Novel coronavirus (COVID-19) diagnosis using computer vision and artificial intelligence techniques: a review

Multimedia Tools and Applications - The universal transmission of pandemic COVID-19 (Coronavirus) causes an immediate need to commit in the fight across the whole human population. The emergencies...     

Synthesis of some organic poly(aminium phosphate)s: 4

Poly(aminium phosphate)s were prepared by precipitation from aqueous solution. The composition of these derivatives was established by analysing for nitrogen and phosphorus. Weight average molecular weights were determined by intrinsic viscosity determination. The intrinsic viscosity has been determined by replacing the usual extrapolation of specific viscosity to zero concentration ($\text{η}{}_{\mathrm{<mtext>sp</mtext>}}\text{C}$ vs. CO) with the extrapolation of linear transformation. G = AF + B where $\text{G =}\text{y}\text{α ? x}$, $\text{F =}\text{x}\text{α ? x}$ and α = x_M + x_m (where $\text{y =}\text{η}{}_{\mathrm{<mtext>sp</mtext>}}\text{C}$ and x_m and x_M denote concentration). The values for Huggins constants (k′ + k″) were also calculated and found to be characteristic of linear chain polymers. The R_g values for poly(aminium phosphate)s have been determined in New Ebel's solvent, by a paper chromatographic technique. A linear relationship between degree of polymerization and R_g values is indicative of the linear chain polymeric character of these derivatives. The polyelectrolyte behaviour of these polymers has also been established by conductivity measurements.     

Rapid prototyping assisted fabrication of patient specific β-tricalciumphosphate scaffolds for bone tissue regeneration

Beta Tri calcium phosphate scaffolds were produced by inverse casting methodology using rapid prototyping technology. Β-TCP scaffold sintered at different temperatures were analyzed by using Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, uniaxial compression test and cytotoxicity test. Results incorporate scaffold pore size, bonding, phase chance, porosity, mechanical strength, and cytotoxic profile with an increase in the sintering temperatures. Together, these properties are required for scaffold fabrication in the field of bone tissue regeneration.     

Polypropylene/Cellulose Composites for Material Extrusion Additive Manufacturing

The preparation of polypropylene (PP)/microcrystalline cellulose (MCC) composites and their applicability for material extrusion additive manufacturing (ME‐AM) is reported. MCC is modified by grafting onto its surface with different silanes, in particular perfluorooctyltriethoxysilane, n‐octyltriethoxysilane (OTS), or aminopropyltriethoxysilane. The efficacy of the surface modification is confirmed by attenuated total reflectance and X‐ray photoelectron spectroscopy. The affinity of the modified MCC to the polar PP matrix is investigated by direct melt‐compounding, and the applicability of the resulting composites for material ME‐AM is accessed by fabrication of filaments and evaluating the relevant property requirements. The surface modification of the MCC improves their dispersibility in PP and enhances the mechanical properties of the composites. Moreover, the OTS‐modified MCC shows the best reinforcement, good surface finish of the filament, and flawless printability.     

Modelling and finite-time stability analysis of psoriasis pathogenesis

A new systems model of psoriasis is presented and analysed from the perspective of control theory. Cytokines are treated as actuators to the plant model that govern the cell population under the reasonable assumption that cytokine dynamics are faster than the cell population dynamics. The analysis of various equilibria is undertaken based on singular perturbation theory. Finite-time stability and stabilisation have been studied in various engineering applications where the principal paradigm uses non-Lipschitz functions of the states. A comprehensive study of the finite-time stability properties of the proposed psoriasis dynamics is carried out. It is demonstrated that the dynamics are finite-time convergent to certain equilibrium points rather than asymptotically or exponentially convergent. This feature of finite-time convergence motivates the development of a modified version of the Michaelis–Menten function, frequently used in biology. This framework is used to model cytokines as fast finite-time actuators.     

Investigation on flammability of rigid polyurethane foam‐mineral fillers composite

This study investigates the incorporation of castor oil–based rigid polyurethane foam with mineral fillers feldspar or kaolinite clay in order to enhance the mechanical, thermal, and flame retardant properties. Influence of mineral fillers on the mechanical strength was characterized by compressive strength and flexural strength measurement. Thermogravimetric analysis (TGA) was performed to diagnose the changes in thermal properties, while cone calorimeter test was performed to ascertain the flame retardancy of the mineral filler–incorporated rigid polyurethane foam composites. Results showed that the foams incorporated with mineral filler demonstrated up to 182% increase in compressive strength and 351% increase in flexural strength. Thermal stability of these composite foams was also found to be enhanced on the incorporation of kaolinite clay filler with an increase in 5% weight loss temperature (T_5%) from 192°C to 260°C. Furthermore, peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) were also found to decreased on the incorporation of mineral filler in the rigid polyurethane foam. So mineral fillers are ascertained as a potential filler to enhance the mechanical, thermal, and flame retardant behaviors of bio‐based rigid polyurethane foam composites.     

Cancer Development,Progression, and Therapy: An Epigenetic Overview

Carcinogenesis involves uncontrolled cell growth, which follows the activation of oncogenes and/or the deactivation of tumor suppression genes. Metastasis requires down-regulation of cell adhesion receptors necessary for tissue-specific, cell–cell attachment, as well as up-regulation of receptors that enhance cell motility. Epigenetic changes, including histone modifications, DNA methylation, and DNA hydroxymethylation, can modify these characteristics. Targets for these epigenetic changes include signaling pathways that regulate apoptosis and autophagy, as well as microRNA. We propose that predisposed normal cells convert to cancer progenitor cells that, after growing, undergo an epithelial-mesenchymal transition. This process, which is partially under epigenetic control, can create a metastatic form of both progenitor and full-fledged cancer cells, after which metastasis to a distant location may occur. Identification of epigenetic regulatory mechanisms has provided potential therapeutic avenues. In particular, epigenetic drugs appear to potentiate the action of traditional therapeutics, often by demethylating and re-expressing tumor suppressor genes to inhibit tumorigenesis. Epigenetic drugs may inhibit both the formation and growth of cancer progenitor cells, thus reducing the recurrence of cancer. Adopting epigenetic alteration as a new hallmark of cancer is a logical and necessary step that will further encourage the development of novel epigenetic biomarkers and therapeutics.     

University of Miami/Jackson Memorial Medical Center restructures its health care system for the 21st century

Change, challenge, and commitment motivate staff at the University of Miami/Jackson Memorial Medical Center in Miami, Florida, to prepare its health care system for the 21st century. Doctors, nurses, environmental workers, pharmacists, cashiers, nursing assistants, laboratory technologists, and many others are participating on a variety of teams to bring about the changes needed for our delivery system to be competitive.