Dye-sensitized solar cells (DSSCs) have attracted extensive interest in past decade as a promising candidate for the future generation of cost-effective photovoltaic solar cells. [1][2][3][4][5] Since the first demonstration of 10.4% photoconversion efficiency on TiO 2 -based DSSC, [6] intensive work in DSSC research has been devoted to the synthetic chemistry and structural and photovoltaic characterization of mesoporous nanocrystalline TiO 2 materials. [7][8][9] In contrast, other metal oxide semiconductors, such as tin and zinc oxides, have received less attention, though they have required band-gap widths and photoelectrochemical properties as TiO 2 . In fact, SnO 2 has at least two advantageous features compared to TiO 2 for DSSC applications: its higher electron mobility ($100-200 cm 2 V À1 S À1[10]) than TiO 2 ($0.1-1.0 cm 2 V À1 S À1[11]), suggesting a faster diffusion transport of photoinduced electrons in SnO 2 than in TiO 2 ; and its larger band gap (3.6 eV) than anatase TiO 2 (3.2 eV), which would create fewer oxidative holes in the valence band, so as to facilitate the long-term stability of DSSCs. However, SnO 2 -based DSSCs were developed with less success, and the conversion efficiencies of SnO 2 photoelectrodes reported so far are much less than those of TiO 2 . [12,13]

A self-decoupled porphyrin with a tripodal anchor has been synthesized and deposited on Au(111) using different wet-chemistry methods. Nanoscale electroluminescence from single porphyrin molecules or aggregates on Au(111) has been realized by tunneling electron excitation. The molecular origin of the luminescence is established by the vibrationally resolved fluorescence spectra observed. The rigid tripodal anchor not only acts as a decoupling spacer but also controls the orientation of the molecule. Intense molecular electroluminescence can be obtained from the emission enhancement provided by a good coupling between the molecular transition dipole and the axial nanocavity plasmon. The unipolar performance of the electroluminescence from the designed tripodal molecule suggests that the porphyrin molecule is likely to be excited by the injection of hot electrons, and then the excited state decays radiatively through Franck-Condon π*-π transitions. These results open up a new route to generating electrically driven nanoscale light sources.

The emulation of the complex cellular and bacterial vesicles used to transport materials through fluids has the potential to add revolutionary capabilities to fluidic platforms. Although a number of artificial motile vesicles or microdroplets have been demonstrated previously, control over their movement in liquid in 3D has not been achieved. Here it is shown that by adding a chemical "fuel," a photoactive material, to the droplet, it can be moved in any direction (3D) in water using simple light sources without the need for additives in the water. The droplets can be made up of a range of solvents and move with speeds as high as 10.4 mm s toward or away from the irradiation source as a result of a light-induced isothermal change in interfacial tension (Marangoni flow). It is further demonstrated that more complex functions can be accomplished by merging a photoactive droplet with a droplet carrying a "cargo" and moving the new larger droplet to a "reactor" droplet where the cargo undergoes a chemical reaction. The control and versatility of this light-activated, motile droplet system will open up new possibilities for fluidic chemical transport and applications.

Here we report that GNE-783, a novel checkpoint kinase-1 (CHK1) inhibitor, enhances the activity of gemcitabine by disabling the S-and G 2 cell-cycle checkpoints following DNA damage. Using a focused library of 51 DNA-damaging agents, we undertook a systematic screen using three different cell lines to determine which chemotherapeutics have their activity enhanced when combined with GNE-783. We found that GNE-783 was most effective at enhancing activity of antimetabolite-based DNA-damaging agents; however, there was a surprisingly wide range of activity within each class of agents. We, next, selected six different therapeutic agents and screened these in combination with GNE-783 across a panel of cell lines. This revealed a preference for enhanced chemopotentiation of select agents within tumor types, as, for instance, GNE-783 preferentially enhanced the activity of temozolomide only in melanoma cell lines. Additionally, although p53 mutant status was important for the overall response to combinations with some agents; our data indicate that this alone was insufficient to predict synergy. We finally compared the ability of a structurally related CHK1 inhibitor, GNE-900, to enhance the in vivo activity of gemcitabine, CPT-11, and temozolomide in xenograft models. GNE-900 significantly enhanced activity of only gemcitabine in vivo, suggesting that strong chemopotentiation in vitro can translate into chemopotentiation in vivo. In conclusion, our results show that selection of an appropriate agent to combine with a CHK1 inhibitor needs to be carefully evaluated in the context of the genetic background and tumor type in which it will be used. Mol Cancer Ther; 12(11); 2285-95. Ó2013 AACR.