Sharif Digital Repository

Environmental problems have been one of the considerable issues since the irreversible characteristics of nature and its effect on human life were recognized. Scientists have proposed a variety of solutions in order to overcome such problems. Green marketing can be regarded as one of the solutions in this area. Similar to most other issues, this concept has been noticed less in developing countries compared to developed countries. Therefore, researchers in this study conducted a comprehensive research on the concept of green marketing in Iran focusing on consumers’ behavior.
To achieve relevant results, two types of research were conducted: qualitative and quantitative. The results of... 

Enzymes, the nanometric biocatalysts that play a key role in biochemical reactions of living cells and bio-organisms, offer various applications including biosensing, bioremediation and chemical synthesis. A simple bio-conjugation procedure to surround a single horseradish peroxidase (HRP) enzyme molecule with dendritic polyester macromolecules (Polyester-32-hydroxyl-1-carboxyl bis-MPA Dendron, Generation 5) was proposed in this project. The characterization of resultant nanoparticles entitled HRP dendrozyme, was performed by TEM, DLS, GPC and FTIR spectroscopy. The results showed that HRP nanoparticles were spherical in shape and have an average size of 14 nm in diameter. Furthermore,... 

In recent years, advances in medical science and increasing the level of healthcare have increased the life expectancy index; But in the meantime, a phenomenon called “diseases related to life expectancy” has appeared. Bone and skeletal diseases have a significant share in this category because the passage of time reduces bone mineral density and this is the source of many diseases, including osteoporosis. Current bone therapies, which include autologous and allogeneic bone grafts, will not meet this high need. Bone tissue engineering has been proposed as a potential alternative to solve this challenge. In bone tissue engineering, the essential components required for bone formation and... 

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... 

Skin, the largest organ in the body, presents sophisticated functions for maintaining the structural integrity of the entire body. Skin can regulate the temperature of the body, protect the body against microorganisms, have a sensory function, and produce vitamin-D through UV exposure when in direct sunlight.Due to the self-healing property of skin tissue, skin can be repaired by itself. Nevertheless, if extensive skin loss happens, owing to diabetic ulcers or deep burns, skin will not be able to repair the wound by itself. Therefore, it will lose its functions, and the fabrication of a skin equivalent will be necessary. These skin equivalents will cover the wound, regenerate the native... 

Combined composites consisting of nanofibers and hydrogels were fabricated to grow cells in an environment that mimicked the extracellular matrix. Electrospan nanofibers were spun and hydrolyzed under optimized conditions consisting of polycaprolactone (PCL) and gelatin and then incorporated into alginate and gelatin hydrogels. Nanofibril-containing (NF / hydrogel) hydrogel hybrids were ligated by calcium chloride in the presence of encapsulated beta cells. The mechanical properties of NF / hydrogel scaffolds were significantly increased in proportion to the NF content in NF / hydrogels. Beta cells killed in NF / hydrogels showed higher adhesion to the matrix compared to samples without NF.... 

Type 1 diabetes, formerly known as insulin-dependent diabetes, may present at any age, but is the most common type of diabetes affecting children and adolescents. People with type 1 diabetes do not produce enough insulin. This type accounts for 5-10% of all types of diabetes. In this type of diabetes, beta cell destruction occurs in the pancreas. In type 1 diabetes, the pancreas does not secrete any insulin; insulin is a hormone that enables the body to convert glucose in food into energy. If sugar in the blood cannot enter the cells, it accumulates in the arteries and results in high blood sugar. High blood sugar over time can have irreversible effects on various parts of the body. Curcumin... 

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... 

Wastewater, especially with heavy metal contamination, is a global environmental concern. Numerous techniques have been tested for online controlling and monitoring the concentration of heavy metal ions; yet, there are many challenges in performing these techniques. Biosensor is cheap, easily available, simple, fast, selective, sensitive, and repeatable so it is an excellent alternative for the detection and quantification of hazardous particles in the wastewater. In this study, a Nano biosensor with high detection of copper ions has been fabricated. PEDOT:PSS as a highly conductive polymer is coupled with gold nanoparticles to modify the surface of graphite electrode and results in higher... 

Isolation and characterization of circulating tumor cells (CTCs) found in blood samples of cancer patients have been considered as a reliable source for cancer prognosis and diagnosis. A new continuous microfluidic platform has been designed in this investigation for simultaneous capture and characterization of CTCs based on their deformability. The deformability-based chip (D-Chip) consists of two sections of separation and characterization where slanted weirs with a gap of 7 μm were considered. Although sometimes CTCs and leukocytes have the same size, the deformability differs in such a way that can be exploited for enrichment purposes. MCF7 and MDA-MB-231 cell lines were used for the... 

Malaria is one of the most important infectious diseases in the tropical and subtropical regions of the world and is caused in humans by the bite of the female Anopheles mosquito of five species of Plasmodium. According to the World Health Organization, about 229 million people worldwide were infected in 2019 by the disease, and 409,000 people died from the disease. Resistance of the parasite against drugs and resistance of vectors to insecticides and larvicides, which prevents the elimination and eradication of malaria, shows the need for new strategies, such as having an effective vaccine against this disease. In the second generation of vaccines, to develop malaria vaccines, recombinant... 

Cancer is an abnormal growth of cells which is one of the major cause of worldwide’s mortality. Circulating Tumor Cells (CTCs) are rare cancer cells released from the primary or metastatic tumors and transported though the peripheral circulatory system and spreads in body and seize healthy organs. Early detection of CTCs can help in overtaking the cancer, hence isolation of CTCs is an essential step for many therapeutics. 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), similarity to white blood cell in size and also variability in terms of... 

Cancer is the second leading cause of death among humans as one of the major human concerns. More than 500,000 people die of cancer each year in the United States alone. Cancer mortality is mainly due to cancer metastasis. Metastasis is the escape of cancer cells from a primary tumor, the circulation of cells in the circulatory system (CTSs), the penetration of/from vessel wall, and the formation of a secondary tumor. It is still not clear how the cells survive in the circulatory system, along with the mechanical pressures and stresses that exist in the body's capillary channals. In this study, a microcirculation model for circulating cells with barriers was designed and constructed by the... 

Physical processes such as adsorption and membrane filtration are in progress and considered as efficient methods in separation and treatment of organic pollutants from petrochemical and colored wastewaters. The advantages of these methods include high energy efficiency, low cost, facile process, and regeneration and implementation ability for a wide range of contaminants. Nevertheless,requirement of suitable materials as adsorbents with high adsorption capacity, capability of preparing membranes based on these materials, optimization of process conditions and removal improvement have still remained as the main challenges; therefore, these topics have been mentioned as main aims of this... 

Bacterial cellulose is a kind of cellulose with high purity and Crystallization, which is mainly produced by gram-negative bacteria in aqueous media containing a sugar source.Cellulose produced by this method is in the form of nanofibers and one of its considerable aspects, nowadays, is that this kind of cellulose is used as a drug carrier system for treating various diseases. Azithromycin is used as an antibiotic for the treatment of a wide range of bacterial infections. In this study, cellulose nanofibers were synthesized by gluconacetobacter and its surface was modified using 0.5, 1, and 1.5 mg/ml carboxymethylcellulose solution in sodium acetate buffer. Then, by stabilizing azithromycin... 

This study aimed to prepare a type of microcapsule that microencapsulates folic acid and iron at the same time and protects these two substances against environmental and gastrointestinal conditions. Simultaneous release of these two nutrients has dual health properties and improves the efficiency of folic acid microencapsulation. In this study, biocomposites were formed containing alginate, pectin, and carboxymethylcellulose, and the microcapsules were synthesized by the ionization of calcium-alginate ions. Biocomposite optimization mixture with 13 experiments using experimental design software, optimal combination design method based on repopulation separator, restoring folic acid... 

Polymerase Chain Reaction (PCR) is a process in which a special piece of a gene is amplified millions of times over a short period. This method has been of paramount importance in different fields of research and has been applied for different applications. PCR requires thermal cycling, or repeated temperature changes between two or three discrete temperatures to amplify specific nucleic acid target sequences. To achieve such thermal cycling, conventional bench-top thermal cyclers generally use a metal heating block powered by Peltier elements or benefit from forced convection heat transfer. Due to the fact that these methods are time consuming, it seems that design and fabrication of a fast... 

In recent years, it is expected that the fabrication of multilayer scaffolds and the use of different methodologies in one product can be a new progressing method in skin substitute production. Accordingly, this project aims to fabricate a bilayered composite scaffold with a combination of hydrogel and electrospinning method. We have tried to prepare a scaffold made of oxidized alginate (OAL), gelatin (G), and silk fibroin (SF) without using corrosive solvents and toxic crosslinking agents as a scaffold and drug delivery system. As different biological, chemical, physical, and mechanical factors play a vital role in the healing process, we have characterized the proposed scaffold via DSC,...