73 research outputs found
Molecular communication in fluid media: The additive inverse Gaussian noise channel
We consider molecular communication, with information conveyed in the time of
release of molecules. The main contribution of this paper is the development of
a theoretical foundation for such a communication system. Specifically, we
develop the additive inverse Gaussian (IG) noise channel model: a channel in
which the information is corrupted by noise with an inverse Gaussian
distribution. We show that such a channel model is appropriate for molecular
communication in fluid media - when propagation between transmitter and
receiver is governed by Brownian motion and when there is positive drift from
transmitter to receiver. Taking advantage of the available literature on the IG
distribution, upper and lower bounds on channel capacity are developed, and a
maximum likelihood receiver is derived. Theory and simulation results are
presented which show that such a channel does not have a single quality measure
analogous to signal-to-noise ratio in the AWGN channel. It is also shown that
the use of multiple molecules leads to reduced error rate in a manner akin to
diversity order in wireless communications. Finally, we discuss some open
problems in molecular communications that arise from the IG system model.Comment: 28 pages, 8 figures. Submitted to IEEE Transactions on Information
Theory. Corrects minor typos in the first versio
COMPARATIVE IN-VITRO ANTIBACTERIAL AND ANTIFUNGAL ATTRIBUTES OF DIFFERENT SOLVENT EXTRACTS FROM LEAF, BARK, ROOT AND INFLORESCENCE OF MEMECYLON UMBELLATUM BURM.
This paper describes the antibacterial and antifungal activities and Minimum Inhibitory Concentration (MIC) of different solvent (pet. ether, chloroform, ethyl acetate, acetone, methanol and water) extracts of leaves, bark, root and inflorescence of Memecylon umbellatum burm. The percent yields from leaves, bark, root and inflorescence was found to be 0.2062 to 2.836, 0.0601 to 0.5142, 0.050 to 1.425, 0.0210 to 0.717 respectively. Overall, acetone extract produced from the leaves exhibited significantly (P < 0.05) higher antibacterial activity along with superior antifungal activity. MIC for acetone and ethyl acetate extract of leaf was found to be 0.5 mg for the entire organisms compared to 3-15 mg for other extracts. Such study will explore pharmacological activity of the tested parts of Memecylon umbellatum burm especially, the leaves which might be valuable for therapeutic applications
Examining the spectroscopic features and quantum chemical computations of a Quinoline derivative: Experimental and theoretical insights into the photophysical characteristics
503-515The solvatochromic studies in a Quinoline derivative molecule namely Quinolin-8-ol (QO) have been carried out at ambient temperature using absorption and fluorescence spectroscopy. The QO molecule shows the bathochromic shift with increase in solvent polarity demonstrating π → π* transition. The solvatochromic data coupled with quantum mechanical calculations has been used to estimate change in dipole moment of the molecule after excitation. It has been found that excited state dipole moment is greater than the corresponding ground state dipole moment. Further, it is observed that excited and ground state dipole moments are parallel. The chemical reactivity and kinetic stability of QO molecule are investigated using Frontier molecular orbital (FMO) analysis. Natural bond orbital (NBO) analysis shows proton transfer within the selected donor-acceptor depicting large energy of stabilization for QO molecule. The calculated Fukui functions infer the local softness and local eletrophilicity index of QO molecule. The theoretically simulated UV-Vis absorption spectrum of QO molecule matches well with the experimental spectrum
Examining the spectroscopic features and quantum chemical computations of a Quinoline derivative: Experimental and theoretical insights into the photophysical characteristics
The solvatochromic studies in a Quinoline derivative molecule namely Quinolin-8-ol (QO) have been carried out at ambient temperature using absorption and fluorescence spectroscopy. The QO molecule shows the bathochromic shift with increase in solvent polarity demonstrating π → π* transition. The solvatochromic data coupled with quantum mechanical calculations has been used to estimate change in dipole moment of the molecule after excitation. It has been found that excited state dipole moment is greater than the corresponding ground state dipole moment. Further, it is observed that excited and ground state dipole moments are parallel. The chemical reactivity and kinetic stability of QO molecule are investigated using Frontier molecular orbital (FMO) analysis. Natural bond orbital (NBO) analysis shows proton transfer within the selected donor-acceptor depicting large energy of stabilization for QO molecule. The calculated Fukui functions infer the local softness and local eletrophilicity index of QO molecule. The theoretically simulated UV-Vis absorption spectrum of QO molecule matches well with the experimental spectrum
New 1,3-dipolar cycloadducts of 3-azidoacetylcoumarins with DMAD and their antimicrobial activity
591-5943-Bromoacetylcoumarins 1 have been treated with sodium azide in aqueous acetone to give
3-azidoacetylcoumarins 2 which on
further reaction with dimethylacetylenedicarboxylate 3 in dry xylene
produce 1,3-dipolar cycloadducts 4. All the newly synthesized
azidoacetylcoumarins and their DMAD cycloadducts have been characterized by IR,
NMR and mass spectroscopic techniques and also screened for their antimicrobial
activity
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