74 research outputs found
Signatures of the disk-jet coupling in the Broad-line Radio Quasar 4C+74.26
Here we explore the disk-jet connection in the broad-line radio quasar
4C+74.26, utilizing the results of the multiwavelength monitoring of the
source. The target is unique in that its radiative output at radio wavelengths
is dominated by a moderately-beamed nuclear jet, at optical frequencies by the
accretion disk, and in the hard X-ray range by the disk corona. Our analysis
reveals a correlation (local and global significance of 96\% and 98\%,
respectively) between the optical and radio bands, with the disk lagging behind
the jet by days. We discuss the possible explanation for this,
speculating that the observed disk and the jet flux changes are generated by
magnetic fluctuations originating within the innermost parts of a truncated
disk, and that the lag is related to a delayed radiative response of the disk
when compared with the propagation timescale of magnetic perturbations along
relativistic outflow. This scenario is supported by the re-analysis of the
NuSTAR data, modelled in terms of a relativistic reflection from the disk
illuminated by the coronal emission, which returns the inner disk radius
. We discuss the global energetics in
the system, arguing that while the accretion proceeds at the Eddington rate,
with the accretion-related bolometric luminosity erg s , the jet total kinetic energy
erg s, inferred from the dynamical
modelling of the giant radio lobes in the source, constitutes only a small
fraction of the available accretion power.Comment: 9 pages and 6 figures, ApJ accepte
16. Tolerance of radiotherapy (3D-CRT) and androgen ablation for patients with prostate cancer
PurposeEvaluation acute tolerance of combined treatment (XRT and HT).Material/methodsBetween April 1999 and September 2000, 22 patients with prostate cancer (T1-T3NXMO) were treated with 3D-CRT and HT. Median age of patients was 68 years. EBRT was administered daily fraction of 1.8 Gy,total dose 70.2 Gy. Planning target volume (PTV) was defined as clinical target volume CTV (prostate and seminal vesicles) with 10 mm margins around prostate except posterior margin where 5 mm were used to decrease risk of rectum morbidity. Acute toxicities were evaluated using RTOG scoring scale. Median follow-up was 11 months.ResultsAcute effects in gastrointestinal tract (GI) noted were; rectal discomfort and mild diarrhea. Acute genitourinary (GU) symptoms included urgency, nocturia and dysuria. GI toxicity was observed in 75% of patients (grade 0 and 1), and 25% of patients (grade 2). GU toxicities were as follow: grade 0 and 1 – 80% of patients) and grade 2 – (20% of patients). No grade 3 or 4 GI and GU toxicities were observed.ConclusionsPreliminary results of treatment with 3D-CRT suggested that such modality is well tolerated. HT did not exacerbate radiation toxicity
Radial Velocity Studies of Close Binary Stars. IX
Radial-velocity measurements and sine-curve fits to the orbital velocity
variations are presented for the eighth set of ten close binary systems: AB
And, V402 Aur, V445 Cep, V2082 Cyg, BX Dra, V918 Her, V502 Oph, V1363 Ori, KP
Peg, V335 Peg. Half of the systems (V445 Cep, V2082 Cyg, V918 Her, V1363 Ori,
V335 Peg) were discovered photometrically by the Hipparcos mission and all
systems are double-lined (SB2) contact binaries. The broadening function method
permitted improvement of the orbital elements for AB And and V502 Oph. The
other systems have been observed for radial velocity variations for the first
time; in this group are five bright (V<7.5) binaries: V445 Cep, V2082 Cyg, V918
Her, KP Peg and V335 Peg. Several of the studied systems are prime candidates
for combined light and radial-velocity synthesis solutions.Comment: 17+ pages, 2 tables, 4 figure
Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions
Since pulsating subdwarf B (sdBV or EC14026) stars were first discovered
(Kilkenny et al, 1997), observational efforts have tried to realize their
potential for constraining the interior physics of extreme horizontal branch
(EHB) stars. Difficulties encountered along the way include uncertain mode
identifications and a lack of stable pulsation mode properties. Here we report
on Feige 48, an sdBV star for which follow-up observations have been obtained
spanning more than four years, which shows some stable pulsation modes.
We resolve the temporal spectrum into five stable pulsation periods in the
range 340 to 380 seconds with amplitudes less than 1%, and two additional
periods that appear in one dataset each. The three largest amplitude
periodicities are nearly equally spaced, and we explore the consequences of
identifying them as a rotationally split l=1 triplet by consulting with a
representative stellar model.
The general stability of the pulsation amplitudes and phases allows us to use
the pulsation phases to constrain the timescale of evolution for this sdBV
star. Additionally, we are able to place interesting limits on any stellar or
planetary companion to Feige 48.Comment: accepted for publication in MNRA
Implementation of High-Quality Warm-White Light-Emitting Diodes by a Model-Experimental Feedback Approach Using Quantum Dot-Salt Mixed Crystals
In this work, a model-experimental feedback approach is developed and applied to fabricate high-quality, warm-white light-emitting diodes based on quantum dots (QDs) as color-conversion materials. Owing to their unique chemical and physical properties, QDs offer huge potential for lighting applications. Nevertheless, both emission stability and processability of the QDs are limited upon usage from solution. Incorporating them into a solid ionic matrix overcomes both of these drawbacks, while preserving the initial optical properties. Here borax (Na2B4O7·10H2O) is used as a host matrix because of its lower solubility and thereby reduced ionic strength in water in comparison with NaCl. This guarantees the stability of high-quality CdSe/ZnS QDs in the aqueous phase during crystallization and results in a 3.4 times higher loading amount of QDs within the borax crystals compared to NaCl. All steps from the synthesis via mixed crystal preparation to the warm-white LED preparation are verified by applying the model-experimental feedback, in which experimental data and numerical results provide feedback to each other recursively. These measures are taken to ensure a high luminous efficacy of optical radiation (LER) and a high color rendering index (CRI) of the final device as well as a correlated color temperature (CCT) comparable to an incandescent bulb. By doing so, a warm-white LED with a LER of 341 lm/Wopt, a CCT of 2720 K and a CRI of 91.1 is produced. Finally, we show that the emission stability of the QDs within the borax crystals on LEDs driven at high currents is significantly improved. These findings indicate that the proposed warm-white light-emitting diodes based on QDs-in-borax hold great promise for quality lighting. © 2015 American Chemical Society
R/V MARIA S. MERIAN Cruise Report MSM57, Gas Hydrate Dynamics at the Continental Margin of Svalbard, Reykjavik – Longyearbyen – Reykjavik, 29 July – 07 September 2016
Immunotoxicity of polystyrene nanoplastics in different hemocyte subpopulations of Mytilus galloprovincialis
Plastic represents 60-80% of litter in the ocean. Degradation of plastic to small fragments leads to the formation of microplastics (MPs <5mm) and nanoplastics (NPs <1 mu m). One of the most widely used and representative plastics found in the ocean is polystyrene (PS). Among marine organisms, the immune system of bivalves is recognized as suitable to assess nanomaterial toxicity. Hemocyte subpopulations [R1 (large granular cells), R2 (small semi-granular cells) and R3 (small agranular or hyaline cells)] of Mytilus galloprovincialis are specialized in particular tasks and functions. The authors propose to examine the effects of different sizes (50 nm, 100 nm and 1 mu m) PS NPs on the different immune cells of mussels when they were exposed to (1 and 10mg.L-1) of PS NPs. The most noteworthy results found in this work are: (i) 1 mu m PS NPs provoked higher immunological responses with respect to 50 and 100nm PS NPs, possibly related to the higher stability in size and shape in hemolymph serum, (ii) the R1 subpopulation was the most affected with respect to R2 and R3 concerning immunological responses and (iii) an increase in the release of toxic radicals, apoptotic signals, tracking of lysosomes and a decrease in phagocytic activity was found in R1
Clear and independent associations of several HLA-DRB1 alleles with differential antibody responses to hepatitis B vaccination in youth
To confirm and refine associations of human leukocyte antigen (HLA) genotypes with variable antibody (Ab) responses to hepatitis B vaccination, we have analyzed 255 HIV-1 seropositive (HIV+) youth and 80 HIV-1 seronegatives (HIV−) enrolled into prospective studies. In univariate analyses that focused on HLA-DRB1, -DQA1, and -DQB1 alleles and haplotypes, the DRB1*03 allele group and DRB1*0701 were negatively associated with the responder phenotype (serum Ab concentration ≥ 10 mIU/mL) (P = 0.026 and 0.043, respectively). Collectively, DRB1*03 and DRB1*0701 were found in 42 (53.8%) out of 78 non-responders (serum Ab <10 mIU/mL), 65 (40.6%) out of 160 medium responders (serum Ab 10–1,000 mIU/mL), and 27 (27.8%) out of 97 high responders (serum Ab >1,000 mIU/mL) (P < 0.001 for trend). Meanwhile, DRB1*08 was positively associated with the responder phenotype (P = 0.010), mostly due to DRB1*0804 (P = 0.008). These immunogenetic relationships were all independent of non-genetic factors, including HIV-1 infection status and immunodeficiency. Alternative analyses confined to HIV+ youth or Hispanic youth led to similar findings. In contrast, analyses of more than 80 non-coding, single nucleotide polymorphisms within and beyond the three HLA class II genes revealed no clear associations. Overall, several HLA-DRB1 alleles were major predictors of differential Ab responses to hepatitis B vaccination in youth, suggesting that T-helper cell-dependent pathways mediated through HLA class II antigen presentation are critical to effective immune response to recombinant vaccines
Choice of the initial antiretroviral treatment for HIV-positive individuals in the era of integrase inhibitors
BACKGROUND: We aimed to describe the most frequently prescribed initial antiretroviral therapy (ART) regimens in recent years in HIV-positive persons in the Cohort of the Spanish HIV/AIDS Research Network (CoRIS) and to investigate factors associated with the choice of each regimen. METHODS: We analyzed initial ART regimens prescribed in adults participating in CoRIS from 2014 to 2017. Only regimens prescribed in >5% of patients were considered. We used multivariable multinomial regression to estimate Relative Risk Ratios (RRRs) for the association between sociodemographic and clinical characteristics and the choice of the initial regimen. RESULTS: Among 2874 participants, abacavir(ABC)/lamivudine(3TC)/dolutegavir(DTG) was the most frequently prescribed regimen (32.1%), followed by tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC)/elvitegravir(EVG)/cobicistat(COBI) (14.9%), TDF/FTC/rilpivirine (RPV) (14.0%), tenofovir alafenamide (TAF)/FTC/EVG/COBI (13.7%), TDF/FTC+DTG (10.0%), TDF/FTC+darunavir/ritonavir or darunavir/cobicistat (bDRV) (9.8%) and TDF/FTC+raltegravir (RAL) (5.6%). Compared with ABC/3TC/DTG, starting TDF/FTC/RPV was less likely in patients with CD4100.000 copies/mL. TDF/FTC+DTG was more frequent in those with CD4100.000 copies/mL. TDF/FTC+RAL and TDF/FTC+bDRV were also more frequent among patients with CD4<200 cells//muL and with transmission categories other than men who have sex with men. Compared with ABC/3TC/DTG, the prescription of other initial ART regimens decreased from 2014-2015 to 2016-2017 with the exception of TDF/FTC+DTG. Differences in the choice of the initial ART regimen were observed by hospitals' location. CONCLUSIONS: The choice of initial ART regimens is consistent with Spanish guidelines' recommendations, but is also clearly influenced by physician's perception based on patient's clinical and sociodemographic variables and by the prescribing hospital location
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