Effects of TiO2 Particle Size On the Performance of Dye Sensitized Solar Cells Using Ionic Liquid Electrolytes

Different-sized nanocrystalline-TiO2 particles have been used for the optimization of photovoltaic er effects of dye-sensitized solar cells (DSCs) using an ionic-liquid (IL) electrolyte. Ru dye (Z907) was used for the IL-DSC optimization. The TiO2 nanoparticle sizes and the thickness of nanocrystalline- TiO2 electrodes ranged from 13 nm to 81 nm and 2 mu m to 23 mu m, respectively. The particle size of the nanocrystalline TiO2 film greatly a r ected the photovoltaic characteristics, particularly for the IL electrolyte due to limitation of the photocurrent by I-/I-3(-)-diffusion. The optimized electrode for IL-DSC had a 15 mu m thickness using a 27 nm diameter of nanocrystallineTiO(2) particles. In order to characterize the e r ect of the TiO2 particle size on the photovoltaic e r ects of IL-DSCs, a scanning electron micrograph (surface and cross section of nanoparticles), BET specific surface area analysis, pore-size distribution analysis, photocurrent transien

A Complete Gear System in <i>N</i>‑Benzoyl-Carbazole Derivatives

2′,6′-Disubstituted <i>N</i>-benzoylated carbazole derivatives were found to exhibit atropisomerism. The bulky substituents restricted rotation about the N–C7′ and C7′–C1′ bonds to separate four atropisomers, in which rotation about the C7′–C1′ bond was in perfect concert with rotation about the N–C7′ bond. Complete geared rotation without slippage at 37 °C for 7 days was observed for the first time. Conformational analysis clarified the preference for the gear system over other internal conversion pathways

Induction of Heat Shock Protein 70 Ameliorates Ultraviolet-Induced Photokeratitis in Mice

Acute ultraviolet (UV) B exposure causes photokeratitis and induces apoptosis in corneal cells. Geranylgeranylacetone (GGA) is an acyclic polyisoprenoid that induces expression of heat shock protein (HSP)70, a soluble intracellular chaperone protein expressed in various tissues, protecting cells against stress conditions. We examined whether induction of HSP70 has therapeutic effects on UV-photokeratitis in mice. C57 BL/6 mice were divided into four groups, GGA-treated (500 mg/kg/mouse) and UVB-exposed (400 mJ/cm2), GGA-untreated UVB-exposed (400 mJ/cm2), GGA-treated (500 mg/kg/mouse) but not exposed and naive controls. Eyeballs were collected 24 h after irradiation, and corneas were stained with hematoxylin and eosin (H&amp;amp;E) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). HSP70, reactive oxygen species (ROS) production, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and protein kinase B (Akt) expression were also evaluated. Irradiated corneal epithelium was significantly thicker in the eyes of mice treated with GGA compared with those given the vehicle alone (p &amp;lt; 0.01). Significantly fewer TUNEL-positive cells were observed in the eyes of GGA-treated mice than controls after irradiation (p &amp;lt; 0.01). Corneal HSP70 levels were significantly elevated in corneas of mice treated with GGA (p &amp;lt; 0.05). ROS signal was not affected by GGA. NF-κB activation was reduced but phospho-(Ser/Ther) Akt substrate expression was increased in corneas after irradiation when treated with GGA. GGA-treatment induced HSP70 expression and ameliorated UV-induced corneal damage through the reduced NF-κB activation and possibly increased Akt phosphorilation