Analytical characterization of the aroma of Tinta Negra Mole red wine: Identification of the main odorants compounds

A method for the simultaneous determination of major and minor volatiles composition in different types (dry, medium dry, sweet and medium sweet) of a young Tinta Negra Mole (TNM) monovarietal red wine from 2003 harvest has been validated. Wine samples preparation includes a dichloromethane liquid–liquid extraction followed by concentration under a nitrogen atmosphere. The extracted fraction was analysed by gas chromatography–mass spectrometry and give quantitative information for more than 86 analytes whose concentration range from few μg l−1 to 259.1 mg l−1. The method enables high recovery of volatile compounds in wine good linearity with (r2) values higher than 0.980 and good sensitivity. The limits of detection range from 0.003 to 0.534 mg l−1 and limits of quantification from 0.009 to 1.170 mg l−1. The method allows satisfactory determination of more than 80 compounds in the TNM red wines. These wines are characterized by a high content of higher alcohols, ethyl esters, fatty acids and lactones. The levels of sulphur compounds in Tinta Negra Mole medium sweet wines are very low, but they have the highest concentration of carbonyl compounds. Quantitative analysis of the main odorants followed by the determination of aroma index allow us elucidate the aroma of these varieties. On the basis of their odour description and odour threshold, the most powerful odorants of Tinta Negra Mole wines were tentatively established

Circulating concentrations of GDF11 are positively associated with TSH levels in humans

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor (TGF)-beta superfamily which declines with age and has been proposed as an anti-aging factor with regenerative effects in skeletal muscle in mice. However, recent data in humans and mice are conflicting, casting doubts about its true functional actions. The aim of the present study was to analyze the potential involvement of GFD11 in energy homeostasis in particular in relation with thyroid hormones. Serum concentrations of GDF11 were measured by enzyme-linked immunosorbent assay (ELISA) in 287 subjects. A highly significant positive correlation was found between GDF11 and thyroid-stimulating hormone (TSH) concentrations (r = 0.40, p 0.05 for both) with GDF11 levels. In a multiple linear regression analysis, the model that best predicted logGDF11 included logTSH, leptin, body mass index (BMI), age, and C-reactive protein (logCRP). This model explained 37% of the total variability of logGDF11 concentrations (p < 0.001), with only logTSH being a significant predictor of logGDF11. After segregating subjects by TSH levels, those within the low TSH group exhibited significantly decreased (p < 0.05) GDF11 concentrations as compared to the normal TSH group or the high TSH group. A significant correlation of GDF11 levels with logCRP (r = 0.19, p = 0.025) was found. GDF11 levels were not related to the presence of hypertension or cardiopathy. In conclusion, our results show that circulating concentrations of GDF11 are closely associated with TSH concentrations and reduced in subjects with low TSH levels. However, GDF11 is not related to the regulation of energy expenditure. Our data also suggest that GDF11 may be involved in the regulation of inflammation, without relation to cardiac function. Further research is needed to elucidate the role of GDF11 in metabolism and its potential involvement in thyroid pathophysiology

EXAFS characterization and catalytic properties of alumina supported iridium catalysts derived from Ir

The adsorption of Ir2(µ-Cl)2(COD)2 (1) (COD=Cyclooctadiene) in alumina has been studied by EXAFS at the LIII edge of Ir. The reactivity of the surface complex formed upon adsorption of (1) towards Co and PPh3 has been investigated by FT-IR. The fixation of (1) on γ-alumina involves the substitution of the bridging chlorides by aluminato groups from the support, to form a dimeric surface complex that is formulated as Ir2(µ-O-alumina)2(COD)2. The room temperature reaction of this species with CO leads to the formulation Ir2(CO)4 (µ-O-alumina)2. This tetracarbonyl surface species react at room temperature with PPh3, leading to trans-Ir2(µ-O-alumina)2(CO)2(PPh3)2. The decomposition of the Ir2(µ-O-alumina)2(COD)2 species under H2 treatment leads to the formation of Ir clusters

Synthesis, reactivity and catalytic properties of rhodium complexes of (R,R)-1-benzyl-3,4-dithioetherpyrrolidines

Complexes [Rh(cod)(degusR)]ClO4, where cod is 1,5-cyclooctadiene and degusR represents the homochiral dithioethers (R,R)-1-benzyl-3,4-bis(methylsulfanyl)pyrrolidine, (R,R)-1-benzyl-3,4-bis(isopropylsulfanyl)pyrrolidine and (R,R)-1-benzyl-3,4-bis(phenylsulfanyl)pyrrolidine were prepared and characterized. Their reactivity with CO and PPh3 was investigated. The complexes were assayed as catalysts in hydroformylation of styrene, hydrogenation of acrylic acids and hydroboration of styrene. Although these complexes containing dithioethers behave as catalytic precursors in hydroformylation reaction, the results suggest that mononuclear hydride rhodium carbonyl species is responsible for the catalytic activity. The cationic complexes are not active in the hydrogenation of acrylic acids in the conditions tested. These complexes are moderately active in the hydroboration of styrene with catecholborane, but their selectivities are not satisfactory.http://www.sciencedirect.com/science/article/B6TG5-3XWJKPH-8/1/2d47b8846a016e0aca3487986250181

Circulating concentrations of GDF11 are positively associated with TSH levels in humans

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor (TGF)-beta superfamily which declines with age and has been proposed as an anti-aging factor with regenerative effects in skeletal muscle in mice. However, recent data in humans and mice are conflicting, casting doubts about its true functional actions. The aim of the present study was to analyze the potential involvement of GFD11 in energy homeostasis in particular in relation with thyroid hormones. Serum concentrations of GDF11 were measured by enzyme-linked immunosorbent assay (ELISA) in 287 subjects. A highly significant positive correlation was found between GDF11 and thyroid-stimulating hormone (TSH) concentrations (r = 0.40, p 0.05 for both) with GDF11 levels. In a multiple linear regression analysis, the model that best predicted logGDF11 included logTSH, leptin, body mass index (BMI), age, and C-reactive protein (logCRP). This model explained 37% of the total variability of logGDF11 concentrations (p < 0.001), with only logTSH being a significant predictor of logGDF11. After segregating subjects by TSH levels, those within the low TSH group exhibited significantly decreased (p < 0.05) GDF11 concentrations as compared to the normal TSH group or the high TSH group. A significant correlation of GDF11 levels with logCRP (r = 0.19, p = 0.025) was found. GDF11 levels were not related to the presence of hypertension or cardiopathy. In conclusion, our results show that circulating concentrations of GDF11 are closely associated with TSH concentrations and reduced in subjects with low TSH levels. However, GDF11 is not related to the regulation of energy expenditure. Our data also suggest that GDF11 may be involved in the regulation of inflammation, without relation to cardiac function. Further research is needed to elucidate the role of GDF11 in metabolism and its potential involvement in thyroid pathophysiology

Tribocorrosion behavior and ions release of CoCrMo alloy coated with a TiAlVCN/CNx multilayer in simulated body fluid plus bovine serum albumin

While the CoCrMo biomaterial is currently employed in artificial joints, there are medical concerns regarding its metal ion release and material loss caused by tribocorrosion. In this work, a TiAlVCN/CNx multilayer coating has been employed to improve the tribocorrosion-resistance of the CoCrMo substrate. During the tribocorrosion test, with the sample immersed in a simulated body fluid containing bovine serum albumin, open-circuit potential measurements showed more noble potential as well as a reduction of both the friction coefficient and wear-rate during the sliding phase. Inductive coupled plasma results demonstrate that the multilayer coating effectively blocked the emigration of metallic ions.Funding Agencies|CONACYT [FOMIX Jal-2010-10-149472]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; Tecnologico de Monterrey research seed fund</p