A Survey of Non-Volatile Main Memory Technologies:State-of-the-Arts,Practices,and Future Directions

Non-Volatile Main Memories (NVMMs) have recently emerged as a promising technology for future memory systems. Generally, NVMMs have many desirable properties such as high density, byte-addressability, non-volatility, low cost, and energy efficiency, at the expense of high write latency, high write power consumption, and limited write endurance. NVMMs have become a competitive alternative of Dynamic Random Access Memory (DRAM), and will fundamentally change the landscape of memory systems. They bring many research opportunities as well as challenges on system architectural designs, memory management in operating systems (OSes), and programming models for hybrid memory systems. In this article, we revisit the landscape of emerging NVMM technologies, and then survey the state-of-the-art studies of NVMM technologies. We classify those studies with a taxonomy according to different dimensions such as memory architectures, data persistence, performance improvement, energy saving, and wear leveling. Second, to demonstrate the best practices in building NVMM systems, we introduce our recent work of hybrid memory system designs from the dimensions of architectures, systems, and applications. At last, we present our vision of future research directions of NVMMs and shed some light on design challenges and opportunities.

Glutamate and aspartate alleviate testicular/epididymal oxidative stress by supporting antioxidant enzymes and immune defense systems in boars

Several potential oxidative agents have damaging effects on mammalian reproductive systems.This study was conducted to investigate the effects of glutamate(Glu)and aspartate(Asp)supplementation on antioxidant enzymes and immune defense systems in the outer scrotum of boars injected with H2O2.A total of 24 healthy boars were randomly divided into 4 treatment groups:control(basal diet,saline-treated),H2O2(basal diet,H2O2-challenged outer scrotum(1 m L kg^–1 BW)),Glu(basal diet+2%Glu,H2O2-challenged),and Asp(basal diet+2%Asp,H2O2-challenged).Our results showed that both Glu and Asp supplementation improved testicular morphology and decreased the genital index in the H2O2-treated boars.Glu and Asp administration increased the antioxidant enzyme activities and affected the testicular inflammatory cytokine secretion but had no effect on sex hormone levels.Furthermore,the m RNA expression of CAT,Cu Zn SOD,and GPx4 was altered in the testes and epididymis of boars treated with Asp and Glu.Glu and Asp supplementation also modulated the expression of TGF-β1,IL-10,TNF-α,IL-6 and IL-1βin the testis and epididymis.These results indicate that dietary Glu and Asp supplementation might enhance antioxidant capacity and regulate the secretion and expression of inflammatory cytokines to protect the testes and epididymis of boars against oxidative stress.