University of Bath

About: University of Bath is a education organization based out in Bath, Bath and North East Somerset, United Kingdom. It is known for research contribution in the topics: Population & Photonic-crystal fiber. The organization has 15830 authors who have published 39608 publications receiving 1358769 citations. The organization is also known as: Bath University.

Characterization and modeling of dye-sensitized solar cells

Abstract: Recent progress toward understanding the processes taking place in dye-sensitized nanocrystalline solar cells (DSC) is reviewed, and some areas characterized by controversy or poor understanding are highlighted. The thermodynamic and kinetic criteria for successful cell design are outlined, and experimental results obtained by a range of methods for characterizing the stationary and dynamic properties of DCS are discussed. These methods include direct measurement of the quasi-Fermi level using an indicator electrode and charge extraction measurements to determine the energetic distribution of electron traps in the nanocrystalline oxide. The influence of electron trapping on dynamic measurements of electron transfer and transport is discussed within the framework of the quasistatic assumption, and a new assessment of the electron diffusion length in the DSC is given, which suggests that collection of photoinjected electrons should be considerably more efficient than previously assumed.

Group-velocity dispersion in photonic crystal fibers.

Abstract: The dispersion properties of photonic crystal fibers are calculated by expression of the modal field as a sum of localized orthogonal functions. Even simple designs of these fibers can yield zero dispersion at wavelengths shorter than 1.27 µm when the fibers are single mode, or a large normal dispersion that is suitable for dispersion compensation at 1.55 µm.

Primate-specific endogenous retrovirus-driven transcription defines naive-like stem cells

Abstract: Naive embryonic stem cells hold great promise for research and therapeutics as they have broad and robust developmental potential. While such cells are readily derived from mouse blastocysts it has not been possible to isolate human equivalents easily, although human naive-like cells have been artificially generated (rather than extracted) by coercion of human primed embryonic stem cells by modifying culture conditions or through transgenic modification. Here we show that a sub-population within cultures of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) manifests key properties of naive state cells. These naive-like cells can be genetically tagged, and are associated with elevated transcription of HERVH, a primate-specific endogenous retrovirus. HERVH elements provide functional binding sites for a combination of naive pluripotency transcription factors, including LBP9, recently recognized as relevant to naivety in mice. LBP9-HERVH drives hESC-specific alternative and chimaeric transcripts, including pluripotency-modulating long non-coding RNAs. Disruption of LBP9, HERVH and HERVH-derived transcripts compromises self-renewal. These observations define HERVH expression as a hallmark of naive-like hESCs, and establish novel primate-specific transcriptional circuitry regulating pluripotency.

Characterization of nicotinic receptor-mediated [3H]dopamine release from synaptosomes prepared from mouse striatum.

Abstract: This study establishes that presynaptic nicotinic receptors modulate dopamine release in the mouse striatum. Nicotinic agonists elicit a dose-dependent increase in the release of [3H]dopamine from synaptosomes prepared from mouse striatum. At low concentrations, this release is Ca2+ dependent, whereas at higher concentrations Ca(2+)-independent, mecamylamine-insensitive release was also observed. The Ca(2+)-dependent nicotine-evoked release was not blocked by alpha-bungarotoxin but was effectively blocked by neuronal bungarotoxin as well as several other nicotinic receptor antagonists. The relationship between potency for stimulation of release for agonists and potency for inhibition of release for antagonists was compared to the affinity of these compounds for the [3H]nicotine binding site. The overall correlation between release and binding potency was not high, but the drugs may be classified into separate groups, each of which has a high correlation with binding. This finding suggests either that more than one nicotinic receptor regulates dopamine release or that not all agonists interact with the same receptor in an identical fashion.