| 1. |
- Tian, Yu-Peng, et al.
(författare)
-
Investigations and facile synthesis of a series of novel multi-functional two-photon absorption materials
- 2007
-
Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 17:34, s. 3646-3654
-
Tidskriftsartikel (refereegranskat)abstract
- Six centrosymmetric D-(pi-A)(3) structural triphenylamine derivatives that can be used as two- photon photopolymerization and optical data storage chromophores, tris[ 4-( 4- pyridylethenyl) phenyl] amine ( 1), tris[ 4-( 2- pyridylethenyl) phenyl] amine ( 2), tris( 4- cyanoethenylphenyl) amine ( 3), tris[ 4- butylacrylatephenyl] amine ( 4), tris[ 4- methylacrylatephenyl] amine ( 5) and tris[ 4- acrylicethenylphenyl] amine ( 6), have been successfully synthesized via a triple palladium-catalyzed Heck coupling reaction, and the novel chromophores were fully characterized by elemental analysis, IR, (1)H-NMR and ESIMS. The structure for 3 was determined by single crystal X-ray diffraction study. One- and two-photon absorption and fluorescence in various solvents were experimentally investigated. Two-photon initiated polymerization microfabrication and optical data recording experiments were carried out under 780 nm laser radiation, and the possible polymerization mechanism is discussed based on theoretical calculations. All the six chromophores have relatively large two-photon absorption crosssections, and exhibit optical memory and highly efficient two-photon initiated polymerization abilities.
|
|
| 2. |
- Sun, Jielin, et al.
(författare)
-
Evidence for two independent prostate cancer risk-associated loci in the HNF1B gene at 17q12
- 2008
-
Ingår i: Nature Genetics. - London : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 40:10, s. 1153-1155
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We carried out a fine-mapping study in the HNF1B gene at 17q12 in two study populations and identified a second locus associated with prostate cancer risk, 26 kb centromeric to the first known locus (rs4430796); these loci are separated by a recombination hot spot. We confirmed the association with a SNP in the second locus (rs11649743) in five additional populations, with P = 1.7 10-9 for an allelic test of the seven studies combined. The association at each SNP remained significant after adjustment for the other SNP.
|
|
| 3. |
- Zhao, Guang-Jiu, et al.
(författare)
-
Photoinduced intramolecular charge transfer and S-2 fluorescence in thiophene-pi-conjugated donor-acceptor systems : Experimental and TDDFT studies
- 2008
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 14:23, s. 6935-6947
-
Tidskriftsartikel (refereegranskat)abstract
- Experimental and theoretical methods were used to study newly synthesized thiophene-pi-cojugated donor-acceptor compounds, which were found to exhibit efficient intramolecular charge-transfer emission in polar solvents with relatively large Stokes shifts and strong solvatochromism. To gain insight into the solvatochromic behavior of these compounds, the dependence of the spectra on solvent polarity was studied on the basis of Lippert-Mataga models. We found that intramolecular charge transfer in these donor-acceptor systems is significantly dependent on the electron-with-drawing substituents at the thienyl 2-position. The dependence of the absorption and emission spectra of these compounds in methanol on the concentration of trifluoroacetic acid was used to confirm intramolecular charge-tranfer emission. Moreover, the calculated absorption and emission energies, which are in accordance with the experimental values, suggested that fluorescence can be emitted from different geometric confirmations. In addition, a novel S-2 fluorescence phenomenon for some of these compounds was also be observed. The fluorescence excitation spectra were used to confirm the S-2 fluorescence. We demonstrate that S-2 fluorescence can be explained by the calculated energy gap between the S-2 and S-1 states of these molecules. Furthermore, nonlinear optical behavior of the thiophene-pi-conjugated compound with diethylcyanomethylphosphonate substituents was predicted in theory.
|
|
| 4. |
|
|
| 5. |
- Clark, Andrew G., et al.
(författare)
-
Evolution of genes and genomes on the Drosophila phylogeny
- 2007
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
-
Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
|
|
| 6. |
- Hao, Fuying, et al.
(författare)
-
Design, crystal structures and enhanced frequency-upconverted lasing efficiencies of a new series of dyes from hybrid of inorganic polymers and organic chromophores
- 2009
-
Ingår i: Journal of Materials Chemistry. - : RSC Publishing. - 0959-9428 .- 1364-5501. ; 19:48, s. 9163-9169
-
Tidskriftsartikel (refereegranskat)abstract
- A new series of hybrid dyes, trans-4-(4′-N,N-dialkylaminostyryl)-N-methyl pyridinium [Cd(SCN)3−]n [alkyl = Me(1), Et(2), Pr(3) and n–Bu(4)] have been successfully synthesized from hybrids of inorganic polymers and organic chromophores. The structures of four new hybrid dyes were characterized by single-crystal X-ray diffraction first. The particular features of the hybrid dyes are (1) the inorganic anions form isolated polymeric one-dimensional zig-zag chains of [Cd(SCN)3−]n with an extended π-conjugation system within the polymeric –[M–S–C≡N]–M… chain and high polarizabilities; and (2) the organic cationic chromophores determine their optical properties. Experimental results revealed that the TPA cross-section values and overall energy conversion efficiencies of hybrid dyes with different alkyl pendant groups have obviously increased from 1 to 4, and in particular, have been substantially enhanced compared to their corresponding iodide analogues 1′–4′. Therefore, we speculate that such increases are attributable to arrangements of infinite anionic [Cd(SCN)3−]n chains and synergic effects with chromophore cations.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Li, Wenjiang, et al.
(författare)
-
Preparation of the gold infiltrated silica opals by electroplating method
- 2006
-
Ingår i: Proceedings of International Symposium on Biophotonics, Nanophotonics and Metamaterials. - 9780780397736 ; , s. 338-341
-
Konferensbidrag (refereegranskat)abstract
- Highly mono-dispersed silica microspheres are fabricated and assembled by a force packing method to form opals with large domain sizes. The opals are then infiltrated with gold by electroplating technique. The SEM images showed the gold nanoparticles could be directly deposited on the surface of silica spheres and the voids among the silica spheres in the opaline structure. The optical properties of the infiltrated opals in the visible range are studied in detail. The gold infiltrated silica opals could provide a simple way to tune the opal properties through controlling the ration of gold in the silica opal.
|
|
| 10. |
|
|
