No abstract

Rechargeable lithium-ion batteries (LIBs) have attracted tremendous attention over the past two decades. [1][2][3][4][5] Given their relatively high cost, as well as their high energy and power densities, LIBs have been considered the most promising technology in small/mid-size applications such as portable devices and electric vehicles (EVs). They are not favourable power options for large-scale stationary energy storage, however, such as in electrical grids. [6][7][8] Various emerging energy storage systems, including lithium-air batteries, [9][10][11][12][13][14][15][16] lithium-sulfur (Li/S) batteries, [11,[17][18][19][20][21][22][23] vanadium redox batteries, [24][25][26][27][28][29][30][31] sodium-ion batteries (SIBs), [32][33][34][35][36][37][38][39][40] and room-temperature sodium-sulfur Room temperature sodium-sulfur (RT-Na/S) batteries have recently regained a great deal of attention due to their high theoretical energy density and low cost, which make them promising candidates for application in large-scale energy storage, especially in stationary energy storage, such as with electrical grids. Research on this system is currently in its infancy, and it is encountering severe challenges in terms of low electroactivity, limited cycle life, and serious self-charging. Moreover, the reaction mechanism of S with Na ions varies with the electrolyte that is applied, and is very complicated and hard to detect due to the multi-step reactions and the formation of various polysulfides. Therefore, understanding the chemistry and optimizing the nanostructure of electrodes for RT-Na/S batteries are critical for their advancement and practical application in the future. In the present review, the electrochemical reactions between Na and S are reviewed, as well as recent progress on the crucial cathode materials. Furthermore, attention also is paid to electrolytes, separators, and cell configuration. Additionally, current challenges and future perspectives for the RT-Na/S batteries are discussed, and potential research directions toward improving RT-Na/S cells are proposed at the end.

The emerging field of optical-triggered actuators based on polymeric nanocomposite continues to be the focus of considerable research in recent years because of their scientific and technological significance. In principle, dispersing nanofiller with unique characteristics in polymer matrix can not only provide superb enhancement of performance but also afford novel actuation schemes to the systems. Graphene, combining its unusual electrical, thermal, mechanical, and optical properties, can provide the ability to act as "energy transfer" and trigger unit in the realm of nanocomposite actuators. Herein, we demonstrate a new dimension to this 2D nanoscale material by showing the excellent light-triggered acutation of its thermoplastic polyurethane nanocomposites with significantly enhanced mechanical properties. These nanocomposite actuators with 1 wt % loading of sulfonated functionalized graphene sheets (sulfonated-graphene) exhibit repeatable infraredtriggered actuation performance which can strikingly contract and lift a 21.6 g weight 3.1 cm with 0.21 N of force on exposure to infrared light and demonstrate estimated energy densities of over 0.33 J/g. Some cases can even reach as high as 0.40 J/g. Dramatic improvement in mechanical properties is also obtained for the graphene nanocomposites with homogeneous dispersion. As the concentration of sulfonated-graphene increases, its nanocomposites show significantly enhanced mechanical properties, that is, the Young's modulus increases by 120% at only 1 wt % loading. Moreover, through comparative study of three kinds of graphene materials, it is found that this infrared-triggered actuation property is principally dependent on the integrity of the aromatic network of graphene and on its dispersion state within the matrix.

In 2006, more than 55,000 patients died of colorectal cancer in the US, accounting for approximately 10% of all cancer deaths. Despite significant progress in screening combined with the development of novel effective therapies, colorectal cancer ranks second to lung cancer as a cause of cancer death. Twin studies indicate that 35% of all colorectal cancers are inherited, but high-penetrance tumor susceptibility genes only account for approximately 3-6% of all cases. The remainder of the unexplained familial risk is presumably due to other high-penetrance genes, but polygenic mechanisms and low-penetrance tumor susceptibility genes are likely to account for a greater proportion of familial colorectal cancers. In this regard, there is growing evidence that a common hypomorphic variant of the type I TGF-beta receptor, TGFBR1*6A, may account for approximately 3% of all colorectal cancer cases, a fraction higher than that attributable to mismatch repair genes MLH1, MSH2, MSH6 and PMS2. Furthermore, TGFBR1*6A is emerging as a potent modifier of colorectal cancer risk among individuals with a strong family of colorectal cancer. The TGF-beta signaling pathway plays a central but paradoxical role in the predisposition and progression of colorectal cancer. TGF-beta is a potent inhibitor of normal colonic epithelial cells acting as a tumor suppressor. However, TGF-beta promotes the survival, invasion and metastasis of colorectal cancer cells, thereby acting as an oncogene. Understanding how selective alterations of the TGF-beta signaling pathway contribute to colorectal cancer development and progression will likely permit the identification of an additional fraction of inherited colorectal cancer cases and provide novel opportunities for therapeutic intervention.