silicon and cupric-chloride

To develop a silicon (Si) and cadmium telluride (CdTe) imaging Compton camera for biomedical application on the basis of technologies used for astrophysical observation and to test its capacity to perform three-dimensional (3D) imaging.. All animal experiments were performed according to the Animal Care and Experimentation Committee (Gunma University, Maebashi, Japan). Flourine 18 fluorodeoxyglucose (FDG), iodine 131 ((131)I) methylnorcholestenol, and gallium 67 ((67)Ga) citrate, separately compacted into micro tubes, were inserted subcutaneously into a Wistar rat, and the distribution of the radioisotope compounds was determined with 3D imaging by using the Compton camera after the rat was sacrificed (ex vivo model). In a separate experiment, indium 111((111)In) chloride and (131)I-methylnorcholestenol were injected into a rat intravenously, and copper 64 ((64)Cu) chloride was administered into the stomach orally just before imaging. The isotope distributions were determined with 3D imaging after sacrifice by means of the list-mode-expectation-maximizing-maximum-likelihood method.. The Si/CdTe Compton camera demonstrated its 3D multinuclear imaging capability by separating out the distributions of FDG, (131)I-methylnorcholestenol, and (67)Ga-citrate clearly in a test-tube-implanted ex vivo model. In the more physiologic model with tail vein injection prior to sacrifice, the distributions of (131)I-methylnorcholestenol and (64)Cu-chloride were demonstrated with 3D imaging, and the difference in distribution of the two isotopes was successfully imaged although the accumulation on the image of (111)In-chloride was difficult to visualize because of blurring at the low-energy region.. The Si/CdTe Compton camera clearly resolved the distribution of multiple isotopes in 3D imaging and simultaneously in the ex vivo model.

Topics: Animals; Cadmium Compounds; Citrates; Copper; Equipment Design; Fluorodeoxyglucose F18; Gallium; Gallium Radioisotopes; Gamma Cameras; Imaging, Three-Dimensional; Indium; Iodine Radioisotopes; Pets; Radiopharmaceuticals; Rats; Rats, Wistar; Silicon; Tellurium; Tomography, Emission-Computed, Single-Photon

Desorption/ionization on porous silicon (DIOS) is a very useful technique in the case of small molecular weight compounds, compared to the matrix-assisted laser desorption ionization (MALDI). This is because MALDI generates matrix-related ions that overlap with the mass range of interest. The aim of our work was to investigate the suitability of the DIOS technique in the case of fatty acids in negative ion mode. The analysis of the chosen fatty acid models, nonadecanoic acid (C(19)H(38)O(2)) and heneicosanoic acid (C(21)H(42)O(2)), gave rise to the observation of the deprotonated monomeric species and selective cationized multimeric species. This cation selectivity was further elucidated by complementary studies based on the addition of various metals such as Ag(I), Zn(II), Fe(II), and also Cu(II). Specific behavior, depending upon the introduced metal, was highlighted by different redox reaction processes and also metastable decompositions (in PSD mode).

Topics: Acetates; Cations; Chlorides; Copper; Dimerization; Fatty Acids; Ferrous Compounds; Mass Spectrometry; Metals, Heavy; Oxidation-Reduction; Porosity; Silicon; Silver Compounds; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Zinc Compounds

We report the use of aqueous surface-initiated atom transfer radical polymerization (SI-ATRP) to grow polymer brushes from a "gigaporous" polymeric chromatography support for use as a novel size exclusion chromatography medium. Poly(N,N-dimethylacrylamide) (PDMA) was grown from hydrolyzable surface initiators via SI-ATRP catalyzed by 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA)/CuCl. Grafted polymer was characterized semiquantitatively by ATR-FTIR and also cleaved and quantitatively characterized for mass, molecular weight, and polydispersity via analytical SEC/MALLS. The synthesis provides control over graft density and allows the creation of dense brushes. Incorporation of negative surface charge was found to be crucial for improving the initiation efficiency. As polymer molecular weight and density could be controlled through reaction conditions, the resulting low-polydispersity grafted polymer brush medium is shown to be suitable for use as a customizable size exclusion chromatography medium for investigating the principals of entropic interaction chromatography. All packed media investigated showed size-dependent partitioning of solutes, even for low graft density systems. Increasing the molecular weight of the grafts allowed solutes more access to the volume fraction in the column available for partitioning. Compared to low graft density media, increased graft density caused eluted solute probes to be retained less within the column and allowed for greater size discrimination of probes whose molecular weights were less than 10(4) kDa.

Topics: Acrylamides; Catalysis; Chromatography, Gel; Copper; Free Radicals; Molecular Structure; Molecular Weight; Silicon; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Trientine; Water