The study was conducted on 20 Holstein X Sahiwal cross bred dairy cows, with an average milk production of 2,752±113.79 liters in 284±5.75 days during a single lactation, that were divided in to two groups of 10 animals. We investigated the oxidative stress and antioxidant status during the transition period in dairy cows. In this study, plasma level of MDA was considered as an indicator of lipid peroxidation and SOD, catalase, GSH and GSHPx as antioxidants. The lipid peroxidation was significantly (p<0.001) higher in cows during early lactation as compared to the cows in advanced pregnancy. A significant positive correlation (r = +0.831, p<0.01) was determined between MDA and catalase in early lactating cows. In early lactating cows, blood glutathione was significantly lower than in advanced pregnant cows. However, early lactating cows showed non-significant negative correlation for all antioxidant enzymes with lipid peroxidation. In conclusion, dairy cows seemed to have more oxidative stress and low antioxidant defense during early lactation or just after parturition than advanced pregnant cows, and this appears to be the reason for their increased susceptibility to production diseases (e.g. mastitis, metritis, retention of fetal membranes etc.) and other health problems.

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Electrostatic dissipative and electromagnetic interference shielding materials were designed using thermally reduced graphene oxide nanosheets incorporated into a thermoplastic polyurethane matrix.

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This article reports the detailed study of dynamic mechanical properties of multiwalled carbon nanotubes/poly(ether ketone) nanocomposites prepared by melt blending. The dynamic mechanical characterisitic parameters such as storage modulus (E′), loss modulus (E″) and damping factor (tan δ) were explored in detail to investigate the adhesion factor (A), strength factor (B), efficiency factor (C), and entanglement density (N). Adhesion factor, which is inversely related to the degree of interaction between nanotubes and matrix, decreased with increase in MWCNT loading. Strength factor (B) which is a direct measure of interaction between MWCNTs and PEK increased with increase in MWCNT loading. The effect of nanotubes on moduli of composites is calculated in terms of coefficient of reinforcement (C factor). Lower is the value of coefficient (C) higher will be the effectiveness of reinforcement on moduli of composites. It decreased from value of 1 at 1 wt% MWCNTs loading in PEK to 0.67 at 5 wt% MWCNTs loading which point towards increased effectiveness of MWCNTs at 5 wt% loading for excellent properties. To compliment these findings, entanglement density (N) was also calculated. Furthermore, Cole–Cole analysis was carried out to demonstrate the compatibility of both the components in composite system. POLYM. COMPOS., 39:2587–2596, 2018. © 2016 Society of Plastics Engineers