Sharif Digital Repository

Incorporating numerical simulation with COMSOL Multiphysics, the aggregation and detection of superparamagnetic nanoparticles in microfluidic channels are investigated. Considering the physical specifications of the implemented microchannels, the parameters which determine the ability of the system for aggregation and detection of the particles are examined and simulated. Based on the simulation results, we propose a new approach for both capturing and detecting of the magnetic nanoparticles passing through microchannels  

Ammonia detoxification is one of the main functions of the liver results in production of urea. In this study ammonia elimination and urea production was simulated in a microchannel mimicking the hepatic porto central axis. Navier- Stockes equations along with convection equations were solved for the related species in the entire domain. Since the Reynolds number was small (~1) the fluid flow regime was laminar. Urea cycle was modeled regarding its four main enzymes. Twelve rate equations were also solved in order to obtain the concentration of each metabolites participating in urea cycle. Concentration of the urea reached its maximum ca. 1.2e-5 M at the end of the channel which is in good... 

Separation and lysis of RBCs play an important role in diagnosis of different diseases. Although they have been partially studied in several researches, a comprehensive study on integrating both separation and lysis units on a single chip has been seen rarely in the literature. Also, the factors related to the chemical lysis process have not been investigated in detail. In this study, we introduce a novel microfluidic channel design for sequential RBC's separation and lysis. For the separation part, an active method with an electric field was applied to the cells. Besides, a novel mixer was designed for mixing the cell solution and lysis reagent. In the lysis section, we used a mathematical... 

Microfluidics based systems could be useful for drug discovery as they allow for miniaturization and could potentially be run as multiple parallel cell based assays. Such miniaturization allows assays at single cell level and reduces the amount of test material needed, which, in the case of natural product extracts, simplifies the preparation. Thyme species extracts have been reported to show some promising anti-cancer effects. In the present work, we used a microfluidics based system to study the effects of Thymus kotschyanusm Boiss plant extract on two human breast cancer cells lines which are MDA-MB-231 and MCF-7. For better understanding a single cancer cell death mechanism and a flow... 

One important functionality of liver cells is ammonia detoxification and urea production. In this study, a numerical model of the urea cycle in hepatocytes was developed. Navier Stokes and convection equations were employed to study the process of ammonia elimination and urea production using a microfluidic channel. The concentration of urea and ammonia throughout the channel was obtained. Furthermore, the urea cycle was modelled with respect to its four main enzymes. This resulted in twelve rate equations that were solved to determine the concentration of each metabolite participating in the urea cycle. Application of results implied common disorders such as hyperammonemia types I and II... 

One important functionality of liver cells is ammonia detoxification and urea production. In this study, a numerical model of the urea cycle in hepatocytes was developed. Navier Stokes and convection equations were employed to study the process of ammonia elimination and urea production using a microfluidic channel. The concentration of urea and ammonia throughout the channel was obtained. Furthermore, the urea cycle was modelled with respect to its four main enzymes. This resulted in twelve rate equations that were solved to determine the concentration of each metabolite participating in the urea cycle. Application of results implied common disorders such as hyperammonemia types I and II...