937 research outputs found
Strong Pinning in High Temperature Superconductors
Detailed measurements of the critical current density jc of YBa2Cu3O7 films
grown by pulsed laser deposition reveal the increase of jc as function of the
filmthickness. Both this thickness dependence and the field dependence of the
critical current are consistently described using a generalization of the
theory of strong pinning of Ovchinnikov and Ivlev [Phys. Rev. B 43, 8024
(1991)]. From the model, we deduce values of the defect density (10^21 m^-3)
and the elementary pinning force, which are in good agreement with the
generally accepted values for Y2O3-inclusions. In the absence of clear evidence
that the critical current is determined by linear defects or modulations of the
film thickness, our model provides an alternative explanation for the rather
universal field dependence of the critical current density found in YBa2Cu3O7
films deposited by different methods.Comment: 11 pages; 8 Figures; Published Phys. Rev. B 66, 024523 (2002
Relating jet structure to photometric variability: the Herbig Ae star HD 163296
Herbig Ae/Be stars are intermediate-mass pre-main sequence stars surrounded
by circumstellar dust disks. Some are observed to produce jets, whose
appearance as a sequence of shock fronts (knots) suggests a past episodic
outflow variability. This "jet fossil record" can be used to reconstruct the
outflow history. We present the first optical to near-infrared (NIR)
VLT/X-shooter spectra of the jet from the Herbig Ae star HD 163296. We
determine physical conditions in the knots, as well as their kinematic "launch
epochs". Knots are formed simultaneously on either side of the disk, with a
regular interval of ~16 yr. The velocity dispersion versus jet velocity and the
energy input are comparable in both lobes. However, the mass loss rate,
velocity, and shock conditions are asymmetric. We find Mjet/Macc ~ 0.01-0.1,
consistent with magneto-centrifugal jet launching models. No evidence for dust
is found in the high-velocity jet, suggesting it is launched within the
sublimation radius (<0.5 au). The jet inclination measured from proper motions
and radial velocities confirms it is perpendicular to the disk. A tentative
relation is found between the structure of the jet and the photometric
variability of the source. Episodes of NIR brightening were previously detected
and attributed to a dusty disk wind. We report for the first time significant
optical fadings lasting from a few days up to a year, coinciding with the NIR
brightenings. These are likely caused by dust lifted high above the disk plane;
this supports the disk wind scenario. The disk wind is launched at a larger
radius than the high-velocity atomic jet, although their outflow variability
may have a common origin. No significant relation between outflow and accretion
variability could be established. Our findings confirm that this source
undergoes periodic ejection events, which may be coupled with dust ejections
above the disk plane.Comment: 20 pages, 11 figures, accepted for publication in Astronomy &
Astrophysic
Angiogenesis in gynecological cancers and the options for anti-angiogenesis therapy.
Angiogenesis is required in cancer, including gynecological cancers, for the growth of primary tumors and secondary metastases. Development of anti-angiogenesis therapy in gynecological cancers and improvement of its efficacy have been a major focus of fundamental and clinical research. However, survival benefits of current anti-angiogenic agents, such as bevacizumab, in patients with gynecological cancer, are modest. Therefore, a better understanding of angiogenesis and the tumor microenvironment in gynecological cancers is urgently needed to develop more effective anti-angiogenic therapies, either or not in combination with other therapeutic approaches. We describe the molecular aspects of (tumor) blood vessel formation and the tumor microenvironment and provide an extensive clinical overview of current anti-angiogenic therapies for gynecological cancers. We discuss the different phenotypes of angiogenic endothelial cells as potential therapeutic targets, strategies aimed at intervention in their metabolism, and approaches targeting their (inflammatory) tumor microenvironment
The MIRI Medium Resolution Spectrometer calibration pipeline
The Mid-Infrared Instrument (MIRI) Medium Resolution Spectrometer (MRS) is
the only mid-IR Integral Field Spectrometer on board James Webb Space
Telescope. The complexity of the MRS requires a very specialized pipeline, with
some specific steps not present in other pipelines of JWST instruments, such as
fringe corrections and wavelength offsets, with different algorithms for point
source or extended source data. The MRS pipeline has also two different
variants: the baseline pipeline, optimized for most foreseen science cases, and
the optimal pipeline, where extra steps will be needed for specific science
cases. This paper provides a comprehensive description of the MRS Calibration
Pipeline from uncalibrated slope images to final scientific products, with
brief descriptions of its algorithms, input and output data, and the accessory
data and calibration data products necessary to run the pipeline.Comment: 10 pages, 8 figure
Severe heart failure in the setting of inflammatory cardiomyopathy with likely pathogenic titin variant
Ebstein’s anomaly may be caused by mutations in the sarcomere protein gene MYH7
Ebstein's anomaly is a rare congenital heart malformation characterised by adherence of the septal and posterior leaflets of the tricuspid valve to the underlying myocardium. Associated abnormalities of left ventricular morphology and function including left ventricular noncompaction (LVNC) have been observed. An association between Ebstein's anomaly with LVNC and mutations in the sarcomeric protein gene MYH7, encoding β-myosin heavy chain, has been shown by recent studies. This might represent a specific subtype of Ebstein's anomaly with a Mendelian inheritance pattern. In this review we discuss the association of MYH7 mutations with Ebstein's anomaly and LVNC and its implications for the clinical care for patients and their family members.Congenital Heart Diseas
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