The effect of Nb2O5 and ZrO2 additions on the behaviour of Li/MgO and Li/Na/MgO catalysts for the oxidative coupling of methane

Incorporation of Nb2O5 or ZrO2 into both Li/MgO and Li/Na/MgO systems produced ternary and quaternary catalysts, respectively, capable of attaining optimal C2 yields and selectivities at lower temperatures relative to the unpromoted materials. The degree of enhancement effected by these metal oxide additives was compared to that produced by Li/MgO and Li/Na/MgO catalysts promoted with SnO2 or Co3O4. At reaction temperatures < 700°C, the Li/Co/MgO ternary system showed marked differences in behaviour compared to the other ternary catalysts tested. This was particularly evident in the variation in C2 selectivity with time on stream during ageing studies of (i) untreated materials, (ii) materials pretreated in CO2, and (iii) materials dosed periodically with CHCI3

Number Partitioning on a Quantum Computer

We present an algorithm to compute the number of solutions of the (constrained) number partitioning problem. A concrete implementation of the algorithm on an Ising-type quantum computer is given.Comment: 5 pages, 1 figure, see also http://rugth30.phys.rug.nl/compphys/qce.ht

Selective decline of 5-HT1A receptor binding sites in rat cortex, hippocampus and cholinergic basal forebrain nuclei during aging

The effect of aging on 5-HT1A receptor binding in several forebrain areas associated with the basal forebrain cholinergic system was investigated in rats of 3-, 24- and 30-months-old by receptor autoradiography and biochemical binding assay using [H-3]8-OH-DPAT as a ligand. Autoradiographic measurements demonstrated a marked region-specific decline of ligand binding in: (i) regions of the basal forebrain cholinergic cell groups, i.e. the medial septum, diagonal band nuclei and magnocellular nucleus basalis, (ii) the frontal and parietal neocortex and (iii) the dentate gyrus of the hippocampus. No change or- only a slight decrease of the 5-HT1A receptor density was found in other areas investigated: the CA1 and CA3 sectors of hippocampus, the cingular and perirhinal cerebral cortex and the lateral septum. The autoradiographic findings were substantiated by the biochemical binding assay, which revealed a comparable loss of 5-HT1A receptor in the hippocampus and neocortex at the age of 30 months. The results clearly show that with increasing age the decrement of 5-HT1A receptor binding in the rat forebrain is remarkably region-selective and particularly affects the cholinergic cell groups that innervate cortex and hippocampus. This phenomenon appears to be especially significant in relation to the neuronal substrates underlying the age-related alterations of mood and cognition. (C) 1997 Elsevier Science B.V

Potential of Mycobacterium tuberculosis resuscitation-promoting factors as antigens in novel tuberculosis sub-unit vaccines

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Evaluation of reverse phase protein array (RPPA)-based pathway-activation profiling in 84 non-small cell lung cancer (NSCLC) cell lines as platform for cancer proteomics and biomarker discovery

AbstractThe reverse phase protein array (RPPA) approach was employed for a quantitative analysis of 71 cancer-relevant proteins and phosphoproteins in 84 non-small cell lung cancer (NSCLC) cell lines and by monitoring the activation state of selected receptor tyrosine kinases, PI3K/AKT and MEK/ERK1/2 signaling, cell cycle control, apoptosis, and DNA damage. Additional information on NSCLC cell lines such as that of transcriptomic data, genomic aberrations, and drug sensitivity was analyzed in the context of proteomic data using supervised and non-supervised approaches for data analysis. First, the unsupervised analysis of proteomic data indicated that proteins clustering closely together reflect well-known signaling modules, e.g. PI3K/AKT- and RAS/RAF/ERK-signaling, cell cycle regulation, and apoptosis. However, mutations of EGFR, ERBB2, RAF, RAS, TP53, and PI3K were found dispersed across different signaling pathway clusters. Merely cell lines with an amplification of EGFR and/or ERBB2 clustered closely together on the proteomic, but not on the transcriptomic level. Secondly, supervised data analysis revealed that sensitivity towards anti-EGFR drugs generally correlated better with high level EGFR phosphorylation than with EGFR abundance itself. High level phosphorylation of RB and high abundance of AURKA were identified as candidates that can potentially predict sensitivity towards the aurora kinase inhibitor VX680. Examples shown demonstrate that the RPPA approach presents a useful platform for targeted proteomics with high potential for biomarker discovery. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge