Sharif Digital Repository

Ciprofloxacin is an alternative to vancomycin for treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. The objective of this study was to optimization of niosomes encapsulated ciprofloxacin and evaluate their antibacterial and anti-biofilm efficacies against ciprofloxacin-resistant methicillin-resistant S. aureus (CR-MRSA) strains. Formulation of niosomes encapsulated ciprofloxacin were optimized by changing the proportions of Tween 60, Span 60, and cholesterol. The optimized ciprofloxacin encapsulated niosomal formulations based on Span 60 and Tween 60 were prepared and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM) and... 

Inserting the distal locking screws is a challenging step of the intramedullary nailing procedures due to the nail deformation that makes the proximally mounted targeting systems ineffective. A pre-planning methodology is proposed, based on an analytical model of the nail–bone construct, to predict the nail deformation during surgery using orthogonal preoperative radiographs. Each of the femoral shaft and the nail was modeled as a curved tubular Euler–Bernoulli beam. The unknown positions and forces of the nail–bone interaction were found using a systematic trial and error approach, which minimized the total strain energy of the system while satisfying the force and geometrical constraints.... 

An efficient and selective drug delivery vehicle for cancer cells can remarkably improve therapeutic approaches. In this study, we focused on the synthesis and characterization of magnetic Ni1−x Cox Fe2 O4 nanoparticles (NPs) coated with two layers of methionine and polyethylene glycol to increase the loading capacity and lower toxicity to serve as an efficient drug car-rier. Ni1−x Cox Fe2 O4 @Methionine@PEG NPs were synthesized by a reflux method then charac-terized by FTIR, XRD, FESEM, TEM, and VSM. Naproxen was used as a model drug and its loading and release in the vehicles were evaluated. The results for loading efficiency showed 1 mg of Ni1−x Cox Fe2 O4 @Methionine@PEG NPs could load... 

Curcumin (Cur) is a traditional herb with known anticancer properties against various malignancies such as breast cancer. In this study, a metal-organic framework (MOF) based on UIO-66 with excellent water stability was prepared to deliver Cur into MDA-MB-231 and SKBR3 human breast cancer cell lines. The size of the fabricated UIO-66 ranged from 100 to 150 nm with a spherical shape and triangular base pyramid morphology. Favorable adsorption of Cur on the UIO-66 was approved by Fourier transform infrared spectroscopy (FTIR). The release profile exhibited a slow pH-dependent release of Cur from UIO-66 with significant enhancement in the acidic microenvironment (50, 55, and 70% Cur release... 

Distal locking is a challenging subtask of intramedullary nailing fracture fixation due to the nail deformation that makes the proximally mounted targeting systems ineffective. A patient specific finite element model was developed, based on the QCT data of a cadaveric femur, to predict the position of the distal hole of the nail postoperatively. The mechanical interactions of femur and nail (of two sizes) during nail insertion was simulated using ABAQUS in two steps of dynamic pushing and static equilibrium, for the intact and distally fractured bone. Experiments were also performed on the same specimen to validate the simulation results. A good agreement was found between the model... 

In this paper the torsion problem of a circular bar with fixed ends is solved using a finite deformation constitutive model based on the corotational rates of the logarithmic strain. The logarithmic, Green-Naghdi and Eulerian corotational rates of the logarithmic strain are used in the model. The solution is based on a von Mises type yield function that incorporates isotropic and kinematic hardenings. For the kinematic hardening, a modified Armstrong-Fredrick hardening model with the corotational rate of the logarithmic strain is used. Assuming incompressible behavior, the fixed-end torsion problem is simplified to the simple shear problem. Solving the problem, the stress components are... 

Reservoir permeability is an important parameter that its reliable prediction is necessary for reservoir performance assessment and management. Although many empirical formulas are derived regarding permeability and porosity in sandstone reservoirs, these correlations cannot be accurately depicted in carbonate reservoir for the wells that are not cored and for which there are no welltest data. Therefore, having a framework for estimation of these parameters in reservoirs with neither coring samples nor welltest data is crucial. Rock properties are characterized by using different well logs. However, there is no specific petrophysical log for estimating rock permeability; thus, new methods... 

Small high-quality Au/P-Si Schottky barrier diodes (SBDs) with an extremely low reverse leakage current using wet lithography were produced. Their effective barrier heights (BHs) and ideality factors from current-voltage (I -V) characteristics were measured by a conducting probe atomic force microscope (C-AFM). In spite of the identical preparation of the diodes there was a diode-to-diode variation in ideality factor and barrier height parameters. By extrapolating the plots the built in potential of the Au /p-Si contact was obtained as Vbi D 0:5425 V and the barrier height value φB(C-V) was calculated to be φB(C-V) D 0:7145 V for Au/p-Si. It is found that for the diodes with diameters... 

The permeability is one of the most important reservoir parameters and its accurate prediction is necessary for reservoir management and enhancement. Although many empirical formulas are derived regarding permeability and porosity in sandstone reservoirs [1], these correlations cannot be modified accurately in carbonate reservoir for the wells which are not cored and there is no welltest data. Therefore estimation of these parameters is a challenge in reservoirs with no coring sample and welltest data. One of the most powerful tools to estimate permeability from well logs is Artificial Neural Network (ANN) whose advantages and disadvantages have been discussed by several authors [2]. In this... 

Over-the-top (OTT) video streaming services have been growing rapidly in the last decade, and thus increasing Quality-of-Experience (QoE) of end users is of great interest in emerging services. Although, numerous subjective studies have been conducted to investigate the impact of video presentation quality and playback interruptions, understanding the interactions between impairment types is still an open problem. In this work, we develop a streaming video dataset that contains compressed videos with different distortion levels as well as playback stalling events. Then, a subjective user study is performed to measure the QoE of these videos. The results of our experiment reveal strong... 

Reservoir permeability is an important parameter that its reliable prediction is necessary for reservoir performance assessment and management. Although many empirical formulas are derived regarding permeability and porosity in sandstone reservoirs, these correlations cannot be accurately depicted in carbonate reservoir for the wells that are not cored and for which there are no welltest data. Therefore, having a framework for estimation of these parameters in reservoirs with neither coring samples nor welltest data is crucial. Rock properties are characterized by using different well logs. However, there is no specific petrophysical log for estimating rock permeability; thus, new methods... 

Clustering is one of the most useful methods of data mining, in which a set of real or abstract objects are categorized into clusters. The DBSCAN clustering method, one of the most famous density based clustering methods, categorizes points in dense areas into same clusters. In DBSCAN a point is said to be dense if the ε-radius circular area around it contains at least MinPts points. To find such dense areas, region queries are fired. Two points are defined as density connected if the distance between them is less than ε and at least one of them is dense. Finally, density connected parts of the data set extracted as clusters. The significant issue of such a method is that its parameters (ε... 

Increasing power densities in future technology nodes is a crucial issue in multicore platforms. As the number of cores increases in them, power budget constraints may prevent powering all cores simultaneously at full performance level. Therefore, chip manufacturers introduce a power budget constraint as Thermal Design Power (TDP) for chips. Meanwhile, multicore platforms are suitable for implementation of fault-tolerance techniques to achieve high reliability. Task Replication is a known technique to tolerate transient faults. However, careless task replication may lead to significant peak power consumption. In this paper, we consider the problem of achieving a given reliability target... 

Motivated by the problem of automatically composing network accessible services, such as those on the World Wide Web, this paper proposes an approach to exploit all semantic information available for semantic web services to complete this task. For semantic web services, we propose a prioritized and limited list of other web services, with composability measure value based on feasibility of being succeeding service in a composition to fulfill the request. Due to the fact that in semantic web services, semantic information- all description and signatures- is defined by ontology language, we use some of the mapping rules to estimate a correlation between services for composability. Then we... 

Increasing power densities in future technology nodes is a crucial issue in multicore platforms. As the number of cores increases in them, power budget constraints may prevent powering all cores simultaneously at full performance level. Therefore, chip manufacturers introduce a power budget constraint as Thermal Design Power (TDP) for chips. Meanwhile, multicore platforms are suitable for the implementation of fault-tolerance techniques to achieve high reliability. Task Replication is a well-known technique to tolerate transient faults. However, careless task replication may lead to significant peak power consumption. In this article, we consider the problem of achieving a given reliability...