Table of Contents - Volume 19 Number 1

The nitrogen containing heterocyclic compounds play a very important role in defining their biological and pharmacological properties. Two such important compounds having known crystal structure, viz. 5-Methoxy-1H-benzo[d]imidazole-2(3H)-thione (M1) and 4, 5- Dimethylbenzimidazolene-2-thione (M2), have been investigated for their optimal molecular geometry, atomic Mulliken charges, molecule electrostatic potential, HOMO (highest occupied molecular orbital)-LUMO (lowest unoccupied molecular orbital), and associated molecular characteristics using DFT (density functional theory). The optimized geometry of (M1) and (M2), slightly deviates from the X-ray structure. The N-H...S and N-H...O hydrogen bonding contribute to the Hirshfeld surface in the molecular structure M1 [24.2 % and 7.1 % of the overall contribution, respectively] while the N-H...S hydrogen bonding contribution is 25.4% in M2. The crystal void analysis has also been reported, besides the energy frameworks built using distinct intermolecular interaction energies. The computational antibacterial activity of both structures has been analyzed in silico with Staphylococcus epidermidis bacterial protein (PDB ID: 4EJV). The results indicate that M1 and M2 possess higher binding energy with more interactions as compared to the standard drug chloramphenicol with receptor complex and this observation leads us to the state that these two derivatives could be the potential candidates for the antibacterial drug development process.

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Silver nanoparticles have been shown to increase postnatal toxicity in breastfeeding female rats, with negative consequences for their offspring. We wanted to investigate more about the differences in toxicity between silver nitrate and silver nanoparticles, as well as the impact of zinc chloride treatment on the silver nitrate induced toxicity on female albino rats. For 21 days, 30 breastfeeding female albino rats were divided into 4 groups; the first three group received orally 0, 50,100 mg/kg of silver nitrate. While the fourth group received 100 mg/kg of silver nitrate plus 300 ppm of zinc chloride in drinking water and fifth group received only AG-NPs at dose of 100 ppm.  The results demonstrated that silver nitrate were more hazardous than nano-silver, as evidenced by higher free radical release, increased MDA levels, and decreased antioxidant enzyme levels (SOD). In addition, the silver ions-treated group had higher levels of liver enzymes and creatinine.

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This study was focused on evaluation of conducting and tensile properties of rGO/ Polybutylene adipate terephthalate (PBAT) nanocomposite intended to use in electronic applications which require biodegradability. This study was also considered to be worthwhile since very little work has been done in this regard so far. PBAT was specifically selected for the study as it is an extensively used biodegradable polymer for variety of applications. The solvent casting method was employed to prepare rGO/PBAT nanocomposites where rGO was dispersed in a solution of PBAT by ultrasonication followed by evaporation of the solvent components. Electrical conductivity (σ) of rGO/PBAT nanocomposites showed a percolation behavior as rGO content was increased from 0.5 % to 1.5 %(σ increased drastically with the increase of rGO content). The percolation threshold was approximately 0.0045, (i.e., 0.75 w/w % of rGO). The average critical exponent (t) related to the percolation theory was 1.49 ± 0.19 which is well within the expected range 1< t < 2. According to impedance studies, the electrical impedance of GO/PBAT composites decreased with the increasing rGO content, which agreed well with the behavior of the electrical conductivity investigated previously. The same equivalent circuit was shown by each composite except the values for constant phase element CPE and resistor R; the equivalent electrical circuit was a parallel combination of CPE and R.  The dielectric analysis of the composites indicated that dielectric parameters ϵ”, ϵ’ and dissipation factor increased significantly with increasing rGO content. The tensile strength of the composites was better than that of neat PBAT up to 1.5 % of rGO loading and decreased on further increasing of rGO. However, their tensile strain at break decreased with increasing rGO content. The results indicated that PBAT/rGO polymer composite is promising candidate for various electronic applications.

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A high-quality, single-crystal ZnO nanorod thin film was successfully deposited onto p-type monocrystalline silicon (P-Si) substrates using an RF sputtering technique. An XRD analysis of ZnO nanorods was carried out to investigate crystallinity and aspect ratio of the deposited thin film. Adjusting deposition conditions makes it possible to grow single-crystalline ZnO nanorods with preferred orientations (002) on the substrate. More than the substrate type, crystal size is determined by single-crystal growth conditions. These sample had the exact. With the exception of a small variance at Raman shifts 414 cm-1, which correspond to E2. Raman spectra measurements with a slight variation at Raman shifts 414 cm-1, corresponding to E2 (high). In response to the compressive stress, the peak shifts upwards (blue dress). Data from FE-SEM shows vertical growth of hexagonal prism. Finally, the hall effect measurement and UV-vis spectroscopy were carried out the electrical and optical properties of the sample respectively.

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Thermal modification or heat treatment was performed on the samples of Toonaciliataat various temperatures (80°C, 120°C, 160°C, 200°C) and durations (2h, 4h, and 6h) which revealed that chemical and mechanical properties of the wood improved at particular temperature with certain time duration. These results suggest that thermal treatment considerably improves wood properties like dimensional stability and durability. Vacuumoven was used to assess the process of thermal modification and different procedures were used to study the chemicaland mechanical properties of Toona wood. In chemical properties the maximum value of holocellulose content (71.73%) and lignin content (27.52%), were observed at 200°C. While, the minimum value of holocellulose content (61.29%) and lignin content (24.42%), were found to be at 200°C and at control, respectively. In mechanical properties the maximum value of tensile strength (0.072), bending strength 0.022), compression parallel to the grain (0.052) and compression perpendicular (0.039) to the grain was observed at 120°C. Whereas, the minimum tensile strength (0.039), bending strength (0.008), compression parallel (0,041) the grain and perpendicular (0.027) to the grain was found at 200°C.All the chemical and mechanical properties of Toona wood improved after heat treatment at particular temperature and duration.

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