Solvent effects on the dipole moments and photo physical properties of laser dye

The absorption and emission spectra of fluorescent laser dye namely, 4,4”’-bis-2-butyyloctyl-oxy)-P-quaterphenyl have been recorded at room temperature in solvents of different polarities. The exited state dipole moments (µe) have been estimated from Lippert’s, Bakhshiev’s and Kawski-Chamma-Viallet’s equations using the variation of Stoke’s shift with the solvent dielectric constant and refractive index. The geometry of the molecule has been fully optimized and the µg has also been calculated theoretically by Gaussian 03 software using B3LYP/6-31g* level of theory. The µg and µe have been calculated by means of solvatochromic shift method. It has been observed that µe is higher than µg, indicating a substantial redistribution of the π-electron densities in a more polar excited state for the selected laser dye. Further, the changes in the dipole moment (µ) has been calculated both from solvatochromic shift method and microscopic empirical solvent polarity parameter (E) and values are compared.

Interaction of water molecules in non-identical protein structures

The interaction of the protein atoms with the surrounding water oxygen atoms has been computed for 392 protein chains from 369 protein structures belonging to 90% non-homologous high resolution (<= 1.5 angstrom) protein Structures with a crystallographic R-factor <= 20%. The percentage composition of the polar atoms is found to be 36.3%. An average of 82.55% of water oxygen atoms are found to be in the primary hydration shell and 15.12% in the secondary hydration shell. The average Percentage of interactions of water oxygen atoms with the polar atoms of the main chain and side chain are 54% and 46%. respectively. The interaction of the acidic residues, aspartate and glutamate, with the water oxygen atoms is more when compared to that of the other residues

Solvent effects on the dipole moments and photo physical properties of laser dye

749-754The absorption and emission spectra of fluorescent laser dye namely, 4,4”’-bis-2-butyyloctyl-oxy)-P-quaterphenyl have been recorded at room temperature in solvents of different polarities. The exited state dipole moments (µe) have been estimated from Lippert’s, Bakhshiev’s and Kawski-Chamma-Viallet’s equations using the variation of Stoke’s shift with the solvent dielectric constant and refractive index. The geometry of the molecule has been fully optimized and the µg has also been calculated theoretically by Gaussian 03 software using B3LYP/6-31g* level of theory. The µg and µe have been calculated by means of solvatochromic shift method. It has been observed that µe is higher than µg, indicating a substantial redistribution of the π-electron densities in a more polar excited state for the selected laser dye. Further, the changes in the dipole moment (µ) has been calculated both from solvatochromic shift method and microscopic empirical solvent polarity parameter (E) and values are compared.

COVID-19: Understanding the Pandemic Emergence, Impact and Infection Prevalence Worldwide

Coronavirus disease (COVID-19) has showed high transmission across the continents due to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) with total infected cases of around ~ 44 million people. This communicable virus that initiated from the Wuhan city of China in the month of December 2020 has now spread to 189 different countries with 1.1 million fatalities worldwide (till 28 Oct, 2020). The World Health Organization (WHO) declared this outbreak as Public Health Emergency of International Concern in January, 2020. The infection spreads mainly due to contact with infected droplets or fomites, highlighting flu like symptoms initially, which may further progress into severe pneumonia and respiratory failure, often observed in elderly patients with prehistory of other diseases. The diagnosis is based on detection of viral antigen, human antibody and viral gene (RT-PCR). Further, various other diagnostic tools including X-ray, CT-scan are used for imaging purpose, recently artificial intelligence based imaging (contactless scanning) gained popularity. Generally testing of existing drugs (repurposing) and development of new molecules are the main strategies adopted by researchers. However, as per initial findings, various drugs, monoclonal antibody and plasma therapy were found to show effectiveness against COVID-19. Further, many vaccine candidates have entered or will soon enter phase III clinical testing. This disease has further challenged the global economy. Thus, this review uniquely compares the strategies adopted by developed and developing countries worldwide including protective measures like lockdown, continuous testing, utilizing latest tools (artificial intelligence) in curbing this infection spread