2,074 research outputs found

    Physiological and psychological effects of acute intentional hyperventilation

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    Research is reviewed which suggests that hyperventilation syndrome is an underdiagnosed disorder for the presentation of many patients experiencing apparent anxiety states. In a test of this hypothesis, 21 normal individuals (9 female) underwent a 2 min period of intentional hyperventilation following a 10 min baseline phase. Hyperventilation was accompanied by increased subjective anxiety and tachycardia, and indications of peripheral vasoconstriction. Following hyperventilation, Ss experienced increased levels of state anxiety and perceived autonomic arousal, as indexed by self-report instruments. These results support the hypothesis that undiagnosed hyperventilatory phenomena may be etiologically implicated in states of pathologic anxiety.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25018/1/0000445.pd

    Supercritical extraction as an effective first-step in a maize stover biorefinery

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    Supercritical carbon dioxide (scCO2) has been investigated for the generation of valuable waxy compounds and as an added-value technology in a holistic maize stover biorefinery. ScCO2 extraction and fractionation was carried out prior to hydrolysis and fermentation of maize stover. Fractionation of the crude extracts by scCO2 resulted in wax extracts having different compositions and melting temperatures, enabling their utilisation in different applications. One such fraction demonstrated significant potential as a renewable defoaming agent in washing machine detergent formulations. Furthermore, scCO2 extraction has been shown to have a positive effect on the downstream processing of the maize stover. Fermentation of the scCO2 extracted maize stover hydrolysates exhibited a higher glucose consumption and greater potential growth for surfactant (in comparison with non-scCO2 treated stover) and ethanol production (a 40% increase in overall ethanol production after scCO2 pre-treatment). This work represents an important development in the extraction of high value components from low value wastes and demonstrates the benefits of using scCO2 extraction as a first-step in biomass processing, including enhancing downstream processing of the biomass for the production of 2nd generation biofuels as part of an integrated holistic biorefinery

    Alcoholic fermentation of thermochemical and biological hydrolysates derived from Miscanthus biomass by Clostridium acetobutylicum ATCC 824

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    © 2019 This laboratory scale study aims to demonstrate the effectiveness of thermochemical and biological saccharification of Miscanthus giganteus (MG) for generation of fermentable saccharides and its subsequent fermentation into solvents i.e. acetone, ethanol and butanol (ABE) using Clostridium acetobutylicum ATCC 824. Saccharide hydrolysates were derived from MG by thermochemical (water, acid and alkali at 130 °C) and biological saccharification (Fibrobacter succinogenes S85) processes and were subjected to batch fermentation for 120 h using C. acetobutylicum ATCC 824. At the end of fermentation of thermochemically-derived hydrolysates, 742 g m−3 of saccharides from water treatment, 9572 g m−3 of saccharides from acid treatment and 4054 g m−3 of saccharides from alkali treatment were fermented and yielded 0.045, 0.0069 and 0.01 g g−1 of total solvents, respectively. Similarly, at the end of fermentation of biological hydrolysate (using F. succinogenes), 2504 g m−3 of saccharides was fermented and yielded 0.091 g g−1 of total solvents. The highest yield of total solvents was achieved by water (thermochemical) and biological saccharification of MG using C. acetobutylicum. Whereas, acid and alkali-treated hydrolysates showed lower yields of solvents presumably due to production of inhibitory compounds during saccharification. Compared to thermochemical saccharification, biological saccharification using F. succinogenes is a promising approach since it yielded the highest amount of solvents whilst being eco-friendly. Our future studies will focus on optimisation of biological saccharification (using F. succinogenes) and sequential co-culture fermentation (using C. acetobutylicum). The development of alternative consolidated bioprocessing approach using biological saccharification will contribute towards making lignocellulosic biofuels a reality

    Bacterial Pneumonias during an Influenza Pandemic: How Will We Allocate Antibiotics?

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    We are currently in the midst of the 2009 H1N1 pandemic, and a second wave of flu in the fall and winter could lead to more hospitalizations for pneumonia. Recent pathologic and historic data from the 1918 influenza pandemic confirms that many, if not most, of the deaths in that pandemic were a result of secondary bacterial pneumonias. This means that a second wave of 2009 H1N1 pandemic influenza could result in a widespread shortage of antibiotics, making these medications a scarce resource. Recently, our University of Michigan Health System (UMHS) Scarce Resource Allocation Committee (SRAC) added antibiotics to a list of resources (including ventilators, antivirals, vaccines) that might become scarce during an influenza pandemic. In this article, we summarize the data on bacterial pneumonias during the 1918 influenza pandemic, discuss the possible impact of a pandemic on the University of Michigan Health System, and summarize our committee's guiding principles for allocating antibiotics during a pandemic.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78141/1/bsp.2009.0019.pd

    KELT-11b: A Highly Inflated Sub-Saturn Exoplanet Transiting the V=8 Subgiant HD 93396

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    We report the discovery of a transiting exoplanet, KELT-11b, orbiting the bright (V=8.0V=8.0) subgiant HD 93396. A global analysis of the system shows that the host star is an evolved subgiant star with Teff=5370±51T_{\rm eff} = 5370\pm51 K, M∗=1.438−0.052+0.061M⊙M_{*} = 1.438_{-0.052}^{+0.061} M_{\odot}, R∗=2.72−0.17+0.21R⊙R_{*} = 2.72_{-0.17}^{+0.21} R_{\odot}, log g∗=3.727−0.046+0.040g_*= 3.727_{-0.046}^{+0.040}, and [Fe/H]=0.180±0.075 = 0.180\pm0.075. The planet is a low-mass gas giant in a P=4.736529±0.00006P = 4.736529\pm0.00006 day orbit, with MP=0.195±0.018MJM_{P} = 0.195\pm0.018 M_J, RP=1.37−0.12+0.15RJR_{P}= 1.37_{-0.12}^{+0.15} R_J, ρP=0.093−0.024+0.028\rho_{P} = 0.093_{-0.024}^{+0.028} g cm−3^{-3}, surface gravity log gP=2.407−0.086+0.080{g_{P}} = 2.407_{-0.086}^{+0.080}, and equilibrium temperature Teq=1712−46+51T_{eq} = 1712_{-46}^{+51} K. KELT-11 is the brightest known transiting exoplanet host in the southern hemisphere by more than a magnitude, and is the 6th brightest transit host to date. The planet is one of the most inflated planets known, with an exceptionally large atmospheric scale height (2763 km), and an associated size of the expected atmospheric transmission signal of 5.6%. These attributes make the KELT-11 system a valuable target for follow-up and atmospheric characterization, and it promises to become one of the benchmark systems for the study of inflated exoplanets.Comment: 15 pages, Submitted to AAS Journal

    Patient acceptance of universal screening for hepatitis C virus infection

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    <p>Abstract</p> <p>Background</p> <p>In the United States, about 70% of 2.9-3.7 million people with hepatitis C (HCV) are unaware of their infection. Although universal screening might be a cost-effective way to identify infections, prevent morbidity, and reduce transmission, few efforts have been made to determine patient opinions about new approaches to screening.</p> <p>Methods</p> <p>We surveyed 200 patients in August 2010 at five outpatient clinics of a major public urban medical center in Seattle, WA, with an 85.8% response rate.</p> <p>Results</p> <p>The sample was 55.3% women, median 47 years of age, and 56.3% white and 32.7% African or African-American; 9.5% and 2.5% reported testing positive for HCV and HIV, respectively. The vast majority of patients supported universal screening for HCV. When presented with three options for screening, 48% preferred universal testing without being informed that they were being tested or provided with negative results, 37% preferred testing with the chance to "opt-out" of being tested and without being provided with negative results, and 15% preferred testing based on clinician judgment. Results were similar for HIV screening.</p> <p>Conclusions</p> <p>Patients support universal screening for HCV, even if that screening involves testing without prior consent or the routine provision of negative test results. Current screening guidelines and procedures should be reconsidered in light of patient priorities.</p
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