Performance of a 62Zn/62Cu microgenerator in kit-based synthesis and delivery of [62Cu]Cu–ETS for PET perfusion imaging

The performance of a commercially produced 62Zn/62Cu microgenerator system, and an associated kit-based radiopharmaceutical synthesis method, was evaluated for clinical site production of [62Cu]Cu-ETS (ethylglyoxal bis(thiosemicarbazonato)copper(II)), an investigational agent for PET perfusion imaging. Using 37 generators, containing 1.84 ± 0.23 GBq 62Zn at 9:00 AM on the day of clinical use, a total of 45 patient doses of [62Cu]Cu-ETS (672 ± 172 MBq) were delivered without difficulty. 62Cu elution yields were high (approximately 90%), accompanied by extremely low 62Zn breakthrough (<0.001%). Radiopharmaceutical preparation, from the start-of-elution to time-of-injection, consumed less than five minutes. The 62Zn/62Cu microgenerator was a dependable source of short-lived positron-emitting 62Cu, and the kit-based synthesis proved to be rapid, robust, and highly reliable for “on-demand” delivery of [62Cu]Cu-ETS for PET perfusion imaging

The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances

We report data for $I$ band Surface Brightness Fluctuation (SBF) magnitudes, V-I colors, and distance moduli for 300 galaxies. The Survey contains E, S0 and early-type spiral galaxies in the proportions of 49:42:9, and is essentially complete for E galaxies to Hubble velocities of 2000 km/s, with a substantial sampling of E galaxies out to 4000 km/s. The median error in distance modulus is 0.22 mag. We also present two new results from the Survey. (1) We compare the mean peculiar flow velocity (bulk flow) implied by our distances with predictions of typical cold dark matter transfer functions as a function of scale, and find very good agreement with cold, dark matter cosmologies if the transfer function scale parameter $\Gamma$, and the power spectrum normalization $\sigma_8$ are related by $\sigma_8 \Gamma^{-0.5} \approx 2\pm0.5$. Derived directly from velocities, this result is independent of the distribution of galaxies or models for biasing. The modest bulk flow contradicts reports of large-scale, large-amplitude flows in the $\sim200$ Mpc diameter volume surrounding our Survey volume. (2) We present a distance-independent measure of absolute galaxy luminosity, \Nbar, and show how it correlates with galaxy properties such as color and velocity dispersion, demonstrating its utility for measuring galaxy distances through large and unknown extinction.Comment: Accepted for publication in ApJ (10 January 2001); 23 page

COMPTEL all-sky imaging at 2.2 MeV

It is now generally accepted that accretion of matter onto a compact object (white dwarf, neutron star or black hole) is one of the most efficient processes in the universe for producing high energy radiations. Measurements of the γ-ray emission will provide a potentially valuable means for furthering our understanding of the accretion process. Here we focus on neutroncapture processes, which can be expected in any situation where energetic neutrons may be produced and where the liberated neutrons will interact with matter before they decay (where they have a chance of undergoing some type of neutron capture). Line emission at 2.2 MeV, resulting from neutron capture on hydrogen, is believed to be the most important neutroncapture emission. Observations of this line in particular would provide a probe of neutronproduction processes (i.e., the energetic particle interactions) within the accretion flow. Here we report on the results of our effort to image the full sky at 2.2 MeV using data from the COMPTELexperiment on the Compton Gamma-Ray Observatory (CGRO)

Reproducible Isolation of Lymph Node Stromal Cells Reveals Site-Dependent Differences in Fibroblastic Reticular Cells

Within lymph nodes, non-hematopoietic stromal cells organize and interact with leukocytes in an immunologically important manner. In addition to organizing T and B cell segregation and expressing lymphocyte survival factors, several recent studies have shown that lymph node stromal cells shape the naïve T cell repertoire, expressing self-antigens which delete self-reactive T cells in a unique and non-redundant fashion. A fundamental role in peripheral tolerance, in addition to an otherwise extensive functional portfolio, necessitates closer study of lymph node stromal cell subsets using modern immunological techniques; however this has not routinely been possible in the field, due to difficulties reproducibly isolating these rare subsets. Techniques were therefore developed for successful ex vivo and in vitro manipulation and characterization of lymph node stroma. Here we discuss and validate these techniques in mice and humans, and apply them to address several unanswered questions regarding lymph node composition. We explored the steady-state stromal composition of lymph nodes isolated from mice and humans, and found that marginal reticular cells and lymphatic endothelial cells required lymphocytes for their normal maturation in mice. We also report alterations in the proportion and number of fibroblastic reticular cells (FRCs) between skin-draining and mesenteric lymph nodes. Similarly, transcriptional profiling of FRCs revealed changes in cytokine production from these sites. Together, these methods permit highly reproducible stromal cell isolation, sorting, and culture

Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models

Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined into a tracer known as atmospheric potential oxygen (APO ≈ O2/N2 + CO2) that is conservative with respect to terrestrial biological activity. Consequently, APO reflects primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. (1998), we present a set of APO observations for the years 1996-2003 with unprecedented spatial coverage. Combining data from the Princeton and Scripps air sampling programs, the data set includes new observations collected from ships in the low-latitude Pacific. The data show a smaller interhemispheric APO gradient than was observed in past studies, and different structure within the hemispheres. These differences appear to be due primarily to real changes in the APO field over time. The data also show a significant maximum in APO near the equator. Following the approach of Gruber et al. (2001), we compare these observations with predictions of APO generated from ocean O2 and CO2 flux fields and forward models of atmospheric transport. Our model predictions differ from those of earlier modeling studies, reflecting primarily the choice of atmospheric transport model (TM3 in this study). The model predictions show generally good agreement with the observations, matching the size of the interhemispheric gradient, the approximate amplitude and extent of the equatorial maximum, and the amplitude and phasing of the seasonal APO cycle at most stations. Room for improvement remains. The agreement in the interhemispheric gradient appears to be coincidental; over the last decade, the true APO gradient has evolved to a value that is consistent with our time-independent model. In addition, the equatorial maximum is somewhat more pronounced in the data than the model. This may be due to overly vigorous model transport, or insufficient spatial resolution in the air-sea fluxes used in our modeling effort. Finally, the seasonal cycles predicted by the model of atmospheric transport show evidence of an excessive seasonal rectifier in the Aleutian Islands and smaller problems elsewhere. Copyright 2006 by the American Geophysical Union

The incidence of ventilator-associated pneumonia using the PneuX System with or without elective endotracheal tube exchange: A pilot study

<p>Abstract</p> <p>Background</p> <p>The PneuX System is a novel endotracheal tube and tracheal seal monitor, which has been designed to minimise the aspiration of oropharyngeal secretions. We aimed to determine the incidence of ventilator-associated pneumonia (VAP) in patients who were intubated with the PneuX System and to establish whether intermittent subglottic secretion drainage could be performed reliably and safely using the PneuX System.</p> <p>Findings</p> <p>In this retrospective observational study, data was collected from 53 sequential patients. Nine (17%) patients were initially intubated with the PneuX System and 44 (83%) patients underwent elective exchange to the PneuX System. There were no episodes of VAP while the PneuX System was <it>in situ</it>. On an intention to treat basis, the incidence VAP was 1.8%. There were no complications from, or failure of, subglottic secretion drainage during the study.</p> <p>Conclusions</p> <p>Our study demonstrates that a low incidence of VAP is possible using the PneuX System. Our study also demonstrates that elective exchange and intermittent subglottic secretion drainage can be performed reliably and safely using the PneuX System.</p

A multinuclear solid state NMR, density functional theory and X-Ray diffraction study of hydrogen bonding in Group I hydrogen dibenzoates

An NMR crystallographic approach incorporating multinuclear solid state NMR (SSNMR), X-ray structure determinations and density functional theory (DFT) are used to characterise the H bonding arrangements in benzoic acid (BZA) and the corresponding Group I alkali metal hydrogen dibenzoates (HD) systems. Since the XRD data often cannot precisely confirm the proton position within the hydrogen bond, the relationship between the experimental SSNMR parameters and the ability of gauge included plane augmented wave (GIPAW) DFT to predict them becomes a powerful constraint that can assist with further structure refinement. Both the 1H and 13C MAS NMR methods provide primary descriptions of the H bonding via accurate measurements of the 1H and 13C isotropic chemical shifts, and the individual 13C chemical shift tensor elements; these are unequivocally corroborated by DFT calculations, which together accurately describe the trend of the H bonding strength as the size of the monovalent cation changes. In addition, 17O MAS and DOR NMR form a powerful combination to characterise the O environments, with the DOR technique providing highly resolved 17O NMR data which helps verify unequivocally the number of inequivalent O positions for the conventional 17O MAS NMR to process. Further multinuclear MAS and static NMR studies involving the quadrupolar 7Li, 39K, 87Rb and 133Cs nuclei, and the associated DFT calculations, provide trends and a corroboration of the H bond geometry which assist in the understanding of these arrangements. Even though the crystallographic H positions in each H bonding arrangement reported from the single crystal X-ray studies are prone to uncertainty, the good corroboration between the measured and DFT calculated chemical shift and quadrupole tensor parameters for the Group I alkali species suggest that these reported H positions are reliable