There is not enough clinical evidence to make a strong recommendation on the optimal duration of thromboprophylaxis using low-molecular weight heparins (LMWH) in patients undergoing major cancer ...surgery.
CANBESURE is a randomized, double-blind study which enrolled patients admitted for abdominal or pelvic surgery for cancer. They received 3500 IU of bemiparin subcutaneously once daily for 8 days and were then randomized to receive either bemiparin or placebo for 20 additional days. Bilateral venography was performed after 20 days and evaluated blinded. The primary efficacy outcome was the composite of deep vein thrombosis (DVT), non-fatal pulmonary embolism (PE) and all-cause mortality at the end of double-blind period. Major venous thromboembolism (proximal deep-vein thrombosis, non-fatal pulmonary embolism and venous thromboembolism-related deaths) was also evaluated. The primary safety outcome was major bleeding.
Six hundred and twenty-five and 488 patients were included in the safety and main efficacy analyzes, respectively. The primary efficacy outcome occurred in 25 out of 248 patients (10.1%) in the bemiparin group and 32 out of 240 (13.3%) in the placebo group (relative risk reduction 24.4%; 95% CI: -23.7-53.8%; P = 0.26). At the end of double-blind period, major venous thromboembolism occurred in 2 (0.8%) and 11 (4.6%) patients, respectively (relative risk reduction 82.4%; 95% CI: 21.5-96.1%; P = 0.010). No significant difference was found in major bleedings.
Four weeks compared with 1 week of prophylaxis with bemiparin after abdominal or pelvic cancer surgery did not significantly reduce the primary efficacy outcome, but decreased major venous thromboembolism (VTE) without increasing hemorrhagic complications.
The origin of the unification model for active galactic nuclei (AGN) was the detection of broad hydrogen recombination lines in the optical polarized spectrum of the Seyfert 2 galaxy (Sy2) NGC 1068. ...Since then, a search for the hidden broad-line region (HBLR) of nearby Sy2s started, but polarized broad lines have only been detected in ∼30–40 per cent of the nearby Sy2s observed to date. Here we present new VLT/FORS2 optical spectropolarimetry of a sample of 15 Sy2s, including Compton-thin and Compton-thick sources. The sample includes six galaxies without previously published spectropolarimetry, some of them normally treated as non-hidden BLR (NHBLR) objects in the literature, four classified as NHBLR, and five as HBLR based on previous data. We report ≥4σ detections of a HBLR in 11 of these galaxies (73 per cent of the sample) and a tentative detection in NGC 5793, which is Compton-thick according to the analysis of X-ray data performed here. Our results confirm that at least some NHBLRs are misclassified, bringing previous publications reporting differences between HBLR and NHBLR objects into question. We detect broad Hα and Hβ components in polarized light for 10 targets, and just broad Hα for NGC 5793 and NGC 6300, with line widths ranging between 2100 and 9600 km s−1. High bolometric luminosities and low column densities are associated with higher polarization degrees, but not necessarily with the detection of the scattered broad components.
We investigate the emergence of magnetic flux in the quiet Sun at very small spatial scales, focusing on the magnetic connection between the photosphere and chromosphere. The observational data ...consist of spectropolarimetric measurements and filtergrams taken with the Hinode satellite and the Dutch Open Telescope. We find that a significant fraction of the magnetic flux present in internetwork regions appears in the form of Omega-shaped loops. The emergence rate is 0.02 loops per hour and arcsec-2, which brings 1.1 × 1012 Mx s-1 arcsec-2 of new flux to the solar surface. Initially, the loops are observed as small patches of linear polarization above a granular cell. Shortly afterward, two footpoints of opposite polarity become visible in circular polarization within or at the edges of the granule and start moving toward the adjacent intergranular space. The orientation of the footpoints does not seem to obey Hale's polarity rules. The loops are continuously buffeted by convective motions, but they always retain a high degree of coherence. Interestingly, 23% of the loops that emerge in the photosphere reach the chromosphere (16 cases out of 69). They are first detected in Fe I 630 nm magnetograms and 5 minutes later in Mg I b 517.3 nm magnetograms. After about 8 minutes, some of them are also observed in Ca II H line-core images, where the footpoints produce small brightness enhancements.
Abstract
The Sun is the only star where we can resolve the intricate magnetism that all convective stars harbor. Yet, more than 99% of its visible surface along the solar cycle (the so-called quiet ...Sun) is filled with a tangled, unresolved magnetism. These “hidden” fields are thought to store enough magnetic energy to play a role in the heating of the Sun’s outer atmosphere, but its field strength is still not constrained. Previous investigations based on the Hanle effect in atomic lines claim a strong magnetization of about 100 G, while the same effect in molecules show a factor of 10 weaker fields. The discrepancy disappears if the magnetic field strength of the hidden field is not homogeneous in the solar surface. In this Letter, we prove using magnetohydrodynamical simulations that it is possible to infer the average field strength of the hidden quiet-Sun magnetic fields using multiline inversions of intensity profiles in the Zeeman regime. Using this technique with 15 spectral lines in the 1.5
μ
m spectral range, we reveal that the spatial distribution of the hidden field is strongly correlated with convection motions, and that the average magnetization is about 46 G. Reconciling our findings with the Hanle ones is not obvious and will require future work on both sides, since it implies an increase of the field strength with height, something that is physically questionable.
Standard statistical analysis of the magnetic properties of the quiet Sun rely on simple histograms of quantities inferred from maximum-likelihood estimations. Because of the inherent degeneracies, ...either intrinsic or induced by the noise, this approach is not optimal and can lead to highly biased results. We carried out a meta-analysis of the magnetism of the quiet Sun from Hinode observations using a hierarchical probabilistic method. This method allowed us to infer the statistical properties of the magnetic field vector over the observed field-of-view, consistently taking into account the uncertainties in each pixel that are due to noise and degeneracies. Our results imply that the magnetic fields are very weak, below 275 G with 95% probability, with a slight preference for horizontal fields, although the distribution is not far from a quasi-isotropic distribution.
Context. Solar chromospheric fibrils, as observed in the core of strong chromospheric spectral lines, extend from photospheric field concentrations suggesting that they trace magnetic field lines. ...These images have been historically used as proxies of magnetic fields for many purposes. Aims. Use statistical analysis to test whether the association between fibrils and magnetic field lines is justified. Methods. We use a Bayesian hierarchical model to analyze several tens of thousands of pixels in spectro-polarimetric chromospheric images of penumbrae and chromospheric fibrils. We compare the alignment between the field azimuth inferred from the linear polarization signals through the transverse Zeeman effect and the direction of the fibrils in the image. Results. We conclude that, in the analyzed fields of view, fibrils are often well aligned with the magnetic field azimuth. Despite this alignment, the analysis also shows that there is a non-negligible dispersion. In penumbral filaments, we find a dispersion with a standard deviation of ~ 16°, while this dispersion goes up to ~ 34° in less magnetized regions.
Summary
Background
Suboptimal response to ursodeoxycholic acid occurs in 40% of primary biliary cholangitis (PBC) patients, affecting survival. Achieving a deep response (normalisation of alkaline ...phosphatase ALP and bilirubin ≤0.6 upper limit of normal) improves survival. Yet, the long‐term effectiveness of second‐line treatments remains uncertain.
Aims
To evaluate the long‐term effectiveness of obeticholic acid (OCA) ± fibrates. Focusing on biochemical response (ALP ≤1.67 times the upper limit of normal, with a decrease of at least 15% from baseline and normal bilirubin levels), normalisation of ALP, deep response and biochemical remission (deep response plus aminotransferase normalisation).
Methods
We conducted a longitudinal, observational, multicentre study involving ursodeoxyccholic acid non‐responsive PBC patients (Paris‐II criteria) from Spain and Portugal who received OCA ± fibrates.
Results
Of 255 patients, median follow‐up was 35.1 months (IQR: 20.2–53). The biochemical response in the whole cohort was 47.2%, 61.4% and 68.6% at 12, 24 and 36 months. GLOBE‐PBC and 5‐year UK‐PBC scores improved (p < 0.001). Triple therapy (ursodeoxycholic acid plus OCA plus fibrates) had significantly higher response rates than dual therapy (p = 0.001), including ALP normalisation, deep response and biochemical remission (p < 0.001). In multivariate analysis, triple therapy remained independently associated with biochemical response (p = 0.024), alkaline phosphatase normalisation, deep response and biochemical remission (p < 0.001). Adverse effects occurred in 41.2% of cases, leading to 18.8% discontinuing OCA. Out of 55 patients with cirrhosis, 12 developed decompensation. All with baseline portal hypertension.
Conclusion
Triple therapy was superior in achieving therapeutic goals in UDCA‐nonresponsive PBC. Decompensation was linked to pre‐existing portal hypertension.
Longitudinal, real‐world study on 255 UDCA‐nonresponsive PBC patients (Per Paris II criteria); median follow‐up of 35.1 months (IQR: 20–53). All patients received obeticholic acid (OCA), with 25% receiving later add‐on fibrate treatment (triple therapy). In multivariate analysis, triple therapy outperformed dual therapy across all surrogate biochemical endpoints of outcomes.
The polarized spectrum of stellar radiation encodes valuable information on the conditions of stellar atmospheres and the magnetic fields that permeate them. In this paper, we give explicit ...expressions to estimate the magnetic field vector and its associated error from the observed Stokes parameters. We study the solar case where specific intensities are observed and then the stellar case, where we receive the polarized flux. In the second case, we concentrate on the explicit expression for the case of a slow rotator with a dipolar magnetic field geometry. Moreover, we also give explicit formulae to retrieve the magnetic field vector from the least-squares deconvolution (LSD) profiles without assuming mean values for the LSD artificial spectral line. The formulae have been obtained assuming that the spectral lines can be described in the weak-field regime and using a maximum likelihood approach. The errors are recovered by means of the Hermitian matrix. The bias of the estimators is analysed in depth.
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