542 research outputs found
An alternative search for the electron capture of Te-123
A search for the electron capture of Te-123 has been performed using CdZnTe
detectors. After a measuring time of 195 h no signal could be found resulting
in a lower half-life limt of yrs (95 % CL) for
this process. This clearly discriminates between existing experimental results
which differ by six orders of magnitude and our data are in strong favour of
the result with longer half-lifes.Comment: 2 pages, 2 eps-figures, reanalysis of data set
Dynamics of dispersive single qubit read-out in circuit quantum electrodynamics
The quantum state of a superconducting qubit nonresonantly coupled to a
transmission line resonator can be determined by measuring the quadrature
amplitudes of an electromagnetic field transmitted through the resonator. We
present experiments in which we analyze in detail the dynamics of the
transmitted field as a function of the measurement frequency for both weak
continuous and pulsed measurements. We find excellent agreement between our
data and calculations based on a set of Bloch-type differential equations for
the cavity field derived from the dispersive Jaynes-Cummings Hamiltonian
including dissipation. We show that the measured system response can be used to
construct a measurement operator from which the qubit population can be
inferred accurately. Such a measurement operator can be used in tomographic
methods to reconstruct single and multiqubit states in ensemble-averaged
measurements.Comment: Revised version: corrected typos, 8 pages, 6 figures, version with
high resolution figures available at
http://qudev.ethz.ch/content/science/PubsPapers.htm
Vitamin D status among male late adolescents living in Southern Switzerland: Role of body composition and lifestyle
BACKGROUND: Poor vitamin D status is a worldwide health problem. Yet, knowledge about vitamin D status among adolescents in Southern Europe is limited. This study investigated concentrations and modulating factors of vitamin D in a healthy population of male late adolescents living in Southern Switzerland. METHODS: All apparently healthy subjects attending for the medical evaluation before the compulsory military service in Southern Switzerland during 2014-2016 were eligible. Dark-skin subjects, subjects on vitamin D supplementation or managed with diseases or drugs involved in vitamin D metabolism were excluded. Anthropometric measurements (body height, weight, fat percentage, mid-upper arm and waist circumference) and blood sampling for total 25-hydroxy-vitamin D, total cholesterol and ferritin concentrations testing, were collected. Participants filled in a structured questionnaire addressing their lifestyle. Characteristics of the subjects with adequate ( 6550 nmol/L- 64250 nmol/L) and insufficient (<50 nmol/L) vitamin D values were compared by Kruskal-Wallis test or \u3c72 test. Odds ratios for 25-hydroxy-vitamin D insufficiency were calculated by univariate and AIC-selected multiple logistic regression models. RESULTS: A total of 1045 subjects volunteered to participate in the study. Insufficient concentrations of vitamin D were detected in 184 (17%). The season of measurement was the most significant factor associated with vitamin D levels and approximately 40% of subjects presented insufficient vitamin D concentrations in winter. After model selection, body fat percentage, frequency and site of recreational physical activity, and the seasonality were significantly associated with the risk of vitamin D insufficiency. CONCLUSIONS: Among healthy male late adolescents in Southern Switzerland, about one every fourth subject presents a poor vitamin D status in non-summer seasons. Body fat percentage, frequent and outdoor recreational physical activity are modulating factors of vitamin D status in this population
Does Ionized Magnesium Offer a Different Perspective Exploring the Association between Magnesemia and Targeted Cardiovascular Risk Factors?
Evidence of the association of magnesium (Mg) with arterial stiffness has so far been conflicting. The interplay between hypertension and elevated body mass index (BMI), with hypomagnesemia, instead, has been described in the literature in a more consistent way. Our study aims at revisiting the correlations between blood Mg levels and hemodynamic and body composition parameters in the general population, exploring the sensitivity profile of ionized Mg (Ion-Mg) compared to total Mg (Tot-Mg). We collected data from 755 subjects randomly chosen from a Swiss population previously described and stratified our sample into four equivalent classes according to ionized (whole blood) and total (serum) magnesium. After correcting for age, statistically significant differences emerged between: (i) Tot-Mg ≤ 0.70 and 0.81 ≤ Tot-Mg ≤ 0.90 for cf-PWV (p = 0.039); (ii) Tot-Mg ≤ 0.70 and Tot-Mg ≥ 0.91 for o-PWV (p = 0.046). We also found a statistically significant difference among groups of Ion-Mg values for the 24 h extremes of systolic blood pressure (p = 0.048) and among groups of Tot-Mg for BMI (p = 0.050). Females showed significantly lower levels of total magnesium (p = 0.035) and ionized magnesium (p < 0.001) than males. The overall agreement between magnesium analysis methods was 64% (95%CI: 60.8−67.7%). Our results confirm that Ion-Mg compared with Tot-Mg offers a different profile in detecting both correlations with hemodynamic and body composition parameters and dysmagnesemias. Lower levels of magnesium were associated with worse arterial aging parameters, larger 24 h blood pressure excursions, and higher BMI. Ion-Mg was superior in detecting the correlation with blood pressure only. Considering Ion-Mg as a more specific marker of the magnesium status, and the partially contradictory results of our explorative cross-sectional study, to avoid confounding factors and misinterpretations, ionized magnesium should be used as reference in future studies
Which laboratory technique is used for the blood sodium analysis in clinical research? A systematic review.
Circulating sodium is analyzed by flame spectrometry and indirect or direct potentiometry. The differences between estimates returned by the three techniques are often relevant. It is unknown whether peer-reviewed international publications focusing on this parameter provide information about the technique. Objectives of the study were to ascertain if information about the employed technique is provided.
A search in the National Library of Medicine for articles whose title contains "hyponatr[a]emia" was performed. We restricted the search to clinical reports including 10 or more humans published in the 2013-2015 and 2017-2019 periods. Authors of papers not reporting the technique were contacted to obtain this information. The study design and journal quartile ranking of each article were also evaluated.
For the final analysis, we included 361 articles (2013-2015, n=169; 2017-2019, n=192). Information about the laboratory technique was given in 61(17%) articles. Thanks to our inquiry, we collected this information for 116(32%) further reports. Indirect potentiometry was the most frequently used technique, followed by direct potentiometry. Spectrometry was used in a small minority of studies. Study design, journal ranking and study period did not modulate the mentioned frequency.
Most articles focusing on hyponatremia do not provide information on the laboratory technique. This parameter is nowadays analyzed by indirect or, less frequently, direct potentiometry. The figures are similar for high and low impact factor journals and for the 2013-2015 and the 2017-2019 periods. Many authors, reviewers and editors likely assume that the results of this parameter are not influenced by the technique
Renal vein obstruction and orthostatic proteinuria: a review
Objectives. The cause of orthostatic proteinuria is not clear but may often relate to obstruction of the left renal vein in the fork between the aorta and the superior mesenteric artery (= renal nutcracker). However, reports dealing with proteinuria only marginally refer to this possible cause of orthostatic proteinuria. We analysed the corresponding literature. Results. Five reports addressed the frequency of renal nutcracker in 229 subjects with orthostatic proteinuria. Their age ranged between 5.2 and 17years (female-to-male ratio: 0.96:1.00). Imaging studies demonstrated renal nutcracker in 156 (68%) subjects. Renal nutcracker was also demonstrated in 9 anecdotal reports for a total of 53 subjects with postural proteinuria. Very recently, 13 Italian subjects with orthostatic proteinuria associated with renal nutcracker were reassessed 6years after the initial diagnosis: in nine subjects, both orthostatic proteinuria and renal nutcracker had disappeared; in three, both orthostatic proteinuria and renal nutcracker had persisted; and in one, orthostatic proteinuria had persisted unassociated with renal nutcracker. Conclusions. These data provide substantial support for renal nutcracker as a common cause of orthostatic proteinuri
Genetic variability of a Brazilian Capsicum frutescens germplasm collection using morphological characteristics and SSR markers.
Characterization studies provide essential information for the conservation and use of germplasm in plant breeding programs. In this study, 103 Capsicum frutescens L. accessions from the Active Germplasm Bank of Embrapa Hortaliças, representative of all five Brazilian geographic regions, were characterized based on morphological characteristics and microsatellite (or simple sequence repeat - SSR) molecular markers. Morphological characterization was carried out using 57 descriptors, and molecular characterization was based on 239 alleles from 24 microsatellite loci. From the estimates of genetic distances among accessions, based on molecular characterization, a cluster analysis was carried out, and a dendrogram was established. Correlations between morphological and molecular variables were also estimated. Twelve morphological descriptors were monomorphic for the set of C. frutescens accessions, and those with the highest degree of polymorphism were stem length (14.0 to 62.0 cm), stem diameter (1.0 to 4.2 cm), days to flowering (90 to 129), days to fruiting (100 to 140), fruit weight (0.1 to 1.4 g), fruit length (0.6 to 4.6 cm), and fruit wall thickness (0.25 to 1.5 mm). The polymorphism information content for the SSR loci varied from 0.36 (EPMS 417) to 0.75 (CA49), with an overall mean of 0.57. The correlation value between morphological and molecular characterization data was 0.6604, which was statistically significant. Fourteen accessions were described as belonging to the morphological type tabasco, 85 were described as malagueta, and four were malaguetinha, a morphological type confirmed in this study. The typical morphological pattern of malagueta was described. Six similarity groups were established for C. frutescens based on the dendrogram and are discussed individually. The genetic variability analyzed in the study highlights the importance of characterizing genetic resources available for the development of new C. frutescens cultivars with the potential for various niche markets
Measurements of the Correlation Function of a Microwave Frequency Single Photon Source
At optical frequencies the radiation produced by a source, such as a laser, a
black body or a single photon source, is frequently characterized by analyzing
the temporal correlations of emitted photons using single photon counters. At
microwave frequencies, however, there are no efficient single photon counters
yet. Instead, well developed linear amplifiers allow for efficient measurement
of the amplitude of an electromagnetic field. Here, we demonstrate how the
properties of a microwave single photon source can be characterized using
correlation measurements of the emitted radiation with such detectors. We also
demonstrate the cooling of a thermal field stored in a cavity, an effect which
we detect using a cross-correlation measurement of the radiation emitted at the
two ends of the cavity.Comment: 5 pages, 4 figure
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