RESUMEN
The effects of different boron (B) additions from 0 to 0.5 wt.% on the microstructure and properties of Fe-Mo-Cu-Ni-xB-C powder metallurgy (PM) steels were investigated in this work. The results indicated that the ferrite phase quantity decreased and disappeared, Ni/Cu became more homogeneous, and M2B phase formed, with the addition of B. The density and hardness of the sintered steels monotonously increased with increasing B content, whereas the tensile strength and impact toughness first increased and then decreased. The tensile strength of the steels reached a maximum value of 1097 MPa at a 0.2% B content, whereas the impact toughness reached a maximum value of 25.7 J/cm2 at a 0.1% B content and then sharply decreased when the B content exceeded 0.2%. Frictional wear experiments showed that the weight loss of the steels decreased with an increasing B content under low load conditions (100 N), and the lowest weight loss of 0.043 g occurred at a 0.2% B content. Under high load conditions (200 N), the 0.1% B content steel saw the lowest weight loss 0.075 g, exhibiting excellent wear resistance, but the abrasive resistance of the steels decreased with a further increase in the B content due to the germination of microcracks and large spalling caused by the high hardness and brittleness.
RESUMEN
To promote polysulfide conversion in lithium sulfur batteries (LSB) and alleviate the shuttle effect, we designed and fabricated a novel catalyst of vanadium-doped graphite phase carbon nitride with nitrogen defects (V@gC3N4-ND) and high vanadium loading (3.46 at%) by defect engineering and two-step pyrolysis. Employing a V@gC3N4-ND modified separator, the LSB yielded capacities of 934 mA h g-1 at 1C and 404 mA h g-1 at 4C; the former was retained by 61% and 45% after 500 and 1000 cycles, respectively. In particular, the initial capacity of the battery reached 969 mA h g-1 at a sulfur loading of 10.0 mg cm-2. This work provides a facile route to the preparation of high-loading vanadium active site catalysts with nitrogen defects in the support, which are promising for high performance LSB applications.
RESUMEN
7-Ethyl-10-hydroxycamptothecin (SN38), the bioactive metabolite of irinotecan (CPT-11), has been shown to be 100-1000 times more effective than CPT-11. However, the poor water solubility and bioavailability of SN38 constrained its clinical application. In this study, we synthesized a novel SN38-glucose conjugate (FSY04) to address this issue. Our in vitro studies indicated that FSY04 had a potent inhibitory ability against colorectal cancer (CRC) cell lines of SW-480 and HCT-116 compared to the inhibitory capacity of CPT-11. Interestingly, FSY04 possessed lower cytotoxicity against normal cell lines of LO2 and 293T in contrast with CPT-11. Moreover, FSY04 is more active than CPT-11 in inducing apoptosis, inhibiting migration, and invasion. In vivo experiments suggested that half of the equivalent of FSY04 inhibited the growth of SW480 in the xenograft tumor model better than one equivalent of CPT-11. Our data demonstrated FSY04 to be a promising agent in CRC therapy.
