Multifunctional Gadolinium‐Doped Mesoporous TiO2 Nanobeads: Photoluminescence,Enhanced Spin Relaxation,and Reactive Oxygen Species Photogeneration,Beneficial for Cancer Diagnosis and Treatment

Materials with controllable multifunctional abilities for optical imaging (OI) and magnetic resonant imaging (MRI) that also can be used in photodynamic therapy are very interesting for future applications. Mesoporous TiO₂ sub‐micrometer particles are doped with gadolinium to improve photoluminescence functionality and spin relaxation for MRI, with the added benefit of enhanced generation of reactive oxygen species (ROS). The Gd‐doped TiO₂ exhibits red emission at 637 nm that is beneficial for OI and significantly improves MRI relaxation times, with a beneficial decrease in spin–lattice and spin–spin relaxation times. Density functional theory calculations show that Gd³⁺ ions introduce impurity energy levels inside the bandgap of anatase TiO₂, and also create dipoles that are beneficial for charge separation and decreased electron–hole recombination in the doped lattice. The Gd‐doped TiO₂ nanobeads (NBs) show enhanced ability for ROS monitored via ^?OH radical photogeneration, in comparison with undoped TiO₂ nanobeads and TiO₂ P25, for Gd‐doping up to 10%. Cellular internalization and biocompatibility of TiO₂@x Gd NBs are tested in vitro on MG‐63 human osteosarcoma cells, showing full biocompatibility. After photoactivation of the particles, anticancer trace by means of ROS photogeneration is observed just after 3 min irradiation.     

Tamoxifen-loaded solid lipid nanoparticles-induced apoptosis in breast cancer cell lines

An in vitro study was conducted to determine the apoptosis induced by tamoxifen (TAM) and TAM-loaded solid lipid nanoparticles (SLNs) in breast cancer cell lines, MCF-7 and MDA-MB231 cells. The effect of free drug and drug-loaded SLN on the cell lines was characterised by cell morphology and cell cycle distribution using phase contrast microscopy, nuclear morphology and flow cytometry, respectively. The results showed that TAM-loaded SLNs have an equally efficient cytotoxic activity against MCF-7 and MDA-MB231 cells, compared to free TAM, and the half maximal inhibitory concentration (IC₅₀) of TAM-loaded SLNs was generally lower than that of free TAM. In the presence of TAM and TAM-loaded SLN, the viability of the both cells diminishes and the cancer cells lose their normal morphological characteristics, detaches, aggregates and later develops apoptotic bodies. Flow cytometry analysis showed that TAM-loaded SLN like the free TAM caused a dose- and time-dependent apoptosis without cell cycle arrest of human breast cancer cells. Therefore, TAM-loaded SLN has great potential in human medicine for the treatment of breast cancers.     

A study on the thermal behavior of low silica X-type zeolite ion-exchanged with alkaline earth cations

Pure and high crystalline low silica X-type zeolite with Si/Al ratio of 1 was synthesized under specific hydrothermal conditions. After preparation and characterization of Na form of the zeolite (Na-LSX) from the synthesized zeolite, Na cations were exchanged by three alkaline earth cations. The amount of the exchanged cations per 1 g of the zeolite for each cation was determined by wet chemical method. Among the various prepared samples, those containing approximately equal amount of different cations were selected and characterized by XRD, IR, and XRF techniques. TGA/DTG/DTA and XRD techniques were employed to investigate thermal behavior of the cation exchanged zeolites.     

Formulation Optimization of a Palm-Based Nanoemulsion System Containing Levodopa

Response surface methodology (RSM) was utilized to investigate the influence of the main emulsion composition; mixture of palm and medium-chain triglyceride (MCT) oil (6%–12% w/w), lecithin (1%–3% w/w), and Cremophor EL (0.5%–1.5% w/w) as well as the preparation method; addition rate (2–20 mL/min), on the physicochemical properties of palm-based nanoemulsions. The response variables were the three main emulsion properties; particle size, zeta potential and polydispersity index. Optimization of the four independent variables was carried out to obtain an optimum level palm-based nanoemulsion with desirable characteristics. The response surface analysis showed that the variation in the three responses could be depicted as a quadratic function of the main composition of the emulsion and the preparation method. The experimental data could be fitted sufficiently well into a second-order polynomial model. The optimized formulation was stable for six months at 4 °C.     

An efficient inexact Full Adder cell design in CNFET technology with high-PSNR for image processing

The design of inexact circuits at the transistor level remarkably improves figures of merits such as power consumption, delay, energy, and area. Therefore, inexact technique for designing circuits has attracted the attention of researchers worldwide. Designing inexact Full Adder cell as a building block of a variety of arithmetic circuits can affect the entire electronic system’s performance. In this paper, two novel inexact 1-bit Full Adder cells are presented using carbon nanotube field effect transistors (CNFETs). The capacitive threshold logic (CTL) is used to realize the proposed cells. Comprehensive simulations at two levels of abstraction, i.e., application and hardware are carried out to evaluate the efficacy of these circuits. First, the motion detector which is one of the image processing applications is deployed in MATLAB software to measure peak signal-to-noise ratio (PSNR) figure of merit. At hardware level, the HSPICE tool is used to carry out simulations and measure power, delay, power-delay product (PDP), energy-delay product (EDP), power-delay-area product (PDAP) and power-delay-area-PSNR product (PDAPP). Simulation results confirmed the superiority of the proposed Full Adder cells compared to others. For instance, the proposed 6TIFA improves PDAPP metric at least 21% and at most 76% compared to its counterparts at 0.9V power supply.     

Morphology enhancement of TiO2/PVP composite nanofibers based on solution viscosity and processing parameters of electrospinning method

In this work, different sol solutions with various titanium tetraisopropoxide (TIP)/glacial acetic acid ratios in 2‐propanol with 5 wt % poly(vinyl pyrrolidone) (PVP) (M_w = 360,000 g/mol) were prepared and electrospun. Composition of the prepared sols and as‐spun TiO₂/PVP nanofibers were determined by Fourier transform infrared and Raman spectroscopy methods. Morphology of the electrospun TiO₂/PVP nanofibers was studied by scanning electron microscopy and transmission electron microscopy (TEM) techniques. Rheometry measurements of the sol solutions showed decrease of viscosity upon the addition of TIP to the polymer solutions with constant polymer and acid concentrations. The sol solution having the lowest viscosity (at shear rate 10 s^?1) but the highest TIP/glacial acetic acid ratio showed beaded nanofibers morphology when electrospun under 10 and 12 kV applied voltage while injection rate, needle tip to collector distance, and needle gauge were kept constant. However, smooth electrospun TiO₂/PVP composite nanofibers with the average nanofibers diameters (148 ± 79 nm) were achieved under the same condition when applied voltage increased to 15 kV. TEM micrographs of the electrospun TiO₂/PVP nanofiber showed that the TiO₂ particles with continuous structure are formed at the middle of the nanofiber and distributed along its axis. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46337.     

A simple and convenient method for the surface coating of TiO2 nanoparticles with bioactive chiral diacids containing different amino acids as the coupling agent

For practical applications, especially in an organic-solution situation, the surface of TiO₂ nanoparticles (NP)s requires modification with an organic coupling agent. Therefore, in this study, the surface of TiO₂ NPs with average diameter of 30 nm was modified with bioactive dicarboxylic acids (DA)s containing different natural amino acids such as l-valine, l-methionine, l-leucine, and l-isoleucine. The prepared DAs-modified TiO₂ NPs were studied with Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis techniques. The results showed that the modifiers were grafted on the surface of TiO₂ NPs. Modified TiO₂ NPs could be environmentally friendly due to the presence of bioactive DAs.     

Comparative study of propylene polymerization using monosupported and bisupported titanium‐based Ziegler–Natta catalysts

Heterogeneous Ziegler–Natta systems—MgCl₂ (ethoxide type)/TiCl₄/di‐n‐butyl phthalate (DNBP)/triethylaluminum (TEA)/dimethoxymethylcyclohexylsilane (DMMCHS) and SiO₂/MgCl₂ (ethoxide type)/TiCl₄/DNBP/TEA/DMMCHS—were studied for the polymerization of propylene. The slurry polymerization of propylene was carried out with the catalyst systems in n‐heptane. Both systems performed with optimum activity at a particular [Al]/[DMMCHS]/[Ti] molar ratio. The ratio to reach the highest activity was much lower for the bisupported catalyst system. The productivity of the bisupported catalyst was higher than that of the monosupported one. Polypropylene of a high isotacticity index (II; >96%) was obtained with both systems and did not significantly change with an increasing [Al]/[DMMCHS]/[Ti] molar ratio. The addition of hydrogen as a chain‐transfer agent reduced II of the polymers obtained with both systems. The effect of the polymerization temperature (40–75°C) on the viscosity‐average molecular weight (M_v) and II showed a decrease in both cases. The bisupported catalyst system produced a polymer with higher M_v. The effect of temperature on II was similar for both the monosupported and bisupported systems. A monomer pressure of 2.02 × 10⁵ to 0.8 × 10⁶ Pa increased M_v of the obtained polymer. II of the polymer slightly decreased with increasing monomer pressure. The titanium content of the catalyst was 1.70 and 3.55% for the monosupported and bisupported systems, respectively. The surface area of the bisupported catalyst was higher than that of the monosupported catalyst. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2220–2226, 2006     

Uncertainty Assessment of the Integrated Hybrid Data Processing Techniques for Short to Long Term Drought Forecasting in Different Climate Regions

Water Resources Management - Accurate prediction of drought indices is a useful method to reduce its undesirable consequences. In this study, the workability of newly integrated hybrid forecasting...     

Drought Vulnerability Assessment Based on a Multi-criteria Integrated Approach and Application of Satellite-based Datasets

Water Resources Management - Drought as a complex event depends on some geo-environmental parameters. The impact of this phenomenon on the economy and environment can be devastating. Recognizing...