Search

One newly bred variety of tea cultivar, purple-shoot tea, was selected to evaluate its antiproliferative effects on colorectal carcinoma cells, as well as normal colon cells. The phytochemicals and identified catechins of purple-shoot tea extract (PTE) were significantly higher than that of ordinary tea, especially the anthocyanins (surpassed by 135-fold) and anthocyanidins (surpassed by 3.5-fold). PTE inhibited the proliferation of COLO 320DM (IC50= 64.9 μg/mL) and HT-29 (IC50= 55.2 μg/mL) by blocking cell cycle progression during the G0/G1phase and inducing apoptotic death. Western blotting indicated that PTE induced cell cycle arrest by reducing the expression of cyclin E and cyclin D1 in COLO 320DM and the upregulation of p21 and p27 cyclin-dependent kinase inhibitors in HT-29. Two cells treated with PTE also indicated the cleavage of PARP, activation of caspase 3, and an increased Bax/Bcl-2 ratio. Our results showed that PTE is a potential novel dietary agent for colorectal cancer chemoprevention.

A single layer of organic solar cells with the Al/P3HT/PEDOT: PSS/ITO structure on glass substrate was investigated in this paper, and examined the performance of the polymer solar cells by changing 60, 70 and 80 nm thickness of the P3HT active layer. These devices had better absorption in the active layer and poor charges collect in the electrode with increase thickness of active layer were observed. It is found that the best properties that the single layer organic solar cell with open-circuit voltage 0.457 V, short-circuit current 1.05E-4 mA and power conversion efficiency of 3.3E-5% was achieved under illumination 100 mW/cm2 when the thickness of P3HT active layer is about 80 nm.

A simple method was found to observe the semiconducting behavior of graphene using the O2gas adsorption property. Graphene was synthesized by thermal chemical vapor deposition with NH3as the nitrogen doping source. The current response increased significantly when the p-type graphene was exposed to an O2environment. The current response decreased gradually when the nitrogen content was increased. When the NH3flow rate was increased to 80 sccm during graphene synthesis, the p-type graphene becomes n-type and the nitrogen-doped graphene current response clearly decreases during O2gas adsorption measurements. We measured the graphene Dirac point using a field-effect transistor to define the graphene semiconducting properties. These results show that gas adsorption measurements can reveal the graphene semiconducting performance and also the n-type graphene synthesis conditions.