We report that Sonic Hedgehog (Shh) regulates both formation and patterning of tracheal cartilage by controlling the expression pattern and level of the chondrogenic gene, Sox9. In Shh 2/2 tracheo-esophageal tubes, Sox9 expression is transient and not restricted ventrally to the site of chondrogenesis, and is absent at the time of chondrogenesis, resulting in the failure of tracheal cartilage formation. Inhibition of Hedgehog signalling with cyclopamine in tracheal cultures prevents tracheal cartilage formation, while treatment of Shh 2/2 tracheal explant with exogenous Shh peptide rescues cartilage formation. Both exogenous Bmp4 and Noggin rescue cartilage phenotype in Shh 2/2 tracheal culture, while promoting excessive cartilage development in wild-type trachea through induction of Sox9 expression. The ventral and segmented expression of Sox9 in tracheal primordia under Shh modulated by Bmp4 and Noggin thus determine where and when tracheal cartilage develops. These results indicate that Shh signalling is a critical determinant in tracheal cartilage development. Developmental Dynamics 239:514-526,

A symmetric squaraine and its related non-symmetric structure are shown to have comparable efficiencies in DSCs, but with undoubtedly advantages in the low cost and easiness of synthesis for the symmetrical structure.

A microwave-assisted method for the preparation of a wide color range of 2,3,3-trimethylindolenine-based squaraines and their intermediates is described. This practical approach allows the rapid preparation of both symmetrical and nonsymmetrical squaraine dyes, reducing reaction time from days to minutes with more than 2-fold improvement in product yields when compared to conventional methods.

An Okounkov body is a convex subset in Euclidean space associated to a big divisor on a smooth projective variety with respect to an admissible flag. In this paper, we introduce two convex bodies associated to pseudoeffective divisors, called the valuative Okounkov bodies and the limiting Okounkov bodies, and show that these convex bodies reflect the asymptotic properties of pseudoeffective divisors as in the case with big divisors. Our results extend the works of Lazarsfeld-Mustat ¸ȃ and Kaveh-Khovanskii. For this purpose, we define and study special subvarieties, called the Nakayama subvarieties and the positive volume subvarieties, associated to pseudoeffective divisors.

The power conversion efficiency of a dye-sensitized solar cell with tailored squaraine dye enhanced by 47%, due to Förster resonance energy transfer from CdSe quantum dots to the squaraine dye. The incident photons to collection efficiency of electrons indicate panchromatic response from the visible to the near-infrared spectrum. IntroductionPhotovoltaic technology is one of the most promising alternative renewable energy sources, harvesting energy from the sun. Dye sensitized solar cells (DSSCs) are inexpensive and use abundant materials for large-scale solar energy conversion. In a typical DSSC the dye absorbs photons and goes to the excited state, generating electron and hole pairs. The electrons are injected into the TiO 2 conduction band and diffuse to the front contact, simultaneously, the holes are scavenged by a redox couple. Currently DSSCs are exceeding power conversion of 12%, 1 despite the fact that many dyes do not absorb strongly over 700 nm. Therefore, Förster resonance energy transfer (FRET) has already been demonstrated in a variety of optoelectronic applications and recently in DSSCs to harvest visible and near infrared (IR) absorption spectra. [2][3][4][5] Usually, the traditional dyes used in DSSCs suffer from low molar extinction coefficients or limited absorption spectra regions. 6 Using FRET to transfer energy from donor to acceptor inside the DSSCs paves a new way for enhancing the photovoltaic performance of DSSCs. This provides the possibility to employ a cascade combination of dyes, which have narrow absorption spectra. Squaraine dyes are well-known for their remarkable optical behavior because of strong absorption from charge transfer between an electron-deficient central squaric core and each side of the substituent in the red to near-infrared region, 7 and they have been widely and successfully used also in DSSCs in recent years. 8 A recent report on FRET based dye sensitized solar cells showed that the acceptor should be anchored to the TiO 2 . In addition it must have lower excitation energy than the donor, enabling fast and efficient electron transfer to TiO 2 9 upon excitation of the energy relay dye.Quantum dots (QDs) have high molar extinction coefficients and broad absorption spectra covering a wide part of the visible spectrum. Hence they can be good candidates as donors in FRET DSSCs in cases where IR dyes that absorb weakly in the visible region are used as acceptors.On the other hand, QDs can be affected by the electrolyte, one possibility to avoid this was described by Zaban et al., [10][11][12] who created an amorphous thin TiO 2 barrier to avoid direct contact with the electrolyte. Another option is to use a more ''friendly'' electrolyte, which will not quench the QDs. Here, we apply the FRET concept to a hybrid QDs/dye-sensitized solar cell. The donors are TOP/TOPO-capped CdSe QDs, while the acceptor is a newly designed symmetric squaraine dye, called VG1-C10, possessing an additional carboxylic group 13 as compared to standard squaraine dyes, and two C 10 -chains. T...

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Inverted quantum dot sensitized solar cells using non-toxic CuInSxSe2–x nanocrystals deposited on mesoporous NiO demonstrate high hole injection rates of 10–8 s–1 and record efficiencies of 1.25%..

New mercaptophosphonic linkers are presented for the attachment of ternary quantum dots to ZnO and TiO2 for photovoltaic applications.