RESUMO
Nanoporous Ti-metal film electrode was fabricated by radio frequency (rf) magnetron sputtering technique on nanoporous TiO2 layer prepared by sol-gel combustion method and investigated with respect to its photo-anode properties of TCO-less DSCs. The porous Ti layer (approximately 1 microm) with low sheet resistance (approximately 17 Omega/sq.) can collect electrons from the TiO2 layer and allows the ionic diffusion of I(-)/I(3-) through the hole. The porous Ti layer with highly ordered columnar structure prepared by 8 mTorr sputtering shows the good impedance characteristics. The efficiency of prepared TCO-less DSCs sample is about 4.83% (ff: 0.6, Voc: 0.65 V, Jsc: 11.2 mA/cm2).
RESUMO
Eucommia ulmoides leaves have been used as a folk remedy for the treatment of diabetes in Korea. The aim of this study was to isolate and identify the compounds which inhibited advanced glycation end-product formation, one of main molecular mechanisms implicated in diabetic complications. A new flavonol glycoside, quercetin 3-O-alpha-L-arabinopyranosyl-(1-->2)-beta-D-glucopyranoside (1), and known flavonols kaempferol 3-O-beta-D-glucopyranoside (astragalin) (2), quercetin 3-O-beta-D-glucopyranoside (isoquercitrin) (3) were isolated from the leaves of Eucommia ulmoides. These compounds exhibited glycation inhibitory activity comparable to that of aminoguanidine, a known glycation inhibitor. The results suggest that the flavonol glycosides with glycation inhibitory activity could be attributed to the anti-diabetic action of Eucommia ulmoides leaves.