Current Applied Sciences
Volume:1 Issue: 1, Winter and Spring 2021

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.

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.

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 D14d. 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.

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.

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.

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.

2-Dmensional silicon carbide (2D SiC) provides several advantages compared to the bulk silicon carbide, due to its two-dimensional structure. Elastic constants and elastic moduli of 2D carbide nanotubes were calculated employing density functional theory (DFT). There are six independent elastic constants for tetragonal lattice with (422, 4mm, -42/m, 4/mmm) point group. The calculated , , , , ,  of 2D SiC are reported in this work. The results suggest that the shear modulus of 2D SiC is 27.78 GPa, which is lower than that of the of single layered graphene sheet (=0.22 TPa). The bulk modulus of 2D SiC is 44.98 GPa as well. Moreover, Young’s modulus of 2D SiC is lower than Young’s modulus of single layered graphene sheet. Compared to Young’s modulus of the amorphous phase of the SiC (=313.6 GPa), Young’s modulus of 2D SiC (=156.19 GPa) is smaller. The main reason is that the stiffness of the 2D SiC in the x direction is smaller than the stiffness of the bulk SiC.

The excessive increase in pesticides consumption has made concerns about aquatic ecosystems. Hence, the present study focused on the toxicity level of Abamectin as a widely used pesticide in Artemia franciscana. The lethality of Abamectin at different pHs and salinity was investigated to simulate the real natural status of A. franciscana. The salinity ranges of 10-255 and 10-130 g.l-1 with the pH range of 4-11 for water with a constant Lethal concentration 50 (LC50) (0.145 μg.l-1 from the toxicity test) were considered and evaluated using response surface methodology (RSM). A significant variation in Artemia mortality was observed at 0.145 μg.l-1 of Abamectin in the salinity ranges of 10-255 g.l-1, irrespective of the effect of pH. In the second phase of the experiment, a significant variation of mortality was observed in the level of LC50 in the salinity range of 10-130 g.l-1, which was associated with pH shifts (p<0.05). In addition, R2 adjusted, and predicted R2 of the model were equal to 0.985, 0.976, and 0.96, respectively. The reduction in the pH from 7.5 and the salinity from 30 g.l-1 intensified the lethal effects of Abamectin. The simultaneous increase in pH and salinity decreased the mortality level. Also, the increase in salinity raised the mortality rate. These findings may reflect the stressor effects induced by the change of physicochemical parameters on the tolerance of A. ftanciscana,s in confronting pollution exposure. Hence, it can be concluded that a severe decrement in salinity and pH can intensify the LC50, which exerts an adverse impact on osmoregulation and high energy demand.

In this work, we intend to investigate the effect of Stone–Wales defect (SW defect) in armchair (14, 14) carbon nanotubes (ACNTs (14, 14)) and how it perturbs the energy states near the Fermi level. The SW defect may occur in graphene, carbon nanotubes (CNTs), and similar carbon frameworks, in which the four adjacent six-membered rings of a pyrene-like region turn into two five-membered rings and two seven-membered rings when the bond uniting two of the adjacent rings rotate. Our calculations indicate that ACNTs (14, 14) with SW defect have semiconducting behavior, although the armchair CNTs are expected to be metal. The band-gap of ACNTS (14, 14) with SW defect is 0.11 eV. In addition, the obtained results show that the density of states of ACNTs (14, 14) with SW defect reaches its zenith at 13 eV. The results show that the C–C bond lengths and diameter of ACNTs (14, 14) with SW defect are 1.40 Å and 18.74 Å, respectively.

The optical spectra of armchair silicon carbide nanoribbons (ASiCNRs) with edges passivated by hydrogen were calculated exploiting density functional theory (DFT). It was found that the dielectric function of the simulated nanoribbon has anisotropic behavior due to the asymmetric crystal lattice. Compared to isotropic behavior, anisotropic means different behavior in all directions. The first peak of the imaginary part of the dielectric function (2.57 eV) suggests that the first optical band-gap of ASiCNRs is 2.57 eV. Besides, the z component of the static refractive index of ASiCNRs is 1.34. Our results show that the first optical absorption’s peak for the z polarization happens at 2.57 eV, which is in agreement with the imaginary part of the dielectric function. The first and second peaks of the optical extinction are located at 2.57 eV and 3.42 eV as well.

Silicon carbide monolayer is a promising material in the semiconductor industry. The silicon and carbon elements in the two-dimensional silicon carbide are arranged in a two-dimensional hexagonal lattice. The quantum of the crystal lattice vibrations, namely phonons, dominate mainly the physical characteristic of the crystals as a result of electron mobility. It is clear that the number of phonons is zero, from 85 meV to 117 meV. In addition, the silicon carbide monolayer sees its phonon density of states (PDOS) maximum at 140 meV, confirming that there are more allowed phonon energy levels at this point of energy. There are four peaks from 0 eV to 85 eV, indicating optical phonons and zone boundary (ZB) phonons. For the low-range energy, all electronic sub-bands correlate acoustic phonons, where the transverse acoustic phonons have lower energy than the longitudinal acoustic modes.

There is a general belief that herbal supplements and remedies have no harmful effects on the human body. However, liver problems caused by the overuse of medicinal plants in recent decades are a growing concern. This study aims at investigating the effects of long-term administration of Aloe vera extracts on liver histology and blood parameters of rats. Three groups of 10-week-old male Wistar rats were treated with Aloe vera leaf pulp, leaf gel, and a mixture of both for 56 consecutive days. Then the liver histology and blood biochemistry of control and experimental groups were analyzed. The hematological study indicated that long-term consumption of Aloe vera extracts affected the levels of AST and ALT enzymes meaningfully in experimental groups compared with the control group. Changes in other blood parameters, including fasting blood sugar, cholesterol, and Lactate Dehydrogenase (LDH) levels, were also detected in test groups in comparison with the control group. The histopathological findings demonstrated that hepatic steatosis was the most prominent effect of long-term consumption of Aloe vera fractions, which was consistent with the rise in the levels of ALP and ALT enzymes in the blood of test groups compared with the control group. The findings of this study are of importance, as they warn against the harmful effects of the overuse of the curative medicinal plant, Aloe vera, on mammals’ liver.