porophyrins and their metal derivatives are strong dna binders with association constant of  to  . some of these compounds have been used for the radiations sensitization therapy of cancer and are targeted to interact with cellular dna. binding of porphyrins to dna changes the expectral and other physic chemical characteristic of porphyrins, the mode of binding can be extracted from inspection ...

In this work, the optical absorption near the fundamental absorption edge of co-evaporated Ce0 -V20 films is studied. It is found that the fundamental optical absorption in these materials is sharp more like that expected for crystals. It is also found that as the V O content increases, the edge becomes less sharp and shifts towards higher wavelengths

objectives in this study, the absorption coefficient of hemoglobin (hb) was used to distinguish between normal and abnormal breast tissue. materials and methods a near-infrared source (637 nm) was transmitted from major and minor vessels of a breast phantom containing 2×, 4× concentrations of oxy- and deoxy-hb. the absorption coefficients were determined from spectrometer (sm) and powermeter (p...

in order to implement an integrated optical quantum circuit, designing waveguides based on the quantum box is of prime importance. to do this we have investigated optical waveguide both with and without optical pumping. the rate of absorption and emission using an array of algaas/gaas quantum box core/shell structure in the optical waveguide with various pumping intensities has computed. by con...

in this study, the nonlinear optical properties and optical limiting performance of the silver nanoparticles (agnps) in distilled water are investigated. the nonlinear absorption coefficient of the colloid is measured by the z-scan technique. the optical limiting behavior of the agnp suspension is investigated under exposure to nanosecond laser pulses at 532 nm. the results show that nonlinear ...

In the present work, KTP crystals have been grown by spontaneous nucleation technique in flux medium using K6P4O13 flux. 0.4-1 °C/h cooling rates were applied in the spontaneous nucleation process. The presence and amount of impurities has been determined by using XRF. The optical transmission spectra of impure KTP crystals in the UV–visible region are discussed. The transmission cut-off is cle...

in this work, we report, optical properties of cd1-xsnxte quantum dots (x= 0.05, 0.10 and 0.15) synthesized in water using thioglycolic acid (tga) as a modifier agent. the optical characterization of the samples was performed through absorption (uv) and photoluminescence spectra (pl). a red shift absorption and fluorescent emission peaks was observed which can be related to the increase of nano...

this work describes the optical and structure properties of nickel sulfide and cobalt sulfide nanoparticles in zsm-5 zeolite. the samples were obtained by sulfidation of the ni2+ and co2+ ion-exchange zsm-5 zeolites in a na2s solution at room temperature. the optical properties of the samples were studied by uv-visible spectroscopy. their crystalline structure and morphology were studied by x-r...

In order to implement an integrated optical quantum circuit, designing waveguides based on the quantum box is of prime importance. To do this we have investigated optical waveguide both with and without optical pumping. The rate of absorption and emission using an array of AlGaAs/GaAs quantum box core/shell structure in the optical waveguide with various pumping intensities has computed. By con...