4.1 Doping of anodic TiO 2 nanotubes 4.2 Doping of hydrothermal TiO 2 nanotubes 4.3 Self-doping/Magneli phases/black titanium 4.4 Conversion of tubes 4.5 Particle decoration, heterojunctions, charge transfer catalysis 4.6 Self-assembled monolayers (SAMs) 5. Applications of TiO 2 nanotubes 5.1 Solar cells 5.2 Photocatalysis 5.3 Ion-intercalation (insertion) devices

TGF-␤-activated kinase 1 (TAK1),[Keywords: JNK; NF-B; TAB1; TAB2; TAK1; TGF-␤] Supplemental material is available at http://www.genesdev.org.

The present article reviews the current status of using TiO(2) nanotubes in Grätzel-type, dye-sensitized solar cells and extends the overview with the latest results and findings. Critical factors in tube geometry (length, diameter, top morphology), crystal structure (amorphous, anatase, rutile) as well as factors affecting dye loading or electron mobility are addressed. The highest solar cell efficiencies today for pure nanotube systems reach approximately 4% while for some mixed systems, around 7% has been reported. For both systems significant room for enhancement is anticipated and some key points and strategies for improvement are outlined.

Upon screening of a human hippocampus library with a bovine Nck5a cDNA, we uncovered a distinct clone encoding a 39-kDa isoform of Nck5a. The isoform, designated the neuronal Cdk5 activator isoform (p39 nck5ai ), showed a high degree of sequence similarity to p35 nck5a with 57% amino acid identity. Northern blot analysis detected its mRNA transcript in bovine and rat cerebrum and cerebellum, but not in any other rat tissues examined. In situ hybridization showed that Nck5ai was enriched in CA1 to CA3 of the hippocampus, but absent in the fimbria of hippocampal formation. Among seven cell lines in proliferating cultures, only PC12 and N2A, two cell lines capable of differentiating into neuron-like cells, were found to contain Nck5ai mRNA. A 30-kDa truncated form of Nck5ai expressed as a glutathione S-transferase fusion protein in Escherichia coli] was found to associate with Cdk5 to form an active Cdk5 kinase. Thus, the isoform shares many common characteristics with p35 nck5a , including Ckd5 activating activity and brain-and neuronspecific expression. Both proteins show limited sequence homology to cyclins, suggesting that they define a new family of cyclin-dependent kinase-activating proteins.The cell division cycle gene, cdc2, in fission yeast performs rate-limiting functions in both G 1 /S and G 2 /M transitions. The protein product of the gene, p34 cdc2

Activation of the transcription factor NF-kappaB after engagement of the T cell receptor (TCR) is important for T cell proliferation and activation during the adaptive immune response. Recent reports have elucidated a signaling pathway that involves the protein kinase C (PKC), the scaffold protein CARD11 (also called CARMA-1), the caspase recruitment domain (CARD)-containing protein Bcl10, and the paracaspase (protease related to caspases) MALT1 as critical intermediates linking the TCR to the IkappaB kinase (IKK) complex. However, the events proximal to the TCR that initiate the activation of this signaling pathway remain poorly defined. We demonstrate that 3-phosphoinositide-dependent kinase 1 (PDK1) has an essential role in this pathway by regulating the activation of PKC and through signal-dependent recruiting of both PKC and CARD11 to lipid rafts. PDK1-associated PKC recruits the IKK complex, whereas PDK1-associated CARD11 recruits the Bcl10-MALT1 complex, thereby allowing activation of the IKK complex through Bcl10-MALT1-dependent ubiquitination of the IKK complex subunit known as NEMO (NF-kappaB essential modifier). Hence, PDK1 plays a critical role by nucleating the TCR-induced NF-kappaB activation pathway in T cells.