinary tract infections. As best of our knowledge, current study first time reports the most potent inhibitors of LasR, a transcriptional activator of biofilm and virulence regulating genes in, Pseudomonas aeruginosa LasR, utilizing newly functionalized imidazoles (5a-d), synthesized via 1,3-dipolar cycloaddition using click approach. The synthesized ligands were characterized through Mass Spectrometry and 1H NMR. The binding potency and mode of biding of ligands. Quantum Mechanical(QM) methods were utilized to investigate the electronic basis, HOMO/LUMO and dipole moment of the geometry of the ligands for their binding potency. Dynamics cross correlation matrix (DCCMs) and protein surface analysis were further utilized to explore the structural dynamics of the protein. Free energy of binding of ligands and protein were further estimated using Molecular Mechanical Energies with the Poisson–Boltzmann surface area (MMPBSA) method. Molecular Docking studies revealed significant negative binding energies (5a − 10.33, 5b −10.09, 5c − 10.11, and 5d −8.33 KJ/mol). HOMO/LUMO and potential energy surface map estimation showed the ligands(5a) with lower energy gaps and larger dipole moments had relatively larger binding potency. The significant change in the structural dynamics of LasR protein due to complex formation with newlyfunctionalized imidazoles ligands. Hydrogen bond surface analysis followed by MMPBSA calculations of free energy of binding further complemented the Molecular docking revelations showing the specifically ligand (5a) having the relatively higher energy of binding(-65.22kj/mol). Communicated by Ramaswamy H. Sarma</p