7,398 research outputs found
Anti-CTLA-4 (CD 152) monoclonal antibody-induced autoimmune interstitial nephritis
Targeted immune-modulating agents are entering clinical practice in many specialties, providing novel therapeutic possibilities but introducing new potential toxicities. We present the first reported case, to our knowledge, of immune-mediated nephritis following the administration of Tremelimumab (CP-675, 206), an anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibody. High-dose steroid therapy led to a rapid improvement in renal function, avoiding the need for renal replacement therapy.Peer reviewe
Characterization and Quantification of Isoprene-Derived Epoxydiols in Ambient Aerosol in the Southeastern United States
Isoprene-derived epoxydiols (IEPOX) are identified in ambient aerosol samples for the first time, together with other previously identified isoprene tracers (i.e., 2-methyltetrols, 2-methylglyceric acid, C5-alkenetriols, and organosulfate derivatives of 2-methyltetrols). Fine ambient aerosol collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS) was analyzed using both gas chromatography/quadrupole mass spectrometry (GC/MS) and gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) with prior trimethylsilylation. Mass concentrations of IEPOX ranged from ~1 to 24 ng m^(−3) in the aerosol collected from the two sites. Detection of particle-phase IEPOX in the AMIGAS samples supports recent laboratory results that gas-phase IEPOX produced from the photooxidation of isoprene under low-NO_x conditions is a key precursor of ambient isoprene secondary organic aerosol (SOA) formation. On average, the sum of the mass concentrations of IEPOX and the measured isoprene SOA tracers accounted for about 3% of the organic carbon, demonstrating the significance of isoprene oxidation to the formation of ambient aerosol in this region
Experimental Modeling of Sterilization Effects for Atmospheric Entry Heating on Microorganisms
The objective of this research was to design, build, and test an experimental apparatus for studying the parameters of atmospheric entry heating, and the inactivation of temperature-resistant bacterial spores. The apparatus is capable of controlled, rapid heating of sample coupons to temperatures of 200 to 350 C and above. The vacuum chamber permits operation under vacuum or special atmospheric gas mixtures
Neutron Correlations in the Decay of the First Excited State of 11Li
The decay of unbound excited 11Li was measured after being populated by a two-proton removal from a 13B beam at 71 MeV/nucleon. Decay energy spectra and Jacobi plots were obtained from measurements of the momentum vectors of the 9Li fragment and neutrons. A resonance at an excitation energy of ∼1.2 MeV was observed. The kinematics of the decay are equally well fit by a simple dineutron-like model or a phase-space model that includes final state interactions. A sequential decay model can be excluded
Precision of FLEET Velocimetry Using High-Speed CMOS Camera Systems
Femtosecond laser electronic excitation tagging (FLEET) is an optical measurement technique that permits quantitative velocimetry of unseeded air or nitrogen using a single laser and a single camera. In this paper, we seek to determine the fundamental precision of the FLEET technique using high-speed complementary metal-oxide semiconductor (CMOS) cameras. Also, we compare the performance of several different high-speed CMOS camera systems for acquiring FLEET velocimetry data in air and nitrogen free-jet flows. The precision was defined as the standard deviation of a set of several hundred single-shot velocity measurements. Methods of enhancing the precision of the measurement were explored such as digital binning (similar in concept to on-sensor binning, but done in post-processing), row-wise digital binning of the signal in adjacent pixels and increasing the time delay between successive exposures. These techniques generally improved precision; however, binning provided the greatest improvement to the un-intensified camera systems which had low signal-to-noise ratio. When binning row-wise by 8 pixels (about the thickness of the tagged region) and using an inter-frame delay of 65 microseconds, precisions of 0.5 meters per second in air and 0.2 meters per second in nitrogen were achieved. The camera comparison included a pco.dimax HD, a LaVision Imager scientific CMOS (sCMOS) and a Photron FASTCAM SA-X2, along with a two-stage LaVision HighSpeed IRO intensifier. Excluding the LaVision Imager sCMOS, the cameras were tested with and without intensification and with both short and long inter-frame delays. Use of intensification and longer inter-frame delay generally improved precision. Overall, the Photron FASTCAM SA-X2 exhibited the best performance in terms of greatest precision and highest signal-to-noise ratio primarily because it had the largest pixels
Copper-doped CdSe/ZnS quantum dots : controllable photoactivated copper(I) cation storage and release vectors for catalysis
The first photoactivated doped quantum dot vector for metal-ion release has been developed. A facile method for doping copper(I) cations within ZnS quantum dot shells was achieved through the use of metal-dithiocarbamates, with Cu(+) ions elucidated by X-ray photoelectron spectroscopy. Photoexcitation of the quantum dots has been shown to release Cu(+) ions, which was employed as an effective catalyst for the Huisgen [3+2] cycloaddition reaction. The relationship between the extent of doping, catalytic activity, and the fluorescence quenching was also explored
MagAO Imaging of Long-period Objects (MILO). I. A Benchmark M Dwarf Companion Exciting a Massive Planet around the Sun-like Star HD 7449
We present high-contrast Magellan adaptive optics (MagAO) images of HD 7449,
a Sun-like star with one planet and a long-term radial velocity (RV) trend. We
unambiguously detect the source of the long-term trend from 0.6-2.15 \microns
~at a separation of \about 0\fasec 54. We use the object's colors and spectral
energy distribution to show that it is most likely an M4-M5 dwarf (mass \about
0.1-0.2 \msun) at the same distance as the primary and is therefore likely
bound. We also present new RVs measured with the Magellan/MIKE and PFS
spectrometers and compile these with archival data from CORALIE and HARPS. We
use a new Markov chain Monte Carlo procedure to constrain both the mass ( \msun ~at 99 confidence) and semimajor axis (\about 18 AU) of the M
dwarf companion (HD 7449B). We also refine the parameters of the known massive
planet (HD 7449Ab), finding that its minimum mass is
\mj, its semimajor axis is AU, and its eccentricity is
. We use N-body simulations to constrain the eccentricity
of HD 7449B to 0.5. The M dwarf may be inducing Kozai oscillations
on the planet, explaining its high eccentricity. If this is the case and its
orbit was initially circular, the mass of the planet would need to be
1.5 \mj. This demonstrates that strong constraints on known planets
can be made using direct observations of otherwise undetectable long-period
companions.Comment: Corrected planet mass error (7.8 Mj --> 1.09 Mj, in agreement with
previous studies
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