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We investigate the performance of multiple relays cooperative go back n automatic repeat request (MRC-GBn-ARQ) protocol with limited retransmission. An lV+2-state Markov transition model is constructed for analyzing arbitrary packet transmission process with limited retransmission. Then the system's steadystate distribution is derived by using the Kolmogorov equations. Further, the mean packet transmission delay and startup delay are obtained respectively; the channel utilization is derived based on discrete-time Geom/G/1 queue model with startup. Also, we get the energy efficiency of the MRC-GBn-ARQ based on energy analytical model. Especially, the presented models are contrary to the classical ARQ protocols of always allowing infinite retransmission, and our analysis of the MRC-GBn-ARQ protocol with limited retransmission provides theoretical results for reducing the system's delay and energy consumption. Finally, analysis is validated through some numerical simulations. [ABSTRACT FROM AUTHOR]

Astilbin is a flavonoid compound isolated from the rhizome of Smilax china L. The effects and possible mechanisms of astilbin on hyperuricemia and nephropathy rats were elucidated in this study. Different dosages of astilbin (1.25, 2.5, and 5.0mg/kg) were administered to 10% fructose-induced hyperuricemic rats. The results demonstrated that astilbin significantly decreased the serum uric acid (Sur) level by increasing the urinary uric acid (Uur) level and fractional excretion of urate (FEUA) but not inhibiting the xanthine oxidase (XOD) activity. In addition, kidney function parameters such as serum creatinine (Scr) and blood urea nitrogen (BUN) were recovered in astilbin-treated hyperuricemic rats. Further investigation indicated that astilbin prevented the renal damage against the expression of transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) and also exerted a renal protective role by inhibiting formation of monosodium urate (MSU) and production of prostaglandin E2 (PGE2) and interleukin-1 (IL-1). These findings provide potent evidence for astilbin as a safe and promising lead compound in the development of a disease-modifying drug to prevent hyperuricemia and nephropathy. [ABSTRACT FROM AUTHOR]