New Insight of microRNAs & short interfering RNA in Treatment of COVID-19; a Narrative Review

Since 31 December 2019, the coronavirus disease 2019 (COVID-19) resulted in a state of hyperinflammation syndrome and multiorgan failure. In areas with pandemic outbreaks, despite several emerging vaccines, supportive treatments to mitigate fatality rates were required. Growing evidence suggests that several small RNAs such as microRNAs (miRNAs) and short interfering RNA (siRNA) could be candidates for the treatment of COVID-19 by inhibiting the expression of crucial virus genes. small RNAs by binding to the 3′-untranslated region (UTR) or 5′-UTR of viral RNA play an important role in COVID-19-host interplay and viral replication. In this review, the authors sought to specify the efficacy and safety of miRNAs and siRNA expressions of patients with COVID-19, which has an axial role in the pathogenesis of human diseases

In-situ detection of atrazine and its metabolites contamination in natural waters

Water and soil contamination caused by extensive atrazine (ATZ) application in agriculture, could be a potential risk to the environment and human health. Common analytical methods are expensive and complex. A sensor for low-cost and simple detection of ATZ and its metabolites, deethylatrazine (DEA) and deisopropylatrazine (DIA), in aqueous solutions was developed by combining colloidal crystal with molecular imprinting technique. The sensor is formed by 3D interconnected macroporous structure with numerous nanocavities derived from ATZ and its metabolites imprinting in a thin polymeric film. The MIPs were fabricated with acrylic acid monomers crosslinked by ethylene glycol dimethacrylate with 4:1 molar ratio, polymerized under UV radiation initiated by azobisisobutyronitrile. The films were characterized by Fourier Transform Infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The MIPs were incubated in solutions of each target at variable concentrations. Target molecules were specifically absorbed in nanocavities and caused swelling in the polymer film resulting in changes of Bragg diffraction peak wavelength. Kinetic tests showed that rebinding equilibrium was reached within 20 minutes. The sensor had a dynamic range of 0.1 to 10 ppb for quantifying target analytes in aqueous solutions with limit of detection of 0.1, 0.2, and 0.3 ppb, and limit of quantification of 0.33, 0.66, and 1 ppb for ATZ, DEA, and DIA, respectively. Cross-reactivity tests were conducted in 1 and 5 ppb solutions combining all three targets and showed absence of positive interferences effects and low probability of false positives given by individual sensors. Ionic strength effect on MIPs investigation showed up to 26 percent decrease and 23 percent increase in MIP response for NaCl and CaCl2, respectively. Presence of NOM caused 28 percent and 35 percent increase in wavelength shift for NIPs and MIPs, respectively. Rinsing NIPs before measuring the reflectance spectra resulted in less increase in wavelength shift. Natural waters samples were collected after rain events and were characterized for physicochemical properties and the content of ATZ, DEA, and DIA to be eventually used for MIPs application in them. MIPs were examined in natural waters spiked with target molecules, showing good agreement with real concentrations of targets. The resulting molecularly imprinted polymer (MIP) yields rapid and efficient detection of target molecules in aqueous solutions close to environmentally relevant concentrations.Includes bibliographical references

EKF and UKF-based estimation of a sensor-less axial flux PM machine under an internal-model control scheme using a SVPWM inverter

This paper presents a comparative estimation study of rotor speed and position of a sensor-less axial flux permanent magnet synchronous motor (AFPMSM) drive system using extended Kalman filter (EKF) and unscented Kalman filter (UKF) algorithms. An internal model control (IMC) strategy is introduced to control the AFPMSM drive through currents, leading to an extension of PI control with integrators added in the off-diagonal elements to remove the cross-coupling effects between the applied voltages and stator currents in a feed-forward manner. The reference voltage is applied through a space vector pulse width modulation (SVPWM) unit. A diverse set of test scenarios has been realized to comparatively evaluate the state estimation of the sensor-less AFPMSM drive performances under the implemented IMC-based control regime using a SVPWM inverter. The resulting MATLAB simulation outcomes in the face of no-load, nominal load and speed reversal clearly illustrate the well-behaved performances of the two estimation algorithms. The UKF seems to be more promising under noisy conditions. Nevertheless, there is no clear preference for either where steady-state performance is more critical

Nanoscale structure and mechanical properties of a Soft Material

Recently, hydrogel have found to be promising biomaterials since their porous structure and hydrophilicity enables them to absorb a large amount of water. In this study the role of water on the mechanical properties of hydrogel are studied using ab-initio molecular dynamics (MD) and coarse-grained simulations. Condensed-Phased Optimized Molecular Potential (COMPASS) and MARTINI force fields are used in the all-atom atomistic models and coarse-grained simulations, respectively. The crosslinking process is modeled using a novel approach by cyclic NPT and NVT simulations starting from a high temperature, cooling down to a lower temperature to model the curing process. Radial distribution functions for different water contents (20%, 40%, 60% and 80%) have shown the crosslinks atoms are more hydrophilic than the other atoms. Diffusion coefficients are quantified in different water contents and the effect of crosslinking density on the water diffusion is studied. Elasticity parameters are computed by constant strain energy minimization in mechanical deformation simulations. It is shown that an increase in the water content results in a decrease in the elastic. Finally, continuum hyper elastic model of contact lens is studied for three different loading scenarios using Finite Element Model

THE EFFECT OF PORE SPACE ON FLUID FLOW AND PHASE BEHAVIOR IN TIGHT FORMATIONS

Unconventional resources have led to a new abundance of natural oil and gas supply all over the world over the past decade and are expected to play a vital role in the future of this industry. Despite tremendous growth of extraction technologies which increased the production of these reserve significantly, knowledge and understanding of flow and phase behavior of the fluid in unconventional resources has remained insufficiently explored. Accurate understanding of phase behavior of fluids trapped in the extremely small pores of these resources, especially shale reservoirs, is the center of attention for a lot of scholars globally. Although numerous mathematical and theoretical studies are available to explain phase behavior of confined fluids, limited number of studies attempted to explore this effect experimentally. Experimental data are invaluable in providing the deep insight needed to explain this effect, validate available models, and introduce methods of characterizations that would help with optimization of production plans. The present work is an attempt to enhance the understanding of fluid phase behavior in tight formations through experimental investigations. Microscopic effects and their macroscopic consequences that plays a crucial role in adding to the complexity of fluid phase behavior in these reservoirs are explored and explained prior to discussing modeling and experimental works. Fundamental knowledge of phase behavior and thermodynamic principals that are essential for exploring this effect and for comparing the shortcomings of established experimental approaches in phase behavior studies of conventional reservoirs are covered. A thorough review on the existing theoretical and experimental studies on the topic, considering their results and predictions, is conducted to shed more light on the need for further experimental investigation of phase behavior alterations in tight gas condensate formations. Isochoric method is an indirect high-precision way of phase transition point determination which is commonly used in other disciplines where a clear non-visual determination of phase transition of a fixed volume of fluid is needed. The present work provides an insight into using this approach in determining dew pint pressure (DPP) for gas mixtures inside and outside of the porous media. A semi-automated apparatus for measuring and monitoring equilibrium conditions along with fluid properties is designed based on the isochoric method. The apparatus provides constant volume, variable pressure (0 to 1500 psi), and variable temperature (290 to 410 K) experimental conditions. Pressure and temperature measurements are used to detect the phase transition point along the constant-mole-constant-volume line based on the change in the slope of this line at the transition point. A packed bed of BaTiO3 nanoparticles, providing a homogenous porous medium with pores of 1 to 70 nm is used as a representative nano-scale porous medium. The synthesized porous medium is very helpful in uncoupling the effect of pore size from the effect of mineralogy on the observed deviations in behavior, providing a volume more than 1000 times larger than typical nano channels. The result is a set of Isochoric lines for bulk and confined sample, plotted on the phase envelope to demonstrate the change in saturation pressure. Phase envelopes (P-T diagrams) of the same mixture using different equations of state are constructed and the accuracy of each of these equations of state in providing an experimentally detected DPP is discussed. Many attempts in explaining the shift in saturation pressures of the reservoir fluid confined in the narrow pores of unconventional reservoirs compared to those of the bulk can be found in the literature. However, there are some contradictions between the predicted behavior using different mathematical approaches. Experimental data could be substantially helpful in both validating models and improving the understanding of the fluid behavior in these formations. Contrary to what many published models predict, the results of the present work show that confinement effects shift the DPP towards higher values compared to the bulk for a fixed temperature in the retrograde region. In the non-retrograde region, however, this shift is towards lower dew point pressure values for the confined fluid compared to the bulk. Capillary condensation is identified to be the main source of the deviations observed in the behavior of fluids inside nanopores. We evaluated published models, including those based on EOS modifications, by comparing it to experimental results to provide a quantification of their accuracy in estimating saturation pressure values for the confined mixture. Future applications of the present work for directing it towards an all-inclusive theory for all reservoir fluids in unconventional formations are clearly outlined.

BIODEGRADABLE MEDICAL DEVICE HAVING AN ADJUSTABLE DEGRADATION RATE AND METHODS OF MAKING THE SAME

Disclosed herein are biodegradable medical devices comprising biodegradable material (e.g., magnesium-calcium alloys) having an adjustable rate of degradation that can be used in various applications, including, but not limited to, drug delivery applications, cardiovascular applications, and orthopedic applications to make biodegradable and biocompatible devices. Also disclosed herein are methods of making biodegradable medical devices comprising biodegradable materials by using, for instance, hybrid dry cutting/hydrostatic burnishing