Bharathiar University

About: Bharathiar University is a education organization based out in Coimbatore, Tamil Nadu, India. It is known for research contribution in the topics: Thin film & Adsorption. The organization has 5812 authors who have published 8628 publications receiving 143934 citations. The organization is also known as: BU.

Photocatalytic degradation of organic pollutants by shape selective synthesis of β-Ga2O3 microspheres constituted by nanospheres for environmental remediation

Abstract: A potential single crystalline photocatalyst β-Ga2O3 with unique spherical morphology has been synthesized using a surfactant assisted hydrothermal process. Organic additive triblock co-polymer pluronic F127 was used as a soft template. The morphology of the material was investigated using scanning electron microscopy and it was confirmed that the nanospheres self-assembled to form microspheres with diameters in the range ∼1–3 μm. The crystal phase and chemical composition of the β-Ga2O3 microspheres were revealed by X-ray diffraction and X-ray photoelectron spectroscopy. Structural characterization exhibits the monoclinic phase of the microspheres with preferential growth along the [111] direction. A plausible mechanism has been proposed to understand the formation of microspheres. The optical absorbance spectrum showed an intense absorption feature in the UV spectral region with a bandgap energy of 4.6 eV. The Brunauer–Emmett–Teller specific surface area was found to be 82 m2 g−1. The photocatalytic activity of the material has been investigated for the degradation of model organic pollutants Rhodamine B and methylene blue under ultraviolet light irradiation. The photocatalytic mechanism towards the degradation of organic dyes has also been proposed.

Induction of Apoptosis by Ginger in HEp-2 Cell Line Is Mediated by Reactive Oxygen Species

Abstract: Ginger (Zingiber officinale Roscoe, Zingiberaceae) is a commonly used medicinal herb throughout the world. Although some studies have demonstrated its antitumour activities on cancer cells in vitro and in vivo, the exact mechanism is not fully elucidated. Hence, the present study was designed to examine the in vitro cytotoxic activities of saline extract prepared from ginger extract on HEp-2 cell line. The cytotoxic effect of the drug was confirmed by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and cell counting and estimation of protein, DNA and RNA. Meanwhile, propidium iodide staining and agarose gel electrophoresis were performed for determining the induction of apoptosis. In addition, superoxide radical generation, nitrite formation and glutathione studies show involvement of free radicals. The present results show that the extract exerts dose-dependent suppression of cell proliferation; the IC(50) value was found to be 900 microg/ml. At a dose of 250 microg/ml, marked morphological changes including cell shrinkage and condensation of chromosomes were observed. Agarose gel electrophoresis of DNA from HEp-2 cells treated with 250 microg/ml ginger powder for 24 hr showed marked DNA ladder pattern. The involvement of free radicals was confirmed by increased superoxide production, decreased nitrate formation and depletion of glutathione in ginger-treated cells. Further screening of active components using gas chromatography-mass spectrometry analyses showed the presence of clavatol, geraniol and pinostrobin in the extract. The results of the present study suggest that ginger might be useful as a potential antitumour agent.

In vitro investigation of domain specific interactions of phenothiazine dye with serum proteins by spectroscopic and molecular docking approaches

Abstract: In the present study the interaction of the chemotherapeutic agent, Azure A (AZA) with Human Serum Albumin (HSA) and Bovine Serum Albumin (BSA) was investigated by multi spectroscopic and molecular docking methods. The influence of inner filter effect (IFE) on the emission quenching of HSA/BSA at low concentration of AZA (absorption value <0.1) suggested the need to employ an IFE correction factor even for the low concentration regime. The emission titration experiments of HSA/BSA with AZA revealed the formation of AZA–HSA/BSA complexes. The binding parameters calculated from corrected emission intensities showed that AZA binds to HSA/BSA with moderately strong binding affinities. The negative free energy obtained for the binding of AZA with HSA/BSA indicated that the complexation process is spontaneous. The results from site maker competitive experiments with specific site markers revealed that the probable binding location of AZA is located near site I of HSA/BSA. An AutoDock based molecular docking approach was utilized to characterize the binding models of AZA–HSA/BSA complexes. The free energy calculations for the most stable conformer from molecular docking studies were utilized to examine the energy contributions and the role of various amino acid residues of HSA/BSA in AZA binding. The results of site-competitive replacement experiments with specific site markers and molecular docking simulation studies unambiguously helped us to conclude that AZA binds to site I of HSA/BSA. Constant wavelength synchronous emission, excitation–emission matrix (three-dimensional) emission, absorption and circular dichroism spectroscopic techniques have been exploited to unravel AZA induced tertiary and secondary conformational changes of HSA/BSA.

State estimation of memristor-based recurrent neural networks with time-varying delays based on passivity theory

Abstract: This article deals with the state estimation problem of memristor-based recurrent neural networks MRNNs with time-varying delay based on passivity theory The main purpose is to estimate the neuron states, through available output measurements such that for all admissible time delay, the dynamics of the estimation error is passive from the control input to the output error Based on the Lyapunov-Krasovskii functional LKF involving proper triple integral terms, convex combination technique, and reciprocal convex technique, a delay-dependent state estimation of MRNNs with time-varying delay is established in terms of linear matrix inequalities LMIs The information about the neuron activation functions and lower bound of the time-varying delays is fully used in the LKF Then, the desired estimator gain matrix is accomplished by solving LMIs Finally, a numerical example is provided to demonstrate the effectiveness of the proposed theoretical results © 2013 Wiley Periodicals, Inc Complexity 19: 32-43, 2014