Dynamic simulation of carbochlorination of zirconia in a pilot plant fluidized-bed reactor

Zirconium tetrachloride was produced via the chlorination of zirconia in a fluidized bed reactor in the presence of carbon. The fluidized bed zirconia carbochlorination reactor was modeled dynamically via a three-phase hydrodynamic flow assumption. The operating temperature (800-1200 °C), reaction time (30-120 min) and mean particle size (MPS) (70-130 μm) were chosen as the range of operating conditions. The comparison of reaction conversion with experimental measurements was used for model validation. An acceptable compatibility was observed between simulation results and experimental data. Investigation of fluidized bed operating conditions with the validated model was accomplished and the results indicated that smaller zirconia size, higher reactor temperature and reaction time improved chlorination rate. The optimum operating conditions were found to be 1200 ºC, 120 min and 70 μm, in which the maximum zirconia conversion of 91.8% was obtained.Keywords: Zirconia, Fluidized bed reactor, Carbochlorination, zirconium tetrachlorid

AS1411 Aptamer-Anionic Linear Globular Dendrimer G2-Iohexol Selective Nano-Theranostics

Molecular theranostics is of the utmost interest for diagnosis as well as treatment of different malignancies. In the present study, anionic linear globular dendrimer G2 is employed as a suitable carrier for delivery and AS1411 aptamer is exploited as the targeting agent to carry Iohexol specifically to the human breast cancer cells (MCF-7). Dendrimer G2 was prepared and conjugation of dendrimer and aptamer was carried out thereafter. Based on the data yielded by AFM, morphology of smooth and spherical non-targeted dendrimer changed to the rough aspherical shape when it conjugated. Then, conjugation was confirmed using DLS, ELS and SLS methods. Toxicity on nucleolin positive MCF-7 cells and nucleolin negative HEK-293 cells was assessed by XTT and apoptosis/necrosis assays. In vitro uptake was determined using DAPI-FITC staining and ICP-MS methods. In vivo studies including in vivo CT imaging, pathology and blood tests were done to confirm the imaging ability, bio-safety and targeted nature of the Nano-Theranostics in vivo. In a nutshell, the prepared construction showed promising effects upon decreasing the toxicity of Iohexol on normal cells and accumulation of it in the cancer tumors as well as reducing the number of cancer cells. © 2017 The Author(s)

Axial dispersion model in predictive mass transfer correlation for random pulsed packed column

The continuous phase volumetric overall mass transfer coefficient in a ceramic intalox saddle pulsed packed extraction column using axial dispersion model was studied for two different liquid-liquid systems containing water/acetone/toluene and water/acetone/n-butyl acetate. The effects of pulsation intensity, continuous and dispersed phase flow rates on mass transfer coefficient were investigated. The experimental results indicated that the mass transfer coefficient was enhanced by increasing pulsation intensity and dispersed and continuous phase flow rates. The utilization of nonlinear least square method provided a new predictive correlation for the continuous phase overall mass transfer coefficient. The developed mass transfer model was validated via the comparison of the modeling data with experimental results with 18.7% average absolute relative error (AARE). Furthermore, one empirical correlation was developed for prediction of the continuous phase overall mass transfer coefficient as the function of the aforementioned operating variables

Mesopourous Fe3O4@SiO2-hydroxyapatite nanocomposite: Green sonochemical synthesis using strawberry fruit extract as a capping agent, characterization and their application in sulfasalazine delivery and cytotoxicity

The present study introduces a simple, biocompatible and effective drug delivery system by using mesoporous nanocomposite-based platform. To achieve this goal, mesopourous Fe3O4@SiO2-hydroxyapatite nanocomposite (mFSH) was synthesized by sonochemical process in presence of strawberry fruit extract as capping agent (mFSH-SW). The impact of various factors such as sonication time (5, 15, 30 and 45 min), capping agent (cherry (CH), strawberry (SW), malus domestica (MD), andean blackberry (AB)), pH (10, 11 and 12) and sonication power (30, 60 and 80 W) were investigated to reach optimum condition. To reach high efficiency of drug loading, mFSH was grafted with 3-aminopropyl triethoxysilane (APTES). Uniform, regular and spherical morphology of nanocomposite were specified by field emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive x-ray spectroscopy (EDX), dynamic light scattering (DLS), nitrogen adsorption/desorption isotherm and Fourier-transform infrared spectroscopy (FT-IR) techniques. The mean pore size, surface area, and pore volume of mFSH-SW were 63.2 m2 g−1, 14.1 nm and 0.24 cm3 g−1, respectively. Sulfasalazine (SLN) loading and release were carried out by various products. The functionalized mFSH-SW showed high adsorption capacity (approximately 59.1 ) for SLN that possesses amino functional groups. The results showed that 100 of SLN-loaded nanocomposite could be released after 36 h at intestinal conditions (pH = 6.8). In addition, in-vitro and in-vivo toxicity investigations of product were performed with apoptosis/necrosis, XTT and pathology assay, respectively. All in all, unique properties of the nanocomposite including low toxicity, high drug loading, slow release and biodegradable showed that it can be used in biomedical sciences. © 2020 Elsevier B.V

Biogenic and eco-benign synthesis of silver nanoparticles using jujube core extract and its performance in catalytic and pharmaceutical applications: Removal of industrial contaminants and in-vitro antibacterial and anticancer activities

Biosynthesis of nanoparticles has been rapidly developed in various fields, due to their broad spectrum of applications in the fields of environmental, pharmacology, and medicine. In this study, facile, rapid, eco-friendly and cost-effective method was used to green synthesis of silver nanoparticles (AgNPs) using jujube core extract (AgNPs-JCE) and then used as antibacterial, anticancer and catalytic agents. The reaction parameters such as AgNO 3 concentration (1, 5, 10, 20 and 40 mM), reaction time (5, 30 and 60 min) and pH (without pH, 10 and 12) were discussed and optimized. The surface plasmon resonance peak at about 420 nm in the UV–Vis absorption spectrum confirmed the green synthesis of silver nanoparticles. Microscopic results revealed that the synthesized AgNPs-JCE were spherical in morphology with a size range of 25–35 nm.In addition, the subject AgNPs promising catalytic properties in the degradation of pollutants including rhodamine b (RhB) and eriochrome black T (EBT) as cationic and anionic contaminant under UV and visible light irradiations. The photocatalyst (AgNPs-JCE) exhibited the degradation of 90.9 % and 84.7% for RhB and EBT contaminants after 80 min under UV irradiation, respectively. The antibacterial activities of AgNPs-JCE was checked against E. coli as Gram-positive bacteria and K. pneumoniae and S. aureus as Gram-negative bacteria with MIC and MBC values of (1.26 and 1.26 g/ml), (2.5 and 2.5 g/ml), and (2.5 and 10 g/ml), respectively. Finally, the cytotoxicity of synthesized nanoparticles against AGS as human stomach cancer cell line was determined at several concentrations (2.5, 5, 10, 20, 50, and 100 g/ml) using MTT assay. Finding of this research suggested the suitability of AgNPs-JCE as pollutants degradation, antibacterial and anticancer drug development

Synthesis and characterization of novel 99mTc-DGC nano-complexes for improvement of heart diagnostic

In this research, early diagnosis of cardiovascular diseases can reduce their mortality and burden. In our study, we developed a new nano-agent, 99mTc-Dendrimer Glyco Conjugate (99mTc-DGC), and assessed its safety and capability for myocardial viability scan. To develop 99mTc-DGC, we first synthesized the dendrimer and then, glucose has been conjugated. Afterwards, we measured toxicity of the product on normal cells by XTT and apoptosis/necrosis methods. We compared the myocardial viability scan (measured by SPECT and dynamic planar imaging) in two rabbit models, with and without infarction. We also assessed the biodistribution of 99mTc-DGC in rats with no infarction. DGC synthesis was confirmed by Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR), liquid chromatography-mass spectrometry (LC-MS), dynamic light scattering (DLS) and static light scattering techniques (SLS). Then radiochemical purity (RCP) was done to present the stability and potential of DGC to complex formation with 99mTc. In vitro cytotoxicity showed nontoxic concentration up to 8 mg/mL. Single Photon Emission Computed Tomography (SPECT) and dynamic planar imaging clearly showed the accumulation of 99mTc-DGC in myocardial. Biodistribution result showed the 2.60 accumulation of 99mTc-DGC in myocardial after 2 h. Our findings indicated 99mTc-DGC to be safe and can accurately diagnose myocardial infarctions at early stages. Human studies to further assess such effects are critical. © 2020 Elsevier Inc

Synthesis and characterization of novel 99mTc-DGC nano-complexes for improvement of heart diagnostic

In this research, early diagnosis of cardiovascular diseases can reduce their mortality and burden. In our study, we developed a new nano-agent, 99mTc-Dendrimer Glyco Conjugate (99mTc-DGC), and assessed its safety and capability for myocardial viability scan. To develop 99mTc-DGC, we first synthesized the dendrimer and then, glucose has been conjugated. Afterwards, we measured toxicity of the product on normal cells by XTT and apoptosis/necrosis methods. We compared the myocardial viability scan (measured by SPECT and dynamic planar imaging) in two rabbit models, with and without infarction. We also assessed the biodistribution of 99mTc-DGC in rats with no infarction. DGC synthesis was confirmed by Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR), liquid chromatography-mass spectrometry (LC-MS), dynamic light scattering (DLS) and static light scattering techniques (SLS). Then radiochemical purity (RCP) was done to present the stability and potential of DGC to complex formation with 99mTc. In vitro cytotoxicity showed nontoxic concentration up to 8 mg/mL. Single Photon Emission Computed Tomography (SPECT) and dynamic planar imaging clearly showed the accumulation of 99mTc-DGC in myocardial. Biodistribution result showed the 2.60% accumulation of 99mTc-DGC in myocardial after 2 h. Our findings indicated 99mTc-DGC to be safe and can accurately diagnose myocardial infarctions at early stages. Human studies to further assess such effects are critical