Manipal University

About: Manipal University is a education organization based out in Manipal, Karnataka, India. It is known for research contribution in the topics: Population & Health care. The organization has 9525 authors who have published 11207 publications receiving 110687 citations.

Effect of Aluminium doping on photoluminescence and third-order nonlinear optical properties of nanostructured CdS thin films for photonic device applications

Abstract: The work presented here reports the influence of Aluminium (Al) doping on CdS thin films for the structural, morphological, optical and third-order nonlinear optical (NLO) properties. Thin films of Pure CdS and Al-doped CdS (Cd1-xAlxS) with x = 0, 0.01, 0.05 and 0.1 are prepared on the glass substrate at 350 °C using the spray pyrolysis technique. The observed X-Ray Diffraction (XRD) patterns of CdS films are found to a polycrystalline hexagonal structure and are not much affected by Al doping. Also the films have been examined by Field Emission Scanning Electron Microscopy (FESEM) images. The transmittance of the CdS films is observed to be 50–60% in the visible region and that decreased at higher doping concentrations and with higher Al doping the direct optical band gap is decreased from 2.52 to 2.38 eV. To understand the defect states characteristics, the corresponding room-temperature photoluminescence (RTPL) spectra have also been taken and found the nonlinear behavior in a band to band-edge emission in the prepared samples upon Al incorporation. The sign and the magnitude of the third-order NLO properties were determined using the Z-scan technique with a continuous wave laser as the excitation source. It is observed that the material exhibit strong two-photon absorption (2PA) with the nonlinear absorption (NLA) coefficient (β) in the range of 10−4 cmW−1 and nonlinear refractive index (NRI) n2 ∼10−9 cm2W−1. The third-order NLO susceptibility has found to be enhanced from 3.12 × 10−5 esu to 6.36 × 10−5 esu upon Al incorporation. Optical limiting characteristics of the prepared films are studied at the experimental wavelength. The results suggest that the Cd1-xAlxS is a promising material for nonlinear optical devices at 532 nm and optical power limiting applications.

Localized In Situ Nanoemulgel Drug Delivery System of Quercetin for Periodontitis: Development and Computational Simulations.

Abstract: This study was aimed at formulating a bioabsorbable, controlled-release, nanoemulgel of Quercetin, a potent antimicrobial and anti-inflammatory agent for the treatment of periodontitis that could improve its solubility and bioavailability. Screening of components was carried out based on the solubility studies. Nanoemulsion containing cinnamon oil as the oil phase, tween 80 and Carbitol® as the surfactant-cosurfactant mixture (Smix) and water as the aqueous phase containing 125 µg/200 µL of Quercetin was prepared by using spontaneous emulsification method. Nanoemulgel was prepared using 23% w/v poloxamer 407 as gel base. Comprehensive evaluation of the formulated nanoemulgel was carried out, and the optimized formulation was studied for drug release using Franz vertical diffusion cells. The formulated nanoemulgelexhibited a remarkable release of 92.4% of Quercetin at the end of 6 h, as compared to that of pure Quercetin-loaded gel (<3% release). The viscosity of the prepared nanoemulgel was found to be 30,647 ± 0.32 cPs at 37 °C. Also, molecular dynamics (MD) simulation was utilized to understand the gelation process and role of each component in the formulation. The present study revealed that the developed nanoemulgel of Quercetin could be a potential delivery system for clinical testing in periodontitis.

Synthesis,in Vitro Anticancer and Antioxidant Activity of Thiadiazole Substituted Thiazolidin-4-ones

Abstract: A series of novel 5-alkyl/aryl thiadiazole substituted thiazolidin-4-ones were synthesized by a two-step process. In the first step, 5-alkyl/aryl substituted 2-aminothiadiazoles were synthesized, which on reaction with substituted aromatic aldehydes and thioglycolic acid in the presence of dicyclohexylcarbodiimide afforded thiazolidin- 4-ones. All the compounds were synthesized in fairly good yields and their structures were confirmed by spectral and physical data. The title compounds were screened for in vitro anti-proliferative activity on human breast adenocarcinoma cells (MCF-7) by MTT assay. Most of the derivatives showed an IC₅₀ less than 150 μmol L⁻¹. Among the compounds tested, 2-(2-nitrophenyl)- 3-(5-methyl-1,3,4-thiadiazol-2-yl)-thiazolidin-4-one (3f), 2-(3-fluorophenyl)-3-(5-methyl-1,3,4-thiadiazol-2- -yl)-thiazolidin-4-one (3b), and 2-(4-chlorophenyl)-3- -(5-methyl-1,3,4-thiadiazol-2-yl)-thiazolidin-4-one (3c) were found to be the most active derivatives with IC50 values of 46.34, 66.84, and 60.71 μmol L⁻¹, respectively. Antioxidant studies of all the synthesized compounds were carried out by diphenylpicrylhydrazyl (DPPH) assay. Among the compounds tested, 2-phenyl-3-(5-styryl- -1,3,4-thiadiazol-2-yl)-thiazolidin-4-one (3s) elicited superior antioxidant activity with IC₅₀ of 161.93 μmol L⁻¹.