4,055 research outputs found
Standardization of a traditional polyherbo-mineral formulation Brahmi vati
The present study deals with standardization of an in-house standard preparation and three marketed samples of Brahmi vati, which is a traditional medicine known to be effective in mental disorders, convulsions, weak memory, high fever and hysteria. Preparation and standardization have been done by following modern scientific quality control proceduresfor raw material and the finished products. The scanning electron microscopic (SEM) analysis showed the reduction of metals and minerals (particle size range 2-5 ìm) which indicates the proper preparation of bhasmas, the important ingredient of Brahmi vati. Findings of EDX analysis of all samples of Brahmi vati suggested the absence of Gold, an importantconstituent of Brahmi vati in two marketed samples. All the samples of Brahmi vati were subjected to quantitative estimation of Bacoside A (marker compound) by HPTLC technique. Extraction of the samples was done in methanol and the chromatograms were developed in Butanol: Glacial acetic acid: water (4.5:0.5:5 v/v) and detected at 225nm. The regression analysis of calibration plots of Bacoside A exhibited linear relationship in the concentration range of 50-300 ng, while the %recovery was found to be 96.06% w/w, thus proving the accuracy and precision of the analysis. The Bacoside A content in the in-house preparation was found to be higher than that of the commercial samples. The proposed HPTLC method was found to be rapid, simple and accurate for quantitative estimation of Bacoside A in different formulations. The results of this study could be used as a model data in the standardization of Brahmi vati.Keywords: Brahmi vati( BV); Standardization; EDX; HPTLC; Bacoside-
Herbal Cosmeceuticals for Photoprotection from Ultraviolet B Radiation: A Review
Ultraviolet B (UVB) rays vary with time and season and are the major cause of sunburns. Sunburned skin is a leading risk factor for melanoma and non-melanoma skin cancers. Protection against exposure to UVB rays may be achieved by a combination of various approaches such as use of broad spectrum sunscreen formulations. UV radiations (UVR) absorbed by the skin surface can produce harmful compounds called free radicals or reactive oxygen species (ROS), which can cause skin cancer and premature aging. To reduce ROS generation and damage, researchers recommend using sunscreen to protect the skin from harmful UVR. The realm of possibilities in photoprotection may include the development of sunscreens which remain at the surface of the skin for a longer time and may incorporate antioxidants that can neutralize ROS. By quenching free radicals, antioxidants may aid photoprotection effect. This review focuses on photoprotection from UVB radiation and discusses potential herbal candidates with antioxidant properties that can serve as a strong barrier in cosmeceuticals to protect skin against harmful UVB rays.Keywords: Cosmeceutials; Herbs; Reactive oxygen species (ROS); Photoprotection; Antioxidant activity; Ultraviolet radiation
DESIGN AND ANTIINFLAMATORY ACTIVITY OF SOME NOVEL OXADIAZOLE DERIVATIVES – AN OVERVIEW
Oxadiazole derivates play vital role in biological field suchas anti-microbial, anti-viral, anti-tubercular, antiinflammatoryand anti-convulsant activity. Therapeuticsignificance of these clinically useful drugs in treatment ofinflammation encouraged the development of some morepotent and significant compounds. oxadiazole derivativesare remarkably effective compounds for inflammation andanalgesic activity. Extensive biochemical andpharmacological studies have confirmed that thesemolecules are effective in inflammation. Thiscomprehensive overview summarizes the chemistry ofdifferent derivatives of substitute
Mechanistic insights into the Cu(I) oxide-catalyzed conversion of CO2 to fuels and chemicals: A DFT approach
Periodic, self-consistent, density functional theory calculations with corrections via a Hubbard U parameter, and inclusion of dispersive forces (DFT-D2), have been employed to study CO2 activation and conversion on the Cu2O (1 1 1) surface. CO2 hydrogenation on the Cu2O (1 1 1) surface was investigated systematically, and the respective microscopic reaction mechanisms were elucidated. We show that, whereas CO2 dissociation is not energetically allowed on the Cu2O (1 1 1) surface, CO2 hydrogenation to a formate intermediate is more favourable than the formation of a carboxyl intermediate. Further hydrogenation from formate to formic acid is energetically allowed, where formate combines with strongly adsorbed surface hydrogen to form bidentate formic acid moieties. Formation of both the formate and the formic acid from adsorbed CO2 and surface hydrogen are exothermic reactions
Understanding the Persistence of Caste: A Commentary on Cotterill, Sidanius, Bhardwaj and Kumar (2014)
We contextualise Cotterill, Sidanius, Bhardwaj, and Kumar’s (2014) paper within a broader literature on caste and collective mobilisation. Cotterill and colleagues’ paper represents a fresh and timely attempt to make sense of the persistence of caste from the perspective of Social Dominance Theory. Cotterill and colleagues, however, do not examine caste differences in the endorsement of karma, and take behavioural asymmetry among lower castes for granted. Cotterill and colleagues also adhere to a Varna model of the caste system that arguably is simplistic and benefits the upper castes of Indian society. We caution that emphasising behavioural asymmetry and endorsing the Varna model might further stigmatise lower castes, especially Dalits, and feed into a conformity bias already predominant in caste-related psychological research. We argue that the conceptualisation and operationalisation of Right-Wing Authoritarianism, Social Dominance Orientation and legitimising myths in the Indian context needs to take into account the particular meaning and functions of these constructs in specific intergroup contexts, and for identity positions salient within these contexts. We contend that any examination aimed at better understanding the nature of social hierarchy and oppression within the caste system and Indian society in general remains inconclusive without including a focus on the construction and contestation of social categories and social identities
A study of rainfall along the west coast of India in relation to low level jet and air-sea interactions over the Arabian Sea
Indian summer monsoon has a large inter-annual as well as intra-seasonal variability over temporal and spatial scales. Onset dates, monsoon activity within a monsoon season and quantity of monsoon rainfall are also found to vary from year to year. One important synoptic feature associated with the onset of monsoon is the existence of a strong cross equatorial low level jet (LLJ), with its core around 850 hPa over the Indian Ocean and South Asia. This LLJ generally supports the large-scale moisture and momentum transport from ocean to atmosphere and the consequent rainfall over the Indian mainland. In the present study, buoy data at a stationary position in the Arabian Sea (15.5°N, 61.5°E) have been used to understand the air-sea interface processes before, during and after the onset of monsoon 1995
A simple and efficient method for extraction of genomic DNA from tropical tuber crops
DNA extraction in many plants is difficult because of metabolites that interfere with DNA isolation procedures and subsequent applications, such as DNA restriction, amplification and cloning. We havedeveloped a reliable and efficient method for isolating genomic DNA free from polysaccharide, polyphenols and protein contaminants from tropical tuber crops (Elephant foot yam, Cassava, Sweetpotato Taro and Tannia). The method involves inactivation of contaminant proteins by using CTAB/Proteinase K and precipitation of polysaccharides in the presence of high concentration of salt.The purity of genomic DNA was confirmed by A260/280 and A260/230 ratios calculated from the spectrophotometric readings and further by restriction analysis of the isolated DNA using restriction enzymes EcoRI and Hind III. The described protocol also resulted in the isolation of sufficiently higher yield of DNA from leaf sample of tropical tuber crops. The new protocol can be successfully used forboth small and large scale preparation of genomic DNA from leaf tissues of tuber crops which is highly suitable for further down stream processes like PCR amplification and restriction digestion analysis
Comparative study of EVA-Cloisite® 20A and heat-treated EVA-Cloisite® 20A on heavy-metal adsorption properties
Ethylene vinyl acetate (EVA)/ Cloisite® 20A (C20A) composite fabricated via the melt-blending method was used for the development of a heavy-metal adsorbent through acid and heat treatment. Heat-treated composites were produced at 400°C to 1 000°C in air and N2 atmospheres. The materials were characterised through TGA, FT-IR, contact angle and Zetasizer. Treating EVA/C20A composites with H2SO4 at 130°C reduced the contact angle from 99.73° to 30.40°. The acid-functionalised composite was tested for the removal of Pb2+ and an adsorption capacity of 49 mg·g-1 was recorded while the heat-treated composite exhibited an adsorption capacity of 153 mg·g-1
CuO Surfaces and CO2 Activation: A Dispersion-Corrected DFT+U Study
We have used computational methodology based on the density functional theory to describe both copper(I) and copper(II) oxides, followed by the investigation of a number of different low index CuO surfaces. Different magnetic orderings of all the surfaces were studied and reconstructions of the polar surfaces are proposed. A detailed discussion on stabilities, electronic structure and magnetic properties is presented. CuO(111) and CuO(-111) were found to have the lowest surface energies and their planes dominate in the calculated Wulff morphology of the CuO crystal. We next investigated the
adsorption of CO2 on the three most exposed CuO surfaces, viz. (111), (-111) and (011) by exploring various adsorption sites and configurations. We show that the CO2 molecule is activated on the CuO surfaces, with an adsorption energy of -93 kJ/mol on the (011) surface, showing exothermic adsorption, while (111) and (-111) surfaces show comparatively weak adsorption. The activation of the CO2 molecule is characterized by large structural transformations and significant charge transfer, i.e., forming a negatively charged bent CO2
-δ species with elongated C-O bonds, which is further
confirmed by vibrational analyses showing considerable red shift in the frequencies as a result of the
activation
Indian Ocean dipole mode events in a simple mixed layer ocean model
A precise knowledge of sea surface temperature (SST) is very essential for climate and oceanographic studies. In this paper a simple two dimensional mixed layer ocean model and its numerical code have been developed and used to simulate the SST fields over the north Indian Ocean (20°S-25°N and 35°E-115°Î) for a period of 10 years (1992-2001). The model simulated the SST variability reasonably well. The simple model could simulate the observed dipole of 1997 and 1994 very well, especially the eastern cooling. The model study showed that the interannual SST variability in the western equatorial Indian Ocean is not only due to the variability in the surface heat fluxes, but also due to the variability in wind and sea surface height (SSH). The OLR anomaly also shows positive (negative) anomaly over the negative (positive) anomalous SST region. The variability in the latent heat flux is found to be greatly influencing the SST variability in the eastern equatorial Indian Ocean
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