Synthesis and characterization of a novel Fe3O4-SiO2@Gold core-shell biocompatible magnetic nanoparticles for biological and medical applications

Objectives: The study of core-shell magnetic nanoparticles has a wide range of applications because of the unique combination of the nanoscale magnetic core and the functional shell. Characterization and application of one important class of core-shell magnetic nanoparticles (MNPs), i.e., iron oxide core (Fe3O4/¿-Fe2O3) with a silica shell and outer of gold (Fe3O4-SiO2@Gold (FSG)) in Boron Neutrons Capture Therapy (BNCT) highlighted. The main problem dealing with cancer cells is that the tumor and normal cells ones are mixed without a map of the boron accumulation. Methods: Areas specifically discussed in this report include the possibility of a FSG mediated by liposome as the boron carriers for the transfer of boron compound to tumor tissue. Furthermore, folate receptor was considered as an appropriate substrate that has great potential to attach to tumor on the surface of cancer cells. The present work aimed to study boron biodistribution in the muscle cancer animal model in Bagg Albino (BALB/c) mice employing PEGylated liposome-encapsulated FSG formulations. Results: The predetermined boron concentration was obtained to be 20-35 mg 10B/g. Samples of the tumor tissue, such as kidney, liver, lung, heart, skin, spleen, brain, stomach, and bone were taken as post-administration at different times to measure boron content by Inductively Coupled Plasma (ICP) analysis. The results showed the existence of GLUT-5 expression as an erythrocyte-type glucose transporter protein in a wide variety of tumor cells. Conclusions: Fe3O4-SiO2 nanoparticles are highly biocompatible with biological materials and gold shell also imparts the magnetic nanoparticles with many intriguing functional propertiesPeer ReviewedPostprint (published version

Analysis of the damage mechanisms in mixed-mode delamination of laminated composites using acoustic emission data clustering

In this study, acoustic emission (AE) technique is used to investigate different time-to-failure mechanisms of delamination in glass/epoxy composite laminates. Woven and unidirectional layups were subjected to the double cantilever beam, end notch flexure, and mixed-mode bending tests and the generated AE signals were captured. Discrimination of the AE events, caused by different types of the damage mechanisms, was performed using wavelet packet transform (WPT) and fuzzy clustering method (FCM) associated with a principal component analysis (PCA). The FCM and WPT analyses identified three dominant damage mechanisms. Furthermore, different interface layups and different GII/GT modal ratio values (ratio of mode II strain energy release rate per total strain energy release rate) indicated different time-to-failure mechanisms incidence. Additionally, the damaged mechanisms were observed using scanning electron microscopic (SEM) analysis. The results showed that the dominant damage mechanisms in all the specimens are matrix cracking and fiber–matrix debonding. Besides, some fiber breakage appeared during the tests, and the percentage of this damage mechanism in the unidirectional specimens and mode I condition was higher than those in the woven specimens and mode II. SEM observations were also in good agreement with the obtained results. It was found that the presented methods can be utilized to improve the characterization and discrimination of damage mechanisms in the actual occurring modes of delamination in composite structures

Synthesis and characterization of core-shell Fe3O4-gold-chitosan nanostructure

<p>Abstract</p> <p>Background</p> <p>Fe₃O₄-gold-chitosan core-shell nanostructure can be used in biotechnological and biomedical applications such as magnetic bioseparation, water and wastewater treatment, biodetection and bioimaging, drug delivery, and cancer treatment.</p> <p>Results</p> <p>Magnetite nanoparticles with an average size of 9.8 nm in diameter were synthesized using the chemical co-precipitation method. A gold-coated Fe₃O₄monotonous core-shell nanostructure was produced with an average size of 15 nm in diameter by glucose reduction of Au³⁺which is then stabilized with a chitosan cross linked by formaldehyde. The results of analyses with X-ray diffraction (XRD), Fourier Transformed Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and Atomic Force Microscopy (AFM) indicated that the nanoparticles were regularly shaped, and agglomerate-free, with a narrow size distribution.</p> <p>Conclusions</p> <p>A rapid, mild method for synthesizing Fe₃O₄-gold nanoparticles using chitosan was investigated. A magnetic core-shell-chitosan nanocomposite, including both the supermagnetic properties of iron oxide and the optical characteristics of colloidal gold nanoparticles, was synthesized.</p

Development and analysis of the Soil Water Infiltration Global database

In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements ( ∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76% of the experimental sites with agricultural land use as the dominant type ( ∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it

Analysis of the damage mechanisms in mixed-mode delamination of laminated composites using acoustic emission data clustering

© The Author(s) 2015. In this study, acoustic emission (AE) technique is used to investigate different time-to-failure mechanisms of delamination in glass/epoxy composite laminates. Woven and unidirectional layups were subjected to the double cantilever beam, end notch flexure, and mixed-mode bending tests and the generated AE signals were captured. Discrimination of the AE events, caused by different types of the damage mechanisms, was performed using wavelet packet transform (WPT) and fuzzy clustering method (FCM) associated with a principal component analysis (PCA). The FCM and WPT analyses identified three dominant damage mechanisms. Furthermore, different interface layups and different GII/GT modal ratio values (ratio of mode II strain energy release rate per total strain energy release rate) indicated different time-to-failure mechanisms incidence. Additionally, the damaged mechanisms were observed using scanning electron microscopic (SEM) analysis. The results showed that the dominant damage mechanisms in all the specimens are matrix cracking and fiber-matrix debonding. Besides, some fiber breakage appeared during the tests, and the percentage of this damage mechanism in the unidirectional specimens and mode I condition was higher than those in the woven specimens and mode II. SEM observations were also in good agreement with the obtained results. It was found that the presented methods can be utilized to improve the characterization and discrimination of damage mechanisms in the actual occurring modes of delamination in composite structures

Modeling and Forecasting of Water Demand in Isfahan Using Underlying Trend Concept and Time Series

Introduction: Accurate water demand modeling for the city is very important for forecasting and policies adoption related to water resources management. Thus, for future requirements of water estimation, forecasting and modeling, it is important to utilize models with little errors. Water has a special place among the basic human needs, because it not hampers human life. The importance of the issue of water management in the extraction and consumption, it is necessary as a basic need. Municipal water applications is include a variety of water demand for domestic, public, industrial and commercial. Predicting the impact of urban water demand in better planning of water resources in arid and semiarid regions are faced with water restrictions. Materials and Methods: One of the most important factors affecting the changing technological advances in production and demand functions, we must pay special attention to the layout pattern. Technology development is concerned not only technically, but also other aspects such as personal, non-economic factors (population, geographical and social factors) can be analyzed. Model examined in this study, a regression model is composed of a series of structural components over time allows changed invisible accidentally. Explanatory variables technology (both crystalline and amorphous) in a model according to which the material is said to be better, but because of the lack of measured variables over time can not be entered in the template. Model examined in this study, a regression model is composed of a series of structural component invisible accidentally changed over time allows. In this study, structural time series (STSM) and ARMA time series models have been used to model and estimate the water demand in Isfahan. Moreover, in order to find the efficient procedure, both models have been compared to each other. The desired data in this research include water consumption in Isfahan, water price and the monthly pay costs of water subscribers between 1388 and 1390. In structural time series model, the model was generated by entering the invisibility part of the process and development of a state-space model, as well as using maximum likelihood method and the Kalman-Filter algorithm. Results and Discussion: Given the value of the test statistic ADF, with the exception of changing water use variables with a time difference of the steady rest. Superpopulation different modes of behavior were assessed based on the demand for water. Due to the likelihood ratio statistic is most suitable for the parameters, was diagnosed the steady-state level of randomness and the slope. Price and income elasticities of demand for water, respectively -0.81 and 0.85 shows that water demand is inelastic with respect to price and income and a lot of water is essential. Identify the nature of the request of one of the most important results in estimated water demand in the urban part of the state space time series structure and patterning methods, as an Alternative for variable is Technology preferences use. The model is estimated for the city's water demand time series model, respectively ARMA (3,1). Model performance metrics to compare the structural time series and time series ARMA, the result represents a structural time series model based on the fact that all the performance criteria in this study outperformed the ARMA model to forecast water city demand in the Isfahan. Conclusion: Of a time series model structure to model ARMA in this research is to estimate the model and predict the number the less time is required, and also can be used for modeling of other variables (such as income and price) to this is helping to improve the models. Also, in ARMA time series the best model for data was selected according to the Schwarz Bayesian and Akaike criterion. Results indicate that the estimation of water demand using structural time series method is more efficient than when ARMA time series model is applied. Therefore, structural time series model can be used as an efficient tool for managers and planners in the Management Departmentsin order to forecast water demand. Used was for compare the performance of these two models of standard root mean square error (RMSE), mean absolute error (MAE) and mean absolute percentage error (MAPE)

Fabrication of Poly (Acrylonitrile-Co-Methyl Methacrylate) Nanofibers Containing Boron via Electrospinning Method: A Study on Size Distribution, Thermal, Crystalline, and Mechanical Strength Properties

Electrospun polymeric nanofibers have attracted great attention in filtration systems and protective clothes. One of them is polyacrylonitrile (PAN) nanofibers, which are a suitable choice for the fabrication of protective clothes in the defense industry, due to their good fiber formation and easy optimization with chemical reagents. They do not possess adequate properties for protection against chemical, biological, and radiological agents. In this research, poly (acrylonitrile-co-methyl methacrylate) (PANMM) nanofibers and PANMM nanofibers containing 10B were fabricated via the electrospinning method. The study of the morphology of nanofibers, using scanning electron microscopy (SEM), revealed that smooth and knotted fibers with an average diameter of 259 ± 64 nm were obtained, using 12% (w/v) of PANMM in the solution as the optimal concentration for the electrospinning process. This sample was doped with boron (10%, 30%, and 50% (w/w)) to fabricate the samples of PANMM + boric acid (BA) nanofibers. The results demonstrated an increasing trend in the diameter of the nanofibers with an increase in BA up to 50%. At this concentration, smooth fibers were formed with lower knots. Furthermore, the presence of B-O and O-H groups was observed using Fourier transform infrared (FTIR) spectroscopy. To study the tensile properties, the nanofibrous web was tested, and the results showed that introducing 10B to PANMM nanofiber structures reduced the strength of the nanofibers. Thermal gravimetric analysis (TGA) showed that BA-modified PANMM nanofibers had lower thermal degradability, as compared with pure PANMM