Designing Single-Molecule Magnets as Drugs with Dual Anti-Inflammatory and Anti-Diabetic Effects.

We have designed and synthesized two novel cobalt coordination compounds using bumetanide (bum) and indomethacin (ind) therapeutic agents. The anti-inflammatory effects of cobalt metal complexes with ind and bum were assayed in lipopolysaccharide stimulated RAW 264.7 macrophages by inhibition of nitric oxide production. Firstly, we determined the cytotoxicity and the anti-inflammatory potential of the cobalt compounds and ind and bum ligands in RAW 264.7 cells. Indomethacin-based metal complex was able to inhibit the NO production up to 35% in a concentration-dependent manner without showing cytotoxicity, showing around 6-37 times more effective than indomethacin. Cell cycle analysis showed that the inhibition of NO production was accompanied by a reversion of the differentiation processes in LPS-stimulated RAW 264.7 cells, due to a decreased of cell percentage in G0/G1 phase, with the corresponding increase in the number of cells in S phase. These two materials have mononuclear structures and show slow relaxation of magnetization. Moreover, both compounds show anti-diabetic activity with low in vitro cell toxicities. The formation of metal complexes with bioactive ligands is a new and promising strategy to find new compounds with high and enhanced biochemical properties and promises to be a field of great interest.

Dietary glutamine supplementation effects on amino acid metabolism, intestinal nutrient absorption capacity and antioxidant response of gilthead sea bream (Sparus aurata) juveniles.

A study was undertaken to evaluate dietary glutamine supplementation effects on gilthead sea bream performance, intestinal nutrient absorption capacity, hepatic and intestinal glutamine metabolism and oxidative status. For that purpose gilthead sea bream juveniles (mean weight 13.0g) were fed four isolipidic (18% lipid) and isonitrogenous (43% protein) diets supplemented with 0, 0.5, 1 and 2% glutamine for 6weeks. Fish performance, body composition and intestinal nutrient absorption capacity were not affected by dietary glutamine levels. Hepatic and intestinal glutaminase (GlNase), glutamine synthetase (GSase), alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase activities were also unaffected by dietary glutamine supplementation. In the intestine GlNase activity was higher and GSase/GlNase ratio was two-fold lower than in the liver, suggesting a higher use of glutamine for energy production by the intestine than by the liver. The liver showed higher catalase and glucose-6-phosphate dehydrogenase activities, while the intestine presented higher glutathione peroxidase and glutathione reductase activities and oxidised glutathione content, which seems to reveal a higher glutathione dependency of the intestinal antioxidant response. Total and reduced glutathione contents in liver and intestine and superoxide dismutase activity in the intestine were enhanced by dietary glutamine, though lipid peroxidation values were not affected. Overall, differences between liver and intestine glutamine metabolism and antioxidant response were identified and the potential of dietary glutamine supplementation to gilthead sea bream's antioxidant response was elucidated.

Isolation of Brucella melitensis from a RB51-vaccinated seronegative goat.

The purpose of this study is to determine the etiology of abortions presented in a goat herd declared as free of brucellosis and vaccinated with RB51 located in Mexico. The serological diagnosis of brucellosis in 33 animals was performed. The study included three goats that aborted in the last third of gestation and 15 goats that gave birth normally; samples of milk and vaginal exudate were subjected to bacteriological study. All animals were negative for serological diagnosis, and isolation of Brucella melitensis was achieved in a single goat from vaginal exudate. However, the particularity is that this goat was negative to the card, indirect ELISA, and radial immunodiffusion tests. Isolation of a field strain was confirmed by biochemical test resistance to rifampicin and PCR. It is concluded that a goat which aborted in the last third of gestation was found spreading B. melitensis through vaginal discharge despite being vaccinated with RB51 and seronegative for brucellosis.

Engineering of a novel ruthenium sensitizer and its application in dye-sensitized solar cells for conversion of sunlight into electricity.

A novel ligand 4,4'-bis(carboxyvinyl)-2,2'-bipyridine (L) and its ruthenium(II) complex [Ru(II)L(2)(NCS)(2)] (K8) were synthesized and characterized by analytical, spectroscopic, and electrochemical techniques. The performance of the K8 complex as a charge transfer photosensitizer in nanocrystalline TiO(2) based solar cells was studied. When the K8 complex anchored onto a nanocrystalline TiO(2) film, we achieved very efficient sensitization yielding 77 +/-5% incident photon-to-current efficiencies (IPCE) in the visible region using an electrolyte consisting of 0.6 M methyl-N-butyl imidiazolium iodide, 0.05 M iodine, 0.05 M LiI, and 0.5 M 4-tert-butylpyridine in a 50/50 (v/v) mixture of valeronitrile and acetonitrile. Under standard AM 1.5 sunlight, the complex K8 gave a short circuit photocurrent density of 18 +/- 0.5 mA/cm(2), and the open circuit voltage was 640 +/- 50 mV with fill factor of 0.75 +/- 0.05, corresponding to an overall conversion efficiency of 8.64 +/- 0.5%.

The effect of Al2O3 barrier layers in TiO2/dye/CuSCN photovoltaic cells explored by recombination and DOS characterization using transient photovoltage measurements.

Solid-state dye-sensitized solar cells of the type TiO(2)/dye/CuSCN have been made with thin Al(2)O(3) barriers between the TiO(2) and the dye. The Al(2)O(3)-treated cells show improved voltages and fill factors but lower short-circuit currents. Transient photovoltage and photocurrent measurements have been used to find the pseudo-first-order recombination rate constant (k(pfo)) and capacitance as a function of potential. Results show that k(pfo) is dependent on V(oc) with the same form as in TiO(2)/dye/electrolyte cells. The added Al(2)O(3) layer acts as a "tunnel barrier", reducing the k(pfo) and thus increasing V(oc). The decrease in k(pfo) also results in an increased fill factor. Capacitance vs voltage plots show the same curvature (approximately 150 mV/decade) as found in TiO(2)/dye/electrolyte cells. The application of one Al(2)O(3) layer does not cause a significant shift in the shape or position of the capacitance curve, indicating that changes in band offset play a lesser role in the observed V(oc) increase. Cells made with P25 TiO(2) have, on average, 2.5 times slower recombination rate constants (longer lifetimes) than those made with colloidal TiO(2). The cells with P25 also show 2.3 times higher trap density (DOS), which results in little change in the V(oc) between the two types of TiO(2). It is further noted that the recombination current in these cells cannot be calculated from the total charge times the first order rate constant.

Laser flash photolysis study of Jacobsen catalyst and related manganese(III) salen complexes. Relevance to catalysis.

The laser flash photolysis and emission properties of a set of five-coordinate manganese(III) Schiff-base complexes have been examined. In contrast to the intramolecular electron transfer between Mn3+ and the equatorial salen ligand reported to occur in the absence of axial coordination, our laser flash photolysis study has shown that the reactivity of the respective excited states is appreciably influenced by the electron donor strength of the apical ligand at the metal center. In fact, homolytic and heterolytic photocleavage of the metal-ligand apical bond can be the most important processes upon laser excitation, their relative contribution being influenced by medium effects and the sigma-charge donation of the axial ligand. On the other hand, the detection of reactive intermediates such as the oxomanganese(V) salen complex (lambda(max) 530 nm) by laser flash photolysis opens the way to apply this fast detection technique to the study of reaction mechanisms in catalysis by metallic complexes. As a matter of fact, quenching of oxomanganese(V) salen by simple alkenes has been observed by laser flash.

Characterization of germanium site distribution in zeolite ITQ-7 by photoluminescence.

Zeolite ITQ-7 containing germanium emits luminescence upon excitation at the wavelength of the absorption maxima; control experiments with amorphous GeO2 and all-silica zeolites indicate that the emission is attributable to Ge atoms occupying framework positions; the emission decays on the nanosecond time scale and it fits to variable proportions of three exponential kinetics, this being compatible with the presence of three families of Ge atoms in the solid.