121 research outputs found
Diffuse reflection of a Bose-Einstein condensate from a rough evanescent wave mirror
We present experimental results showing the diffuse reflection of a
Bose-Einstein condensate from a rough mirror, consisting of a dielectric
substrate supporting a blue-detuned evanescent wave. The scattering is
anisotropic, more pronounced in the direction of the surface propagation of the
evanescent wave. These results agree very well with theoretical predictions.Comment: submitted to J Phys B, 10 pages, 6 figure
Inhibition of electromagnetically induced absorption due to excited state decoherence in Rb vapor
The explanation presented in [Taichenachev et al, Phys. Rev. A {\bf 61},
011802 (2000)] according to which the electromagnetically induced absorption
(EIA) resonances observed in degenerate two level systems are due to coherence
transfer from the excited to the ground state is experimentally tested in a
Hanle type experiment observing the parametric resonance on the line of
Rb. While EIA occurs in the transition in a cell
containing only vapor, collisions with a buffer gas ( of )
cause the sign reversal of this resonance as a consequence of collisional
decoherence of the excited state. A theoretical model in good qualitative
agreement with the experimental results is presented.Comment: 8 pages, 7 figures, submitted to Physical Review
Bosons in cigar-shape traps: Thomas-Fermi regime, Tonks-Girardeau regime, and between
We present a quantitative analysis of the experimental accessibility of the
Tonks-Girardeau gas in the current day experiments with cigar-trapped alkalis.
For this purpose we derive, using a Bethe anzats generated local equation of
state, a set of hydrostatic equations describing one-dimensional
delta-interacting Bose gases trapped in a harmonic potential. The resulting
solutions cover the_entire range_ of atomic densities.Comment: 4 pages, 4 figure
Guiding Neutral Atoms
We demonstrate the guiding of neutral atoms by the magnetic fields due to
microfabricated current-carrying wires on a chip. Atoms are guided along a
magnetic field minimum parallel to and above the current-carrying wires. Two
waveguide configurations are demonstrated: one using two wires with an external
magnetic field, and a second using four wires without an external field. These
waveguide geometries can be extended to integrated atom optics circuits,
including beamsplitters.Comment: 11 pages, 4 figure
Monocyte-driven atypical cytokine storm and aberrant neutrophil activation as key mediators of COVID-19 disease severity.
Epidemiological and clinical reports indicate that SARS-CoV-2 virulence hinges upon the triggering of an aberrant host immune response, more so than on direct virus-induced cellular damage. To elucidate the immunopathology underlying COVID-19 severity, we perform cytokine and multiplex immune profiling in COVID-19 patients. We show that hypercytokinemia in COVID-19 differs from the interferon-gamma-driven cytokine storm in macrophage activation syndrome, and is more pronounced in critical versus mild-moderate COVID-19. Systems modelling of cytokine levels paired with deep-immune profiling shows that classical monocytes drive this hyper-inflammatory phenotype and that a reduction in T-lymphocytes correlates with disease severity, with CD8+ cells being disproportionately affected. Antigen presenting machinery expression is also reduced in critical disease. Furthermore, we report that neutrophils contribute to disease severity and local tissue damage by amplification of hypercytokinemia and the formation of neutrophil extracellular traps. Together our findings suggest a myeloid-driven immunopathology, in which hyperactivated neutrophils and an ineffective adaptive immune system act as mediators of COVID-19 disease severity
sox9b Is a Key Regulator of Pancreaticobiliary Ductal System Development
The pancreaticobiliary ductal system connects the liver and pancreas to the intestine. It is composed of the hepatopancreatic ductal (HPD) system as well as the intrahepatic biliary ducts and the intrapancreatic ducts. Despite its physiological importance, the development of the pancreaticobiliary ductal system remains poorly understood. The SRY-related transcription factor SOX9 is expressed in the mammalian pancreaticobiliary ductal system, but the perinatal lethality of Sox9 heterozygous mice makes loss-of-function analyses challenging. We turned to the zebrafish to assess the role of SOX9 in pancreaticobiliary ductal system development. We first show that zebrafish sox9b recapitulates the expression pattern of mouse Sox9 in the pancreaticobiliary ductal system and use a nonsense allele of sox9b, sox9bfh313, to dissect its function in the morphogenesis of this structure. Strikingly, sox9bfh313 homozygous mutants survive to adulthood and exhibit cholestasis associated with hepatic and pancreatic duct proliferation, cyst formation, and fibrosis. Analysis of sox9bfh313 mutant embryos and larvae reveals that the HPD cells appear to mis-differentiate towards hepatic and/or pancreatic fates, resulting in a dysmorphic structure. The intrahepatic biliary cells are specified but fail to assemble into a functional network. Similarly, intrapancreatic duct formation is severely impaired in sox9bfh313 mutants, while the embryonic endocrine and acinar compartments appear unaffected. The defects in the intrahepatic and intrapancreatic ducts of sox9bfh313 mutants worsen during larval and juvenile stages, prompting the adult phenotype. We further show that Sox9b interacts with Notch signaling to regulate intrahepatic biliary network formation: sox9b expression is positively regulated by Notch signaling, while Sox9b function is required to maintain Notch signaling in the intrahepatic biliary cells. Together, these data reveal key roles for SOX9 in the morphogenesis of the pancreaticobiliary ductal system, and they cast human Sox9 as a candidate gene for pancreaticobiliary duct malformation-related pathologies
Broadband telecom to mid-infrared supercontinuum generation in a dispersion-engineered silicon germanium waveguide
We demonstrate broadband supercontinuum generation (SCG) in a dispersion-engineered silicon-germanium waveguide. The 3 cm long waveguide is pumped by femtosecond pulses at 2.4 μm, and the generated supercontinuum extends from 1.45 to 2.79 μm (at the −30 dB point). The broadening is mainly driven by the generation of a dispersive wave in the 1.5–1.8 μm region and soliton fission. The SCG was modeled numerically, and excellent agreement with the experimental results was obtained
Clinical significance in the number of involved lymph nodes in patients that underwent surgery for pathological stage III-N2 non-small cell lung cancer
<p>Abstract</p> <p>Purpose</p> <p>This study investigated whether the number of involved lymph nodes is associated with the prognosis in patients that underwent surgery for pathological stage (p-stage) III/N2 NSCLC.</p> <p>Subjects</p> <p>This study evaluated 121 patients with p-stage III/N2 NSCLC.</p> <p>Results</p> <p>The histological types included 65 adenocarcinomas, 39 squamous cell carcinomas and 17 others. The average number of dissected lymph nodes was 23.8 (range: 6-55). The average number of involved lymph nodes was 5.9 (range: 1-23). The 5-year survival rate of the patients was 51.0% for single lymph node positive, 58.9% for 2 lymph nodes positive, 34.2% for 3 lymph nodes positive, and 30.0% for 4 lymph nodes positive, and 20.4% for more than 5 lymph nodes positive. The patients with either single or 2 lymph nodes positive had a significantly more favorable prognosis than the patients with more than 5 lymph nodes positive. A multivariate analysis revealed that the number of involved lymph nodes was a significant independent prognostic factor.</p> <p>Conclusion</p> <p>Surgery appears to be preferable as a one arm of multimodality therapy in p-stage III/N2 patients with single or 2 involved lymph nodes. The optimal incorporation of surgery into the multimodality approach therefore requires further clinical investigation.</p
Bronchiectasis and asthma: Data from the European Bronchiectasis Registry (EMBARC)
\ua9 2024 The AuthorsBackground: Asthma is commonly reported in patients with a diagnosis of bronchiectasis. Objective: The aim of this study was to evaluate whether patients with bronchiectasis and asthma (BE+A) had a different clinical phenotype and different outcomes compared with patients with bronchiectasis without concomitant asthma. Methods: A prospective observational pan-European registry (European Multicentre Bronchiectasis Audit and Research Collaboration) enrolled patients across 28 countries. Adult patients with computed tomography–confirmed bronchiectasis were reviewed at baseline and annual follow-up visits using an electronic case report form. Asthma was diagnosed by the local investigator. Follow-up data were used to explore differences in exacerbation frequency between groups using a negative binomial regression model. Survival analysis used Cox proportional hazards regression. Results: Of 16,963 patients with bronchiectasis included for analysis, 5,267 (31.0%) had investigator-reported asthma. Patients with BE+A were younger, were more likely to be female and never smokers, and had a higher body mass index than patients with bronchiectasis without asthma. BE+A was associated with a higher prevalence of rhinosinusitis and nasal polyps as well as eosinophilia and Aspergillus sensitization. BE+A had similar microbiology but significantly lower severity of disease using the bronchiectasis severity index. Patients with BE+A were at increased risk of exacerbation after adjustment for disease severity and multiple confounders. Inhaled corticosteroid (ICS) use was associated with reduced mortality in patients with BE+A (adjusted hazard ratio 0.78, 95% CI 0.63-0.95) and reduced risk of hospitalization (rate ratio 0.67, 95% CI 0.67-0.86) compared with control subjects without asthma and not receiving ICSs. Conclusions: BE+A was common and was associated with an increased risk of exacerbations and improved outcomes with ICS use. Unexpectedly we identified significantly lower mortality in patients with BE+A
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