University of Burdwan

About: University of Burdwan is a education organization based out in Barddhamān, West Bengal, India. It is known for research contribution in the topics: Population & Nanocrystalline material. The organization has 2492 authors who have published 5389 publications receiving 74865 citations. The organization is also known as: BU & Burdwan University.

Phase transformation kinetic study and microstructure characterization of ball‐milled m‐ZrO2–10 mol% a‐TiO2 by Rietveld method

Abstract: High-energy ball milling of a monoclinic ZrO 2- 10 mol% anatase TiO 2 mixture results in the formation of a nanocrystalline cubic ZrO 2 polymorphic phase with equimolar fraction of the starting materials. The cubic phase is presumed to have formed from the m-ZrO 2 solid solution based on the (001) plane of the m-ZrO 2 phase. In the course of milling, the most dense (111) plane of the cubic lattice became parallel to the most dense (111) plane of the monoclinic lattice due to an orientation effect. Annealing of a 12 h milled sample at 773, 873 and 973 K for 1 h results in almost complete transformation of the m-ZrO 2 to the c-ZrO 2 phase. At 1273 K annealing temperature (1 h), the nanocrystalline sample decomposed into individual starting phases. This suggests that the cubic phase is a metastable one and its stability depends on particle size as well as the working temperature. Formation of the cubic phase at such a low temperature using anatase TiO 2 as a phase stabilizer has not been reported previously. The microstructures of the unmilled, all the ball-milled and the annealed samples have been characterized by employing Rietveld's X-ray powder structure refinement methodology. The particle size, root mean square (r.m.s.) lattice strain, lattice parameters, molar fraction, etc., of individual phases have been estimated from Rietveld analysis and are utilized to interpret the results.

Attraction of Epilachna dodecastigma (Coleoptera: Coccinellidae) to Momordica charantia (Cucurbitaceae) leaf volatiles

Abstract: Epilachna dodecastigma (Wiedemann) (Coleoptera: Coccinellidae) is an important herbivorous pest of bitter gourd, Momordica charantia Linnaeus (Cucurbitaceae) plant in India and Bangladesh. Volatiles were collected from undamaged bitter gourd plants, and from plants 24 and 120 hours following the initiation of continuous adult female feeding damage, and subsequently identified and quantified by gas chromatography mass spectrometry and gas chromatography flame ionisation detector analyses. Of the 24 volatiles identified in the study, 22 were present in all three treatments (undamaged plants, 24 hours after feeding, and 120 hours after feeding), and all plants significantly increased emissions of these compounds following insect attack. In all plants, the compound 1-tridecanol was the most abundant, followed by phytol. Only two compounds were unique to insect damaged plants: methyl palmitate was characteristic of insect damaged plants, while nerolidol was only detected from plants 120 hours following insect attack, however neither of these insect-damage specific volatiles, when tested individually, elicited attraction in Y-shaped glass tube olfactometer bioassays. Epilachna dodecastigma showed significant preference for the whole volatile blends from insect damaged plants compared with whole volatile blends from undamaged plants. Further, the insect elicited attraction to three individual synthetic compounds: geraniol, 1-tridecanol, and phytol, which had significantly higher emissions from insect damaged leaves compared with those from undamaged plants.

A FRET-based ‘off–on’ molecular switch: an effective design strategy for the selective detection of nanomolar Al3+ ions in aqueous media

Abstract: A new water-soluble rhodamine-based Al3+ ion-selective probe (L1) was synthesised and characterized by physico-chemico and spectroscopic tools. In the presence of a large excess of other competing ions, L1 specifically binds Al3+ ions with a concurrent visually observable change from colorless to pink in electronic spectral behavior, making it possible to detect the presence of Al3+ ions with the naked eye. The addition of Al3+ ions to a solution of L1 in HEPES buffer (1 mM, pH 7.4, 2% EtOH) at 25 °C, results in a decrease in the weak fluorescence intensity at λem = 470 nm, while a new peak (at λem = 588 nm) increases gradually through a fluorescence resonance energy transfer process. This ratiometric enhancement helps to detect Al3+ ions at a very low concentration of 33 nM. The detection limit of L1 for Al3+ ions was estimated to be 6.19 × 10−9 M using the 3σ method. This probe is also useful for imaging Al3+ ions in HeLa cells.

ATP-Decorated Mesoporous Silica for Biomineralization of Calcium Carbonate and P2 Purinergic Receptor-Mediated Antitumor Activity against Aggressive Lymphoma

Abstract: Adenosine triphosphate (ATP) is an important transmitter that mediates various biological effects via purinergic receptors (P2 receptors) in cancer We investigated the antitumor activity of ATP-decorated and doxorubicin (DOX)-loaded mesoporous silica with biomineralization of calcium carbonate against a highly aggressive and metastatic murine lymphoma called Dalton's lymphoma (DL) Our results suggest that this nanocomposite has unique effects with respect to the morphology and properties of calcium carbonate on the surface of the nanoparticle DOX in the nanoparticles was prevented from quick release via the interactions of the phosphate group present on ATP and calcium carbonate This construct is significantly tumoricidal against parental and DOX-resistant DL cells and is thus a promising candidate for applications in drug delivery The composite nanomaterial has excellent biocompatibility with higher uptake and acts via the participation of the purinergic receptor P2X7 The nanocomposite induces significantly higher apoptosis in tumor cells compared with DOX alone Treatment of DL-bearing mice with the construct significantly reduces tumor burden, in addition to augmenting the lifespan of tumor-bearing mice as demonstrated by a sustained healthy life of the animals and improved histopathological parameters