A comprehensive review of various categories of face masks resistant to Covid-19.

The science about the usage of face masks by the common public to avert COVID-19 transmission is proceeding swiftly. A primary route of transmission of COVID-19 is probably through small respiratory droplets, and it is transmissible from asymptomatic and pre-symptomatic individuals. According to the World Health Organization, wearing a mask in public can help reduce the transmission of the COVID-19 virus. Different categories and types of masks and their usage are reviewed in this work. In a nutshell, this review work elucidates the aspects of utilizing the various face masks along with all possibilities to fight against the ongoing pandemic of COVID-19.

Chemical Synthesis of Rare Earth (La, Gd) Doped Cobalt Ferrite and a Comparative Analysis of Their Magnetic Properties.

Lanthanum (La) and gadolinium (Gd) doped cobalt ferrite nanoparticles are synthesized using a soft chemical approach. The analysis of these ferrites using X-ray diffraction (XRD) and transmission electron microscopy (TEM) shows that lattice spacing decreases in the doped ferrite samples. Magnetization data indicates towards the decrease of saturation magnetisation but increase in coercivity with doping. Mössbauer spectroscopy measurements at room temperature indicate increased occupancy of trivalent cations at tetrahedral site. The addition of rare earth dopants reduces the hard-magnetic character of cobalt ferrite.

Dentine microhardness changes following conventional and alternate irrigation regimens: An in vitro study.

AIM: To compare the changes in microhardness of root dentin caused by two novel irrigation regimens with conventional irrigation. MATERIALS AND METHODS: Forty extracted human permanent incisor teeth were selected. Decoronated roots were separated longitudinally to get 80 specimens that were embedded in autopolymerizing acrylic resin and grounded flat with silicon carbide abrasive papers. Of these, 60 root segments without any cracks or defects were selected and divided into four groups according to the irrigation regimen used (n = 15). Group I: 5% sodium hypochlorite (NaOCl) + 17% ethylenediaminetetraacetic acid (EDTA) + 0.2% chlorhexidine digluconate (CHX) (conventional). Group II: 6% Morinda Citrifolia Juice + 17% EDTA (MCJ). Group III: 5% NaOCl + Q Mix 2 in 1 (QMix). Group IV: Distilled water (control). Irrigation regimens were performed for 5 minutes. Dentin microhardness was measured with a Vickers indenter under a 200-g load and a 20-s dwell time at the midroot level of root dentin. The data were analyzed using Kruskal Wallis test and Dunn's multiple comparison tests. RESULTS: A significant difference was seen in the median values of the four groups. The control group showed the least reduction in microhardness when comparison with the other groups. Except for Group III (Q Mix), the other groups that were tested (MCJ and conventional regimens) showed statistically significant difference from the control group. CONCLUSION: Within the limitation of this study, it was concluded that NaOCl + Q Mix were least detrimental to root dentin microhardness when compared with MCJ and conventional irrigation regimens.