Krishna Pal Singh

Bio: Krishna Pal Singh is an academic researcher from G. B. Pant University of Agriculture and Technology. The author has contributed to research in topics: Medicine & Biosensor. The author has an hindex of 17, co-authored 58 publications receiving 1083 citations. Previous affiliations of Krishna Pal Singh include Chaudhary Charan Singh Haryana Agricultural University & Indian Institute of Technology Kanpur.

Preparation, characterization, and in vitro release study of albendazole-encapsulated nanosize liposomes

Abstract: The purpose of the present study was to formulate effective and controlled release albendazole liposomal formulations. Albendazole, a hydrophobic drug used for the treatment of hydatid cysts, was encapsulated in nanosize liposomes. Rapid evaporation method was used for the preparation of albendazole-encapsulated conventional and PEGylated liposomes consisting of egg phosphatidylcholine (PC) and cholesterol (CH) in the molar ratios of (6:4) and PC:CH: polyethylene glycol (PEG) (5:4:1), respectively. In this study, PEGylated and conventional liposomes containing albendazole were prepared and their characteristics, such as particle size, encapsulation efficiency, and in vitro drug release were investigated. The drug encapsulation efficiency of PEGylated and conventional liposomes was 81% and 72%, respectively. The biophysical characterization of both conventional and PEG-coated liposomes were done by transmission electron microscopy and UV-vis spectrophotometry. Efforts were made to study in vitro release of albendazole. The drug release rate showed decrease in albendazole release in descending order: free albendazole, albendazole-loaded conventional liposomes, and least with albendazole-loaded PEG-liposomes. Biologically relevant vesicles were prepared and in vitro release of liposome-entrapped albendazole was determined.

Variabilities in ozone at a semi‐urban site in the Indo‐Gangetic Plain region: Association with the meteorology and regional processes

Abstract: [1] The Indo-Gangetic Plain (IGP) region is one of the most densely populated regions in the World, but ground-based observations of air pollutants are highly limited in this region. Here, surface ozone observations made during March 2009–June 2011 at a semi-urban site (Pantnagar; 29.0°N, 79.5°E, 231 m amsl) in the IGP region are presented. Ozone mixing ratios show a daytime photochemical buildup with ozone levels sometimes as high as 100 ppbv. Seasonal variation in 24-h average ozone shows a distinct spring maximum (39.3 ± 18.9 ppbv in May) while daytime (1130–1630 h) average ozone shows an additional peak during autumn (48.7 ± 13.8 ppbv in November). The daytime, but not daily average, observed ozone seasonality is in agreement with the space-borne observations of OMI tropospheric column NO2, TES CO (681 hPa), surface ozone observations at a nearby high altitude site (Nainital) in the central Himalayas and to an extent with results from a global chemistry transport model (MATCH-MPIC). It is suggested that spring and autumn ozone maximum are mainly due to photochemistry, involving local pollutants and small-scale dynamical processes. Biomass burning activity over the northern Indian region could act as an additional source of ozone precursors during spring. The seasonal ozone photochemical buildup is estimated to be 32–41 ppbv during spring and autumn and 9–14 ppbv during August–September. A correlation analysis between ozone levels at Pantnagar and Nainital along with the mixing depth data suggests that emissions and photochemical processes in the IGP region influence the air quality of pristine Himalayan region, particularly during midday hours of spring. The evening rate of change (8.5 ppbv hr−1) is higher than the morning rate of change, which is dissimilar to those at other urban or rural sites. Ozone seasonality over the IGP region is different than that over southern India. Results from the MATCH-MPIC model capture observed ozone seasonality but overestimate ozone levels. Model simulated daytime ratios of H2O2/HNO3 are higher and suggesting that this region is in a NOx-limited regime. A chemical box model (NACR Master Mechanism) is used to further corroborate this using a set of sensitivity simulations, and to estimate the integrated net ozone production in a day (72.9 ppbv) at this site.

Variability in Indian isolates of Sclerotium rolfsii

Abstract: Variability among 26 isolates of Sclerotium rolfsii collected from various hosts/soil samples and localities in India is reported. The isolates varied in colony morphology, mycelial growth rate, sclerotium formation, teleomorph production and sclerotial size and color. Out of 26 isolates, only 4 produced the teleomorph stage on Cyperus rotundus rhizome meal agar medium. Mycelial incompatibility among the isolates was also seen, and out of 325 combinations, only 29 combinations (8.9%) showed compatible reactions. Based on mycelial compatibility, 13 vegetative incompatibility groups (VCG) were identified among the isolates. HPLC analysis of the ethyl acetate fraction of culture filtrates of the isolates revealed 10-22 peaks. Six peaks were identified as gallic, oxalic, ferulic, indole-3-acetic acid (IAA), chlorogenic, and cinnamic acids. Oxalic, IAA, and cinnamic acids were present in the culture filtrates of all the isolates in varying amounts. The other three phenolic acids were not detected in some of the isolates. A comparative HPLC analysis of sclerotial exudate, sclerotia, mycelia, and culture filtrates of two S. rolfsii isolates (leaf spot- and collar rot-causing) producing different symptoms on their respective hosts revealed variation in the content of phenolic acids, IAA, and oxalic acid.

Global Distribution and Trends of Tropospheric Ozone: An Observation-Based Review

Abstract: Tropospheric ozone plays a major role in Earth’s atmospheric chemistry processes and also acts as an air pollutant and greenhouse gas. Due to its short lifetime, and dependence on sunlight and precursor emissions from natural and anthropogenic sources, tropospheric ozone’s abundance is highly variable in space and time on seasonal, interannual and decadal time-scales. Recent, and sometimes rapid, changes in observed ozone mixing ratios and ozone precursor emissions inspired us to produce this up-to-date overview of tropospheric ozone’s global distribution and trends. Much of the text is a synthesis of in situ and remotely sensed ozone observations reported in the peer-reviewed literature, but we also include some new and extended analyses using well-known and referenced datasets to draw connections between ozone trends and distributions in different regions of the world. In addition, we provide a brief evaluation of the accuracy of rural or remote surface ozone trends calculated by three state-of-the-science chemistry-climate models, the tools used by scientists to fill the gaps in our knowledge of global tropospheric ozone distribution and trends.

Molecular imprinting science and technology: a survey of the literature for the years 2004-2011.

Abstract: Herein, we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004-2011. In total, 3779 references to the original papers, rev ...

Controlled Intracellular Release of Doxorubicin in Multidrug-Resistant Cancer Cells by Tuning the Shell-Pore Sizes of Mesoporous Silica Nanoparticles

Abstract: In this work, hollow mesoporous silica nanoparticles (HMSNs) with three pore sizes were manufactured to control the drug release rate, and the biological roles of these HMSNs were evaluated in multidrug-resistant (MDR) cancer cells. As novel pore-size-controllable inorganic materials, HMSNs showed negligible cytotoxicity and efficient cellular uptake toward drug-sensitive MCF-7 and drug-resistant MCF-7/ADR cells. Doxorubicin (DOX)-loaded HMSNs (DMSNs) not only demonstrated effective drug loading and a pH-responsive drug release character but also exhibited pore-size-dependent and sustained drug release performance in both in vitro and intracellular drug release experiments. In addition, DMSNs exhibited pore-size-dependent anticancer activity against MCF-7/ADR cells. DMSNs with larger pore size could mediate more cellular uptake of DOX and faster intracellular drug release, which led to more intracellular drug accumulation and stronger MDR-reversal effects. The MDR-overcoming mechanism could be due to the efficient cellular uptake, P-gp inhibition, and ATP depletion. These results demonstrate that HMSNs could be a very promising drug delivery system for pore-size-controllable drug release and cancer MDR reversion.