The contribution of Narrow-Line Seyfert 1 galaxies to the soft X-ray background

The ROSAT Ultradeep HRI survey in the Lockman Hole contains a complete sample of 91 X-ray sources with fluxes in the 0.5-2 keV band larger than 1.2 times 10e-15 erg cm-2 s-1, where over about 75 per cent of the sources are quasars or Seyfert galaxies. During the course of our optical identification work, we have obtained optical spectra of 67 narrow emission line galaxies (NELG), which are physically not associated with the X-ray sources. We have derived the equivalent width (EW) and the full width at half maximum (FWHM) for the most prominent emission lines of 41 quasars and Seyfert galaxies taken from the ROSAT Deep Survey (RDS), which has a flux limit of 5.5 times 10e-15 erg cm-2 s-1 in the 0.5-2.0 keV band. Furthermore we have obtained the EW and FWHM values of the field NELGs. Here we present the spectroscopic discrimination between RDS Seyfert galaxies and field galaxies (NELG). The analysis of the emission lines has revealed that a single object out of 69 spectroscopically identified AGN fits the optical criteria of Narrow-Line Seyfert 1 galaxies (NLS1). This may indicate that NLS1 contribute only marginally to the soft X-ray background, but we can not exclude a possible larger contribution.Comment: Invited talk presented at the Joint MPE,AIP,ESO workshop on NLS1s, Bad Honnef, Dec. 1999, to appear in New Astronomy Reviews; also available at http://wave.xray.mpe.mpg.de/conferences/nls1-worksho

Application of hand-held near-infrared and Raman spectrometers in surface treatment authentication of cork stoppers

The aim of this paper was to evaluate the potential of using near-infrared (NIR) spectroscopy and multivariate analysis as a rapid tool to non-destructively determine the presence of surface treatments applied to cork stoppers. Density and dimensions of 6 closure varieties were characterized and the extraction force was measured on those produced for still wines. Cork stoppers were also analyzed using hand-held NIR and Raman spectrometers. Soft independent modelling of class analogy (SIMCA) models showed significant differences among treated and untreated samples, linked to components of the coating agents applied (silicone and paraffin). SIMCA model''s classification performance was tested and high sensitivity (93.33 %) and specificity (100 %) values were obtained. Partial least squares regression (PLSR) model accurately predicted the extraction forces measured with low standard error of prediction (SEP = 4.0 daN). Our results are promising for the future application of this technology in cork industry, reducing time and economic losses. © 2021 The Author(s

Electronic Structure of Calcium Hexaboride within the Weighted Density Approximation

We report calculations of the electronic structure of CaB$_6$ using the weighted density approximation (WDA) to density functional theory. We find a semiconducting band structure with a sizable gap, in contrast to local density approximation (LDA) results, but in accord with recent experimental data. In particular, we find an $X$-point band gap of 0.8 eV. The WDA correction of the LDA error in describing the electronic structure of CaB$_6$ is discussed in terms of the orbital character of the bands and the better cancelation of self-interactions within the WDA.Comment: 1 figur

Anomalous NMR Spin-Lattice Relaxation in SrB_{6} and Ca_{1-x}La_{x}B_{6}

We report the results of {11}B nuclear magnetic resonance (NMR) measurements of SrB_{6} and Ca_{0.995}La_{0.05}B_{6} below room temperature. Although the electrical resistivities of these two materials differ substantially, their {11}B-NMR responses exhibit some strikingly common features. Both materials exhibit ferromagnetic order, but their {11}B-NMR spectra reveal very small hyperfine fields at the Boron sites. The spin lattice relaxation T_{1}^{-1} varies considerably with external field but changes with temperature only below a few K. We discuss these unusual results by considering various different scenarios for the electronic structure of these materials.Comment: Accepted for publication in Phys. Rev. B Rapid communication, 4 pages, 3 figures. This manuscript replaces an earlier version and includes some minor changes in the text and in Fig.

Charge dynamics and "ferromagnetism" of A1-xLaxB6 (A=Ca and Sr)

Ferromagnetism has been reported recently in La-doped alkaline-earth hexaborides, A1-xLaxB6 (A=Ca, Sr, and Ba). We have performed the reflectivity, Hall resistivity, and magnetization measurements of A1-xLaxB6. The results indicate that A1-xLaxB6 can be regarded as a simple doped semimetal, with no signature of an excitonic state as suggested by several theories. It is also found that the surface of as-grown samples (10 micrometer in thickness) has a different electronic structure from a bulk one, and a fairly large number of paramagnetic moments are confined in this region. After eliminating these paramagnetic moments at the surface, we could not find any evidence of an intrinsic ferromagnetic moment in our samples, implying the possibility that the ferromagnetism of A1-xLaxB6 reported so far is neither intrinsic.Comment: 7 pages, 8 figure

Fermi Surface Measurements on the Low Carrier Density Ferromagnet Ca1-xLaxB6 and SrB6

Recently it has been discovered that weak ferromagnetism of a dilute 3D electron gas develops on the energy scale of the Fermi temperature in some of the hexaborides; that is, the Curie temperature approximately equals the Fermi temperature. We report the results of de Haas-van Alphen experiments on two concentrations of La-doped CaB6 as well as Ca-deficient Ca1-dB6 and Sr-deficient Sr1-dB6. The results show that a Fermi surface exists in each case and that there are significant electron-electron interactions in the low density electron gas.Comment: 4 pages, 5 figures, submitted to PR

Theory of High \tc Ferromagnetism in SrB6SrB_6 family: A case of Doped Spin-1 Mott insulator in a Valence Bond Solid Phase

Doped divalent hexaborides such as $Sr_{1-x}La_xB_6$ exhibit high \tc ferromagnetism. We isolate a degenerate pair of $2p$-orbitals of boron with two valence electrons, invoke electron correlation and Hund coupling, to suggest that the undoped state is better viewed as a spin-1 Mott insulator; it is predicted to be a type of 3d Haldane gap phase with a spin gap $\sim 0.1 eV$, much smaller than the charge gap of $> 1.0 eV$ seen in ARPES. The experimentally seen high \tc `ferromagnetism' is argued to be a complex magnetic order in disguise - either a canted 6-sublattice AFM ($\approx 120^0$) order or its quantum melted version, a chiral spin liquid state, arising from a type of double exchange mechanism.Comment: 4 pages, 2 figures; minor corrections, references adde

Health-related quality of life outcomes among breast cancer survivors

Background: Data from a nationwide sample of US breast cancer survivors were used to examine associations between patient characteristics (breast cancer clinical features, prognostic factors, and treatments) and health-related quality of life (HRQOL). Associations between postdiagnosis HRQOL and mortality were then evaluated. Methods: The authors identified female breast cancer survivors (n = 2453) from the Sister Study or Two Sister Study who were at least 1 year from breast cancer diagnosis and who had responded to a survivorship survey in 2012. HRQOL was assessed with the Patient-Reported Outcomes Measurement Information System (PROMIS) Global 10 measures. Multivariable linear regression was used to assess predictors associated with HRQOL. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between HRQOL and all-cause mortality. Results: HRQOL, assessed an average of 4.9 years after the cancer diagnosis (standard deviation of 1.9 years), was negatively associated with a higher cancer stage at diagnosis; a higher comorbidity score at the survey; experience of surgical complications; dissatisfaction with breast surgery; and experience of any recent recurrence, metastasis, or secondary malignancy. Since the completion of the survey, there were 85 deaths (3.5%) during a mean follow-up of 4 years (standard deviation of 0.5 years). In multivariate models, decreases in PROMIS physical T scores and mental T scores were associated with increased mortality (HR for physical T scores, 1.08; 95% CI, 1.05-1.11; HR for mental T scores, 1.03; 95% CI, 1.01-1.06). Conclusions: Prognostic and cancer treatment–related factors affect HRQOL in breast cancer survivors and may inform targeted survivorship care. PROMIS global health measures may offer additional insights into patients' well-being and mortality risk. Lay Summary: Findings from a study suggest that prognostic and cancer treatment–related factors affect health-related quality of life (HRQOL) in breast cancer survivors and that poor HRQOL may increase the mortality risk. The evaluation of HRQOL is important because it may hold potential as a tool for optimizing survivorship care

Pd-(L)1 inhibitors as monotherapy for the first-line treatment of non-small-cell lung cancer patients with high pd-l1 expression : A network meta-analysis

Altres ajuts: RocheProgrammed cell death-ligand 1 (PD-L1) has emerged as a potential biomarker for selec-tion of patients more likely to respond to immunotherapy and as a prognostic factor in non-small cell lung cancer (NSCLC). In this network meta-analysis, we aimed to evaluate the efficacy of first-line anti-PD-(L)1 monotherapy in advanced NSCLC patients with high PD-L1 expression (≥50%) compared to platinum-based chemotherapy. We also evaluated efficacy outcomes according to tumor mutational burden (TMB). To that end, we conducted a systematic review. Six clinical trials with 2111 patients were included. In head-to-head comparisons, immunotherapy showed a significant improvement in progression-free survival (PFS: HRpooled = 0.69, 95% CI: 0.52-0.90, p = 0.007), overall survival (OS: HRpooled = 0.69, 95% CI: 0.61-0.78; p < 0.001) and overall response rate (ORR) (Risk ratio (RR)pooled = 1.354, 95% CI: 1.04-1.762, p = 0.024). In the assessment of relative efficacy for PFS through indirect comparisons, pembrolizumab (results from KEYNOTE-024) ranked highest followed by cemiplimab and atezolizumab, with statistical significance determined for some of the drugs. In terms of OS, cemiplimab ranked highest followed by atezolizumab and pembrolizumab, although non-significant OS was determined for these drugs. In conclusion, PD-(L)1 inhibitor mon-otherapy improves efficacy outcomes in the first line setting of advanced NSCLC patients with high PD-L1 expression. Evaluations with longer follow up are still needed to determine the superiority of any specific drug

Long-Term Satisfaction and Body Image After Contralateral Prophylactic Mastectomy

Background: Contralateral prophylactic mastectomy (CPM) rates have been increasing in the US, and although high levels of satisfaction with CPM have been reported, few studies have evaluated the long-term effects on body image, comparing CPM with breast-conserving surgery (BCS) and unilateral mastectomy (UM). Methods: We analyzed responses from a survey of women with both a personal and family history of breast cancer who were enrolled in the Sister Study (n = 1176). Among women who underwent mastectomy, we examined satisfaction with the mastectomy decision, as well as variation in the use of reconstruction and experience of complications. Five survey items, evaluated individually and as a summed total score, were used to compare body image across surgery types (BCS, UM without reconstruction, CPM without reconstruction, UM with reconstruction, and CPM with reconstruction). Results: Participants were, on average, 3.6 years post-diagnosis at the time of survey (standard deviation 1.7). The majority of women (97% of CPM, 89% of UM) were satisfied with their mastectomy decision. Reconstruction was more common after CPM than after UM (70 vs. 47%), as were complications (28 vs. 19%). Body image scores were significantly worse among women who underwent CPM than among women who underwent BCS, with the lowest scores among women who underwent CPM without reconstruction. Conclusions: In our sample, most women were highly satisfied with their mastectomy decision, including those who elected to undergo CPM. However, body image was lower among those who underwent CPM than among those who underwent BCS. Our findings may inform decisions among women considering various courses of surgical treatment