Sharif Digital Repository

Over the past few decades, gold nanomaterials have shown great promise in the field of nanotechnology, especially in medical and biological applications. They have become the most used nanomaterials in those fields due to their several advantageous. However, rod-shaped gold nanoparticles, or gold nanorods (GNRs), have some more unique physical, optical, and chemical properties, making them proper candidates for biomedical applications including drug/gene delivery, photothermal/photodynamic therapy, and theranostics. Most of their therapeutic applications are based on their ability for tunable heat generation upon exposure to near-infrared (NIR) radiation, which is helpful in both... 

Cancer is a deadly disease that has long plagued humans and has become more prevalent in recent years. The common treatment modalities for this disease have always faced many problems and complications, and this has led to the discovery of strategies for cancer diagnosis and treatment. The use of magnetic nanoparticles in the past two decades has had a significant impact on this. One of the objectives of the present study is to introduce the special properties of these nanoparticles and how they are structured to load and transport drugs to tumors. In this study, iron oxide (Fe3O4) nanoparticles with 6 nm sizes were coated with hyperbranched polyglycerol (HPG) and folic acid (FA). The... 

Cancer has long been a leading cause of death. The primary tumor, however, is not the main cause of death in more than 90% of cases. It is the complex process of metastasis that makes cancer deadly. The invasion metastasis cascade is the multi-step biological process of cancer cell dissemination to distant organ sites and adaptation to the new microenvironment site. Unraveling the metastasis process can provide great insight into cancer death prevention or even treatment. Microfluidics is a promising platform, that provides a wide range of applications in metastasis-related investigations. Cell culture microfluidic technologies for in vitro modeling of cancer tissues with fluid flow and the... 

Abstract: In the present paper, an efficient Cu-catalyzed regioselective acylation of indoles with phenylglyoxals was developed which is the first example of indolyl diketones synthesis by a heterogeneous catalyst. The magnetic polyacrylonitrile was synthesized through anchoring acrylonitrile monomers on Fe3O4 nanoparticles surface and then modified with 2-aminopyridine. At the final step, copper nanoparticles were immobilized onto the polymeric support containing stable ligands from functionalized nitrile groups of polyacrylonitrile. The different techniques such as Fourier transmission infrared spectroscopy, X-ray diffraction, Field emission scanning electron microscopy, Transmission... 

Cardiac troponin-I (cTnI) is a well-known biomarker for the diagnosis and control of acute myocardial infarction in clinical practice. To improve the accuracy and reliability of cTnI electrochemical immunosensors, we propose a multilayer nanostructure consisting of Fe3O4-COOH labeled anti-cTnI monoclonal antibody (Fe3O4-COOH-Ab1 ) and anti-cTnI polyclonal antibody (Ab2 ) conjugated on Au-Ag nanoparticles (NPs) decorated on a metal–organic framework (Au-Ag@ZIF-67-Ab2 ). In this design, Fe3O4-COOH was used for separation of cTnI in specimens and signal amplification, hierarchical porous ZIF-67 extremely enhanced the specific surface area, and Au-Ag NPs synergically promoted the conductivity... 

Systemic chemotherapy has lost its position to treat cancer over the past years mainly due to drug resistance, side effects, and limited survival ratio. Among a plethora of local drug delivery systems to solve this issue, the combinatorial strategy of chemo-hyperthermia has recently received attention. Herein we developed a magneto-thermal nanocarrier consisted of superparamagnetic iron oxide nanoparticles (SPIONs) coated by a blend formulation of a three-block copolymer Pluronic F127 and F68 on the oleic acid (OA) in which Curcumin as a natural and chemical anti-cancer agent was loaded. The subsequent nanocarrier SPION@OA-F127/F68-Cur was designed with a controlled gelation temperature of... 

An investigation into the addition of different weight percentages of Fe3O4 nanoparticles to find the optimum wt.% and its effect on the microstructure, thermal, magnetic, and electrical properties of aluminum matrix composite was conducted using the powder metallurgy method. The purpose of this research was to develop magnetic properties in aluminum. Based on the obtained results, the value of density, hardness, and saturation magnetization (Ms) from 2.33 g/cm3, 43 HV and 2.49 emu/g for Al-10 Fe3O4 reached a maximum value of 3.29 g/cm3, 47 HV and 13.06 emu/g for the Al-35 Fe3O4 which showed an improvement of 41.2%, 9.3%, and 424.5%, respectively. The maximum and minimum coercivity (Hc) was... 

Iron oxyhydroxide (α-FeOOH, Goethite) is one of the most thermodynamically stable iron oxides and a widespread soil mineral. In this study, a mixture of two phenolic extracts of rosemary and Echinacea was utilized as stabilizing and reducing agents for the synthesis of Goethite (FeOOH) nanoparticles without utilizing harmful toxic solvents. The resulting nanoparticles were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM)-energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), vibrating-sample magnetometer (VSM), thermogravimetry/differential thermal analysis (TG/DTA), and Brunauer–Emmett-Teller (BET). MTT assay was... 

Sufficient quantity of trace metals is essential for a well performing anaerobic digestion (AD) process. Among the essential trace elements in active sites of multiple important enzymes for AD are iron and nickel ions. In the present study, iron and nickel in the form of Fe2O3 and NiO were coated on TiO2 nanoparticles to be used in batch and continuous operation mode. The effect of TiO2, Fe2O3–TiO2, and NiO–TiO2 nanoparticles on each step of AD process was assessed utilizing simple substrates (i.e. cellulose, glucose, acetic acid, and mixture of H2–CO2) as well as complex ones (i.e. municipal biopulp). The hydrolysis rate of cellulose substrate increased with higher dosages of the coated... 

Flat plate solar collectors lose a massive part of heat accumulated near the contact region because of the poor thermal characteristics of the working fluid. A new cost-effective design is numerically studied to cover up such deficiency by equipping the flat plate collector with revolutionary tubes and magnetic field inducer to affect Fe3O4/water working nanofluid in the collector tubes. Results substantiate that each of the applied rotary tubes and magnetic field inducer improves the convection mechanism in the tubes by circulating the flow inside the tubes and saves more of available solar energy. Results reveal that 27.8% and 10.44% of lost energy are restored in the solar collector... 

In the present study, the effects of rotary tubes and magnetic-induced nanofluid on heat transfer characteristics of a compact heat exchanger are individually investigated. Two-phase Eulerian model is employed to predict the hydrothermal and entropic characteristics of Fe3O4/water ferrofluid in the heat exchanger. Results indicate that utilizing each rotary tubes and magnetic field method can improve the energy and exergy efficiencies of the compact heat exchanger under specific circumstances by forming different types of secondary flow. It is found that employing each method individually can increase the maximum heat transfer rate by more than 60%. In comparison with methods like passive... 

In this paper, the hydrodynamic and thermal behavior of a Fe3O4 ferrofluid flow was experimentally investigated inside a cupric u-shaped tube on a horizontal surface, under the effect of a variable magnetic field. The inlet flow regime was laminar and considered under the thermal boundary conditions of the tube with a uniform heat flux, which was affected by the variable magnetic field in some regions. The purpose of the study was to investigate the effect of parameters such as volume fraction of nanoparticles, Reynolds number of the flow, the radius of the curvature, and magnetic field frequency at three levels and four factors in the flow behavior in order to increase the convection heat... 

Natural convective heat transfer of Fe3O4/ethylene glycol nanofluids around the platinum wire as a heater in the absence and presence of the high electric field was investigated, numerically. The control volume finite element method was employed for the numerical simulation. Effects of the flow model, the volume fraction of nanoparticles, Rayleigh number, and the electric field intensity on the natural heat transfer coefficient (NHTC) of nanofluid were studied. Simulation results of single-phase and two-phase flow models showed that the two-phase model could better predict experimental data than the single-phase model due to take into account the velocity of each phase in the mixture. The... 

Latent thermal energy storage dependent on Phase Change Materials (PCMs) proposes a possible answer for modifying the availability of alternating energy from renewable sources such as wind and solar. They can possibly store large amounts of energy in moderately tiny dimensions as well as through almost isothermal procedures. Notwithstanding, low thermal conductivity values is a significant disadvantage of the present PCMs which critically restrict their energy storage usage. Likewise, this unacceptably decreases the solidification/melting rates, hence causing the system response time to be excessively lengthy. The present examination accomplished a better PCM solidification rate with a... 

Abstract: In the present paper, an efficient Cu-catalyzed regioselective acylation of indoles with phenylglyoxals was developed which is the first example of indolyl diketones synthesis by a heterogeneous catalyst. The magnetic polyacrylonitrile was synthesized through anchoring acrylonitrile monomers on Fe3O4 nanoparticles surface and then modified with 2-aminopyridine. At the final step, copper nanoparticles were immobilized onto the polymeric support containing stable ligands from functionalized nitrile groups of polyacrylonitrile. The different techniques such as Fourier transmission infrared spectroscopy, X-ray diffraction, Field emission scanning electron microscopy, Transmission... 

Herein, a novel Pt-APA composite (APA = pyridinium bromide salt) based on magnetic graphene oxide was synthesized and used as an effective catalyst. In this way, Fe3O4 nanoparticles are grown on graphene oxide (GO) nanosheets by a simple and practical method which creates a unique nanostructure (Fe3O4/GO) through dispersing uniformly among graphene nanosheets. The resulted Pt-APA composite was obtained via adding PtCl2 to an ethanol solution of Fe3O4/GO and α-keto stabilized pyridinium ylide in related conditions. The synthesized nanocomposite structure was identified using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive... 

Carbon-based nanocarriers such as multiwall carbon nanotubes (MWCNTs) and reduced graphene oxide (rGO) have shown promising delivery capabilities due to their low immunogenicity, superior internalization, and suitable cell penetration efficiency. Herein, a molecular engineering strategy is advanced for the one-pot synthesized rGO/MWCNT/Fe3O4/ZnO to enhance the stability of the nanocarrier in the biological matrix; green synthesized ZnO was responsible for water uptake and reduced cytotoxicity, while Fe3O4controlled the cellular internalization for gene delivery. Surface morphology of the ensuing nanocomposite was correlated with photocatalytic and gene delivery (CRISPR/Cas9) features. For... 

The low thermal conductivity of phase change materials has resulted in prolonged melting and freezing processes (charge and discharge) in these materials. This problem has limited the application of these materials in the field of thermal energy storage. In the present study, the effects of adding Fe3O4 magnetic nanoparticles at various concentrations as well as applying the magnetic field on the melting process of paraffin as phase change material have been experimentally studied. Thereupon, a cubic chamber in which the left wall applied a constant heat flux was used. At the optimum concentration of nanoparticles (1 mass%), the constant magnetic field with the intensities of 0.01 T and... 

Developing high-performance supercapacitors is of great significance in the area of renewable energies by virtue of having both high energy and power densities. In this work, an innovative strategy is employed for the fabrication of binder-free binary nickel–cobalt-sulfide (NCS) nanosheets (NSs) directly decorated onto the hydrothermal nickel-sulfide (Ni3S2) nanowires (NWs) as the positive electrodes. The NCS/Ni3S2-nickel foam (NF) positive electrodes rendered superior specific capacity of 499.1 mAh.g−1 at 6 A.g−1. Encapsulated iron into the carbon sphere hosts (Fe-HTCSs) are used as the negative counterparts, exhibiting remarkable specific capacitance of 336.6 F.g−1 (at 0.1 A.g−1). The... 

A novel colorimetric nanosensor is reported for the selective and sensitive determination of cysteine using magnetic-sulfur, nitrogen graphene quantum dots (Fe3O4/S, N-GQDs), and gold nanoparticles (Au NPs). Thus, S, N-GQDs was firstly immobilized on Fe3O4 nanoparticles through its magnetization in the presence of Fe3+ in the alkali solution. The prepared Fe3O4/S, N-GQDs were dispersed in cysteine solution resulting in its quick adsorption on the surface of the Fe3O4/S, N-GQDs through hydrogen bonding interaction. Then, Au NPs solution was added to this mixture that after a short time, the color of Au NPs changed from red to blue, the intensity of surface plasmon resonance peak of Au NPs at...