Association of COVID-19 with obesity Association of COVID-19 with obesity

COVID-19 is a disease that cause respiratory illness due to novel corona virus. It was reported to WHO on December 31,2019 for the first time. The outbreak of this disease started from Wuhan city, China. Now COVID-19 pandemic is spreading worldwide mostly in Europe and North America, these regions have high prevalence of obesity. In the pathogenesis of COVID-19 disease, obesity assumes a significant job. Theinsusceptible framework, which is official in the pathogenesis of COVID19, assumes asignificant job in weight instigated fat tissue aggravation. In the fat tissue the irritationbrings about metabolic brokenness conceivably prompting dyslipidemia, type 2diabetes mellitus, insulin obstruction, hypertension and cardiovascular sickness. Obesity has been expanded the vulnerability to contaminations. In this pandemic, a large number of obese individual with Covid-19 are reported. Infection rate in obese is greater due to poor immunity, comorbidity and inadequate nutritional needs. Statistical analysis showed that about 41.7% patients reported in New York city were obese. Whereas 40% obese have been reported in United State of America with Covid-19. A report from UK indicated that 38% obese were admitted in ICU with Covid-19. According to Chinese researchers, obese individuals are 3-timesmore prone toward the development of Covid-19. So recent analysis indicated that obesity is the major risk factor of Covid-19. In COVID-19, overweight and obese patients have high danger of metabolic difficultiesand eternal infections that stoutness works. More nutrition care is required for such patients. As nutrition is a key factor for keeping up human wellbeing, for example, denseimpervious framework and satisfactory admission of supplements and dietaryenhancements. Tolerant with COVID-19 create contamination from slight to seriousindications bound to the dietary status. Consequently, assessing wholesome status ofindividuals with contamination turns out to be increasingly significant. Through dietaryhelp, we can bring down the danger of oxidative pressure, infection contamination andexpands invulnerability framework among obese people especially.

Fabrication, Characterization and Structural Study of Ferrites of Technical Importance

Ferrites are widely used in power electronics applications where the frequency range is from KHz to MHz. No other alternative materials except ferrites are available at such high frequencies. The areas of magnetic nanoparticles and thin films lead to revolutionary new approaches in basic and advanced magnetism, and are more effective in the field of high density storage media. The main objective of the present study was to produce single phase ferrites in the form of bulk, nano and thin films with improved structural, electrical and magnetic properties. This thesis examines the issue encountered in the growth, structural, microstructural, electrical and magnetic properties of ferrites in the form of bulk, nanoparticles and thin films. Here the materials examined include Cu 0.5 Zn 0.5 Fe 2- x Al x O 4 (x=0.0 to 0.5) ferrites prepared with solid state reaction method, Co 0.5 Mn 0.5 Fe 2 O 4 (calcined at 500, 600, 700, 800, 900°C), Mn 0.5 Cu 0.5-x Zn x Fe 2 O 4 (x=0.0 to 0.5), Mn 0.5 Cu 0.5-x Ni x Fe 2 O 4 (x=0.0 to 0.5) ferrites prepared with sol-gel combustion method and Fe 3 O 4 thin films prepared with pulsed laser deposition technique. The effect of Al3+ on the structural, electrical and magnetic properties were investigated in Cu 0.5 Zn 0.5 Fe 2-x Al x O 4 (x=0.0 to 0.5) ferrites prepared with solid state reaction method. Single phase cubic spinel structure was revealed by X-ray diffraction analysis. For all the samples, crystallite size remained in the range of 25-30 nm. Lattice constants of all the samples decreased, whereas porosity increased with increasing Al+3 concentration due to the substitution of smaller Al3+ ion (0.51 Å) for large Fe3+ ion (0.64 Å). Due to non-magnetic trend of Al3+ concentrations for a magnetic element Fe3+ at the B-site gradually decreased the saturation magnetization. Al+3 has significant impact on the dielectric constant ( ε /), tangent of dielectric loss angle (tanδ) and dielectric loss factor ( ε //). The possible reason for the variation in dielectric properties has been understood on the basis of space charge polarization. Three series of ferrites Co 0.5 Mn 0.5 Fe 2 O 4 (calcined at 500, 600, 700, 800, 900°C), Mn 0.5 Cu 0.5-x Zn x Fe 2 O 4 (x=0.0 to 0.5), Mn 0.5 Cu 0.5-x Ni x Fe 2 O 4 (x=0.0 to 0.5) were prepared by sol-gel combustion method. In Co 0.5 Mn 0.5 Fe 2 O 4 ferrites, crystallite size was determined with Scherrer’s formula. Crystallite size increases with calcination temperature but coercivity decreases. The decrease in coercivity at larger crystallite size can be attributed to domain walls. Single phase nanocrystalline Mn 0.5 Cu 0.5-x Zn x Fe 2 O 4 (x=0.0 to 0.5) ferrites were successfully prepared at low temperature of 300°C using citric acid as a fuel and nitrates as oxidants by sol-gel method. X-ray diffraction (XRD) and room temperature vibrating sample magnetometer (VSM) studies have been carried out in order to understand the structural and magnetic properties as a function of zinc concentration. The variations of observed lattice parameter and crystallite size have been explained by considering the larger ionic radius of zinc. The coercivity decreases as the crystallite size increases, attaining a minimum value of 46.32 Oe. This decrease at larger crystallite size could be due to three reasons. First, the crossover of single domain to multiphase domain, second combined effect of surface and surface anisotropy, third migration of Fe+3 ions from A to B-site. Another series of single phase nano-crystalline Mn 0.5 Cu 0.5- x Zn x Fe 2 O 4 (x=0.0 to 0.5) ferrites were successfully synthesized by combustion method at a temperature as low as 300°C. The presence of Ni2+ ions did not show a consistent trend in diffraction peaks shifting to either lower or higher angles. It was observed that with increasing nickel concentration, saturation magnetization (M s ) increased but coercivity (H c ) decreased which could be attributed to the substitution of soft ferromagnetic Ni2+ ions in place of diamagnetic Cu2+ ions. The minimum value of coercivity (87.20 Oe) was observed for the composition Mn 0.5 Ni 0.5 Fe 2 O 4 . Fe 3 O 4 thin films were deposited on Si(100) substrates with pulsed laser deposition technique. First we studied the effect of annealing and deposition temperature, and second the effect of annealing time of 30, 60 and 90 minutes on the structural and magnetic properties of Fe 3 O 4 thin films. Scanning electron microscopy, X-ray diffractometery and vibrating sample magnetometry were used to find the film thickness, Fe 3 O 4 phase and magnetic properties respectively. We demonstrate optimized deposition and annealing condition for an enhanced magnetization of 854 emu/cc that is very high as compared to the bulk sample. Effect of annealing time on Fe 3 O 4 thin films were studied by X-ray diffractometer and vibrating sample magnetometer. Single phase [111] oriented Fe 3 O 4 thin films independent of substrate orientation was obtained after ninety minutes annealing. This preferred [111] oriented growth was explained on the basis of the achievement of a thermodynamic stable state.