Little has been published on the contribution of food moisture (FM) to total water intake (TWI); therefore, the European Food Safety Authority assumed FM to contribute 20%-30% to TWI. The aim of the ...present analysis was to estimate and compare TWI, the percentage of water from FM and from fluids in population samples of France and UK. Data from 2 national nutrition surveys (Enquête Comportements et Consommations Alimentaires en France (CCAF) 2013 and the National Diet and Nutrition Survey (NDNS) 2008/2009-2011/2012) were analyzed for TWI and the contribution of water from FM and fluids. Children and adults TWI were significantly lower in France than in the UK. The contribution of water from foods was lower in the UK than in France (27% vs. 36%). As TWI increased, the proportion of water from fluids increased, suggesting that low drinkers did not compensate by increasing intake of water-rich foods. In addition, 80%-90% of the variance in TWI was explained by differences in water intake from fluids. More data on the contribution of FM to TWI is needed to develop more robust dietary recommendations on TWI and guidance on fluid intake for the general public.
We study the Fano-Kondo effect in a closed Aharonov-Bohm (AB) interferometer which contains a single-level quantum dot and predict a frequency doubling of the AB oscillations as a signature of ...Kondo-correlated states. Using the Keldysh formalism, the Friedel sum rule, and the numerical renormalization group, we calculate the exact zero-temperature linear conductance G as a function of the AB phase phi and level position epsilon. In the unitary limit, G(phi) reaches its maximum 2e(2)/h at phi = pi/2. We find a Fano-suppressed Kondo plateau for G(epsilon) similar to recent experiments.
Dietary intake of sodium, potassium, calcium and magnesium has a strong impact on personal health. In order to understand possible correlations with regional occurrence of diseases and to develop new ...dietary strategies, it is necessary to evaluate food choices in defined geographic areas. The aim of this study was to analyze daily consumption and major food sources of electrolytes with an emphasis on dietary patterns. In this representative, cross-sectional study, daily foods of 463 adults were assessed with two nonconsecutive 24-h recalls. Our results show high sodium and low potassium consumption in all age groups in both men and women. Furthermore, more than half of investigated persons had low calcium, and 40% indicated low dietary magnesium intake. Only 1% of our study population reached the recommended values for all electrolytes, while 13% consumed adequate levels of three electrolytes. Moreover, 14% did not reach reference levels for any of the four minerals. A further comparison of dietary patterns and food preferences showed significant differences in major food groups including nonalcoholic drinks, fruits, vegetables, legumes, milk products, vegetable oil, bread and sweets. Our results are important for further evaluations of nutrition intake and the development of new dietary strategies.
The rate of gut inflammatory diseases is growing in modern society. Previously, we showed that caloric restriction (CR) shapes gut microbiota composition and diminishes the expression of inflammatory ...factors along the gastrointestinal (GI) tract. The current project aimed to assess whether prominent dietary restrictive approaches, including intermittent fasting (IF), fasting-mimicking diet (FMD), and ketogenic diet (KD) have a similar effect as CR. We sought to verify which of the restrictive dietary approaches is the most potent and if the molecular pathways responsible for the impact of the diets overlap. We characterized the impact of the diets in the context of several dietary restriction-related parameters, including immune status in the GI tract; microbiota and its metabolites; bile acids (BAs); gut morphology; as well as autophagy-, mitochondria-, and energy restriction-related parameters. The effects of the various diets are very similar, particularly between CR, IF, and FMD. The occurrence of a 50 kDa truncated form of occludin, the composition of the microbiota, and BAs distinguished KD from the other diets. Based on the results, we were able to provide a comprehensive picture of the impact of restrictive diets on the gut, indicating that restrictive protocols aimed at improving gut health may be interchangeable.
We analyze spin-dependent transport through spin valves composed of an interacting quantum dot coupled to two ferromagnetic leads. The spin on the quantum dot and the linear conductance as a function ...of the relative angle theta of the leads' magnetization directions is derived to lowest order in the dot-lead coupling strength. Because of the applied bias voltage spin accumulates on the quantum dot, which for finite charging energy experiences a torque, resulting in spin precession. The latter leads to a nontrivial, interaction-dependent, theta dependence of the conductance. In particular, we find that the spin-valve effect is reduced for all theta not equal pi.
Multilevel coherences in quantum dots Maurer, Martin T.; König, Jürgen; Schoeller, Herbert
Physical review research,
09/2020, Letnik:
2, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We study transport through strongly interacting quantum dots with N energy levels that are weakly coupled to generic multichannel metallic leads. In the regime of coherent sequential tunneling, where ...level spacing and broadening are of the same order but small compared to temperature, we present a unified SU(N)-invariant form of the kinetic equation for the reduced density matrix of the dot and the tunneling current. This is achieved by introducing the concept of flavor polarization for the dot and the reservoirs and splitting the kinetic equation in terms of flavor accumulation, anisotropic flavor relaxation, and exchange-field- and detuning-induced flavor rotation. In particular, we identify the exchange field as the cause of negative differential conductance at off-resonance bias voltages appearing in generic quantum-dot models. To illustrate the notion of flavor polarization, we analyze the nonlinear current through a triple-quantum-dot device.
The use of single electron spins in quantum dots as qubits requires detailed knowledge about the processes involved in their initialization and operation as well as their relaxation and decoherence. ...In optical schemes for such spin qubits, spin-flip Raman as well as Auger processes play an important role, in addition to environment-induced spin relaxation. In this paper, we demonstrate how to quantitatively access all the spin-related processes in one go by monitoring the charge fluctuations of the quantum dot. For this, we employ resonance fluorescence and analyze the charge fluctuations in terms of waiting-time distributions and full counting statistics characterized by factorial cumulants.
Spin pumping through quantum dots Rojek, Stephan; Governale, Michele; König, Jürgen
Physica Status Solidi B-basic Solid State Physics,
September 2014, Letnik:
251, Številka:
9
Journal Article
Recenzirano
Odprti dostop
We propose schemes for generating spin currents into a semiconductor by adiabatic or non‐adiabatic pumping of electrons through interacting quantum dots. The appeal of such schemes lies in the ...possibility to tune the pumping characteristics via gate voltages that control the properties of the quantum dot. The calculations are based on a systematic perturbation expansion in the tunnel‐coupling strength and the pumping frequency, expressed within a diagrammatic real‐time technique. Special focus is put on the possibility of pure spin pumping, i.e., of pumping spin currents without charge currents.
Setup of a device for generating a spin current into a semiconductor by adiabatic or non‐adiabatic pumping of electrons through an interacting quantum dot.
A substantial aspect of semiconductor spintronics is the generation of spin currents. This goal may be achieved by schemes that rely on pumping of electrons through interacting quantum dots. Their appeal lies in the tunability of the pumping characteristics via gate voltages. Rojek et al. put special focus on the possibility of pure spin pumping in the absence of charge pumping.
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