Candida albicans possesses an ability to grow under different host-driven stress conditions by developing robust protective mechanisms. In this investigation the focus was on the impact of osmotic (2M NaCl) and oxidative (5 mM H2O2) stress conditions during C. albicans biofilm formation. Oxidative stress enhanced extracellular DNA secretion into the biofilm matrix, increased the chitin level, and reduced virulence factors, namely phospholipase and proteinase activity, while osmotic stress mainly increased extracellular proteinase and decreased phospholipase activity. Fourier transform infrared and nuclear magnetic resonance spectroscopy analysis of mannan isolated from the C. albicans biofilm cell wall revealed a decrease in mannan content and reduced β-linked mannose moieties under stress conditions. The results demonstrate that C. albicans adapts to oxidative and osmotic stress conditions by inducing biofilm formation with a rich exopolymeric matrix, modulating virulence factors as well as the cell wall composition for its survival in different host niches.

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Plant derived small molecules, which interact with and stabilize G-quadruplex DNA, act as inhibitors of telomere elongation and oncogene expression in humans. The inhibition of telomerase enzyme has immense potential since it is over expressed in most cancer cells. Interaction of palmatine, an antitumor alkaloid, to parallel G-quadruplex DNA, [d(TTGGGGT)] and [d(TTAGGGT)], has been investigated using Nuclear Magnetic Resonance (NMR), fluorescence and Circular Dichroism (CD) spectroscopy. Titrations were monitored by H andP NMR spectra and solution structure of palmatine-[d(TTGGGGT)] complex was obtained by restrained Molecular Dynamics (rMD) simulations using distance restraints from 2D NOESY spectra. Thermal stabilization of DNA was determined by CD, H NMR and Differential Scanning Calorimetry (DSC). Binding of palmatine induces 98% enhancement of fluorescence accompanied by blue shift ∼8 nm. CD spectral bands of DNA show minor changes. Diffusion NMR studies confirm formation of a stable complex. Proton NMR signals of palmatine shift upfield upon binding and NOE cross peaks of H10, H3, H28, 5OCH protons with T2, A3/G3, G6 and T7 residues reveal dual recognition sites in both G-quadruplex DNA sequences, resulting in thermal stabilization of G-quadruplex by ∼13-17 °C. Restrained molecular dynamics simulations using NOE distance restraints for 2:1 palmatine-[d(TTGGGGT)] complex reveal end-stacking of palmatine at G6pT7 step and groove binding along T2pG3 step. Binding to [d(TTAGGGT)] takes place at T2pA3pG4 and G6pT7 steps. Structural features of molecular recognition of two different G-quadruplex DNA sequences by palmatine have relevance in rational drug development for anti-cancer therapy.

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This paper addresses the approach to improve the efficiency of the quasi Z-source inverter. In order to increase the efficiency the reduction of conduction losses is one way to approach. Sequentially to decrease the conduction losses in the quasi z-source inverter the replacement of diode is replacing with switches is proposed which is also called as synchronous rectification. The paper represents basics of the approach, analysis and comparison of the power losses of the traditional and proposed designs of the grid connected PV-system with quasi z-source inverter system. The proposed approach validated on the computer simulations in the MATLAB environment. Keyword:Inverter Photovoltaic application Quasi Z-source Copyright © 2017 Institute of Advanced Engineering and Science.All rights reserved.Corresponding Author:C. Bharatiraja, School Electrical and Electronics Engineering, SRM University, Chennai, India. Email: bharatiraja@gmail.com INTRODUCTIONThe quasi z-source inverters (q-ZSI) are drawing more attention than other impedance source networks in photovoltaic (PV) application due to its ability to deal with wide input voltage variation and its shoot-through capabilities and suitable for renewable energy system with large of gain. Feature of the qZSI is that it can draw continuous and constant current. The qZSI boost the input voltage by utilizing an extra switching state is the simultaneous conduction of both switches of the same leg in inverter-which is called as the shoot-through state [1]. This kind of operation forbidden in the traditional voltage source inverters (VSI) because it causes short circuit of the DC link capacitors.in the qZSI, shoot-through state is used to boost the magnetic energy stored in the dc-side inductors (L 1 and L 2 in Figure 1) without short-circuiting the dc capacitors C1 and C2. During this state, energy is first stored in the impedance network, and then released into the capacitors and load at non-shoot-through states. This increase in inductive energy, in turn, provides the boost of the output voltage VOduring the traditional operating states (active states) of the inverter.Most of the commercially available grid connected systems for renewable applications include a transformer, which enables the selection of a suitable dc voltage input for the inverter and isolates the energy source from the utility grid [2]. Converters including a transformer either use a line transformer or a highfrequency transformer. Line-frequency transformers are regarded as poor components due to increased size, weight, and prize. Converters with high-frequency transformers include various power stages and are pretty complex. In this paper a new system is proposed, which is having quasi z-source for the boost the voltage and inverter used as grid connected transformer-less system [3], which reduces size and cost. Unipolar pulse width modulation which is most commonly used PWM technique for this kind of system. To reduce the