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The role of oxidant stress in the causation of chronic tissue damage is being increasingly recognized. Oxidant stress is usually countered by abundant supply of antioxidants. If concomitant antioxidant deficiency occurs, oxidant stress may produce tissue damage. We took up a study on antioxidant status in non-insulin dependent diabetes mellitus (NIDDM) patients with and without retinopathy and compared them with a control non-diabetic group. The levels of superoxide dismutase (SOD) were significantly reduced in all diabetic patients, i.e., those with and without retinopathy. However, the lowest levels were found in the diabetic patients with retinopathy. Vitamin E and vitamin C levels were also markedly lower in the diabetic patients. There was a paradoxical rise in the catalase and glutathione peroxidase (GPx) in the diabetic patients with retinopathy. This may be a compensatory mechanism by the body to prevent tissue damage by increasing the levels of the two alternative antioxidant enzymes.

The study's main objective is to design and develop pressure vessels in underwater applications using Hybrid composites-Fibre Metal Laminates (FML) so that the weight will be reduced. The proposed pressure vessel accommodates electronics in the underwater ambient noise measurement system under an external hydrostatic pressure of 1 MPa (10 bar). The research study aims initially to design and develop a pressure vessel with stainless steel 316 L and subsequently design a pressure vessel with hybrid composites with a combination of composite materials of E-glass and carbon/epoxy materials with a metal alloy stainless steel 316 L. The pressure vessel has been optimised with varying metal and composite percentage combinations. The cylinder's wall thickness has been pivotal in optimizing pressure vessel design. Classical Laminate Theory (CLT) transforms the FML pressure vessel or cylinder into a rectangular plate. As preliminary measures, FML specimen with a size of 0.45 m square laminate and 0°orientation has been developed with 50 % metal layer and 50 % fibre composites, and corresponding mechanical tests have been carried out as per the standards. The tensile strength of the developed FML is 420 MPa compared to base metal (SS316 L) strength of 556 MPa, and similarly, Flexural and Impact properties have shown a higher level when compared to other types of FMLs. [ABSTRACT FROM AUTHOR]

N95 masks filter 95% of the small particles and respiratory droplets (>03 pm diameter). Therefore, they are widely used both by general public and health workers during pandemic. When physical activity or exercise is performed wearing N95 mask, it induces hypercapnic environment The heat burden is also increased leading to discomfort and reduced compliance. This study was done to compare physiological effects and subjective perceptions while wearing N95 mask and powered air-purifying respirator (PAPR) (2 fans, N95 filter) during incremental exercise. ECG, respiratory movement, SpO2, temperature inside the mask were recorded and perception of discomfort was also assessed. Heart rate variability (HRV) values during baseline were within normal limits in both the mask conditions signifying that cardiac autonomic tone is comparable. During incremental exercise, fall in SpO2 was significantly lesser in PAPR as compared to N95 mask at 60-70% and 70-80% of maximum achievable heart rate. The temperatures inside both the mask conditions were significantly higher than ambient temperature. The scores of humid, hot, breath resistance and fatigue were significantly lower in PAPR than N95 mask. In conditions where prolonged use of mask is required with strenuous physical exertion or exercise, PAPR could be preferred over N95 mask. [ABSTRACT FROM AUTHOR]