An ellipsoidal mirror for focusing neutral atomic and molecular beams

Manipulation of atomic and molecular beams is essential to atom optics applications including atom lasers, atom lithography, atom interferometry and neutral atom microscopy. The manipulation of charge-neutral beams of limited polarizability, spin or excitation states remains problematic, but may be overcome by the development of novel diffractive or reflective optical elements. In this paper, we present the first experimental demonstration of atom focusing using an ellipsoidal mirror. The ellipsoidal mirror enables stigmatic off-axis focusing for the first time and we demonstrate focusing of a beam of neutral, ground-state helium atoms down to an approximately circular spot, (26.8±0.5) μm×(31.4±0.8) μm in size. The spot area is two orders of magnitude smaller than previous reflective focusing of atomic beams and is a critical milestone towards the construction of a high-intensity scanning helium microscope

An ellipsoidal mirror for focusing neutral atomic and molecular beams

Manipulation of atomic and molecular beams is essential to atom optics applications including atom lasers, atom lithography, atom interferometry and neutral atom microscopy. The manipulation of charge-neutral beams of limited polarizability, spin or excitation states remains problematic, but may be overcome by the development of novel diffractive or reflective optical elements. In this paper, we present the first experimental demonstration of atom focusing using an ellipsoidal mirror. The ellipsoidal mirror enables stigmatic off-axis focusing for the first time and we demonstrate focusing of a beam of neutral, ground-state helium atoms down to an approximately circular spot, (26.8±0.5) μm×(31.4±0.8) μm in size. The spot area is two orders of magnitude smaller than previous reflective focusing of atomic beams and is a critical milestone towards the construction of a high-intensity scanning helium microscope

Enzyme immunoassay for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae.

An enzyme immunoassay (EIA) for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae was developed. The EIA was evaluated on the basis of results in the M. pneumoniae complement fixation (MPCF) test and the cold agglutinin test. Serum samples from 430 patients with respiratory infections of known or unknown etiology, from 91 healthy children and adults and from 20 patients with rheumatoid factor, were investigated. By the criteria chosen for positive diagnostic EIA values, we found that the combined measurement of specific IgM and IgG gave a specificity of 99.7% and a sensitivity of 97.8%. If only IgM antibodies were measured, the specificity was 100% and the sensitivity was 88%. For IgG alone the specificity was 99.7%, but the sensitivity was only 46% because of the high EIA cutoff value chosen for IgG. We found no false positives among serum samples from patients with non-M. pneumoniae respiratory infection of known etiology, and there were no false IgM positives due to rheumatoid factor. In some cases the IgM EIA results became positive earlier in the course of illness than the MPCF titer. While children and teenagers responded predominantly with IgM antibodies, patients older than 40 years often had an IgG response only (56% of cases), probably because of reinfection. We conclude that this EIA is a good alternative to the combined MPCF and cold agglutinin tests in the diagnosis of M. pneumoniae infection

Fibrinogen function is impaired in whole blood from patients with cyanotic congenital heart disease

Background: Patients with cyanotic congenital heart disease (CCHD) have haemostatic abnormities associated with bleeding and thrombo-embolic events. The haemostatic abnormalities are not fully understood, but recent studies indicate that elevated haematocrit and fibrinogen function may be of importance. The aim of this study was to characterise the haemostatic profile and examine the potential role of haematocrit on clot formation and strength in CCHD patients. Furthermore to examine whether CCHD patients with history of haemoptysis have diminished fibrinogen function compared to those without haemoptysis. Methods: In a prospective study 75 adult CCHD patients had haematocrit, platelet count, and plasma fibrinogen concentration examined. Furthermore thrombelastography(TEG) as well as TEG Functional Fibrinogen(TEG FF) assay evaluating fibrinogen function(FLEV) was performed. Data were compared with historical data regarding previous haemoptysis in CCHD patients. Results: Haematocrit was 57 +/- 8% and platelet counts in the lower normal range. TEG revealed a hypocoagulable condition with impaired clot formation. TEG values were correlated to haematocrit, indicating that elevated haematocrit causes impaired clot formation and strength. Despite high levels of plasma fibrinogen, TEG FF demonstrated that FLEV was diminished and negatively correlated to haematocrit. Furthermore CCHD patients with previous history of haemoptysis had significantly lower FLEV compared to CCHD patients without haemoptysis. Conclusion: Patients with CCHD are hypocoagulable mainly due to impaired fibrinogen function. Despite a low platelet count, platelet function does not seem to be severely affected in CCHD patients. Haemostasis, and especially fibrinogen function, is negatively affected by elevated haematocrit, and fibrinogen function is diminished in CCHD patients with haemoptysis. (C) 2012 Elsevier Ireland Ltd. All rights reserved