Search results for "Lung"
showing 10 items of 2389 documents
Analysis of discrete and continuous distributions of ventilatory time constants from dynamic computed tomography.
2005
In this study, an algorithm was developed to measure the distribution of pulmonary time constants (TCs) from dynamic computed tomography (CT) data sets during a sudden airway pressure step up. Simulations with synthetic data were performed to test the methodology as well as the influence of experimental noise. Furthermore the algorithm was applied to in vivo data. In five pigs sudden changes in airway pressure were imposed during dynamic CT acquisition in healthy lungs and in a saline lavage ARDS model. The fractional gas content in the imaged slice (FGC) was calculated by density measurements for each CT image. Temporal variations of the FGC were analysed assuming a model with a continuous…
Analysis of intrapulmonary O2concentration by MR imaging of inhaled hyperpolarized helium-3
1999
Inhalation of hyperpolarized 3He allows magnetic resonance imaging (MRI) of ventilated airspaces.3He hyperpolarization decays more rapidly when interacting with paramagnetic O2. We describe a method for in vivo determination of intrapulmonary O2 concentrations ([O2]) based on MRI analysis of the fate of measured amounts of inhaled hyperpolarized3He in imaged regions of the lung. Anesthetized pigs underwent controlled normoventilation in a 1.5-T MRI unit. The inspired O2 fraction was varied to achieve different end-tidal [O2] fractions ([Formula: see text]). With the use of a specifically designed applicator,3He (100 ml, 35–45% polarized) was administered at a predefined time within single …
Sympathetic cooling of a trapped proton mediated by an LC circuit
2021
Efficient cooling of trapped charged particles is essential to many fundamental physics experiments1,2, to high-precision metrology3,4 and to quantum technology5,6. Until now, sympathetic cooling has required close-range Coulomb interactions7,8, but there has been a sustained desire to bring laser-cooling techniques to particles in macroscopically separated traps5,9,10, extending quantum control techniques to previously inaccessible particles such as highly charged ions, molecular ions and antimatter. Here we demonstrate sympathetic cooling of a single proton using laser-cooled Be+ ions in spatially separated Penning traps. The traps are connected by a superconducting LC circuit that enable…
Sympathetic cooling of protons and antiprotons with a common endcap Penning trap.
2017
We present an experiment to sympathetically cool protons and antiprotons in a Penning trap by resonantly coupling the particles to laser cooled beryllium ions using a common endcap technique. Our analysis shows that preparation of (anti)protons at mK temperatures on timescales of tens of seconds is feasible. Successful implementation of the technique will have immediate and significant impact on high-precision comparisons of the fundamental properties of protons and antiprotons. This in turn will provide some of the most stringent tests of the fundamental symmetries of the Standard Model.
Evidence for thermal equilibration in multifragmentation reactions probed with bremsstrahlung photons
2001
The production of nuclear bremsstrahlung photons (E$_{\gamma}>$ 30 MeV) has been studied in inclusive and exclusive measurements in four heavy-ion reactions at 60{\it A} MeV. The measured photon spectra, angular distributions and multiplicities indicate that a significant part of the hard-photons are emitted in secondary nucleon-nucleon collisions from a thermally equilibrated system. The observation of the thermal component in multi-fragment $^{36}$Ar+$^{197}$Au reactions suggests that the breakup of the thermalized source produced in this system occurs on a rather long time-scale.
Development of spontaneous airway changes consistent with human asthma in mice lacking T-bet.
2002
Human asthma is associated with airway infiltration by T helper 2 (TH2) lymphocytes. We observed reduced expression of the TH1 transcription factor, T-bet, in T cells from airways of patients with asthma compared with that in T cells from airways of nonasthmatic patients, suggesting that loss of T-bet might be associated with asthma. Mice with a targeted deletion of the T-bet gene and severe combined immunodeficient mice receiving CD4+cells from T-bet knockout mice spontaneously demonstrated multiple physiological and inflammatory features characteristic of asthma. Thus, T-bet deficiency, in the absence of allergen exposure, induces a murine phenotype reminiscent of both acute and chronic h…
Specialized subsets of innate-like T cells and dendritic cells protect from lethal pneumococcal infection in the lung
2021
SummaryInnate-like T cells, including invariant natural killer T (iNKT) cells, mucosal-associated invariant T (MAIT) cells and γδ T cells, are present in various barrier tissues, including the lung. They carry out protective responses during infections, but the mechanisms for protection are not completely understood. Here, we investigated their roles during pulmonary infection with Streptococcus pneumoniae. Following infection, innate-like T cells rapidly increased in lung tissue, in part through recruitment, but TCR activation and cytokine production occurred mostly in IL-17-producing NKT17 and γδ T cells. NKT17 cells were preferentially located outside the vasculature prior to infection, …
Editorial: Activation, functions, and generation of immunological memory in γδ T lymphocytes: lessons from nonhuman primates
2014
T cells constitute an unconventional lymphocyte population with distinct functions complementary to those of CD4 and CD8 T cells. As such, they have both adaptive features, such as expression of the TCR, and innate-like functions reminiscent of NK cells, with whom they share extensive repertoires of activating and inhibitory receptors [1, 2]. Although most antigens recognized by murine T cells remain obscure, advances have been made in identifying ligands for human T cells. The majority of circulating human T lymphocytes expresses a TCR formed by the preferentially-paired V 9 and V 2 chains (here and thereafter, called V 9V 2 T cells). Instead of binding peptides associated with molecules b…
Bruno Taut a Berlino
2003
È un’approfondita esposizione dei temi della ricerca architettonica nei principali quartieri berlinesi del maestro tedesco, letta nei suoi rapporti con la contemporaneità.
2-Hydroxyoleic Acid Induces ER Stress and Autophagy in Various Human Glioma Cell Lines
2012
Background: 2-Hydroxyoleic acid is a synthetic fatty acid with potent anti-cancer activity which does not induce undesired side effects. However, the molecular and cellular mechanisms by which this compound selectively kills human glioma cancer cells without killing normal cells is not fully understood. The present study was designed to determine the molecular bases underlying the potency against 1321N1, SF-767 and U118 human glioma cell lines growth without affecting non cancer MRC-5 cells. Methodology/Principal Findings: The cellular levels of endoplasmic reticulum (ER) stress, unfolded protein response (UPR) and autophagy markers were determined by quantitative RT-PCR and immunoblotting …