Christ University

About: Christ University is a education organization based out in Bengaluru, India. It is known for research contribution in the topics: Computer science & Convection. The organization has 2267 authors who have published 2715 publications receiving 14575 citations. The organization is also known as: Christ College & Christ University.

Influence of different media, medium strength and carbon sources on adventitious shoot cultures and production of bacoside A in Bacopa monnieri (L.)

Abstract: Bacopa monnieri (L.) Wettst. (Plantaginaceae), commonly known as Brahmi, is used in Ayurveda as a medicinal herb, found throughout the Indian subcontinent in wet, damp and marshy areas. The herb yields pharmaceutically active compounds called bacosides. The current investigation was carried out to assess the potential for increasing biomass and the concentration of bacoside A from the in vitro regenerated shoots in different media (MS, B5, NN and N6), the strength of the MS medium (0.25, 0.50, 0.75, 1.0, 1.50 and 2.0X) and carbon source [sucrose, glucose, fructose, maltose, sucrose + glucose (1:1), sucrose + maltose (1:1), glucose + fructose (1:1), glucose + maltose (1:1), fructose + sucrose (1:1) and fructose + maltose (1:1)]. All the culture media were supplemented with 2 mg/L Kinetin (Kin) at pH 5.8. High performance liquid chromatography (HPLC) was used to determine the bacoside A content from the regenerated shoots. Optimum number of adventitious shoots (70.75 shoots per explant), fresh weight (2.344 g), dry weight (0.166 g) and bacoside A content (13.052 mg/g DW) were obtained from the cultures grown in the MS medium. Bacoside A production was highest in the shoots grown in the glucose + fructose combination (15.588 mg/g DW) among the different carbon sources tested. These findings suggest that B. monnieri culture requires full strength MS medium and a moderate level of sucrose. The present study is useful to obtain optimum production of biomass and bacoside A from the in vitro regenerated shoots of B. monnieri.

A stochastic propagation model to the energy dependent rapid temporal behaviour of Cygnus X-1 as observed by AstroSat in the hard state

Abstract: We report the results from analysis of six observations of Cygnus X-1 by Large Area X-ray Proportional Counters (LAXPC) and Soft X-ray Telescope (SXT) on-board AstroSat, when the source was in the hard spectral state as revealed by the broad band spectra. The spectra obtained from all the observations can be described by a single temperature Comptonizing region with disk and reflection components. The event mode data from LAXPC provides unprecedented energy dependent fractional root mean square (rms) and time-lag at different frequencies which we fit with empirical functions. We invoke a fluctuation propagation model for a simple geometry of a truncated disk with a hot inner region. Unlike other propagation models, the hard X-ray emission (> 4 keV) is assumed to be from the hot inner disk by a single temperature thermal Comptonization process. The fluctuations first cause a variation in the temperature of the truncated disk and then the temperature of the inner disk after a frequency dependent time delay. We find that the model can explain the energy dependent rms and time-lag at different frequencies.

Cold spray deposition of hydroxyapatite powder onto magnesium substrates for biomaterial applications

Abstract: A simple, modified, cold spray process was developed in which hydroxyapatite powder was coated onto pure magnesium substrates preheated to 350 or 550°C and ground to either 240 or 2000 grit surface roughness, with stand-off distances of 20 or 40 mm. The procedure was repeated five and 10 times. The hydroxyapatite coatings did not show any phase changes. Atomic force microscopy revealed a uniform coating topography, and scanning electron microscopy revealed good bonding between the coated layers and the substrates. As the p values were < 0·05, all factors except the number of sprays were considered to be significant. The response optimiser indicated that a 22·7 mm stand-off distance, a 649·2 grit surface roughness and a 496°C substrate heating temperature produced good hydroxyapatite coatings of 46·3 μm thickness, 436·5 MPa nanohardness and 43·9 GPa elastic modulus. The modified cold spray technique with substrate heating showed promising results in terms of product coating thickness and mechanical properties.

Green Luminescence and Irradiance Properties of Carbon Dots Cross-linked with Polydimethylsiloxane

Abstract: In the present report, we have synthesized carbon dots by using anthracite coal as a precursor. The purpose of this work is to address the sensitivity and surface coating ability of carbon dots wit...