5,644 research outputs found

    The Effects of a Carbohydrate Hydrogel System for the Delivery of Bicarbonate Mini-Tablets on Acid–Base Buffering and Gastrointestinal Symptoms in Resting Well-trained Male Cyclists

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    Background: A new commercially available sodium bicarbonate (SB) supplement claims to limit gastrointestinal (GI) discomfort and increase extracellular buffering capacity. To date, no available data exists to substantiate such claims. Therefore, the aim of this study was to measure blood acid–base balance and GI discomfort responses following the ingestion of SB using the novel “Bicarb System” (M-SB). Twelve well-trained male cyclists completed this randomised crossover designed study. Maximal oxygen consumption was determined in visit one, whilst during visits two and three participants ingested 0.3 g∙kg−1 BM SB using M-SB (Maurten, Sweden) or vegetarian capsules (C-SB) in a randomised order. Finger prick capillary blood samples were measured every 30 min for pH, bicarbonate (HCO3−), and electrolytes (potassium, chloride, calcium, and sodium), for 300 min. Visual analogue scales (VAS) were used to assess GI symptoms using the same time intervals. Results: Peak HCO3− was 0.95 mmol∙L−1 greater following M-SB (p = 0.023, g = 0.61), with time to peak HCO3− achieved 38.2 min earlier (117 ± 37 vs. 156 ± 36 min; p = 0.026, r = 0.67) and remained elevated for longer (p = 0.043, g = 0.51). No differences were observed for any electrolytes between the conditions. Aggregated GI discomfort was reduced by 79 AU following M-SB (p < 0.001, g = 1.11), with M-SB reducing stomach cramps, bowel urgency, diarrhoea, belching, and stomach-ache compared to C-SB. Conclusions: This is the first study to report that M-SB can increase buffering capacity and reduce GI discomfort. This presents a major potential benefit for athletes considering SB as an ergogenic supplement as GI discomfort is almost eliminated. Future research should determine if M-SB is performance enhancing

    Real structured singular value synthesis using the scaled Popov criterion

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77238/1/AIAA-21537-608.pd

    Time-lapse 3-D measurements of a glucose biosensor in multicellular spheroids by light sheet fluorescence microscopy in commercial 96-well plates

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    Light sheet fluorescence microscopy has previously been demonstrated on a commercially available inverted fluorescence microscope frame using the method of oblique plane microscopy (OPM). In this paper, OPM is adapted to allow time-lapse 3-D imaging of 3-D biological cultures in commercially available glass-bottomed 96-well plates using a stage-scanning OPM approach (ssOPM). Time-lapse 3-D imaging of multicellular spheroids expressing a glucose Förster resonance energy transfer (FRET) biosensor is demonstrated in 16 fields of view with image acquisition at 10 minute intervals. As a proof-of-principle, the ssOPM system is also used to acquire a dose response curve with the concentration of glucose in the culture medium being varied across 42 wells of a 96-well plate with the whole acquisition taking 9 min. The 3-D image data enable the FRET ratio to be measured as a function of distance from the surface of the spheroid. Overall, the results demonstrate the capability of the OPM system to measure spatio-temporal changes in FRET ratio in 3-D in multicellular spheroids over time in a multi-well plate format

    Electronic structure of NiS1x_{1-x}Sex_x across the phase transition

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    We report very highly resolved photoemission spectra of NiS(1-x)Se(x) across the so-called metal-insulator transition as a function of temperature as well as composition. The present results convincingly demonstrate that the low temperature, antiferromagnetic phase is metallic, with a reduced density of states at EF_F. This decrease is possibly due to the opening of gaps along specific directions in the Brillouin zone caused by the antiferromagnetic ordering.Comment: Revtex, 4 pages, 3 postscript figure

    Low spin wave damping in the insulating chiral magnet Cu2_{2}OSeO3_{3}

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    Chiral magnets with topologically nontrivial spin order such as Skyrmions have generated enormous interest in both fundamental and applied sciences. We report broadband microwave spectroscopy performed on the insulating chiral ferrimagnet Cu2_{2}OSeO3_{3}. For the damping of magnetization dynamics we find a remarkably small Gilbert damping parameter of about 1×1041\times10^{-4} at 5 K. This value is only a factor of 4 larger than the one reported for the best insulating ferrimagnet yttrium iron garnet. We detect a series of sharp resonances and attribute them to confined spin waves in the mm-sized samples. Considering the small damping, insulating chiral magnets turn out to be promising candidates when exploring non-collinear spin structures for high frequency applications.Comment: 5 pages, 5 figures, and supplementary materia

    Development of toxicity indices for assessing the quality of the Illinois River

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    Individual toxicant concentrations in the Illinois River were expressed as fractions of their 96-hr LC50 values to bluegills, yielding their component toxicities in bluegill toxic units (BGTU’s). A solution having a toxicity of 1.0 BGTU was defined as being lethal to 50 percent of the bluegills exposed to it for 96 hr. River toxicants included aldrin, undissociated ammonia (ammonia₍ᵤ₎), arsenic, cadmium, hexavalent and trivalent chromium, copper, cyanide, fluoride, linear alkylate sulfonate (LAS), lead, mercury, phenols, and zinc. Component toxicities at different locations on the river were summed to produce the toxicity index, or total toxicity, of the river. Preliminary mean toxicity indices developed from previously published data during 1972 and 1973 ranged from 0.045 to 0.168 BGTU's, on the Illinois and Des Plaines rivers. However, maximum component toxicities of ammonia₍ᵤ₎ and cyanide during this period reached 0.630 and 0.467 BGTU's, respectively. LAS, copper, fluoride, and zinc also contributed to the preliminary river toxicity indices. Mean toxicity indices developed during field tests, in which bluegills were exposed directly to river water, and the lack of mortality at these tests, indicated that the Illinois River is not normally acutely toxic to fish. The 96-hr LC50 values of ammonia₍ᵤ₎ and LAS to bluegills were found to be 1.65 and 6.5 mg/liter, respectively, using continuous-flow bioassays with dilution water similar in hardness, alkalinity and pH to Illinois River water.U.S. Department of the InteriorU.S. Geological SurveyOpe

    WFPC2 LRF Imaging of Emission Line Nebulae in 3CR Radio Galaxies

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    We present HST/WFPC2 Linear Ramp Filter images of high surface brightness emission lines (either [OII], [OIII], or H-alpha+[NII]) in 80 3CR radio sources. We overlay the emission line images on high resolution VLA radio images (eight of which are new reductions of archival data) in order to examine the spatial relationship between the optical and radio emission. We confirm that the radio and optical emission line structures are consistent with weak alignment at low redshift (z < 0.6) except in the Compact Steep Spectrum (CSS) radio galaxies where both the radio source and the emission line nebulae are on galactic scales and strong alignment is seen at all redshifts. There are weak trends for the aligned emission line nebulae to be more luminous, and for the emission line nebula size to increase with redshift and/or radio power. The combination of these results suggests that there is a limited but real capacity for the radio source to influence the properties of the emission line nebulae at these low redshifts (z < 0.6). Our results are consistent with previous suggestions that both mechanical and radiant energy are responsible for generating alignment between the radio source and emission line gas.Comment: 80 pages, 54 figures. Accepted for publication in ApJ

    Stability of Bose Einstein condensates of hot magnons in YIG

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    We investigate the stability of the recently discovered room temperature Bose-Einstein condensate (BEC) of magnons in Ytrrium Iron Garnet (YIG) films. We show that magnon-magnon interactions depend strongly on the external field orientation, and that the BEC in current experiments is actually metastable - it only survives because of finite size effects, and because the BEC density is very low. On the other hand a strong field applied perpendicular to the sample plane leads to a repulsive magnon-magnon interaction; we predict that a high-density magnon BEC can then be formed in this perpendicular field geometry.Comment: Submitted to Physical Review Letter
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