1,949 research outputs found
Picosecond dynamics of internal exciton transitions in CdSe nanorods
The picosecond dynamics of excitons in colloidal CdSe nanorods are directly
measured via their 1s to 2p-like internal transitions by ultra-broadband
terahertz spectroscopy. Broadened absorption peaks from both the longitudinal
and transverse states are observed at 8.5 and 11 THz, respectively. The onset
of exciton-LO phonon coupling appears as a bleach in the optical conductivity
spectra at the LO phonon energy for times > 1 ps after excitation. Simulations
show a suppressed exciton temperature due to thermally excited hole states
being rapidly captured onto ligands or unpassivated surface states. The
relaxation kinetics are manipulated and the longitudinal transition is quenched
by surface ligand exchange with hole capturing pyridine
Convenient synthesis of EDOT-based dyes by CH-activation and their application as dyes in dye-sensitized solar cells
Precursors to three new 3,4-ethylenedioxythiophene (EDOT) incorportaing dyes have been synthesised via a one-pot CâH activation route using N,N-dimethylaniline as a donor group. We have extended this methodology to provide a convenient one-pot route to dye EDOT-Ph. The electrochemical and optical properties of the new dyes have been correlated with IV and EQE data for 1 cm2 dye-sensitized solar cell (DSSC) devices prepared using these dyes. The device data show that dye performance is strongly affected by the amount of chenodeoxycholic acid (CDCA) co-sorbent used. The best performance is for EDOT-Ph (Ρ = 4.0%) at 10 mM CDCA compared to (Ρ = 6.0% and Ρ = 5.8%) for N719 and D205 control cells
SNP data reveals the complex and diverse evolutionary history of the blue-ringed octopus genus (Octopodidae: Hapalochlaena) in the Asia-Pacific
The blue-ringed octopus species complex (Hapalochlaena spp.), known to occur from Southern Australia to Japan, currently contains four formally described species (Hapalochlaena maculosa, Hapalochlaena fasciata, Hapalochlaena lunulata and Hapalochlaena nierstraszi). These species are distinguished based on morphological characters (iridescent blue rings and/or lines) along with reproductive strategies. However, the observation of greater morphological diversity than previously captured by the current taxonomic framework indicates that a revision is required. To examine species boundaries within the genus we used mitochondrial (12S rRNA, 16S rRNA, cytochrome c oxidase subunit 1 [COI], cytochrome c oxidase subunit 3 [COIII] and cytochrome b [Cytb]) and genome-wide SNP data (DaRT seq) from specimens collected across its geographic range including variations in depth from 3 m to >100 m. This investigation indicates substantially greater species diversity present within the genus Hapalochlaena than is currently described. We identified 10,346 SNPs across all locations, which when analysed support a minimum of 11 distinct clades. Bayesian phylogenetic analysis of the mitochondrial COI gene on a more limited sample set dates the diversification of the genus to âź30 mya and corroborates eight of the lineages indicated by the SNP analyses. Furthermore, we demonstrate that the diagnostic lined patterning of H. fasciata found in North Pacific waters and NSW, Australia is polyphyletic and therefore likely the result of convergent evolution. Several âdeep waterâ (>100 m) lineages were also identified in this study with genetic convergence likely to be driven by external selective pressures. Examination of morphological traits, currently being undertaken in a parallel morphological study, is required to describe additional species within the complex
Gallery of contemporary noted mycologists
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43269/1/11046_2005_Article_BF02155513.pd
Biologically relevant oxidants and terminology, classification and nomenclature of oxidatively generated damage to nucleobases and 2-deoxyribose in nucleic acids
A broad scientific community is involved in investigations aimed at delineating the mechanisms of formation and cellular processing of oxidatively generated damage to nucleic acids. Perhaps as a consequence of this breadth of research expertise, there are nomenclature problems for several of the oxidized bases including 8-oxo-7,8-dihydroguanine (8-oxoGua), a ubiquitous marker of almost every type of oxidative stress in cells. Efforts to standardize the nomenclature and abbreviations of the main DNA degradation products that arise from oxidative pathways are reported. Information is also provided on the main oxidative radicals, non-radical oxygen species, one-electron agents and enzymes involved in DNA degradation pathways as well in their targets and reactivity. A brief classification of oxidatively generated damage to DNA that may involve single modifications, tandem base modifications, intrastrand and interstrand cross-links together with DNA-protein cross-links and base adducts arising from the addition of lipid peroxides breakdown products is also included
High-Density Genetic Linkage Map of the Southern Blue-ringed Octopus (Octopodidae: Hapalochlaena maculosa)
Genetic linkage maps provide a useful resource for non-model genomes and can aid in genome reassembly to form more contiguous pseudo-chromosomes. We present the first linkage map of any cephalopod, H. maculosa, composed of 47 linkage groups (LG). A total of 2166 single nucleotide polymorphisms and 2455 presenceâabsence variant loci were utilised by Lep-Map3 in linkage map construction. The map length spans 2016.62 cM with an average marker distance of 0.85 cM. Integration of the recent H. maculosa genome allowed 1151 scaffolds comprising 34% of the total genomic sequence to be orientated and/or placed using 1278 markers across all 47 LG. The linkage map generated provides a new perspective on HOX gene distribution in octopods. In the H. maculosa linkage map three (SCR, LOX4 and POST1) of six identified HOX genes (HOX1/LAB, SCR, LOX2, LOX4, LOX5, POST1) were located within the same LG (LG 9). The generation of a linkage map for H. maculosa has provided a valuable resource for understanding the evolution of cephalopod genomes and will provide a base for future work
Libri novi
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43268/1/11046_2005_Article_BF02155512.pd
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