Sharif Digital Repository

Humic compounds are considered the most portion of natural organic matter (NOM) found in many surface water sources.Humic substances have been known as precursors to disinfection by-products.because conventional treatment process can not meet disinfection by-product standards,novel method have been increasingly applied for the removal of disinfection by-products precursors.The〖UV/TiO〗_2 process is one of the advanced oxidation process using the photocatalytic technology.The most important advantages of this process are its stability and high efficiency removal.The present study aims to investigate the effect of 〖UV/TiO〗_2photo-catalytic technology on removal of humic substances.In this... 

In this thesis, photocatalytic oxidation as a potential method for the treatment of organic environmental contaminants is deeply investigated. While the photocatalytic degradation of various organic compounds under UV light irradiation has been widely investigated, visible-light-induced photocatalytic degradation of low-levels of the pollutants such as Dibenzothiophene (DBT) and 2-Nitrophenol (2-NP) are occasionally reported. In the present work, Lanthanide / Polyethylene glycol -modified TiO2 (La/PEG/TiO2) and Fe,Cu,S/TiO2 have been successfully synthesized by a sol–gel method. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission... 

In this research, fabrication of a mediator free nano-biosensor for the detection of cyanide has been studied. This biosensor utilizes 75 nm diameter (nano) ZnO particles synthesized with sol- gel method for modification and immobilization of Horseradish peroxidase (HRP). Cyanide plays inhibitory role in decomposition of H2O2 while HRP plays catalyst role in this reaction. Cyanide inhibits enzyme activity thorough binding with enzyme active sites and result in decreasing electrical current in electrochemical decomposition of H2O2. Amperometery response of biosensor shows linear relation between inhibition percent and cyanide concentration in range of 3µM - 24µM with detection limit of 0.62µM... 

Nowadays with the extension of industry and factories as well as different kinds of plants, a wide range of pollution and circumference hazardous has been entered to the people`s life. Industrial wastewater has been always a threat for health of our environment and efforts for reducing its dangerous effects are still under studies. Dairy wastewater is one of the main branches of food industrial pollutions and it has been studied in this specific project. The goal was to reduce the Chemical Oxygen Demands (COD) of dairy wastewater with oxidation of Titanium Dioxide Nanophotocatalyst oxidation under UV irradiation. Among the various methods for synthesizing of this Nanophotocatalyst, the... 

In this study, differentiation of rabbit embryonic-derived mesenchymal stem cells to osteogenic cells has been characterized. Bone tissue engineering is based upon the understanding of bone tissue construct and it’s formation in-vivo, and the Preparation of tissue engineered bone constructs to repair large size defects is it’s major goal. We sought to investigate the combined effect of three elemnts of tissue engineering: cells, scaffolds and growth factors. Mesenchymal stem cells are unspecialized cells which due to their unlimited self-renewal capacity and the remarkable ability to differentiate along multiple linage pathways are natural choice for application in tissue repair and... 

L-asparaginase enzyme is a well known enzyme due to itschemotherapeutic properties. However, this is not the only feature of the enzyme. L- asparaginase can be also used in food processing to reduce of acrylamide which is a carcinogenic substance. furthermore, acrylamide formation, is prevented by addition of the enzyme before cooking process of some foods such as chips, which contains sugar and asparagine amino acid. Due to use of the enzyme in food industry, we need to produce enzyme with high activity and cheaper raw material. In the present study, Candida utilis ATCC 9950 was used to produce asparaginase enzyme, and beet molasses and yeast extract was used as a carbohydrate and... 

Lipopolysaccharide (LPS), also known as endotoxin, is a highly toxic component exists in the outer membrane of gram negative bacteria. It releases into the environment during every phase of bacterial growth cycle, so it causes contamination of a wide range of biopharmaceutical products. Even small quantities of endotoxin injected to human body can result in fever, septic shock, and death. Therefore, it is highly important to detect and also quantify endotoxin of biopharmaceutical products in quality control laboratories. The most validated method used for endotoxin detection is Limulus Amebocyte Lysate (LAL). Although this method is sensitive, it has some unavoidable drawbacks such as highly... 

Burns are one of the most important accidents related to human health. Due to the intense physical and mental complications and high fatality rate associated with them, receiving proper treatment is of paramount importance. The control of infection in wounds would cure and eliminates the effect of wounds and treatment of skin lesions with engineered scaffolds can be an effective method. The purpose of this project is proposing a hydrogel scaffold based on natural polymers of oxidized alginate and gelatin loaded with an herbal drug to control infection and treat burn wounds. For this purpose, the Iranian Oak extract that it's main content is Tanin and PolyPhenolinc materials, was prepared and... 

Cancer is a major cause of mortality worldwide, with a disease burden estimated to grow over the coming decades. Circulating tumor cells (CTCs) are rare cancer cells released from the primary or metastatic tumors and transported though the peripheral circulatory system to their specific secondary locations. The presence of CTCs in a cancer patient’s blood has been used as a prognostic biomarker, with lower CTC count correlating with greater overall survival. In spite of its clinical potential, the isolation and detection of CTCs has been a challenging task due to its rare presence amongst other blood cells (as low as 1–10 CTCs per billions of blood cells) and variability in terms of both... 

Convenient medical diagnostics and treatments can replace conventional healthcare procedures because of their fast and profitable applications with reduced infection risk. Meanwhile, early diagnosis of cancer is leading research subject due to the high fatality rate of the disease and being a vital precursor in the treatment effectiveness. Electrochemical-based micro-biosensors are the best candidates for measuring biomarker concentrations in body fluids. To address this need, we used a simple fabrication approach to develop an effective immunosensor for the early detection of cancer, in particular prostate cancer. The carbon fibers, obtained from the electrospinning technique, decorate the... 

Application of nanoparticles in targeted delivery and controlled drug release is recently highly attracted especially in cancer therapy. In this study with the aim of developing a novel drug vector based on metallic nanoparticles, gold nanoparticles with their unique characteristics were used to design a vector for targeted anti-cancer drug delivery to tumor. First, gold nanoparticles were chemically synthesized therough sodium citrate and sodium brohydrate reductions with average diameters of 22 and 11 nm, respectively. Then, the activated poly ethylene glycol (PEG) and activated folic acid were conjugated to the lysine-capped gold nanoparticles. Subsequently, the widely used anticancer... 

L-Asparaginase has two major uses. For decades it has been known and used as an antitumor agent. Besides, it has been introduced as a food processing aid in the last trench against acrylamide formation in foods. Here, we have produced extracellular L-Asparaginase from Candida utilis and studied the parameters surrounding its production. Thus, two species of yeast were cross-examined: Saccharomyces cerevisiae (BBRC 30006) and Candida utilis (ATCC 9950). Moreover, the most suitable method for detecting and determining L-Asparaginase activity was investigated and selected for this purpose which is via L-Aspartate determination with Hydroxylamine. Furthermore, six deferent parameters of... 

With the rapid development of biotechnology, peptide and protein drugs are now playing an increasingly important role in therapeutics. Compared with chemical drugs, peptide and protein drugs have some limitations such as low stability and rapid deactivation. Biodegradable and biocompatible polymeric micro carriers have been shown to have a high potential for the delivery of peptides and proteins. Among these polymers, alginate has been widely investigated as a biomaterial. Alginates are natural polysaccharide polymers isolated from brown seaweed. Bovine serum albumin (BSA) loaded calcium alginate microspheres produced in this study by a modified w/o emulsification method. The influence of... 

There is increasing evidence that injecting modified brines has a significant impact on the amount of oil recovered, but the exact mechanism by which this occurs is an unsettled issue, and is supposed to be a cause of the complex interactions occurring between the phases insitu. In this thesis, surface chemistry of smart water has been investigated. Fluid/solid and fluid/fluid interactions for Bangestan crude oil in tfhe presence of designed solutions and a set of dilutions of Persian Gulf seawater have been studied and compared. Fluid/solid interactions were investigated through wettability studies. Impact of salinity and ionic composition on this interaction was measured through contact... 

In this research, start-up, performance and stability of a A2O system (Anaerobic/ Anoxic/ Oxic) combined with a Moving Bed Bio Reactor (MBBR), using Kaldnes packings, have been investigated in treating synthetic dairy wastewater. Also the effect of influent Chemical Oxygen Demand (COD), Hydroulic Retention Time (HRT) and Ruturn Activated Sludge (RAS) ratio on removing pollutants such as COD, Total Nitrogen and Total Phosphorous have been studied. The experiments have been designed using ‘Design Of Experiments’ software, and at the end the results have been optimized based on desired terms. The performance and capability of the reactor in removing pollutants in 8, 12 and 16 hours of HRT,... 

Alpha amylase enzyme is one of the most important enzymes used in a wide range of industries. The enzyme is used in industries such as detergents, food, pharmaceuticals, paper making and textile. Various national and international articles have been published on this enzyme that focused on specific targets. Despite the extensive studies carried out in this area inside the country, there is still no industrial production of alpha amylase and other enzymes in our country. In the view of the fundamental problem of the lack of industrialization of these studies, in addition to the lack of a riskier investor, it seems that there is a lack of industrial vision in these studies.In this study, the... 

Beta cells are responsible for secreting insulin to maintain normoglycaemia throughout the individual’s life. Type 1 Diabetes Mellitus (T1DM) is a metabolic disorder characterized by an autoimmune response that promotes the destruction of beta-cells within the pancreatic islets, resulting in lifelong inadequate insulin secretion. Encapsulating beta cells inside a semipermeable membrane to protect encapsulated cells from direct contact with the host immune system, is a new way to treat type 1 diabetes without the need for long-term immunosuppression. . In this case, the semipermeable membrane surrounds the cells and allows oxygen, nutrients, and cell products to penetrate bilaterally while... 

Chlorinated hydrocarbons such as trichloroethylene form a kind of dense non-aqueous phase liquid contaminants in groundwater and soil that are so difficult to remediate. In recent years, many field research has been demonstrated application of nano scale zero valent iron can degrade these contaminants.
In this research, nZVI particle synthesized by liquid phase reduction method. Nickel (25%wt ) has been added to increase the reduction rate and also reduce intermediate pollutions. However, the combination of a noble metal to nZVI, leads to more rapid oxidation and tendency to agglomeration. So nZVI particles coated by applying a water soluble-starch solution (0.4%wt) as a stabilizer. The... 

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 recent years, many studies have conducted research about stem cells due to their prominent features such as proliferation and differentiation. By changing the specific parameters of the cellular micro-environment, it is possible to determine the stem cells fate and thereby use them in medical affairs. For this purpose, various devices and methods have been designeds such as microfluidic devices and scaffolds. The microfluidic devices has been especially focuced in the researchs due to their unique features, like the possibility of testing with small amounts of samples, the creation and control of low cost cellular micro-environment and low practical time. Two-dimensional scaffolds made up...