Comparison of three models to estimate the slant path atmospheric attenuation in central receiver solar thermal plants under Indian climatic conditions

This paper compares three attenuation models for the distinct meteorological conditions of India and assesses the feasibility of using the satellite data to calculate the slant path extinction coefficient and the slant path transmissivity of the lower atmosphere. The attenuation models are compared for the sites of Pune, Kanpur, and Jaipur. The AERONET data is used with REST2 to model the direct normal irradiance and the total optical depth. The results indicate that the three models give similar transmissivity values for low aerosol concentrations. As the aerosol concentrations increase, the difference in the slant path transmissivity as calculated by two of the models increases with respect to the third reference model. The slant path transmissivity comparison shows that for AERONET AOD at 550 nm (AOD550) less than 0.3, the relative error in the transmissivity values estimated by two of the compared models with respect to the third model is not higher than 10 % for Pune, 18 % for Kanpur, and 12 % for Jaipur. The mean relative error in the slant path transmissivity values obtained from the reference model using MODIS data with respect to the values obtained using AERONET data is 4.8 %, 10.2 %, and 9.2 % for Pune, Kanpur, and Jaipur, respectively. A difference of 0.2 between AERONET AOD550 and MODIS AOD550 values resulted in a difference of 0.05–0.08 between the transmissivity values calculated by the reference model using AERONET AOD550 and using MODIS AOD550 for the three sites

Inhibitory effects of isatin Mannich bases on carbonic anhydrases, acetylcholinesterase, and butyrylcholinesterase

The effects of isatin Mannich bases incorporating (1-[piperidin-1-yl (P1)/morpholin-4-yl (P2)/N-methylpiperazin-1-yl (P3)]methyl)-1H-indole-2,3-dione) moieties against human (h) carbonic anhydrase (CA, EC 4.2.1.1) isoenzymes hCA I and hCA II, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) enzymes were evaluated. P1-P3 demonstrated impressive inhibition profiles against AChE and BChE and also inhibited both CAs at nanomolar level. These inhibitory effects were more powerful in all cases than the reference compounds used for all these enzymes. This study suggests that isatin Mannich bases P1-P3 are good candidate compounds especially for the development of new cholinesterase inhibitors since they were 2.2-5.9 times better inhibitors than clinically used drug Tacrine

Functionalized Benzimidazole Scaffolds: Privileged Heterocycle for Drug Design in Therapeutic Medicine

Benzimidazole derivatives are crucial structural scaffolds found in diverse libraries of biologically active compounds which are therapeutically useful agents in drug discovery and medicinal research. They are structural isosteres of naturally occurring nucleotides, which allows them to interact with the biopolymers of living systems. Hence, there is a need to couple the latest information with the earlier documentations to understand the current status of the benzimidazole nucleus in medicinal chemistry research. This present work unveils the benzimidazole core as a multifunctional nucleus that serves as a resourceful tool of information for synthetic modifications of old existing candidates in order to tackle drug resistance bottlenecks in therapeutic medicine. This manuscript deals with the recent advances in the synthesis of benzimidazole derivatives, the widespread biological activities as well as pharmacokinetic reports. These present them as a toolbox for fighting infectious diseases and also make them excellent candidates for future drug design