Current Applied Sciences

Abstract There are a number of challenging problems facing humanity today. One major challenge is the ongoing Coronavirus disease (COVID-19) pandemic started in late 2019. A second major challenge is the environmental crisis due to fossil fuels combustion causing an increase of greenhouse gases in the atmosphere. While the first challenge seems to be a temporary remedy for the second one, due to less travels by individuals, the actual solution of both problems may require comprehensive scientific, technological, and socioeconomic decisions. In this report, we look at the role of nanotechnology and nanoscale materials towards the solution of these two major challenges.

Abstract Detection of a new molecular marker for diagnosis and treatment of cancer is a growing field of recent research. The main challenge for molecular investigation is nucleic acid extraction from formalin-fixed, paraffin-embedded tissue (FFPE) of fine-needle aspiration (FNA) samples. In this research, we have compared four different commercially available RNA isolation kits by evaluating the quality and quantity of total RNA. RNA extraction of 10 FNA-FFPE of hepatocellular carcinoma and 10 normal tissue samples were compared and optimized using four commercially available kits: Isol-RNA lysis Reagent (5-PRIME), Cinna Pure RNA kit (SinaClon BioScience), Denazist RNA extraction kit (DENAzist Asia Biotechnology), and RNeasy FFPE Kit (Qiagen) to use in downstream applications. Evaluation of RNA extracting was done by spectrophotometer and electrophoresis. Also, quantitative reverse-transcription PCR was used for assessing the expression of SOX2. RNeasy FFPE Kit had the highest concentration of RNA between the four commercial kits (106.2 ± 17.15) and also, the highest RNA integrity with some modification. The most preferred kit for RNA extraction based on gene amplification was the RNeasy FFPE Kit, which has the lowest CT due to the high quality and integrity of RNA compared to the other three kits with the same modification. Our results suggested that RNeasy FFPE Kit with some modifications in temperature and incubation time was the best kit for RNA extraction from FNA-FFPE issues to a considerable extent with high purity and maintaining the integrity of RNA.

Abstract Investigating the physical properties of carbon nanotubes is a useful method to recognize their nature and clarify the operation of these nanostructures in nanotechnology market. In this work we have used the tight binding method to simulate the geometrical parameters, the effect of chirality on the number of non-degenerate and degenerate sub-bands, and the sub-bands of armchair (14, 14) carbon nanotubes. The results show that the C–C bond lengths and diameter of CNTs (14, 14) are 1.39 Å and 18.53 Å, respectively. The other calculated parameters haven’t been reported yet to assess the accuracy of the data. The symmetry operations of the infinitely long CNTs (14, 14) can be described via the symmetry groups D_14d. The crossing sub-bands at Fermi level suggest that CNTs (14, 14) has metallic behavior. The origin of energy was arbitrarily set to be at the maximum valence band. The band structure shows 56 sub-bands and it is clear that 13 conduction (valence) sub-bands are doubly degenerate, and 2 conductions and 2 valence sub-bands are non-degenerate sub-bands.

Abstract A novel outbreak with global implications, COVID-19 can be compared with the 1918 Spanish flu in many aspects. Thus, preventive and therapeutic strategies that once proved to be effective in the containment of the old pandemic, such as self-isolation and convalescent plasma therapy, respectively, might once again come to our aid and prevent further outbreaks of the disease in the years to come. In our opinion, the COVID-19 pandemic can be harnessed in a way similar to the Spanish flu, provided that the preventive and therapeutic strategies are properly executed.

Abstract Hexagonal photon crystal structure with seven nanorods on each side where the rods are arranged in air and with a triangular arrangement was studied. The structure has a symmetry, and each rod can be repeated in any direction, and the unit cell in two dimensions of the surface contains two basic vectors and is actually the smallest component in terms of surface which can be reconstructed and repeated to reconstruct the whole photon crystal. Usually, the simplest selection for a triangular photon crystal is a rhombus with sides equal to the lattice constant (a = 0.5 μm). The plate wave development method by energy band simulation of two-dimensional photonic crystals using RSOFT software has been proposed. The RSoft is the core program in the RSoft Photonics Suite and acts as a control program for RSoft’s passive. Photonic crystals, Zinc Oxide, Silicon and Zinc Oxide - Silicon by different refractive index (hazardous toxic gases) and air were considered as background. The full band gap and wavelengths that do not allow photon crystals to enter were determined. Also, the correlation spectrum and the wavelength transmission direction with different relative power for each photon crystal were determined.

Abstract Silicon carbide (SiC) has unique mechanical and electronic properties. SiC nanoribbons (SiCNRs) are known as outstanding inorganic counterparts of carbon-based nanostructures. The structural parameters and electronic characteristics of armchair silicon carbide nanoribbons (ASiCNRs) with edges passivated by hydrogen have been simulated. The calculated carbon-silicon bond length is in agreement with previous data. Moreover, compared to the zigzag SiCNRs with tetragonal unite cell, the proper crystal lattice for the armchair SiCNR is orthorhombic. The partial density of states (PDOS) shows that the p orbitals of carbon and silicon dominate the electronic structure of ASiCNR (w=3) near the Fermi level. In addition, the outputs show that the electronic bandgap of ASiCNRs (w=3) is larger than that of ZSiCNRs (w=3) (w stands for the width of the nanoribbon). Furthermore, the armchair nanoribbons with smaller width have a smaller bandgap due to the quantum size effects in ultra-small nanoribbon.