In order to develop minimally invasive, fast and precise diagnostic and therapeutic methods in medicine by using optical methods, first step is to examine how the light propagates, scatters and transmitted through medium. So as to find out appropriate wavelengths, it is required to correctly determine the optical properties of tissues. The aim of this study is to measure the optical properties of both cancerous and normal ex-vivo pancreatic tissues. Results will be compared to detect how cancerous and normal tissues respond to different wavelengths. Double-integrating-sphere system and computational technique inverse adding doubling method (IAD) were used in the study. Absorption and reduced scattering coefficients of normal and cancerous pancreatic tissues have been measured within the range of 500-650 nm. Statistical significant differences between cancerous and normal tissues have been obtained at 550 nm and 630 nm for absorption coefficients. On the other hand; there were no statistical difference found for scattering coefficients at any wavelength.
In this study, effect of a novel LED-based light source developed for 96-well-plates cell culture applications, was tried on AGS stomach
cancer cell line, in combination with Poly(amido amine) (PAMAM) modified – porhyrin molecule. For each 4 generation of modified
PpIX molecule 5 different concentrations tried. According to results PAMAM molecule doesnt have any photosensitizer property
also didn’t show any toxic effect even if higher concentrations. Morphology and real time monitoring analysis results hold up each
other and confirmed that, PpIX molecules with and without modificated high concentrations (>100μM) caused cell death via toxicicity
this reason optimal concentration for PAMAM modified PpIX should be between 25 - 50 μm concentration .
<strong>Objective:</strong> In-vitro investigation of Ho:YAG-laser induced stone fragmentation was performed to identify potential impacts of different pulse durations on stone fragmentation characteristics. <strong>Materials and Methods:</strong> An innovative Ho:YAG laser system (Swiss LaserClast, EMS S.A., Nyon, Switzerland) with selectable long- or short pulse mode was tested with regard to its fragmentation properties. The pulse duration depends on the specific laser parameter used. Fragmentation tests (hand held, hands free, single pulse induced crater) on artificial BEGO-Stones and fiber burn back tests were performed under reproducible experimental conditions. Additionally, the repulsion of long versus short laser pulses was compared using the pendulum set-up. <strong>Results:</strong> Differences in fragmentation rates between the two pulse duration regimes were seen. The difference was, however, not statistically significant. Using long pulse mode, the fiber burn back is nearly negligible while in short pulse mode an increased burn back was seen. The results of the pendulum test showed that the deviation induced by the momentum of shorter pulses is increased compared to longer pulses. <strong>Conclusion:</strong> Long pulse-mode showed reduced side effects like repulsion and fiber burn back in comparison to short pulse-mode while fragmentation rates remained at a comparable level. Lower push back and reduced burn back of longer laser pulses may results in better clinical outcome of laser lithotripsy and more convenient handling during clinical use.