Gold Nanoparticle Effects on the Hounsfield Unit of Computed Tomography in Hepatocellular Carcinoma: Systematic Review

Background: The present study has attempted to gather all the original and relevant data on the application of gold nanoparticles aimed at the improvement of computed tomography image quality and Hounsfield unit in hepatocellular carcinoma. We performed a systematic review on the studies indexed in PubMed from January 2000 to January 2020. Afterwards, the study design and quality were evaluated. Results: An increase in the nanoparticles concentration and incubation time was associated with improved image quality and the Hounsfield Unit of computed tomography. Conclusion: This study highlights the considerable diagnostic role of gold nanoparticle as novel contrast agents in the early detection of hepatocellular carcinoma.

Size- and concentration-dependence of antiviral and virucidal activity of Au nanoparticles against adenoviruses and influenza viruses H1N1

Over the past 10 years, many scientific groups have experimentally shown that non-functionalized nanoparticles show a pronounced antiviral and antimicrobial action against different pathogens. In order to understand the mechanism of nanoparticles action it is important to know its peculiarities, i.e. dependences on different nanoparticles and pathogen properties.In this work we studied how Au nanoparticles act on the viruses outside and inside the cell, and compare this action for two sizes of nanoparticles and two types of the viruses. The study has been conducted for adenovirus and H1N1 influenza virus, and nanoparticles of 5 nm and 20 nm diameter.Virucidal and antiviral actions were observed experimentally for both types of nanoparticles against both viruses. It has been shown that intensity of virucidal action depends on the nanoparticles concentration non-monotonically for adenovirus. It has also been shown with electron microscopy that the viruses are destructed after 5 nm nanoparticles adsorption on their surface; and that the viruses change their shape after 20 nm nanoparticles adsorption on their surface. The model of physical adsorption of nanoparticles on the virus surface due to near-field interaction proposed in previous works may explain observed results on virucidal action of nanoparticles.

Impact of Joule heating and viscous dissipation on magnetohydrodynamics boundary layer flow of viscous nanofluid subject to the stretched surface

The two-dimensional magnetohydrodynamics incompressible flow of nanofluid about a stretching surface is investigated with the existence of viscous dissipation and Joule heating. Moreover, the impact of the convective condition and mass suction is applied with the viscous nanofluid containing copper nanoparticles and the base fluid water. The similarity variables have been employed to transform the coupled nonlinear partial differential equations into the ordinary differential equations and the numerical scheme bp4c is implemented for the further analysis of the solution. The diverse results of temperature, skin friction coefficient, velocity, and the Nusselt number according to numerous parameters have been shown graphically. It appears that the Nusselt number and the skin friction reduces, which is caused by the enhancement of both Hartman number and nanoparticles concentration. Moreover, the fluid temperature surges with the growth of Biot number, and Eckert number whereas the growth of nanoparticles concentration and suction parameter diminishes the velocity and temperature profile. The inclusion of a significant quantity of nanoparticles in the base fluid increases the density of the corresponding nanofluids and accordingly the temperature of the coupled nanoparticles in the base fluids can be modified. Hence, nanofluids build an outstanding performance in electronic components appliances and other electrical devices. The existing research is further effective in refrigerators for stabilizing their rate of cooling.

Effects of non-uniform nanoparticle concentration on entropy generation

The entropy generation analysis of a thermal process is capable of determining the efficiency of that process and is therefore helpful to optimize the thermal system operating under various conditions. There are several ingredients upon which the phenomenon of entropy generation can depend, such as the nature of flow and the fluid, the assumed conditions, and the material properties of the working fluid. However, the dependence of entropy generation phenomenon upon such properties has so far not been fully realized, in view of the existing literature. On the other hand, based upon the existing studies, it has been established that the non-uniform concentration of nanoparticles in the base fluid does cause to enhance the heat transfer rate. Therefore, it is logical to investigate the entropy production under the impact of non-homogenous distribution of nanoparticles. Based upon this fact the aim of current study is to explore a comprehensive detail about the influence of non-homogeneous nanoparticles concentration on entropy production phenomenon by considering a laminar viscous flow past a moving continuous flat plate. Non-uniform concentration is considered in the nanofluid modeling in which the Brownian and thermophoretic diffusions are considered which impart significant effects on velocity and temperature profiles. An exact self-similar solution to this problem is observed to be possible and is reported. The effects of various controlling physical parameters such as Brinkman number, Schmidt number, Prandtl number, diffusion parameter, and concentration parameter on both local as well as total entropy generation number and Bejan number are elaborated by several graphs and Tables. The obtained results reveal a significant impact of all aforementioned parameters on entropy generation characteristics. It is observed that by a 20% increase in nanoparticles concentration the total entropy generation is increased up to 67% for a set of fixed values of remaining parameters.

Fabrication of Polyethersulfone (PES) Membrane Incorporated with Graphitic Carbon Nitride (g-C3N4) Nanoparticles in Palm Oil Mill Effluent (POME) Wastewater Treatment

Backed by the evolution in the nanotechnology field, membrane modified with nanoparticles as an additive has become increasingly prominent nowadays. The enormous potential of graphitic carbon nitride (g-C3N4) photocatalyst in wastewater treatment has been disclosed extensively. In this study, 4 Polyethersulfone (PES) membranes with different concentration of g-C3N4nanoparticles as additive were fabricated and their performances were investigated. Scanning Electron Microscopy (SEM) analysis showed that the membrane top surface layer was getting denser with the higher g-C3N4nanoparticles concentration which subsequently decreased the membrane mean pore size, porosity and flux. However the membrane with higher additive concentration was demonstrated a better improvement in anti-fouling properties where the flux recovery ratio (FRR) of the membranes showed an uptrend movement from 23.43% (membrane without additive) to 64.64% (membrane with 6 wt.% of additive). The enhancement of COD and colour removal rate from 61.50 % to 66.50 % and 78.75 % to 83.75 % was also observed in this study where the finding has signified the increased g-C3N4 nanoparticles concentration was constructive in PES membrane modification.

An Experimental and Theoretical Study on the Effect of Silver Nanoparticles Concentration on the Structural, Morphological, Optical, and Electronic Properties of TiO2 Nanocrystals

In this work, pure and silver (Ag)-loaded TiO2 nanocrystals (NCs) with various concentrations of Ag were prepared by soft chemical route and the effect of Ag nanoparticles (NPs) on the functional properties of TiO2 was studied. X-ray diffraction (XRD) and Raman studies confirmed that the synthesized product had single-phase nature and high crystalline quality. The crystallite size was decreased from 18.3 nm to 13.9 nm with the increasing in concentration of Ag in TiO2 NCs. FESEM micrographs showed that the pure and AgNPs-loaded TiO2 have spherical morphology and uniform size distribution with the size ranging from 20 to 10 nm. Raman spectroscopy performed on pure and AgNPs-loaded TiO2 confirms the presence of anatase phase and AgNPs. Optical properties show the characteristics peaks of TiO2 and the shifting of the peaks position was observed by changing the concentration of Ag. The tuning of bandgap was found to be observed with the increase in Ag, which could be ascribed to the synergistic effect between silver and TiO2 NCs. Density functional theory calculations are carried out for different Ag series of doped TiO2 lattices to simulate the structural and electronic properties. The analysis of the electronic structures show that Ag loading induces new localized gap states around the Fermi level. Moreover, the introduction of dopant states in the gap region owing to Ag doping can be convenient to shift the absorption edge of pristine TiO2 through visible light.

Engineering Escherichia coli biofilm to increase contact surface for shikimate and L-malate production

Microbial organelles are a promising model to promote cellular functions for the production of high-value chemicals. However, the concentrations of enzymes and nanoparticles are limited by the contact surface in single Escherichia coli cells. Herein, the definition of contact surface is to improve the amylase and CdS nanoparticles concentration for enhancing the substrate starch and cofactor NADH utilization. In this study, two biofilm-based strategies were developed to improve the contact surface for the production of shikimate and L-malate. First, the contact surface of E. coli was improved by amylase self-assembly with a blue light-inducible biofilm-based SpyTag/SpyCatcher system. This system increased the glucose concentration by 20.7% and the starch-based shikimate titer to 50.96 g L−1, which showed the highest titer with starch as substrate. Then, the contact surface of E. coli was improved using a biofilm-based CdS-biohybrid system by light-driven system, which improved the NADH concentration by 83.3% and increased the NADH-dependent L-malate titer to 45.93 g L−1. Thus, the biofilm-based strategies can regulate cellular functions to increase the efficiency of microbial cell factories based on the optogenetics, light-driven, and metabolic engineering. Graphical Abstract