858 research outputs found
Long term isothermal aging and thermal analysis of N-CYCAP polyimides
The N-CYCAP polyimides utilize a (2,2) paracyclophane endcap that polymerizes and does not generate volatile gases during the cure process. These polyimides have both high glass temperatures (390 C) and an onset of decomposition in air of 560 C. Thermal oxidative stability (TOS) weight loss studies show that replacing 25 percent by weight of the paraphenylene diamine in the polymer backbone with metaphenylene diamine improves the weight loss characteristics. N-CYCAP neat resin samples performed better than PMR-II-50 when exposed at 343 and 371 C in air for up to 1000 hours. Preliminary composite studies show that both PMR-II-50 and N-CYCAP have better thermal stability when fabricated on T-40R. Higher isothermal aging temperatures of longer aging times are needed to determine the differences in TOS between composite samples of PMR-II-50 and N-CYCAP polyimides
Validation and Reliability Testing of the EORTC QLQ-NMIBC24 Questionnaire Module to Assess Patient-reported Outcomes in Non–Muscle-invasive Bladder Cancer
Funding/Support and role of the sponsor: Trial recruitment was facilitated within centres by the National Institute for Health Research Cancer Research Network. Pfizer provided study medication free of charge within the BOXIT trial.Peer reviewedPublisher PD
Evidence for a very slow X-ray pulsar in 2S0114+650 from RXTE All-Sky Monitor Observations
Rossi X-ray Timing Explorer (RXTE) All-Sky Monitor (ASM) observations of the
X-ray binary 2S0114+650 show modulations at periods close to both the optically
derived orbital period (11.591 days) and proposed pulse period (~ 2.7 hr). The
pulse period shows frequency and intensity variability during the more than 2
years of ASM observations analyzed. The pulse properties are consistent with
this arising from accretion onto a rotating neutron star and this would be the
slowest such period known. The shape of the orbital light curve shows
modulation over the course of the entire orbit and a comparison is made with
the orbital light curve of Vela X-1. However, the expected phase of eclipse,
based on an extrapolation of the optical ephemeris, does not correspond with
the observed orbital minimum. The orbital period derived from the ASM light
curve is also slightly longer than the optical period.Comment: To be published in the Astrophysical Journal, 1999, volume 511. 9
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Gas Morphology of Milky Way-like Galaxies in the TNG50 Simulation: Signals of Twisting and Stretching
We present an in-depth analysis of gas morphologies for a sample of 25 Milky
Way-like galaxies from the IllustrisTNG TNG50 simulation. We constrain the
morphology of cold, warm, hot gas, and gas particles as a whole using a Local
Shell Iterative Method (LSIM) and explore its observational implications by
computing the hard-to-soft X-ray ratio, which ranges between
- in the inner of the distribution and
- at the outer portion of the hot gas distribution. We group
galaxies into three main categories: simple, stretched, and twisted. These
categories are based on the radial reorientation of the principal axes of the
reduced inertia tensor. We find that a vast majority () of the galaxies
in our sample exhibit twisting patterns in their radial profiles. Additionally,
we present detailed comparisons between 1) the gaseous distributions belonging
to individual temperature regimes, 2) the cold gas distributions and stellar
distributions, and 3) the gaseous distributions and dark matter (DM) halos. We
find a strong correlation between the morphological properties of the cold gas
and stellar distributions. Furthermore, we find a correlation between gaseous
distributions with DM halo that increases with gas temperature, implying that
we may use the warm-hot gaseous morphology as a tracer to probe the DM
morphology. Finally, we show gaseous distributions exhibit significantly more
prolate morphologies than the stellar distributions and DM halos, which we
hypothesize is due to stellar and AGN feedback.Comment: 26 pages, 12 figure
P-glycoprotein, but not multidrug resistance protein 4, plays a role in the systemic clearance of irinotecan and SN-38 in mice
The ATP-binding cassette transporters P-glycoprotein (ABCB1, MDR1) and multidrug resistance protein 4 (MRP4) efflux irinotecan and its active metabolite SN-38 in vitro, and thus may contribute to system clearance of these compounds. Mdr1a/b(-/-), Mrp4(-/-), and wild-type mice were administered 20 or 40 mg/kg irinotecan, and plasma samples were collected for 6 hours. Irinotecan and SN-38 lactone and carboxylate were quantitated and data were analyzed with nonlinear mixed-effects modeling. Mdr1a/b genotype was a significant covariate for the clearance of both irinotecan lactone and SN-38 lactone. Exposures to irinotecan lactone and SN-38 lactone after a 40 mg/kg dose were 1.6-fold higher in Mdr1a/b(-/-) mice compared to wild-type mice. Plasma concentrations of irinotecan lactone, irinotecan carboxylate, and SN-38 lactone in Mrp4(-/-) mice were similar to the wild-type controls. These results suggest that P-gp plays a role in irinotecan and SN-38 elimination, but Mrp4 does not affect irinotecan or SN-38 plasma pharmacokinetics.Fil: Tagen, Michael. St. Jude Children's Research Hospital; Estados UnidosFil: Zhuang, Yanli. St. Jude Children's Research Hospital; Estados UnidosFil: Zhang, Fan. St. Jude Children's Research Hospital; Estados UnidosFil: Harstead, K. Elaine. St. Jude Children's Research Hospital; Estados UnidosFil: Shen, Jun. St. Jude Children's Research Hospital; Estados UnidosFil: Schaiquevich, Paula Susana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. St. Jude Children's Research Hospital; Estados UnidosFil: Fraga, Charles H.. St. Jude Children's Research Hospital; Estados UnidosFil: Panetta, John C.. St. Jude Children's Research Hospital; Estados UnidosFil: Waters, Christopher M.. St. Jude Children's Research Hospital; Estados UnidosFil: Stewart, Clinton F.. St. Jude Children's Research Hospital; Estados Unido
Radio Astronomy
Contains reports on isx research projects.National Aeronautics and Space Administration, Langley Research Center (Contract NAS1-10693)National Science Foundation (Grant GP-21348)National Science Foundation (Grant GP-14589)California Institute of Technology Contract 952568Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DAAB07-71-C-030
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