Atomic line radiation in the infrared

The present paper considers atomic infrared line emission from states of high angular momentum, which should be significally populated in a high-temperature, equilibrium (LTE) gas. Such states are shown to give rise to a “universal” series of strong lines, the first member of which is at ～4μ, and corresponds to the puzzling 4 μ-feature by Taylor and Caledonia.Several of the higher members of the predicated series are found in cesium spectra taken in our laboratory.     

Efficient synthesis of fluorescent rosamines: multifunctional platforms for cellular imaging

Substituted rosamines are efficiently prepared through a new organometallic addition to an imine-substituted xanthone as a novel primary amine equivalent. The synthesis reduces the number of synthetic steps to the targeted rosamines, for convenient and facile access to potential libraries of rosamine dyes. The prepared rosamine derivatives represent unique multifunctional platforms that possess radiolabeling capability and fluorescence. Rosamines have (i) useful non-specific binding properties in mammalian cells and plant root hair, and (ii) positive uptake or binding properties in microbial systems.     

Orbital Reactions Through Space. Part III. Rate Enhancement in Epoxidation of an Olefin by a Proximate Hydroxyl Group

As part of a programme directed towards the synthesis of polycyclic systems containing a bicyclo[4.2.0]octa-2,4-diene moiety (or a potential precursor thereof) joined at the 7,8 position, suitable as substrates for the 1,2-photoarmatisation reaction¹, we sought a simple route to the epixide (5). We considered this offered the opening to prepare the 8-oxatricyclo-     

Cell surface receptors and their dynamics on toxin-treated malignant cells.

The binding, mobility, and mode of cell entry of the plant toxin ricin (or RCAII) were investigated on susceptible and partially resistant murine cell lines. When susceptible cells (SV40-transformed 3T3 fibroblast cells and BW5147 lymphoma cells) were examined, ricin bound rapidly, induced endocytosis, and entered the cell cytoplasm via broken endocytotic vesicles to inhibit cell protein synthesis, as found previously (1). Addition of lactose within 15 min after initial ricin binding prevented toxicity. After this time lactose addition no longer blocked the inhibition of protein synthesis. In a partially resistant lymphoma (BW5147/RCA3) that shows only a slight reduction in the total number of ricin-binding sites, ricin bound rapidly to the cell surface, but was endocytosed significantly less at low ricin doses compared to its parental line, indicating a possible difference in cell surface behavior. The exposed surface proteins on the BW5147 parental and BW5147/RCA3 resistnat lines were examined by 125I-labeling utilizing lactoperoxidase-catalyzed iodination. The radiolabeled components were solubilized and separated by slab electrophoresis in sodium dodecyl sulfate. Autoradiograms of the slab gels indicated that two surface components of approximately 80,000 and 35,000 mol wt were much less exposed or were missing on the resistant line.     

Identifying coherent structures in nonlinear wave propagation

Nonlinear wave phenomena are often characterized by the appearance of "solitary wave coherent structures" traveling at speeds determined by their amplitudes and morphologies. Assuming that time intervals exist in which these structures are essentially noninteracting, a method for identifying the number of independent features and their respective speeds is proposed and developed. The method is illustrated with a variety of increasingly realistic specific applications, beginning with a simple nonlinear but analytically tractable Gaussian model, continuing with (numerically generated) data describing multisoliton solutions to the Korteweg-de Vries equation, and concluding with (numerical) data from a realistic simulation of nonlinear wave interactions in plasma turbulence. These studies reveal both strengths and limitations of the method in its present incarnation and suggest topics for future investigations.     

Development and validation of a fast high pressure liquid chromatography method for the analysis of lignocellulosic biomass hydrolysis and fermentation products

A simple, precise, and accurate 10-min high pressure liquid chromatography (HPLC) method was developed and validated for the analysis of organic acids, alcohols, and furans from processing biomass into renewable fuels. The method uses an H⁺ form cation-exchange resin stationary phase that has a five-fold shorter analysis time versus that in the traditional method. The new method was used for the analysis of acetic acid, ethanol, 5-hydroxymethyl furfural, and furfural. Results were compared with a legacy method that has historically has been used to analyze the same compounds but with a 55 min run time. Linearity was acceptable on the new method with r² > 0.999 for all compounds using refractive index detection. Limits of detection were between 0.003 and 0.03 g/L and limits of quantification were between 0.1 and 0.01 g/L. The relative standard deviations for precision were less than 0.4% and recoveries ranged from 92% to 114% for all compounds.     

Reaction pathways for ethanol on model Co/ZnO(0001) catalysts

The pathways for the reaction of ethanol on model catalysts consisting of Co and CoO films and particles supported on single crystal ZnO(0001) surfaces were studied using X-ray Photoelectron Spectroscopy (XPS) and Temperature Programmed Desorption (TPD). On supported metallic Co films and particles ethanol was found to primarily undergo decarbonylation forming CO, H(2), and adsorbed methyl groups. In contrast, supported CoO particles were found to be largely unreactive toward ethanol. High selectivity to the dehydrogenation product, acetaldehyde, was only observed when the supported Co was partially oxidized and contained both Co(0) and Co(2+). Since acetaldehyde is thought to be a critical intermediate during steam reforming of ethanol (SRE) to produce H(2) and CO(2), the results of this study suggest that partially oxidized Co species provide the active sites for this reaction. This result is consistent with studies of high surface area Co/ZnO catalysts which also suggest that both Co(0) and Co(2+) species are present under typical SRE reaction conditions.