MetA-SIMS

The mechanisms of MetA-SIMS are still under investigation. Recent simulations explained the sputtering yield enhancement due to the presence of the metal upon atomic bombardment [336], but the effect of the metal on the ionization mechanisms is not well understood yet. Metallization creates or enhances different ionization pathways for molecules departing the surface, the most obvious being the cationization by a metal atom/ion [132,324,325]. The enhancement observed for bare fragment [322] and parent ions [322,323], both... 

There are only a relatively small number of articles reporting on the use of specific sample preparation techniques in combination with cluster beams for sensitivity improvement, and even fewer with pronaising results. Several studies demonstrated that MetA-SIMS with cluster projectiles at the usual impact energies often lead to lower, instead of enhanced, molecular ion yields [333,341]. In particular, MD simulations showed that 10-15 keV Cw projectiles were inefficient at generating bond scissions and energetic subcascades in the organic sample when impinging on metallic clusters [336]. 

The described protocol for IMS allows the mapping of molecular distributions directly in tissue sections and on cell surfaces. The different approaches to SIMS are able to deliver images of distributions of small organic compounds like lipids and steroids. Since ME-SIMS and especially MetA-SIMS are capable of imaging biological surfaces with very high spatial resolution, these techniques could be very well suited for direct analysis of lipid distributions on single-cell surfaces. 

ME-SIMS and MetA-SIMS Imaging Mass Spectrometry... 

IMS experiments can be performed using ME-SIMS or MetA-SIMS. In the cases described here, these experiments are conducted on a ToF-SIMS equipped with an In liquid metal ion gun. The experimental procedure for ME-SIMS and MetA-SIMS data acquisition is identical. 

Following the procedures discussed in Section 3 images were acquired as shown in Fig. 11.1. In panel A ME-SIMS images of lymnaea Sta nalis brain tissue are shown and in panel B MetA-SIMS images of single neuroblastoma cells are shown. The plasma coating procedure in MetA SIMS enhances des-orption/ionization of membrane components such as lipids and sterols in SIMS imaging of tissues and cells. As shown... 

Sim and co-workers have also studied the conformation of l,3,5-triarylhexahydro-l,3,5-triazines. X-ray analysis of l,3,5-tris(o-, m-, and/7-fluorophenyl)hexahydro-l,3,5-triazines shows that the eaa conformation is adopted, as is also found in 1,3,5-triphenylhexahydro-1,3,5-triazine the two rings are virtually coplanar in the p-fluorophenylhexahydro-l,3,5-triazine as in the 1,3,5-triphenyl-hexahydro-l,3,5-triazine. The two rings move from coplanarity as the fluorine moves from the para to meta to ortho positions. The p-fluoro compound has an angle between the phenyl ring and the symmetry plane of the hexahydrotriazine ring of 90° it is 54.7° for the m-fluoro and 22.5° for the o-fluoro compound <89JCS(P2)583>. 

Sim, Y Neelakantan, N Wu, Y van Dam, RM. Poster Abstraet Presentations Session Title Nutrition 1 Abstraet P065 Effeets of Palm Oil Consumption on Blood Lipids A Meta-Analysis of Clinieal Trials. Circulation, 2014 129 AP065. 

This glossary has been rigorously alphabetized in order to facilitate the location of appropriate references. Please note, however, that Latin prefixes (cis, trans, sec, terc, vec), Greek prefixes (a, 6, Y, meta, orto, para, uns, sim), and position indicators (N- 1,4- etc.) have not been taken into consideration for alphabetizing. 

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