8,468 research outputs found

    Structure/activity relationships applied to the hydrogenation of α,β-unsaturated carbonyls: The hydrogenation of 3-butyne-2-one over alumina-supported palladium catalysts

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    The gas phase hydrogenation of 3-butyne-2-one, an alkynic ketone, over two alumina-supported palladium catalysts is investigated using infrared spectroscopy in a batch reactor at 373 K. The mean particle size of the palladium crystallites of the two catalysts are comparable (2.4 ± 0.1 nm). One catalyst (Pd(NO3)2/Al2O3) is prepared from a palladium(II) nitrate precursor, whereas the other catalyst (PdCl2/Al2O3) is prepared using palladium(II) chloride as the Pd precursor compound. A three-stage sequential process is observed with the Pd(NO3)2/Al2O3 catalyst facilitating complete reduction all the way through to 2-butanol. However, hydrogenation stops at 2-butanone with the PdCl2/Al2O3 catalyst. The inability of the PdCl2/Al2O3 catalyst to reduce 2-butanone is attributed to the inaccessibility of edge sites on this catalyst, which are blocked by chlorine retention originating from the catalyst’s preparative process. The reaction profiles observed for the hydrogenation of this alkynic ketone are consistent with the site-selective chemistry recently reported for the hydrogenation of crotonaldehyde, an alkenic aldehyde, over the same two catalysts. Thus, it is suggested that a previously postulated structure/activity relationship may be generic for the hydrogenation of α,β-unsaturated carbonyl compounds over supported Pd catalysts

    Exposure of a 23F serotype strain of <i>Streptococcus pneumoniae</i> to cigarette smoke condensate is associated with selective upregulation of genes encoding the two-component regulatory system 11 (TCS11)

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    Alterations in whole genome expression profiles following exposure of the pneumococcus (strain 172, serotype 23F) to cigarette smoke condensate (160 μg/mL) for 15 and 60 min have been determined using the TIGR4 DNA microarray chip. Exposure to CSC resulted in the significant (P &#60; 0.014–0.0006) upregulation of the genes encoding the two-component regulatory system 11 (TCS11), consisting of the sensor kinase, hk11, and its cognate response regulator, rr11, in the setting of increased biofilm formation. These effects of cigarette smoke on the pneumococcus may contribute to colonization of the airways by this microbial pathogen

    Mary Pettenger Interview 2020

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    Dr. Mary Pettenger discusses what her day looks like as a Division Chair and professor at Western Oregon university. She talks about her daily routine, her favorite memories at Western, and her goals for the future

    Length of stay and mortality associated with healthcare-associated urinary tract infections: a multi-state model

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    SummaryBackgroundThe emergence of antimicrobial resistance is of particular concern with respect to urinary tract infections, since the majority of causative agents are Gram-negative bacteria. Healthcare-associated urinary tract infections (HAUTIs) are frequently associated with instrumentation of the urinary tract, specifically with indwelling catheters.AimTo evaluate the current incidence, mortality, and length of hospital stay associated with HAUTIs.MethodsA non-concurrent cohort study design was used, conducted between January 1st, 2010 and June 30th, 2014. All patients admitted to one of the eight participating Australian hospitals and who were hospitalized for more than two days were included. The primary outcome measures were the incidence, mortality, and excess length of stay associated with HAUTIs.FindingsFrom 162,503 patient admissions, 1.73% [95% confidence interval (CI): 1.67–1.80] of admitted patients acquired a HAUTI. Using a multi-state model, the expected extra length of stay due to HAUTI was four days (95% CI: 3.1–5.0 days). Using a Cox regression model, infection significantly reduced the rate of discharge (hazard ratio: 0.78; 95% CI: 0.73–0.83). Women were less likely to die (0.71; 0.66–0.75), whereas older patients were more likely to die (1.40; 1.38–1.43). Death was rarer in a tertiary referral hospital compared to other hospitals, after adjusting for age and sex (0.74; 0.69–0.78).ConclusionThis study is the first to explore the burden of HAUTIs in hospitals using appropriate statistical methods in a developed country. Our study indicates that the incidence of HAUTI, in addition to its associated extra length of stay in hospital, presents a burden to the hospital system. With increasing incidence of UTI due to antimicrobial-resistant organisms, surveillance and interventions to reduce the incidence of HAUTI are required

    Renovating Pastures with Glyphosate Tolerant Soybeans

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    Pasture renovation is expensive because of lost production, costs for eliminating existing vegetation by tillage or herbicides, and direct replanting costs. Reducing costs, reducing risk of failure, and producing income from pasture land during renovation can significantly increase the profitability of improving pastures

    Parity (and time-reversal) anomaly in a semiconductor

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    The physics of a parity anomaly, potentially observable in a narrow-gap semiconductor, is revisited. Fradkin, Dagotto, and Boyanovsky have suggested that a Hall current of anomalous parity can be induced by a Peierls distortion on a domain wall. I argue that a perturbation inducing the parity anomaly must break the time reversal symmetry, which rules out the Peierls distortion as a potential cause. I list all possible perturbations that can generate the anomaly.Comment: 11 pages, 1 figure. Sign errors fixe

    Registration of ‘Goldmine’ Big Bluestem

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    ‘Goldmine’ big bluestem [Andropogon gerardii Vitman.] (Reg. no. CV-14, PI 641702) was released in May 2004 by the USDA-ARS and the Agricultural ResearchDivision, Institute of Agriculture and Natural Resources, University of Nebraska. Goldmine is a perennial warm-season grass cultivar that produces forage with moderately improved in vitro dry matter digestibility (IVDMD), protein concentration, and improved forage yields in some hay management systems. Animal gains from Goldmine were greater than its parent cultivar when utilized by beef cattle in well-managed grazing systems. Goldmine was tested as Kaw C3

    Application of Structured Decision Making to Wildlife Management in Montana

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    Good decision-making is essential to conserving wildlife populations. Whereas there may be multiple ways to address a problem, perfect solutions rarely exist. Managers are therefore tasked with identifying optimal decisions that will best achieve desired outcomes. Structured decision making (SDM) is a method of decision analysis used to identify the most effective, efficient, and realistic optimal decisions while accounting for values and priorities of the decision maker. The stepwise process includes identifying the management problem, defining objectives for solving the problem, developing alternative approaches to achieve the objectives, and formally evaluating which alternative is most likely to accomplish the objectives. The SDM process can be more effective than informal decision-making because it provides a transparent way to quantitatively evaluate decisions for addressing multiple management objectives while incorporating science, uncertainty, and risk tolerance. We illustrate the application of this process to management needs, including an SDM-based decision tool developed to identify optimal decisions for proactively managing risk of pneumonia epizootics in bighorn sheep (Ovis canadensis). Pneumonia epizootics are a major challenge for managers, including in terms of knowing how or when to manage risk. The decision tool facilitates analysis of alternative decisions for how to manage herds based on predictions from a risk model, herd-specific objectives, and predicted costs and benefits of each alternative. Managers can be confident resulting decisions are most effective, efficient, and realistic because they explicitly account for important considerations managers implicitly weigh when making decisions, including competing management objectives, uncertainty in potential outcomes and risk tolerance
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