Realization of Ternary Reversible Circuits Using Improved Gate Library

AbstractTernary logic has some distinct advantage over binary logic. In this paper we propose a synthesis approach for ternary reversible circuits using ternary reversible gates. Our method takes a boolean function as input. The input is provided as .pla file. The .pla file is first converted into ternary logic function, which can be represented as permutation. The gate library used for synthesis is Ternary Not, Ternary Toffoli and Ternary Toffoli+ (NT ,TT ,TT +). The proposed constructive method, generates 3-cycles from the permutation, and then each 3-cycle is mapped to (NT ,TT ,TT +) gate library. Experimental results show that the method generates lesser number of gates for some circuits compared to previously reported works

Fluorescence resonance energy transfer from tryptophan in human serum albumin to a bioactive indoloquinolizine system

The interaction between a bioactive molecule, 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ), with human serum albumin (HSA) has been studied using steady-state absorption and fluorescence techniques. A 1:1 complex formation has been established and the binding constant (K) and free energy change for the process have been reported. The AODIQ-HSA complex results in fluorescence resonance energy transfer (FRET) from the tryptophan moiety of HSA to the probe. The critical energy-transfer distance (R0) for FRET and the Stern-Volmer constant (Ksv) for the fluorescence quenching of the donor in the presence of the acceptor have been determined. Importantly, KSV has been shown to be equal to the binding constant itself, implying that the fluorescence quenching arises only from the FRET process. The study suggests that the donor and the acceptor are bound to the same protein at different locations but within the quenching distance

Identification and characterization of EhCaBP2: a second member of the calcium-binding protein family of the protozoan parasite entamoeba histolytica

Entamoeba histolytica, an early branching eukaryote, is the etiologic agent of amebiasis. Calcium plays a pivotal role in the pathogenesis of amebiasis by modulating the cytopathic properties of the parasite. However, the mechanistic role of Ca2+ and calcium-binding proteins in the pathogenesis of E. histolytica remains poorly understood. We had previously characterized a novel calcium-binding protein (EhCaBP1) from E. histolytica. Here, we report the identification and partial characterization of an isoform of this protein, EhCaBP2. Both EhCaBPs have four canonical EF-hand Ca2+ binding domains. The two isoforms are encoded by genes of the same size (402 bp). Comparison between the two genes showed an overall identity of 79% at the nucleotide sequence level. This identity dropped to 40% in the 75-nucleotide central linker region between the second and third Ca2+ binding domains. Both of these genes are single copy, as revealed by Southern hybridization. Analysis of the available E. histolytica genome sequence data suggested that the two genes are non-allelic. Homology-based structural modeling showed that the major differences between the two EhCaBPs lie in the central linker region, normally involved in binding target molecules. A number of studies indicated that EhCaBP1 and EhCaBP2 are functionally different. They bind different sets of E. histolytica proteins in a Ca2+-dependent manner. Activation of endogenous kinase was also found to be unique for the two proteins and the Ca2+ concentration required for their optimal functionality was also different. In addition, a 12-mer peptide was identified from a random peptide library that could differentially bind the two proteins. Our data suggest that EhCaBP2 is a new member of a class of E. histolytica calcium-binding proteins involved in a novel calcium signal transduction pathway

N- and C-Terminal Domains of the Calcium Binding Protein EhCaBP1 of the Parasite Entamoeba histolytica Display Distinct Functions

Entamoeba histolytica, a protozoan parasite, is the causative agent of amoebiasis, and calcium signaling is thought to be involved in amoebic pathogenesis. EhCaBP1, a Ca2+ binding protein of E. histolytica, is essential for parasite growth. High resolution crystal structure of EhCaBP1 suggested an unusual arrangement of the EF-hand domains in the N-terminal part of the structure, while C-terminal part of the protein was not traced. The structure revealed a trimer with amino terminal domains of the three molecules interacting in a head-to-tail manner forming an assembled domain at the interface with EF1 and EF2 motifs of different molecules coming close to each other. In order to understand the specific roles of the two domains of EhCaBP1, the molecule was divided into two halves, and each half was separately expressed. The domains were characterized with respect to their structure, as well as specific functional features, such as ability to activate kinase and bind actin. The domains were also expressed in E. histolytica cells along with green fluorescent protein. The results suggest that the N-terminal domain retains some of the properties, such as localization in phagocytic cups and activation of kinase. Crystal structure of EhCaBP1 with Phenylalanine revealed that the assembled domains, which are similar to Calmodulin N-terminal domain, bind to Phenylalanine revealing the binding mode to the target proteins. The C-terminal domain did not show any of the activities tested. However, over-expression in amebic cells led to a dominant negative phenotype. The results suggest that the two domains of EhCaBP1 are functionally and structurally different from each other. Both the domains are required for structural stability and full range of functional diversity

On Mechanical Response in a Piezoelectric Plate Characterized by a Diffusion and Subjected to a Prescribed Polarization Gradient

The paper is concerned with the mechanical response in a piezoelectric plate transducer under constant voltage input across it; the plate being characterized by a prescribed diffusion and subjected to an exponentially decaying polarization gradient

Structural volume change upon photoisomerization of 2,2´-furil: A photoacoustic calorimetric study

45-50The cis-skew → trans-planar photoisomerization of 1, 2-di(furan-2-yl)ethane-1, 2-dione (2, 2´-furil), a 1,2-dicarbonyl compound, in the photoexcited triplet state has been investigated by photoacoustic calorimetry in a series of n-alkane solvents at room temperature. The photoisomerization process is associated with a structural volume change of the probe. This has been evaluated and compared with the theoretically calculated volumes of cis and trans geometries of furil. The study reveals that an expansion in volume occurs during the photoinduced isomerization process. In low polarity alkane solvents, electrostrictional contribution to the estimated volume change has been argued to be negligible

Structural volume change upon photoisomerization of 2,2'-furil: a photoacoustic calorimetric study

The cis-skew → trans-planar photoisomerization of 1, 2-di(furan-2-yl)ethane-1, 2-dione (2, 2'-furil), a 1,2-dicarbonyl compound, in the photoexcited triplet state has been investigated by photoacoustic calorimetry in a series of n-alkane solvents at room temperature. The photoisomerization process is associated with a structural volume change of the probe. This has been evaluated and compared with the theoretically calculated volumes of cis and trans geometries of furil. The study reveals that an expansion in volume occurs during the photoinduced isomerization process. In low polarity alkane solvents, electrostrictional contribution to the estimated volume change has been argued to be negligible

Laser induced optoacoustic spectroscopy of benzil: evaluation of structural volume change upon photoisomerization

The cis-skew to trans-planar photoisomerization of benzil in the photoexcited state was studied by laser-induced optoacoustic spectroscopy (LIOAS) in a series of normal alkane solvents at room temperature. The structural volume change due to the photoisomerization process has been estimated and compared with the same calculated from the optimized skew and trans structures. The magnitude of the structural volume change is estimated to be 22.9 ± 1.2 mL/mol. This study reveals that an expansion in volume occurs during the photoinduced isomerization process. In non-polar alkane solvents, the estimated volume change has been argued to be free from electrostrictional contribution