447 research outputs found

    Local ras and ros in the hypertrophic differentiation of chondrocytes

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    Newsletter of the Boston University School of Medicine, Student American Medical Association (SAMA

    Changes of Serum Calcium Concentration, Frequency of Ruminal Contraction and Feed Intake Soon after Parturition of Dairy Cows Fed Difructose Anhydride III

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    Requirements to control the large decrease in serum calcium (Ca) due to parturition and to increase the feed intake soon after parturition have been well accepted in dairy cows. This study was aimed to investigate the feed intake affected by serum Ca concentration with difructose anhydride (DFA) III supplement in dairy cows soon after parturition. Fourteen transition Holstein cows were divided into DFA and control (CONT) groups within 1 to 5 parity variations in each group. Measurement schedule for an individual cow was from 14 d before parturition to 7 d following parturition. The cows in DFA group were supplied 0.2 kg/head/d of DFA III feed containing 40 g of pure DFA III while the cows in CONT group received no DFA III. Other feeding procedures were the same for all cows in both groups. At parturition (d 0), serum Ca concentration sharply declined in both groups (p9.0 mg/dL) tended to be faster in DFA group (12 h) than in the CONT group (48 h), but the differences were not significant. Active ruminal contraction was observed in DFA group at following parturition of d 1 (p<0.05), d 3 (p<0.05), and d 5 (p<0.01). Dry matter (DM) intake did not differ between the groups. However, positive correlations were observed between serum Ca concentration and ruminal contraction (p<0.001), and between ruminal contraction and DM intake (p<0.001) during following parturition. According to multiple regression analysis (R2 = 0.824, p<0.001), the DM intake was positively affected by serum Ca concentration and ruminal contraction. These results suggest that feed intake soon after parturition in dairy cows can be increased by improvement of serum Ca concentration and active ruminal contraction, but DFA III supplementation in this study did not improve the lower serum Ca concentration due to parturition

    Electronic and Magnetic Structures of Sr2FeMoO6

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    We have investigated the electronic and magnetic structures of Sr2FeMoO6 employing site-specific direct probes, namely x-ray absorption spectroscopy with linearly and circularly polarized photons. In contrast to some previous suggestions, the results clearly establish that Fe is in the formal trivalent state in this compound. With the help of circularly polarized light, it is unambiguously shown that the moment at the Mo sites is below the limit of detection (< 0.25mu_B), resolving a previous controversy. We also show that the decrease of the observed moment in magnetization measurements from the theoretically expected value is driven by the presence of mis-site disorder between Fe and Mo sites.Comment: To appear in Physical Review Letter

    Soft x-ray magnetic circular dichroism study of Ca_1-xSr_xRuO_3 across the ferromagnetic quantum phase transition

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    Ca_1-xSr_xRuO_3, which is ferromagnetic for Sr concentration x > 0.3, has been studied by x-ray magnetic circular dichroism (XMCD) in Ru 3p and O 1s core-level x-ray absorption. XMCD signals appear at x ~ 0.3 and monotonically increases with x in the ferromagnetic phase. While the monotonic increase of the XMCD signals with x is of a typical Stoner-type, the absence of appreciable change in the spectral line shapes of both the Ru 3p and O 1s XMCD spectra indicate that the itinerant-electron ferromagnetism in Ca_1-xSr_xRuO_3 is influenced by strong electron correlation.Comment: 5 pages, 4 figures, accepted in Phys. Rev. B 1 page, correct the 4th affiliation 5 page, modifiy 9th referenc

    Light-Promoted Hydrogenation of Carbon Dioxide¿An Overview

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    [EN] Hydrogenation of carbon dioxide is considered as a viable strategy to generate fuels while closing the carbon cycle (heavily disrupted by the abuse in the exploitation of fossil resources) and reducing greenhouse gas emissions. The process can be performed by heat-powered catalytic processes, albeit conversion and selectivity tend to be reduced at increasing temperatures owing to thermodynamic constraints. Recent investigations, as summarised in this overview, have proven that light activation is a distinct possibility for the promotion of CO2 hydrogenation to fuels. This effect is particularly beneficial in methanation processes, which can be enhanced under simulated solar irradiation using materials based on metallic nanoparticles as catalysts. The use of nickel, ruthenium and rhodium has led to substantial efficiencies. Light-promoted processes entail performances on a par with (or even superior to) those of thermally-induced, industrially-relevant, commercial technologies.The author thanks the Spanish Government (Ministerio de Economía y Competitividad, MINECO) for financial support via a project for young researchers (CTQ2015-74138-JIN), and the ‘‘Severo Ochoa’’ programme (SEV 2012-0267). The European Union is also acknowledged for the SynCatMatch project (ERCAdG-2014-671093)Puga Vaca, A. (2016). Light-Promoted Hydrogenation of Carbon Dioxide¿An Overview. Topics in Catalysis. 59(15-16):1268-1278. https://doi.org/10.1007/s11244-016-0658-zS126812785915-16Centi G, Perathoner S (2009) Opportunities and prospects in the chemical recycling of carbon dioxide to fuels. Catal Today 148:191–205Aresta M, Dibenedetto A, Angelini A (2014) Catalysis for the valorization of exhaust carbon: from CO2 to chemicals, materials, and fuels. technological use of CO2. Chem Rev 114:1709–1742Centi G, Quadrelli EA, Perathoner S (2013) Catalysis for CO2 conversion: a key technology for rapid introduction of renewable energy in the value chain of chemical industries. Energy Environ Sci 6:1711–1731Wang W, Wang S, Ma X, Gong J (2011) Recent advances in catalytic hydrogenation of carbon dioxide. Chem Soc Rev 40:3703–3727Gao J, Liu Q, Gu F, Liu B, Zhong Z, Su F (2015) Recent advances in methanation catalysts for the production of synthetic natural gas. RSC Adv 5:22759–22776Armaroli N, Balzani V (2011) The hydrogen issue. ChemSusChem 4:21–36Gao J, Wang Y, Ping Y, Hu D, Xu G, Gu F, Su F (2012) A thermodynamic analysis of methanation reactions of carbon oxides for the production of synthetic natural gas. RSC Adv 2:2358–2368Jadhav SG, Vaidya PD, Bhanage BM, Joshi JB (2014) Catalytic carbon dioxide hydrogenation to methanol: a review of recent studies. 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RSC Adv 4:17420–17428Garbarino G, Bellotti D, Riani P, Magistri L, Busca G (2015) Methanation of carbon dioxide on Ru/Al2O3 and Ni/Al2O3 catalysts at atmospheric pressure: catalysts activation, behaviour and stability. Int J Hydrogen Energy 40:9171–9182Carenco S, Wu C-H, Shavorskiy A, Alayoglu S, Somorjai GA, Bluhm H, Salmeron M (2015) Synthesis and structural evolution of nickel-cobalt nanoparticles under H2 and CO2. Small 11:3045–3053Sharafutdinov I, Elkjaer CF, de Carvalho HWP, Gardini D, Chiarello GL, Damsgaard CD, Wagner JB, Grunwaldt J-D, Dahl S, Chorkendorff I (2014) Intermetallic compounds of Ni and Ga as catalysts for the synthesis of methanol. J Catal 320:77–88Studt F, Sharafutdinov I, Abild-Pedersen F, Elkjaer CF, Hummelshøj JS, Dahl S, Chorkendorff I, Nørskov JK (2014) Discovery of a Ni-Ga catalyst for carbon dioxide reduction to methanol. 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    Ultraviolet radiation shapes seaweed communities

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    Measurement of Epstein-Barr virus DNA load using a novel quantification standard containing two EBV DNA targets and SYBR Green I dye

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    <p>Abstract</p> <p>Background</p> <p>Reactivation of Epstein-Barr virus (EBV) infection may cause serious, life-threatening complications in immunocompromised individuals. EBV DNA is often detected in EBV-associated disease states, with viral load believed to be a reflection of virus activity. Two separate real-time quantitative polymerase chain reaction (QPCR) assays using SYBR Green I dye and a single quantification standard containing two EBV genes, Epstein-Barr nuclear antigen-1 (EBNA-1) and BamHI fragment H rightward open reading frame-1 (BHRF-1), were developed to detect and measure absolute EBV DNA load in patients with various EBV-associated diseases. EBV DNA loads and viral capsid antigen (VCA) IgG antibody titres were also quantified on a population sample.</p> <p>Results</p> <p>EBV DNA was measurable in ethylenediaminetetraacetic acid (EDTA) whole blood, peripheral blood mononuclear cells (PBMCs), plasma and cerebrospinal fluid (CSF) samples. EBV DNA loads were detectable from 8.0 × 10<sup>2 </sup>to 1.3 × 10<sup>8 </sup>copies/ml in post-transplant lymphoproliferative disease (n = 5), 1.5 × 10<sup>3 </sup>to 2.0 × 10<sup>5 </sup>copies/ml in infectious mononucleosis (n = 7), 7.5 × 10<sup>4 </sup>to 1.1 × 10<sup>5 </sup>copies/ml in EBV-associated haemophagocytic syndrome (n = 1), 2.0 × 10<sup>2 </sup>to 5.6 × 10<sup>3 </sup>copies/ml in HIV-infected patients (n = 12), and 2.0 × 10<sup>2 </sup>to 9.1 × 10<sup>4 </sup>copies/ml in the population sample (n = 218). EBNA-1 and BHRF-1 DNA were detected in 11.0% and 21.6% of the population sample respectively. There was a modest correlation between VCA IgG antibody titre and BHRF-1 DNA load (rho = 0.13, p = 0.05) but not EBNA-1 DNA load (rho = 0.11, p = 0.11).</p> <p>Conclusion</p> <p>Two sensitive and specific real-time PCR assays using SYBR Green I dye and a single quantification standard containing two EBV DNA targets, were developed for the detection and measurement of EBV DNA load in a variety of clinical samples. These assays have application in the investigation of EBV-related illnesses in immunocompromised individuals.</p

    Metabolic syndrome is associated with change in subclinical arterial stiffness - A community-based Taichung Community Health Study

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to evaluate the effect of MetS on arterial stiffness in a longitudinal study.</p> <p>Methods</p> <p>Brachial-ankle pulse wave velocity (baPWV), a measurement interpreted as arterial stiffness, was measured in 1518 community-dwelling persons at baseline and re-examined within a mean follow-up period of 3 years. Multivariate linear regression with generalized estimating equations (GEE) were used to examine the longitudinal relationship between MetS and its individual components and baPWV, while multivariate logistic regression with GEE was used to examine the longitudinal relationship between MetS and its individual components and the high risk group with arterial stiffness.</p> <p>Results</p> <p>Subjects with MetS showed significantly greater baPWV at the end point than those without MetS, after adjusting for age, gender, education, hypertension medication and mean arterial pressure (MAP). MetS was associated with the top quartile of baPWV (the high-risk group of arterial stiffness, adjusted odds ratio [95% confidence interval] 1.52 [1.21-1.90]), and a significant linear trend of risk for the number of components of MetS was found (p for trend < 0.05). In further considering the individual MetS component, elevated blood pressure and fasting glucose significantly predicted a high risk of arterial stiffness (adjusted OR [95% CI] 3.72 [2.81-4.93] and 1.35 [1.08-1.68], respectively).</p> <p>Conclusions</p> <p>MetS affects the subject's progression to arterial stiffness. Arterial stiffness increased as the number of MetS components increased. Management of MetS is important for preventing the progression to advanced arterial stiffness.</p
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