Sharif Digital Repository

Circulating tumor cells (CTCs) are cancer cells which shed from the primary tumor, enter circulation and spread cancer all over the body. CTCs give valuable information about cancer and can help diagnosis and prognosis. Hence separating and isolating CTCs from blood is a necessity for cancer therapeutics. CTCs are separated from blood cells by their different physical or biochemical properties. Many groups have attempted different methods for separation of CTCs. Inertial microfluidics is one of the newest approaches in CTC separation technologies which separates CTCs based on their size. Current inertial microfluidic systems containing straight, spiral, serpentine and contraction expansion... 

In the competitive facility location problem, two service providers fight over winning consumers by establishing a series of well-located facilities on the line. The consumers seek their required services from the facility which is closest to them. The order in which service providers locate and build their facilities is as follows: the first service provider establishes k facilities after which the second service provider locates another k facilities and this goes on for m rounds. The payoff of each service provider equals the number of consumers that choose that provider’s facilities to seek service from. In this dissertation, we address different types of this problem and try to analyze... 

Trust is a common concept in interpersonal relationships. It is a replacement for strict control mechanisms, helping individuals to have a better estimation of the risks involved in an interaction or relationship. Computational notions of trust have a close relationship with security in computer systems.Different models of trust have been proposed to regulate interactions in: security, collaborative systems, and routing. We focused on two important problems and challenges in this dissertation: proper handling of uncertainty, and uncertainty-aware trust-based decision-making.We propose an integrated approach to modeling, processing, and treating uncertainty, as well as to uncertainty-aware... 

In recent years the rapid rise of polymer consumption especially in the form of packaging materials became a real menace for the environment. Polyolefin are some of the most dominant packaging materials and responsible by part of the problems in the disposal of one-trip packaging. One of the possible ways of solving this problem is the introduction of additives increasing their susceptibility to environmental degradation into non-biodegradable polymers. One such additive is starch- the natural, cheap, and easily biodegradable polymer. Starch was already used as a filler or as a blend with polyolefin. Addition of dry starch granules to polyolefin follows the general trend of filler effects on... 

The purpose of this study is to assess the inhibitory effects of an appropriate nanoparticles loaded with gallic acid on the fibrillation of alpha-synuclein. Alpha-synuclein is a major component of protein plaques in synucleinopathies, particularly Parkinson’s disease. Gallic acid (GA, 3,4,5-trihydroxy benzoic acid) is a well–known small molecule which can inhibit the formation of α-synuclein fibrils. For the process of fibrillation, purified protein was incubated at 37◦C and pH 7.2. Fibrillation was analyzed by the standard fibril methods.after that investigated fabricating of gallic acid trapped in the chitosan nanoparticles and gallic acid loaded in chitosan –coated mesoporous silica... 

Resource sharing is the most important feature of a Grid. Resource discovery enables users to find the most suitable resources to run Grid jobs on. Resource discovery systems are often centralized or hierarchical. These structures are usually prone to a single point of failure, and unbalanced distribution of processing and storage load, making them inefficient as the Grid grows. These challenges have led researchers to adapt distributed approaches, such as Peer-to-Peer file sharing solutions. The important differences between Grid resource discovery and P2P file discovery (e.g. different resource attributes, queries, change patterns etc.) make it difficult to port the existing solutions to... 

Skin tissue engineering, is considered as a method to heal full-thickness wounds. The basis of this method is fabrication a substrate named scaffold in order to replace the lost skin tissue temporarily. The aim of the present study is the fabrication and characterization of skin scaffolds using two natural polymers, which are Chitosan and Gelatin. This study is divided into three phases: first is the investigation of the influence of two cross-linkers named Glutaraldehyde and a kind of carbodiimide on the properties of scaffolds, second is the characterization of scaffolds fabricated by three different ratios of chitosan/gelatin and third is the evaluation of the effect of Allantoin on... 

This research aims to develop a drug delivery system based on mesoporous silica nanoparticles (MSNPs) for hydrophobic drugs and evaluating their cytotoxicity. The internal environment of the body is aqueous, while most of effective drugs display poor aqueous solubility, resulting in insufficient bioavailability. Due to their several unique properties, such as a large surface area, tunable pore size, facile surface multi functionalization and excellent biocompatibility, MSNPs are recognized as promising and powerful tools to overcome this hurdle. In the present study, MSNPs were synthesized using template removing method and then were functionalized through grafting procedure. They were...