3D-QSAR studija afiniteta vezanja na receptor za (R,S)-2-amino-3-(3-hidroksi-5-metilizoksazol-4-il)-propansku kiselinu

An approach for binding affinity evaluation is suggested and exemplified using a set of triazolo [1,5-a] quinoxaline for the (R,S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)-propionic acid (AMPA) receptor. Biological activity toward the AMPA receptor (expressed as -log IC5O) was taken as a dependent variable for building Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Indices Analysis (CoMSIA) models. The resulting models show the ways of increasing the binding affinity to the AMPA receptor as a potential target for epilepsy. The statistically significant results show that the cross-validated r2CV value (0.766) for the CoMFA model is greater than (0.758) for the CoMSIA model. The non-cross validated run giving the coefficient of determination r2 values of 0.944 and 0.919 for CoMFA and CoMSIA, respectively, provided good correlation between the observed and computed affinities of the training set compounds. The resulting CoMFA and CoMSIA models indicate that steric, electrostatic, hydrophobic (lipophilic), hydrogen bond donor and acceptor substituents play a significant role in increasing the binding affinity and selectivity of the compounds toward the AMPA receptor.U radu je vrednovan afinitet vezanja serije triazolo[1,5-a]kinoksalina na receptor za (R,S)-2-amino-3-(3-hidroksi-5-metilizoksazol-4-il)-propansku kiselinu (AMPA). Djelovanje na AMPA receptor (izraženo kao log IC5O) uzeta je kao zavisna varijabla u modelima usporedne analize molekulskih polja (Comparative Molecular Field Analysis, CoMFA) i usporedne analize molekulske sličnosti (Comparative Molecular Similarity Indices Analysis, CoMSIA). Ti modeli pokazuju kako povećati afinitet vezanja na AMPA receptor, što može biti korisno u terapiji epilepsije. Statistički značajni rezultati ukazuju da je križno validirana r2CV vrijednost za CoMFA model (0,766) veća nego za CoMSIA model (0,758). Koeficijenti r2 za CoMFA model (0,944) i CoMSIA (0,919) ukazuju na dobru korelaciju između izračunatih i eksperimentalno određanih afiniteta vezanja proučavane serije spojeva. Prema oba modela za povećanje afiniteta vezanja i selektivnost spojeva za AMPA receptor značajna su sterička, elektrostatska, hidrofobna (lipofilni) svojstva, te sposobnost stvaranja vodikovih veza

Graphical Visualization of MAC Traces for Wireless Ad-hoc Networks Simulated in ns2 1

Abstract- Many network simulators (e.g., ns2) are already being used for performing wired and wireless network simulations. But, with the current graphical visualization support in-built in ns2, it is difficult to understand the node status, packet status and the MAC level events particularly for Ad-hoc networks. In this paper, we extend the visualization support in ns-2 that should help research community in the area of wireless networks to analyze different MAC level events in an efficient manner. In particular, we have developed two types of visualizations namely, temporal and spatial. Temporal visualization helps to analyze success or failure of a packet with respect to time while spatial visualization helps to understand the effects due to proximity of nodes. The trace is made highly configurable in terms of different attributes like specific nodes and time duration. Index terms- Network event tracing, wireless networks, networ