Phase equilibrium of the CO2/glycerol system: Experimental data by in situ FT-IR spectroscopy and thermodynamic modeling

Phase equilibrium experimental data for the CO2/glycerol system are reported in this paper. The measurements were performed using an in situ FT-IR method for temperatures ranging from 40 ◦C to 200 ◦C and pressures up to 35.0 MPa, allowing determination of the mutual solubility of both compounds. Concerning the CO2 rich phase, it was observed that the glycerol solubility in CO2 was extremely low (in the range of 10−5 in mole fraction) in the pressure and temperature domains investigated here. Conversely, the glycerol rich phase dissolved CO2 at mole fractions up to 0.13. Negligible swelling of the glycerol rich phase has been observed. Modeling of the phase equilibrium has been performed using the Peng–Robinson equation of state (PR EoS) with classical van der Waals one fluid and EoS/GE based mixing rules (PSRK and MHV2). Satisfactory agreement was observed between modeling results and experimental measurements when PSRK mixing rules are used in combination with UNIQUAC model, although UNIFAC predictive approach gives unsatisfactory representation of experimental behavior

Early and late systolic wall stress differentially relate to myocardial contraction and relaxation in middle-aged adults: the Asklepios study

Experimental studies implicate late systolic load as a determinant of impaired left ventricular (LV) relaxation. We aimed to assess the relationship between the myocardial loading sequence and left ventricular (LV) contraction and relaxation. Time-resolved central pressure and time-resolved LV geometry were measured with carotid tonometry and speckle-tracking echocardiography, respectively, for computation of time-resolved ejection-phase myocardial wall stress (EP-MWS) among 1,214 middle-aged adults without manifest cardiovascular disease from the general population. Early diastolic annular velocity, systolic annular velocities were measured with tissue Doppler imaging and segmentaveraged longitudinal strain was measured with speckle-tracking echocardiography. After adjustment for age, gender and potential confounders, late EP-MWS was negatively associated with early diastolic mitral annular velocity (e', standardized β=-0.25; P<0.0001) and mitral inflow propagation velocity (Vpe, standardized β=-0.13; P=0.02). In contrast, early EP-MWS was positively associated with e' (standardized β=0.18; P<0.0001) and Vpe (standardized β=0.22; P<0.0001). A higher late EP-MWS predicted a lower systolic mitral annular velocity (S', standardized β=-0.31; P<0.0001) and lesser myocardial longitudinal strain (standardized β=0.32; P<0.0001), whereas a higher early EP-MWS was associated with a higher S' (standardized β=0.16; P=0.002) and greater longitudinal strain (standardized β=-0.24; P=0.002). The loading sequence remained independently associated with e' after adjustment for S' or systolic longitudinal strain. In the context of available experimental data, our findings support the role of the myocardial loading sequence as a determinant of LV systolic and diastolic function. A loading sequence characterized by prominent late systolic wall stress was associated with lower longitudinal systolic function and diastolic relaxation

β(1,3)-Glucanosyl-Transferase Activity Is Essential for Cell Wall Integrity and Viability of Schizosaccharomyces pombe

13 páginas, 7 figuras, 2 tablas.[Background]: The formation of the cell wall in Schizosaccharomyces pombe requires the coordinated activity of enzymes involved in the biosynthesis and modification of b-glucans. The b(1,3)-glucan synthase complex synthesizes linear b(1,3)- glucans, which remain unorganized until they are cross-linked to other b(1,3)-glucans and other cell wall components. Transferases of the GH72 family play important roles in cell wall assembly and its rearrangement in Saccharomyces cerevisiae and Aspergillus fumigatus. Four genes encoding b(1,3)-glucanosyl-transferases -gas1+, gas2+, gas4+ and gas5+- are present in S. pombe, although their function has not been analyzed. [Methodology/Principal Findings]: Here, we report the characterization of the catalytic activity of gas1p, gas2p and gas5p together with studies directed to understand their function during vegetative growth. From the functional point of view, gas1p is essential for cell integrity and viability during vegetative growth, since gas1D mutants can only grow in osmotically supported media, while gas2p and gas5p play a minor role in cell wall construction. From the biochemical point of view, all of them display b(1,3)-glucanosyl-transferase activity, although they differ in their specificity for substrate length, cleavage point and product size. In light of all the above, together with the differences in expression profiles during the life cycle, the S. pombe GH72 proteins may accomplish complementary, non-overlapping functions in fission yeast. [Conclusions/Significance]: We conclude that b(1,3)-glucanosyl-transferase activity is essential for viability in fission yeast, being required to maintain cell integrity during vegetative growth.This research was supported by grants from the Comision Interministerial de Ciencia y Tecnologia (BFU2004-00778) and Junta de Castilla y Leon (GR231) to C.R.V-A and from the European Community (LSHB-CT-2004-511952) to C.R.V-A. and J.P.L. M.M-R. held a fellowship from the Ministerio de Educacion y Ciencia.Peer reviewe

Lipidomic approach in young adult triathletes: effect of supplementation with a polyphenols-rich juice on neuroprostane and F2-dihomo-isoprostane markers

The aim of the this study was to determine the effect of a polyphenols-rich juice (aronia-citrus juice, ACJ) on F4-neuroprostanes and F2-dihomo-isoprostanes—markers of oxidative stress associated with the central nervous system (CNS)—in 16 elite triathletes under a controlled diet for triathlon training (145 days). In the triathletes, a decrease of the lipid peroxidation markers after ACJ intake, associated with neuronal membrane degradation (10-epi-10-F4t-neuroprostane and 10-F4t-neuroprostane), was observed when compared with placebo stage values. Regarding the F2-dihomo-isoprostanes, a significant decrease of the neuromotor system damage biomarkers (17-F2t-dihomo-isoprostane) with an increase of training load during the study was observed, although the decrease of the load training at the last stage showed a significant increase of the values of ent-7-(RS)-7-F2t-dihomo-IsoP, suggesting a possible role in adaptation post-training. On the other hand, the changes in the excretion of 17-epi-17-F2t-dihomo-IsoP provided a positive connection between physical exercise and ACJ intake. Thus, the results showed in this clinical study in young triathletes will help to elucidate novel interactions and mechanisms between the excretion of lipid peroxidation metabolites from CNS, supplementation of polyphenols-rich juice in the diet and physical exercise during a training season.This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). This work has been partially funded by the “Fundación Séneca de la Región de Murcia” Grupo de Excelencia 19900/GERM/15. LAGF was granted a pre-doctoral FPI fellowship (BES2012-060185) by the Spanish government

Assessment oxidative stress biomarkers –neuroprostanes and dihomo-isoprostanes- in elite triathletes urine after two weeks of moderate altitude training

This randomized and controlled trial investigated whether the increase in elite training at different altitudes altered the oxidative stress biomarkers of the nervous system. This is the first study to investigate four F4-neuroprostanes and four F2-dihomo-isoprostanes quantified in 24-hour urine. The quantification was carried out by Ultra High Pressure Liquid Chromatography-triple Quadrupole-Tandem Mass Spectrometry (UHPLC-QqQ-MS/MS). Sixteen elite triathletes agreed to participate in the project. They were randomized in two groups, a group submitted to Altitude Training (n=8) and a group submitted to Sea Level Training (n=8), with a Control group of non-athletes (n=8). After experimental period, the Altitude Training group triathletes gave significant data: 17-epi-17-F2t-dihomo-IsoP (from 5.2 ± 1.4 µg/mL 24 h-1 to 6.6 ± 0.6 µg/mL 24 h-1), ent-7(RS)-7-F2t-dihomo-IsoP (from 6.6 ± 1.7 µg/mL 24 h-1 to 8.6 ± 0.9 µg /mL 24 h-1), and ent-7-epi-7-F2t-dihomo-IsoP (from 8.4 ± 2.2 µg/mL 24 h-1 to 11.3 ± 1.8 µg/mL 24 h-1) increased, while, of the neuronal degeneration-related compounds, only 10-epi-10-F4t-NeuroP (8.4 ± 1.7 µg/mL 24 h-1) and 10-F4t-NeuroP (5.2 ± 2.9 µg/mL 24 h-1) were detected in this group. For the control group and sea level training groups, no significant changes had occurred at the end of the 2-weeks experimental period. Therefore, and as the main conclusion, the training at moderate altitude increased the F4-NeuroPs- and F2-dihomo-isoPs-related oxidative damage of the central nervous system (CNS) compared to similar training at sea level.This study was supported by the project AGL2011-23690 (CICYT) (Spanish Ministry of Economy and Competitiveness). LAGF was granted with a pre-doctoral FPI fellowship BES2012-060185 by the Spanish government. The authors are also grateful to the University of Alicante for its collaboration. Sonia Medina was appointed under a research contract from the project AGL2011-23690 (CICYT)

Dietary antioxidant intake is inversely associated with 2,3-dinor oxylipin metabolites, the major excreted oxylipins in overweight and obese subjects

Cardiometabolic disease risk factors, including obesity, insulin resistance, high blood pressure, and dyslipidemia, are associated with elevated oxidative stress biomarkers like oxylipins. Increased adiposity by itself induces various isomers of this oxidized lipid family, while dietary polyphenols show benefits in its regulation. Previously, we showed that specific co-abundant microorganisms characterized the gut microbiota of Colombians and associated differentially with diet, lifestyle, obesity, and cardiometabolic health status, which led us to hypothesize that urinary oxylipins would reflect the intensity of oxidative metabolism linked to gut microbiota dysbiosis. Thus, we selected a convenience sample of 105 participants (age: 40.2 ± 11.9 years, 47.6% women), grouped according to microbiota, cardiometabolic health status, and body mass index (BMI); and evaluated 33 urinary oxylipins by HPLC-QqQ-MS/MS (e.g., isoprostanes, prostaglandins, and metabolites), paired with anthropometry and blood chemistry information and dietary antioxidants estimated from a 24-h food recall. In general, oxylipins did not show differences among individuals who differed in gut microbiota. While the unmetabolized oxylipin levels were not associated with BMI, the total content of oxylipin metabolites was highest in obese and cardiometabolically abnormal subjects (e.g., insulin resistant), mainly by prostaglandin-D (2,3-dinor-11β-PGF) and 15-F-IsoPs (2,3-dinor-15-F-IsoP and 2,3-dinor-15-epi-15-F-IsoP) metabolites. The total polyphenol intake in this cohort was 1070 ± 627 mg/day. After adjusting for body weight, the polyphenol intake was significantly higher in lean than overweight and showed an inverse association with dinor-oxylipin levels in principal component analysis. These results suggest that the 2,3-dinor-oxylipins could be more specific biomarkers associated with BMI than their parent oxylipins and that are sensitive to be regulated by dietary antioxidants.The authors thank the volunteers who agreed to participate in this study, the Colombian Ministry of science, technology, and innovation (Minciencias; grant number 832-2018), and Grupo Empresarial Nutresa. They also thank the Ibero-American Programme for Science, Technology and Development (CYTED) – Action 112RT0460 CORNUCOPIA networ

Manufacturing and characterization of III-V on silicon multijunction solar cells

Tandem GaInP/GaAs//Si(inactive) solar cells were manufactured by direct wafer bonding under vacuum. At this early stage, an inactive silicon substrate was used (i.e. n+ Si substrate instead of an active n-p Si junction). Bonded devices presented an Sshaped J-V curve with a kink close to Voc caused by a built-in potential barrier at the III-V//Si interface that reduces the fill factor and therefore the efficiency of the device by 7% compared to the stand-alone GaInP/GaAs tandem cells. Nevertheless, losses in Jsc and Voc caused by the bonding process, account for less than 10%. AlGaAs single junction cells, designed to be bonded on a silicon cell for low concentrator photovoltaics (LCPV), were also manufactured reaching an efficiency of 15.9% under one sun AM1.5G spectrum for a 2 cm² cell

Presence of neutrophil myeloperoxidase in lamellar tissue of horses with laminitis induced using a hyperinsulinemic model

peer reviewedLaminitis is a pathology of the equine digit resulting in failure of the dermo-epidermal interface. Inflammation is likely a central player in its pathophysiology. Neutrophil activation and the presence of myeloperoxidase have been observed in the black walnut heartwood extract model, used to investigate sepsis-related laminitis. However, less is known about the role of neutrophil activation in the prolonged euglycemic hyperinsulinemic clamp (pEHC) model. This model is used to investigate the pathophysiology of laminitis related to endocrine disturbances like hyperinsulinemia encountered in pituitary pars intermedia dysfunction and equine metabolic syndrome. Five horses were included in this study and randomly assigned to a control group (n = 2) and a pEHC group (n = 3). Histological sections of lamellar tissue from all horses were obtained and immunohistochemically stained for myeloperoxidase and counterstained with hematoxylin-eosin. The sections were examined for histopathological evidence of laminitis and myeloperoxidase. Histopathological changes that characterize insulin-induced laminitis and increased presence of myeloperoxidase, especially in the dermal lamellae, were observed in histologic sections of pEHC-treated horses compared to control horses. Neutrophil activation with myeloperoxidase release may play a role in the pathophysiology of endocrinopathic laminitis. The implications of this finding warrant further investigation