objective(s): first principles calculations were performed to study four multiple sclerosis drugs namely, ampyra, fingolimod, mitoxantrone and eliprodil in gas and liquid phases using density functional theory (dft). computational chemistry simulations were carried out to compare calculated quantum chemical parameters for ampyra, fingolimod, mitoxantrone and eliprodil. materials and methods: al...

ab initio calculations were employed to investigate nitrogen inversion as a configuration change that can supply an infinitely useful switchable control mechanism for some complex systems. in this paper, design of a new artificial molecular nanohinge is discussed based on nitrogen inversion in which reciprocating motion of substituent in effect of inversion phenomenon, led to an open–close moti...

background: monte carlo (mc) modeling of a linear accelerator is a prerequisite for monte carlo dose calculations in external beam radiotherapy. in this study, a simple and efficient model was developed for elekta sl-25 linear accelerator using mcnp4c monte carlo code materials and methods: the head of elekta sl-25 linac was simulated for 6 and 18 mv photon beams using mcnp4c mc code. energy sp...

Plausible mechanisms of the ultrafast electron injection and the significant dependence of the power conversion efficiency on the anchor group for the triphenylamine-based dye-sensitized TiO2 solar cells have been explored by the density functional calculations. Calculations show that the ultrafast charge recombination on the surface trap state of the dye-sensitized TiO2 system can be ascribed ...

The dynamics of de excitation between highly excited Rydberg states 15 n 60 of Rb in a magnetic field of 0.85 ±0.05 T is studied with far-infrared pulses 90–110 and 50 m originating from a free electron laser. We measured the excitation spectrum to states around n=40 from a deeper bound state near n=25. Moreover, starting from a highly excited state 30 n 60 below and in the n-mixing regime we i...

We present a method to calculate vertical profiles of particle size distributions in condensation clouds of giant planets and brown dwarfs. The method assumes a balance between turbulent diffusion and sedimentation in horizontally uniform cloud decks. Calculations for the Jovian ammonia cloud are compared with results from previous methods. An adjustable parameter describing the efficiency of s...

Oxygen uptake efficiency slope (OUES) and ventilatory efficiency (VE/VCO2 slope) are widely used as submaximal measurements of cardiopulmonary exercise testing as the evaluator or prognosticator of cardiac diseases. However, very few studies have compared the effects of submaximal exercise on these measurements. A total of 58 patients with coronary artery disease underwent maximal cardiopulmona...

Energy transfer via bath gas collisions is an important factor in controlling the kinetics of many combustion reactions. Previous work [1, 2] demonstrated the feasibility and accuracy of trajectory calculations for predicting energy transfer parameters for use in the master equation calculations of pressure dependent rate coefficients. Here we use these methods to study collisions between acety...

The imaging characteristics of an arc-shaped xenon gas ionization chamber for the purpose of megavoltage CT imaging were investigated. The detector consists of several hundred 320 microm thick gas cavities separated by thin tungsten plates of the same thickness. Dose response, efficiency and resolution parameters were calculated using Monte Carlo simulations. The calculations were compared to m...

Three different clusters, Si9H12 , Si15H16 , and Si21H20 , are used in density-functional theory calculations in conjunction with ab initio pseudopotentials to study how the energetics of H2 dissociative adsorption on and associative desorption from Si~001! depends on the cluster size. The results are compared to five-layer slab calculations using the same pseudopotentials and high quality plan...