Comparison and optimization of randomly textured surfaces in thin-film solar cells.

Using rigorous diffraction theory we investigate the scattering properties of various random textures currently used for photon management in thin-film solar cells. We relate the haze and the angularly resolved scattering function of these cells to the enhancement of light absorption. A simple criterion is derived that provides an explanation why certain textures operate more beneficially than others. Using this criterion we propose a generic surface profile that outperforms the available substrates. This work facilitates the understanding of the effect of randomly textured surfaces and provides guidelines towards their optimization.

The H+, K(+)-ATPase inhibitor pantoprazole (BY1023/SK&F96022) interacts less with cytochrome P450 than omeprazole and lansoprazole.

The gastric acid antisecretory compound omeprazole (5-methoxy-2-((4-methoxy- 3,5-dimethyl-2-pyridinylmethyl)-sulphinyl)-1H-benzimidazole), a member of the new class of H+, K(+)-ATPase inhibitors, is known to interact with the metabolism of other drugs in vitro and in vivo. In this study, two other substituted benzimidazoles, pantoprazole (5-difluoromethoxy-2-((3,4-di-methoxy-2-pyridinylmethyl)-s ulp hinyl)-1H- benzimidazole) and lansoprazole (2-((3-methyl-4-(2,2,2-trifluoroethoxy)-2-pyridinylmethyl)- sulphinyl)-1H-benzimidazole) are compared for their ability to inhibit cytochrome P450 dependent biotransformation in vitro with regard to three representative reactions: O-dealkylation of 7-ethoxycoumarin (EC), N-demethylation of ethylmorphine (EM) and hydroxylation of lonazolac (Lona). These reactions can be seen in microsomes from phenobarbital pretreated rats representing the cytochrome P450IIB1 subfamily. As shown in presence of known inhibitors of cytochrome P450, e.g. SK&F 525A, metyrapone, chlorpromazine and nitrendipine, different enzymes seem to be responsible for these three indicator reactions of the cytochrome P450IIB1 complex. These reactions are inhibited to a different extent by the three H+, K(+)-ATPase inhibitors. Pantoprazole shows the lowest inhibitory activity versus the three reactions (Ki, mumol/L): EC, 138; EM, 104; Lona, 128. A greater effect is observed with omeprazole: EC, 38; EM, 68; Lona, 20. Lansoprazole exceeds omeprazole in inhibiting the three cytochrome P450 dependent enzymes: EC, 17; EM, 34; Lona, 8. In microsomes from untreated rats with the predominant cytochrome P450IIA1 subfamily as well as in microsomes from isopropanol treated rats (induction of cytochrome P450IIE1) which catalyse only lonazolac hydroxylation to a detectable amount, the latter reaction was inhibited by pantoprazole with a somewhat lower Ki of 77 whereas the values for omeprazole and lansoprazole remained unchanged in comparison to those found in microsomes from phenobarbital pretreated rats. The biotransformation rate of the substituted benzimidazoles themselves in microsomes from control and induced rats is lowest for pantoprazole followed by lansoprazole and omeprazole.

The hybrid concept for realization of an ultra-thin plasmonic metamaterial antireflection coating and plasmonic rainbow.

We report on the design, simulation, fabrication, and characterization of a novel two layer anti-reflective coating (ARC) based on a plasmonic metamaterial and a dielectric. Promoted by the strong material dispersion of the plasmonic metamaterial, our novel concept (called hybrid ARC) combines two possible arrangements for layers in an anti-reflection coating into a single structure; albeit at two different wavelengths. This, however, causes a broadband reduction of reflection that is less sensitive against oblique incidence when compared to traditional antireflective coatings. Furthermore, we show that the current metamaterial on a metal reflector can be used for the visualization of different coloration such as plasmonic rainbow despite its sub-wavelength thickness.

Phylogenetic relationships between cultivated and wild species of the genusBeta revealed by DNA "fingerprinting".

Forty-one accessions of the genusBeta representing wild and cultivated species of all sections were analyzed by DNA "fingerprinting". Four sugar beet minisatellite DNA probes revealed characteristic banding patterns with Southern-hybridizedBeta DNA restricted withHindIII. A total of 111 polymorphic RFLP bands were scored across all accessions. Cluster analysis based on genetic similarity estimates for all 820 combinations of accessions revealed the following results. (1) All accessions could unambiguously be identified by a characteristic RFLP banding pattern. (2) The sugar beet cultivars examined displayed a low level of genetic diversity; they showed high similarity toB. Vulgaris ssp.maritima but low genetic similarity to the other wild species of section I. (3) In most cases, the present taxonomic classification of the genusBeta was confirmed. Species of sections II, III, and IV were clearly distinguishable from those of section I except forB. Macrocarpa, which showed high similarity to wild species of section II. In a second experiment, 108 single-copy RFLP probes from sugar beet were Southern hybridized withB. procumbens DNA. A surprisingly low degree of homology (34%) was found. The results are discussed with regard to the taxonomic classification of the genusBeta.

Identification of the dopaminergic neurotoxin 1-trichloromethyl-1,2, 3,4-tetrahydro-beta-carboline in human blood after intake of the hypnotic chloral hydrate.

1-Trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo), a potent toxin toward dopaminergic neurons, readily originates in vitro from the biogenic amine tryptamine and the unnatural aldehyde chloral. For this reason, this heterocycle has been postulated to be formed endogenously in humans after administration of the hypnotic chloral hydrate or after exposure to the industrial solvent trichloroethylene by a spontaneous chemical ring closure reaction. In this paper, we report on the first identification of TaClo in blood samples of patients treated orally with chloral hydrate. Using a specific and sensitive gas chromatographic screening procedure based upon electron-capture and mass-selective detection, TaClo was determined after conversion to its volatile trifluoroacetyl derivative. The identity of TaClo in humans was clearly demonstrated by GC-MS analysis in selected-ion-monitoring mode, by the characteristic chlorine isotopic pattern of the molecular ion.

Endogenous alkaloids in man. XXVI. Determination of the dopaminergic neurotoxin 1-trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo) in biological samples using gas chromatography with selected ion monitoring.

Highly chlorinated beta-carbolines have a potential in vivo relevance to Parkinson's disease. In this paper, a gas chromatographic method for the determination of the neurotoxic 1-trichloromethyl-1,2,3,4-tetrahydro-beta-carboline (TaClo), the condensation product of tryptamine and chloral hydrate, is described. The specific and sensitive assay involves purification of the biological samples by solid-phase extraction with C18 cartridges, derivatization with heptafluorobutyric anhydride, and chromatography on a non-polar fused-silica capillary column. Detection of TaClo was achieved by the registration of characteristic mass fragments of the TaClo heptafluorobutyric amide derivative using selected ion monitoring. The method was utilized to detect and quantify TaClo in blood, urine, bile, faeces, and brain tissue of rats treated with this alkaloid-type heterocycle. Four-fold deuterium-labelled TaClo was used as an internal standard.