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The 13th Symposium on Polar Science/Ordinary sessions [OS] Space and upper atmospheric sciences, Wed. 16 Nov.

The 13th Symposium on Polar Science/Ordinary sessions [OS] Space and upper atmospheric sciences, Wed. 16 Nov.

Salamander large cells facilitated identification and localization of lipids by MALDI imaging mass spectrometry. Salamander retina lipid extract showed similarity with rodent retina lipid extract in phospholipid content and composition. Like rodent retina section, distinct layer distributions of phospholipids were observed in the salamander retina section. Phosphatidylcholines (PCs) composing saturated and monounsaturated fatty acids (PC 32:0, PC 32:1, and PC 34:1) were detected mainly in the outer and inner plexiform layers (OPL and IPL), whereas PCs containing polyunsaturated fatty acids (PC 36:4, PC 38:6, and PC 40:6) composed the inner segment (IS) and outer segment (OS). The presence of PCs containing polyunsaturated fatty acids in the OS layer implied that these phospholipids form flexible lipid bilayers, which facilitate phototransduction process occurring in the rhodopsin rich OS layer. Distinct distributions and relative signal intensities of phospholipids also indicated their relative abundance in a particular cell or a cell part. Using salamander large cells, a single cell level localization and identification of biomolecules could be achieved by MALDI imaging mass spectrometry.

Conversion of dimethyl ether and methanol into hydrocarbons was studied over several salts of 12-tungstophosphoric acid, H3PW12O40, at 563 K by a flow method. For acid salts of Na, the catalytic activity decreased in parallel with the acidity as the Na content increased (NaxH3−xPW12O40, x = 0–3). However, the carbon number distribution and the olefin to alkane ratio of the product hydrocarbons were almost independent of the Na content. These results indicate that the acidity determines the activity but its effect on the selectivity is not significant. On the other hand, when the salts of organic bases, Cs and NH3, which showed a low ability to absorb dimethyl ether, were used, the selectivity towards lower olefins was much improved. It was concluded that the olefin to alkane ratios were not correlated with the acidity, but with the ability to absorb dimethyl ether; the ratios increased markedly as this ability decreased. This was explained on the basis of “pseudo-liquid” behaviour of heteropoly compounds.

We found for dehydration of 2-propanol over H3pw12O40 at 80–100 °C that there were at least two pseudo-liquid phases which differed in the amount of alcohol absorbed and the catalytic activity. The transition between the two phases proceeded nearly reversibly depending on the temperature and pressure.

In the conversion of dimethyl ether into hydrocarbons over dodecatungstophosphates, the alkene : alkane ratios in the products depend on the ability of these tungstophosphates to absorb dimethyl ether; the alkene selectivity is greatly increased as the contribution of the bulk phase of the Catalysts (‘pseudo liquid phase’)decreases.