Acid Decomposition Of Yerba Mate (ilex Paraguariensis) Using A Reflux System For The Evaluation Of Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb And Zn Contents By Atomic Spectrometric Techniques

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In the first part of this paper, two acid decomposition procedures for the determination of Al, Ca, Fe, Mg, Mn and Zn contents in yerba mate samples by inductively coupled plasma optical emission spectrometry (ICP OES) were compared. Using a reflux system, the samples were treated with a mixture of HNO3 and H2O2 for 3 hours at 220 degrees C in the digester block. The results from five commercial yerba mate samples were compared with the results obtained from microwave digestion. Good agreement between the procedures at a 95% confidence level was obtained with relative standard deviation (RSD) values lower than 10.0%. The accuracy was evaluated using addition and recovery experiments (80.5 to 112.8%). In the second part, Ca, Cd, Cr, Cu, Fe, K, Mg, Na, Pb and Zn concentrations were evaluated in the yerba mate infusion. The results showed that elements such as Na, K, Mg and Zn are easily transferred to the hot water used for the infusion. For Pb and Cd, the concentrations found in the analyzed samples were lower than the values established by Brazilian legislation.274685693Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) [552197/2011-4]Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Acid decomposition of yerba mate (ilex paraguariensis) using a reflux system for the evaluation of Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb and Zn contents by atomic spectrometric techniques

In the first part of this paper, two acid decomposition procedures for the determination of Al, Ca, Fe, Mg, Mn and Zn contents in yerba mate samples by inductively coupled plasma optical emission spectrometry (ICP OES) were compared. Using a reflux system, the samples were treated with a mixture of HNO3 and H2O2 for 3 hours at 220 °C in the digester block. The results from five commercial yerba mate samples were compared with the results obtained from microwave digestion. Good agreement between the procedures at a 95% confidence level was obtained with relative standard deviation (RSD) values lower than 10.0%. The accuracy was evaluated using addition and recovery experiments (80.5 to 112.8%). In the second part, Ca, Cd, Cr, Cu, Fe, K, Mg, Na, Pb and Zn concentrations were evaluated in the yerba mate infusion. The results showed that elements such as Na, K, Mg and Zn are easily transferred to the hot water used for the infusion. For Pb and Cd, the concentrations found in the analyzed samples were lower than the values established by Brazilian legislation274685693CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DO RIO GRANDE DO SUL - FAPERGSSem informação552197/2011-4Sem informaçã

Evaluation of eplerenone in the subgroup of EPHESUS patients with baseline left ventricular ejection fraction ≤30%

Aims: Because of the prognostic importance of LV dysfunction following an AMI and the increasing use of electrical and/or mechanical interventions in patients with LV systolic dysfunction, this retrospective analysis of EPHESUS patients with LVEF ≤30% at baseline was conducted to determine the value of eplerenone in this setting. Methods and Results: In EPHESUS, 6632 patients with LVEF ≤40% and clinical heart failure (HF) post‐AMI who were receiving standard therapy were randomized to eplerenone 25 mg/day titrated to 50 mg/day or placebo for a mean follow‐up of 16 months. Treatment with eplerenone in the subgroup of patients with LVEF ≤30% ( N =2106) resulted in relative risk reductions of 21% versus placebo in both all‐cause mortality ( P =0.012) and cardiovascular (CV) mortality/CV hospitalization ( P =0.001), and 23% for CV mortality ( P =0.008). The relative risk of sudden cardiac death (SCD) was reduced 33% ( P =0.01) and HF mortality/HF hospitalization was reduced 25% ( P =0.005) with eplerenone compared with placebo. Within 30 days of randomization, eplerenone resulted in relative risk reductions of 43% for all‐cause mortality ( P =0.002), 29% for CV mortality/CV hospitalization ( P =0.006), and 58% for SCD ( P =0.008). Conclusions: Treatment with eplerenone plus standard therapy in patients with post‐AMI HF and LVEF ≤30% provided significant incremental benefits in reducing both early and late mortality and morbidity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102725/1/ejhf2005-11-008.pd

Isotropic Spin Wave Theory of Short-Range Magnetic Order

We present an isotropic spin wave (ISW) theory of short-range order in Heisenberg magnets, and apply it to square lattice S=1/2 and S=1 antiferromagnets. Our theory has three identical (isotropic) spin wave modes, whereas the conventional spin wave theory has two transverse and one longitudinal mode. We calculate temperature dependences of various thermodynamic observables analytically and find good (several per cent) agreement with independently obtained numerical results in a broad temperature range.Comment: 4 pages, REVTeX v3 with 3 embedded PostScript figure

Orbital angular momentum-based dual-comb interferometer for ranging and rotation sensing

We present a dual-comb interferometer capable of measuring both the range to a target as well as the target&rsquo;s transverse rotation rate. Measurement of the transverse rotation of the target is achieved by preparing the probe comb with orbital angular momentum and measuring the resultant phase shift between interferograms, which arises from the rotational Doppler shift. The distance to the target is measured simultaneously by measuring the time-of-flight delay between the target and reference interferogram centerbursts. With 40 ms of averaging, we measure rotation rates up to 313 Hz with a precision reaching 1 Hz. Distances are measured with an ambiguity range of 75 cm and with a precision of 5.9 &micro;m for rotating targets and 400 nm for a static target. This is the first dual-comb ranging system capable of measuring transverse rotation of a target. This technique has many potential terrestrial and space-based applications for lidar and remote sensing systems. &nbsp;</p

Anharmonic Decay of Vibrational States in Amorphous Silicon

Anharmonic decay rates are calculated for a realistic atomic model of amorphous silicon. The results show that the vibrational states decay on picosecond timescales and follow the two-mode density of states, similar to crystalline silicon, but somewhat faster. Surprisingly little change occurs for localized states. These results disagree with a recent experiment.Comment: 10 pages, 4 Postscript figure

Linear approaches to intramolecular Förster Resonance Energy Transfer probe measurements for quantitative modeling

Numerous unimolecular, genetically-encoded Forster Resonance Energy Transfer (FRET) probes for monitoring biochemical activities in live cells have been developed over the past decade. As these probes allow for collection of high frequency, spatially resolved data on signaling events in live cells and tissues, they are an attractive technology for obtaining data to develop quantitative, mathematical models of spatiotemporal signaling dynamics. However, to be useful for such purposes the observed FRET from such probes should be related to a biological quantity of interest through a defined mathematical relationship, which is straightforward when this relationship is linear, and can be difficult otherwise. First, we show that only in rare circumstances is the observed FRET linearly proportional to a biochemical activity. Therefore in most cases FRET measurements should only be compared either to explicitly modeled probes or to concentrations of products of the biochemical activity, but not to activities themselves. Importantly, we find that FRET measured by standard intensity-based, ratiometric methods is inherently non-linear with respect to the fraction of probes undergoing FRET. Alternatively, we find that quantifying FRET either via (1) fluorescence lifetime imaging (FLIM) or (2) ratiometric methods where the donor emission intensity is divided by the directly-excited acceptor emission intensity (denoted R&lt;sub&gt;alt&lt;/sub&gt;) is linear with respect to the fraction of probes undergoing FRET. This linearity property allows one to calculate the fraction of active probes based on the FRET measurement. Thus, our results suggest that either FLIM or ratiometric methods based on R&lt;sub&gt;alt&lt;/sub&gt; are the preferred techniques for obtaining quantitative data from FRET probe experiments for mathematical modeling purpose

Observation of the rotational Doppler shift with spatially incoherent light

The rotational Doppler shift (RDS) is typically measured by illuminating a rotating target with a laser prepared in a simple, known orbital angular momentum (OAM) superposition. We establish theoretically and experimentally that detecting the rotational Doppler shift does not require the incident light to have a well-defined OAM spectrum but instead requires well-defined correlations within the OAM spectrum. We demonstrate measurement of the rotational Doppler shift using spatially incoherent light. &nbsp;</p

High-Redshift Quasars Found in Sloan Digital Sky Survey Commissioning Data II: The Spring Equatorial Stripe

This is the second paper in a series aimed at finding high-redshift quasars from five-color (u'g'r'i'z') imaging data taken along the Celestial Equator by the Sloan Digital Sky Survey (SDSS) during its commissioning phase. In this paper, we present 22 high-redshift quasars (z>3.6) discovered from ~250 deg^2 of data in the spring Equatorial Stripe, plus photometry for two previously known high-redshift quasars in the same region of sky. Our success rate of identifying high-redshift quasars is 68%. Five of the newly discovered quasars have redshifts higher than 4.6 (z=4.62, 4.69, 4.70, 4.92 and 5.03). All the quasars have i* < 20.2 with absolute magnitude -28.8 < M_B < -26.1 (h=0.5, q_0=0.5). Several of the quasars show unusual emission and absorption features in their spectra, including an object at z=4.62 without detectable emission lines, and a Broad Absorption Line (BAL) quasar at z=4.92.Comment: 28 pages, AJ in press (Jan 2000), final version with minor changes; high resolution finding charts available at http://www.astro.princeton.edu/~fan/paper/qso2.htm