161 research outputs found
High resolution measurements of density structures in the Jovian plasma sheet
A recent effort to digitize the plasma density by using the low frequency cutoff of trapped continuum radiation in the vicinity of the Jovian plasma sheet has revealed the existence of sharply defined density structures in the plasma sheet. These structures typically have a plasma density which is relatively constant but of order 50 percent greater or less than in the surrounding plasma. At the boundaries of these structures, the transitions from low to high density occur on time scales of about ten seconds, which correspond to spatial dimensions on the order of a few ion Larmor radii. The structures themselves last for intervals from less than a minute to more than five minutes, corresponding to size scales from a fraction of a Jovian radius to more than a Jovian radius, depending of the velocity of the structure relative to the spacecraft. In view of the importance of near corotation plasma flows, these structures are likely to be limited in both the longitudinal and radial dimensions and, therefore, could represent flux tubes with greatly varying plasma content. These observations are presented as among the first to directly address the theoretically proposed interchange instability
Micron-Sized Dust Particles Detected in the Outer Solar System by the Voyager 1 and 2 Plasma Wave Instruments
During the Voyager 1 and 2 flybys of the outer planets it has been demonstrated that the plasma wave instrument can detect small dust particles striking the spacecraft. In this paper, we examine the Voyager plasma wave data for dust impacts in the interplanetary medium at heliocentric radial distances ranging from 6 to 60 astronomical units (AU). The results show that a small but persistent level of dust impacts exists out to at least 30 to 50 AU. The average number density of these particles is about 2 x 10(exp -8)/cu m, and the average mass of the impacting particles is believed to be a few times 10(exp -11) g, which corresponds to particle diameters in the micron range. Possible sources of these particles are planets, moons, asteroids, comets, and the interstellar medium. Of these, comets appear to be the most likely source. The number densities are only weakly dependent on ecliptic latitude, which indicates that the particles probably do not originate from planets, moons, or asteroids. Comparisons with interstellar dust fluxes measured in the inner regions of the solar system by the Ulysses spacecraft indicate that the particles are not of interstellar origin
Characterization of the metabolism of fenretinide by human liver microsomes, cytochrome P450 enzymes and UDP-glucuronosyltransferases
4-Hydroxyphenylacetic Acid Prevents Acute APAP-Induced Liver Injury by Increasing Phase II and Antioxidant Enzymes in Mice
Acetaminophen (APAP) overdose is the principal cause of drug-induced acute liver failure. 4-hydroxyphenylacetic acid (4-HPA), a major microbiota-derived metabolite of polyphenols, is involved in the antioxidative action. This study seeks to investigate the ability of 4-HPA to protect against APAP-induced hepatotoxicity, as well as the putative mechanisms involved. Mice were treated with 4-HPA (6, 12, or 25 mg/kg) for 3 days, 1 h after the last administration of 4-HPA, a single dose of APAP was intraperitoneally infused for mice. APAP caused a remarkable increase of oxidative stress markers, peroxynitrite formation, and fewer activated phase II enzymes. 4-HPA increased Nrf2 translocation to the nucleus and enhanced the activity of phase II and antioxidant enzymes, and could thereby ameliorate APAP-induced liver injury. Studies reveal that 4-HPA, as an active area of bioactive dietary constituents, could protect the liver against APAP-induced injury, implying that 4-HPA could be a new promising strategy and natural hepatoprotective drug.This work was supported by National Key Research and Development Program of China (Grant No. 2017YFD0501400), SCO Regional collaborative innovation project (Grant No. 2016E03012), Xinjiang; the Key Construction Program of International Cooperation Base in S&T, Shaanxi Province (Grant No. 2015SD0018), Program for Science & Technology Innovation Talents in Universities of Henan Province (Grant No. 18HASTIT035], China strategic program UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P., by the Ministerio da Ciencia, Tecnologia e Ensino Superior (MCTES) and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), Portugal
Australian health care providers' views on opt-out HIV testing
Background: Opt-out HIV testing is a novel concept in Australia. In the opt-out approach, health care providers (HCPs) routinely test patients for HIV unless they explicitly decline or defer. Opt-out HIV testing is only performed with the patients' consent, but pre-test counselling is abbreviated. Australian national testing guidelines do not currently recommend opt-out HIV testing for the general population. Non-traditional approaches to HIV testing (such as opt-out) could identify HIV infections and facilitate earlier treatment, which is particularly important now that HIV is a chronic, manageable disease. Our aim was to explore HCPs' attitudes toward opt-out HIV testing in an Australian context, to further understanding of its acceptability and feasibility. Methods: In this qualitative study, we used purposeful sampling to recruit HCPs who were likely to have experience with HIV testing in Western Australia. We interviewed them using a semi-structured guide and used content analysis as per Graneheim to code the data. Codes were then merged into subcategories and finally themes that unified the underlying concepts. We refined these themes through discussion among the research team. Results: Twenty four HCPs participated. Eleven participants had a questioning attitude toward opt-out HIV testing, while eleven favoured the approach. The remaining two participants had more nuanced perspectives that incorporated some characteristics of the questioning and favouring attitudes. Participants' views about opt-out HIV testing largely fell into two contrasting themes: normalisation and routinisation versus exceptionalism; and a need for proof versus openness to new approaches. Conclusion: Most HCPs in this study had dichotomous attitudes toward opt-out HIV testing, reflecting contrasting analytical styles. While some HCPs viewed it favourably, with the perceived benefits outweighing the perceived costs, others preferred to have evidence of efficacy and cost-effectiveness
Glucuronidation by UGT1A1 Is the Dominant Pathway of the Metabolic Disposition of Belinostat in Liver Cancer Patients
10.1371/journal.pone.0054522PLoS ONE81
Density structures in the Jovian magnetosphere
This paper continues the work of Ansher et al. (1992) by identifying and examining density structures in Jupiter's magnetosphere. The 110 hours of data used are from a 4-second temporal resolution density data set derived from plasma wave instruments on board both Voyager 1 and Voyager 2. One hundred five structures are identified. They are believed to be the same type of structures as seen by Ansher et al. (1992) and are found to have sharp density gradients at the boundaries, average scale sizes of about one Jovian radius, and typical density variations between 50% and 200% of the background. Many structures show good correlation with the magnetic field data. In addition, the existence of the density structures has little if any dependence on radial distance from Jupiter, System III longitude, or magnetic latitude. Comparison with four plasma transport models indicates that the observed structures resemble flux tubes of varying plasma content compared to the background density. These findings are in agreement with those of Ansher et al. (1992)
Book Reviews: Diagnosis and Management of Muscle Disease by Albert Galdi. Published in 1984 by SP Medical and Scientific Books, New York, 240 pages, $30.00
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