957 research outputs found
Ionizing irradiation causes rapid activation of the human intermediate K channel in A549 cells: link to cell migration and proliferation
Magnetically Controlled Exchange Process in an Ultracold Atom-Dimer Mixture
We report on the observation of an elementary exchange process in an
optically trapped ultracold sample of atoms and Feshbach molecules. We can
magnetically control the energetic nature of the process and tune it from
endoergic to exoergic, enabling the observation of a pronounced threshold
behavior. In contrast to relaxation to more deeply bound molecular states, the
exchange process does not lead to trap loss. We find excellent agreement
between our experimental observations and calculations based on the solutions
of three-body Schr\"odinger equation in the adiabatic hyperspherical
representation. The high efficiency of the exchange process is explained by the
halo character of both the initial and final molecular states.Comment: 4 pages, 4 figure
Feshbach spectroscopy and analysis of the interaction potentials of ultracold sodium
We have studied magnetic Feshbach resonances in an ultracold sample of Na
prepared in the absolute hyperfine ground state. We report on the observation
of three s-, eight d-, and three g-wave Feshbach resonances, including a more
precise determination of two known s-wave resonances, and one s-wave resonance
at a magnetic field exceeding 200mT. Using a coupled-channels calculation we
have improved the sodium ground-state potentials by taking into account these
new experimental data, and derived values for the scattering lengths. In
addition, a description of the molecular states leading to the Feshbach
resonances in terms of the asymptotic-bound-state model is presented.Comment: 11 pages, 4 figure
Use and perceived added value of patient-reported measurement instruments by physiotherapists treating acute low back pain:a survey study among Dutch physiotherapists
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59 Recommended doses of ceftazidime (CAZ) are insufficient to treat less susceptible pathogens in cystic fibrosis (CF) patients
Intestinal epithelial cells: at the interface of the microbiota and mucosal immunity.
The intestinal epithelium forms a barrier between the microbiota and the rest of the body. In addition, beyond acting as a physical barrier, the function of intestinal epithelial cells (IECs) in sensing and responding to microbial signals is increasingly appreciated and likely has numerous implications for the vast network of immune cells within and below the intestinal epithelium. IECs also respond to factors produced by immune cells, and these can regulate IEC barrier function, proliferation and differentiation, as well as influence the composition of the microbiota. The mechanisms involved in IEC-microbe-immune interactions, however, are not fully characterized. In this review, we explore the ability of IECs to direct intestinal homeostasis by orchestrating communication between intestinal microbes and mucosal innate and adaptive immune cells during physiological and inflammatory conditions. We focus primarily on the most recent findings and call attention to the numerous remaining unknowns regarding the complex crosstalk between IECs, the microbiota and intestinal immune cells
Structural phase transitions in multipole traps
A small number of laser-cooled ions trapped in a linear radiofrequency
multipole trap forms a hollow tube structure. We have studied, by means of
molecular dynamics simulations, the structural transition from a double ring to
a single ring of ions. We show that the single-ring configuration has the
advantage to inhibit the thermal transfer from the rf-excited radial components
of the motion to the axial component, allowing to reach the Doppler limit
temperature along the direction of the trap axis. Once cooled in this
particular configuration, the ions experience an angular dependency of the
confinement if the local adiabaticity parameter exceeds the empirical limit.
Bunching of the ion structures can then be observed and an analytic expression
is proposed to take into account for this behaviour
Daylight: What Makes a Difference
Light is necessary for vision; it enables us to sense and perceive our surroundings and in many direct and indirect ways, via eye and skin, affects our physiological and psychological health. The use of light in built environments has comfort, behavioural, economic and environmental consequences. Daylight has many particular benefits including excellent visual performance, permitting good eyesight, effective entrainment of the circadian system as well as a number of acute non-image forming effects and the important role of vitamin D production. Some human responses to daylight seem to be well defined whilst others require more research to be adequately understood. This paper presents an overview of current knowledge on how the characteristics of daylight play a role in fulfilling these and other functions often better than electric lighting as conventionally delivered
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