Sharif Digital Repository

Overexpression of proteins/antigens and other gene-related sequences in the bodies could lead to significant mutations and refractory diseases. Detection and identification of assorted trace concentrations of such proteins/antigens and/or gene-related sequences remain challenging, affecting different pathogens and making viruses stronger. Correspondingly, coronavirus (SARS-CoV-2) mutations/alterations and spread could lead to overexpression of ssDNA and the related antigens in the population and brisk activity in gene-editing technologies in the treatment/detection may lead to the presence of pCRISPR in the blood. Therefore, the detection and evaluation of their trace concentrations are of... 

Context: Tangled commits are changes to software that address multiple concerns at once. For researchers interested in bugs, tangled commits mean that they actually study not only bugs, but also other concerns irrelevant for the study of bugs. Objective: We want to improve our understanding of the prevalence of tangling and the types of changes that are tangled within bug fixing commits. Methods: We use a crowd sourcing approach for manual labeling to validate which changes contribute to bug fixes for each line in bug fixing commits. Each line is labeled by four participants. If at least three participants agree on the same label, we have consensus. Results: We estimate that between 17% and... 

Bimodal magnetic-fluorescent materials for diagnostic imaging needs surface-engineered nanoparticles with great biosafety, pronounced colloidal stability, high magnetic moments, and strong photoluminescence (PL) emission. This work presents polymer-coated nanoparticles (PCNPs) based on manganese ferrites covered with a thin shell of nitrogen-doped carbon dots for magnetic-resonance and fluorescent dual mode imaging of cancerous tumors in vivo. An in situ thermolysis of metal oxalates and phenylenediamine in diphenyl ether allows for the facile synthesis of hybrid magneto-fluorescent nanoparticles. They possess an average size of 55 ± 5 nm with strong and excitation-independent PL emission at... 

Developing a uniform polymer-based composite filament is a critical factor for a successful 3D printing process. In this regard, a novel technique for the fabrication of PLA-graphite filament with the potential to be applied to other PLA-based composite filaments was proposed and compared to the solvent casting method. This modified mixing technique involves partial dissolution of the PLA pellets surface by dichloromethane (DCM), which creates a sticky surface for the strong adhesion of reinforcement powders. The manufactured composite filament by this method exhibited excellent structural features, while the solvent casting method yielded a heterogeneous filament with a non-uniform diameter... 

Tissue adhesives have been widely used for preventing wound leaks, sever bleeding, as well as for enhancing drug delivery and biosensing. However, only a few among suggested platforms cover the circumstances required for high-adhesion strength and biocompatibility, without toxicity. Antibacterial properties, controllable degradation, encapsulation capacity, detectability by image-guided procedures and affordable price are also centered to on-demand tissue adhesives. Herein we overview the history of tissue adhesives, different types of polysaccharide-based tissue adhesives, their mechanism of gluing, and different applications of polysaccharide-based tissue adhesives. We also highlight the... 

Faujasite (X, Y) zeolites are considered the main and important catalysts in hydrorefining processes. In order to obtain zeolites with higher acidity and volume of mesopores, post-synthesis modification, dealumination by different pickling techniques (using ethylenediamine tetraacetic acid [EDTA] chelating agent), and thermal treatment (calcination) were employed. The dealumination process led to the removal of the aluminum atoms from the zeolite structure and a rise in acidity while maintaining the zeolite crystalline lattice. X-ray diffraction (XRD), atomic absorption spectrometry (AAS), Fourier-transform infrared (FT-IR), field-emission scanning electron microscopy (FE-SEM),... 

This study focuses on the spectrochemical estimation of pH and titratable acidity (TA) of apples of Fuji variety at different stages of ripening. A novel approach is proposed for near-infrared (NIR) spectral analysis using hybrid machine learning methods that combine artificial neural networks (ANN) and metaheuristic algorithms. One hundred twenty samples were collected at three ripening stages and spectral data within two bands of NIR were extracted from each sample to predict the acidity properties. Alternatively, the 4 most effective wavelengths were also selected using a hybrid of ANN and the cultural algorithm. The experimental results prove that the models using spectral bands and the... 

Supersonic turbulent high-pressure jet flows, which are discharging in low-pressure quiescent ambient, are recognized as imperfectly expanded turbulent jet. Steady-state imperfectly expanded jet flow has been already studied analytically; however, the transient flow has not been thoroughly studied. In the present study, the transient imperfectly expanded jet flow with focus on fuel spray in combustion is investigated analytically employing two-step separation of variables method and Fourier-Bessel expansion. The results are validated using available experimental data. The effects of different parameters such as eddy viscosity and pressure ratio on the behavior of the jet are studied. Results... 

Emergence of reformation and privatization in energy systems has caused the development of multi-agent distribution systems. In this context, each agent as an independent entity aims to efficiently operate its respective resources; while, the distribution network operator (DNO) strives to control the grid in an efficient and reliable manner. Respectively, in case of failure incidences in the grid, DNO should address the economic losses as well as reliability concerns of the agents. Consequently, this paper intends to organize a framework that enables the DNO in order to incentivize the cooperation of agents to alleviate operational effects of the contingency condition. Accordingly, DNO... 

Nowadays, the world is facing a shortage of fresh water. Utilizing adsorbent materials to adsorb air moisture is a suitable method for producing freshwater, especially combining the adsorption desalination system with solar energy devices such as solar collectors. The low temperature of solar collectors has caused some water to remain in the adsorbents in the desorption process and has reduced the possibility of using these systems. In this research, for the first time, an evacuated tube collector (ETC) is used as an adsorbent bed so that the temperature of the desorption process reaches higher values and as a result, more fresh water is expected to produced. In this study, two adsorption... 

Aggressive driving has emerged as one of the most studied behaviors in the traffic safety field, due to its association with the odds of motor vehicle crashes and especially fatal crashes. Previous research has investigated the situations which provoke anger while driving, as well as the emotional (anger) and behavioral (aggression) aspects of aggressive driving. However, surprisingly the cognitive aspects of aggressive driving have largely been neglected. This study investigated the psychometric properties of the short-forms of the Driver's Angry Thoughts Questionnaire (DATQ) and the Driving Anger Expression Inventory (DAX) in a sample of professional drivers. Furthermore, the study aimed... 

Crash forecasting enables safety planners to take appropriate actions before casualty or loss occurs. Identifying and analyzing the attributes influencing forecasting accuracy is of great importance in road crash forecasting. This study aims to model the forecasting accuracy of 31 provinces using their macroeconomic variables and road traffic indicators. Iran's road crashes throughout 2011–2018 are calibrated and cross-validated using the Holt-Winters (HW) forecasting method. The sensitivity of crash forecast reliability is studied by a regression model. The results suggested that the root mean square error (RMSE) of crash prediction increased among the provinces with higher and more variant... 

Second generation immigrant entrepreneurs (SGIEs) in developed economies have contributed to the emergence of new areas of business activity, especially in information technology, business services, and creative industries. An understanding of their growth strategies can shed light on the role of individual immigrants in the founding of potentially global firms competing with large multinational enterprises. Based on eleven case studies of SGIEs of Indian origin in the UK, our findings reveal that SGIEs are heterogeneous in their growth strategies contingent on their a) founding or succession context, and b) use of social ties. Founder SGIEs combining non-co-ethnic ties with non-family... 

A new magnetic composite was synthesized by integration of ZnFe2O4 and MIL-53(Fe) micro-rods by a solvothermal method. This composite served as a heterogeneous catalyst to overcome the high electron-hole recombination rates of ZnFe2O4 and to enhance the degradation of Direct Red 23 under visible light irradiation. Different analytical techniques, including XRD, FTIR, SEM, DRS, VSM, and PL, were employed to characterize the synthesized heterojunction nanocomposite and to evaluate its photocatalytic activity. The ZnFe2O4/MIL-53(Fe)/Vis-light system resulted in significantly higher dye degradation as compared with pristine ZnFe2O4 and MIL-53(Fe) semiconductors at the optimum pH of 3.1 and... 

A novel approach for mesoscale modelling of concrete composites is proposed by combining enriched scaled boundary finite element methods with quad-tree mesh. The concrete meso-structures are comprised of randomly distributed aggregates, mortar matrix, and interface transition zone. An improved random aggregate generation technique is developed to construct digital images of mesoscale concrete models. Based on the quadtree decomposition algorithm, meshes can be generated automatically from the digital images of concrete mesostructure. The whole mesh generation process is highly efficient without any artificial interference and eliminates the issue of hanging nodes faced by standard finite... 

The authors regret that there is an error with the caption of Figure 10 in the article. The magnification of the SEM image shown in Figure 10(b) is 100×. Furthermore, Ameri et al. [1] is the original source of the image. The correct caption is as follows: Fig. 10. Morphology of pumice aggregate: (a) 30× magnification, (b) 100× magnification [1]. The authors would like to apologise for any inconvenience caused. [1] F. Ameri, P. Shoaei, S.A. Zareei, B. Behforouz, Geopolymers vs. alkali-activated materials (AAMs): A comparative study on durability, microstructure, and resistance to elevated temperatures of lightweight mortars, Constr. Build. Mater. 222 (2019) 49–63.... 

Chiral recognition has long been a challenging issue to deal with in biological systems, drug design and food authentication. Implementing nanoparticle-based probes with intrinsic or induced chirality in this field has addressed several issues concerning sensitivity, reliability, rapidness and the cost of chiral sensing platforms. Yet, research into chiral nanoprobes that can be used for visual monitoring of chiral substances is still in its infancy. As part of this study, a visual chiral recognition platform has been developed in which a combination of blue-emitting carbon dots (BCDs) and mercaptopropionic acid-capped CdTe quantum dots (MPA-QDs) with inherent chiroptical activity were... 

Welding of severely plastic deformed aluminum sheets, with high stored strain energy, faces a serious concern, which is decrease in strength of weld and heat-affected zone (HAZ) due to instability in microstructure and related grain growth. In this work, two-passes constrained groove pressed (CGPed) Al-1050 sheets were welded via friction stir welding (FSW), without and with addition of a hybrid powder including 50 vol.% α-Al2O3 nanoparticles+50 vol.% graphite micrometric powders (∼1 vol.% of hybrid powders in stir zone). Al2O3 nanoparticles may result in grain refinement in stir zone by grain boundary pinning. Lubricating nature of graphite may reduce welding heat input resulting in lower... 

Pretrained representations have recently gained attention in various machine learning applications. Nonetheless, the high computational costs associated with training these models have motivated alternative approaches for representation learning. Herein we introduce TripletProt, a new approach for protein representation learning based on the Siamese neural networks. Representation learning of biological entities which capture essential features can alleviate many of the challenges associated with supervised learning in bioinformatics. The most important distinction of our proposed method is relying on the protein-protein interaction (PPI) network. The computational cost of the generated... 

Investigation of nanomachine swarm motion is useful in the design of molecular transportation systems as well as in understanding the assembly process on the surface. Here, we evaluate the motion of the clusters of nanocars on graphene surfaces, using molecular dynamics (MD) simulations. The mechanism of motion of single nanocars is evaluated by considering the rotation of the wheels, direction of the nanocars’ speed and comparing the characteristics of the surface motion of nanocars and similar absorbed molecules. The mentioned analyses reveal that, in the thermally activated surface motion of the nanocars, sliding movements are the dominant mode of motion. A coarse grained (CG) model is...