1,217 research outputs found
Isolated Splenic Metastasis from Colorectal Cancer: Report of a Case
The authors report a case of a patient with splenic metastasis with previous history of colorectal cancer. A 69-year-old woman underwent a left hemicolectomy for sigmoid colon cancer. The tumor was staged T3N0M0. Two years after the operation, there was an elevation of CEA and computed tomography (CT) scan revealed a mass in the spleen, considered as an isolated metastasis. The patient underwent splenectomy. Histological diagnosis confirmed a metastatic adenocarcinoma from colorectal carcinoma. Patient was alive without neoplasic recurrence 5 years after splenectomy. Generally, splenic metastasis is uncommon. However, with the case of colorectal cancers, metastasis to the spleen is particularly rare. As with splenic metastasis of all primary tumors, the literature recommends that the treatment, where possible, is surgical
Simulations for single-dish intensity mapping experiments
HI intensity mapping is an emerging tool to probe dark energy. Observations
of the redshifted HI signal will be contaminated by instrumental noise,
atmospheric and Galactic foregrounds. The latter is expected to be four orders
of magnitude brighter than the HI emission we wish to detect. We present a
simulation of single-dish observations including an instrumental noise model
with 1/f and white noise, and sky emission with a diffuse Galactic foreground
and HI emission. We consider two foreground cleaning methods: spectral
parametric fitting and principal component analysis. For a smooth frequency
spectrum of the foreground and instrumental effects, we find that the
parametric fitting method provides residuals that are still contaminated by
foreground and 1/f noise, but the principal component analysis can remove this
contamination down to the thermal noise level. This method is robust for a
range of different models of foreground and noise, and so constitutes a
promising way to recover the HI signal from the data. However, it induces a
leakage of the cosmological signal into the subtracted foreground of around 5%.
The efficiency of the component separation methods depends heavily on the
smoothness of the frequency spectrum of the foreground and the 1/f noise. We
find that as, long as the spectral variations over the band are slow compared
to the channel width, the foreground cleaning method still works.Comment: 14 pages, 12 figures. Submitted to MNRA
Asteroseismic Theory of Rapidly Oscillating Ap Stars
This paper reviews some of the important advances made over the last decade
concerning theory of roAp stars.Comment: 9 pages, 5 figure
Benefits of Urologic-Dermatologic Consultations for the Diagnosis of Cutaneous Penile Lesions: AÂ Prospective Study
INTRODUCTION: We evaluated the benefits of a specialized consultation created in 2014 for cutaneous penile lesions.
MATERIALS AND METHODS: We performed a descriptive prospective study evaluating all patients sent for a monthly urologic-dermatologic consultation at a French university hospital from September 2014 to September 2015 for cutaneous penile lesions. All patients evaluated were included. We collected the demographic data, clinical examination findings, and the proposed diagnosis and treatment for every patient.
RESULTS: A total of 27 patients were included; 4 (14.8%) had been referred by a general physician and 23 (85.2%) by a specialist. Cutaneous penile lesions had evolved within 12 months in 15 patients (55.6%). Penile cancer was diagnosed in 5 patients (18.5%), of which 3 were squamous cell carcinoma (11.1%), 1 was metastasis of melanoma (3.7%), and 1 was extramammary Paget disease (3.7%). In addition, 1 patient (3.7%) had a premalignant lesion on a condyloma, 12 (44.4%) had balanitis, 2 (7.4%) had psoriasis lesions, 3 (11.1%) had condylomas, 1 (3.7%) had genital melanosis, and 3 (11.2%) had normal findings. Four patients (16.6%) underwent biopsy, 8 (33.3%) underwent surgery, and 12 (50%) received local treatment.
CONCLUSION: The use of urologic-dermatology specialized consultations resulted in encouraging findings. Patients can benefit from multidisciplinary expertise and rapid treatment of various disorders. Thus, it seems important to develop reference centers created specifically for cancerous disease
A large sample of calibration stars for Gaia: log g from Kepler and CoRoT
Asteroseismic data can be used to determine surface gravities with precisions
of < 0.05 dex by using the global seismic quantities Deltanu and nu_max along
with Teff and [Fe/H]. Surface gravity is also one of the four stellar
properties to be derived by automatic analyses for 1 billion stars from Gaia
data (workpackage GSP_Phot). We explore seismic data from MS F, G, K stars
(solar-like stars) observed by Kepler as a potential calibration source for
methods that Gaia will use for object characterisation (log g). We calculate
log g for bright nearby stars for which radii and masses are known, and using
their global seismic quantities in a grid-based method, we determine an
asteroseismic log g to within 0.01 dex of the direct calculation, thus
validating the accuracy of our method. We find that errors in Teff and mainly
[Fe/H] can cause systematic errors of 0.02 dex. We then apply our method to a
list of 40 stars to deliver precise values of surface gravity, i.e. sigma <
0.02 dex, and we find agreement with recent literature values. Finally, we
explore the precision we expect in a sample of 400+ Kepler stars which have
their global seismic quantities measured. We find a mean uncertainty
(precision) on the order of <0.02 dex in log g over the full explored range 3.8
< log g < 4.6, with the mean value varying only with stellar magnitude (0.01 -
0.02 dex). We study sources of systematic errors in log g and find possible
biases on the order of 0.04 dex, independent of log g and magnitude, which
accounts for errors in the Teff and [Fe/H] measurements, as well as from using
a different grid-based method. We conclude that Kepler stars provide a wealth
of reliable information that can help to calibrate methods that Gaia will use,
in particular, for source characterisation with GSP_Phot where excellent
precision (small uncertainties) and accuracy in log g is obtained from seismic
data.Comment: Accepted MNRAS, 15 pages (10 figures and 3 tables), v2=some rewording
of two sentence
Relativistic and Radiative Energy Shifts for Rydberg States
We investigate relativistic and quantum electrodynamic effects for
highly-excited bound states in hydrogenlike systems (Rydberg states). In
particular, hydrogenic one-loop Bethe logarithms are calculated for all
circular states (l = n-1) in the range 20 <= n <= 60 and successfully compared
to an existing asymptotic expansion for large principal quantum number n. We
provide accurate expansions of the Bethe logarithm for large values of n, for
S, P and circular Rydberg states. These three expansions are expected to give
any Bethe logarithms for principal quantum number n > 20 to an accuracy of five
to seven decimal digits, within the specified manifolds of atomic states.
Within the numerical accuracy, the results constitute unified, general formulas
for quantum electrodynamic corrections whose validity is not restricted to a
single atomic state. The results are relevant for accurate predictions of
radiative shifts of Rydberg states and for the description of the recently
investigated laser-dressed Lamb shift, which is observable in a strong
coherent-wave light field.Comment: 8 pages; RevTeX
Synthesis and characterization of core-shell structure silica-coated Fe29.5Ni70.5 nanoparticles
In view of potential applications of magnetic particles in biomedicine and
electromagnetic devices, we made use of the classical Stober method
base-catalysed hydrolysis and condensation of tetraethoxysilane (TEOS) to
encapsulate FeNi nanoparticles within a silica shell. An original stirring
system under high power ultrasounds made possible to disperse the otherwise
agglomerated particles. Sonication guaranteed particles to remain dispersed
during the Stober synthesis and also improved the efficiency of the method. The
coated particles are characterized by electron microscopy (TEM) and
spectroscopy (EDX) showing a core-shell structure with a uniform layer of
silica. Silica-coating does not affect the core magnetic properties. Indeed,
all samples are ferromagnetic at 77 K and room temperature and the Curie point
remains unchanged. Only the coercive force shows an unexpected non-monotonous
dependence on silica layer thickness.Comment: Regular paper submited to international peer-reveiwed journa
Evolution of INPOP planetary ephemerides and Bepi-Colombo simulations
We give here a detailed description of the latest INPOP planetary ephemerides
INPOP20a. We test the sensitivity of the Sun oblateness determination obtained
with INPOP to different models for the Sun core rotation. We also present new
evaluations of possible GRT violations with the PPN parameters ,
and . With a new method for selecting acceptable alternative
ephemerides we provide conservative limits of about and
for and respectively using the
present day planetary data samples. We also present simulations of Bepi-Colombo
range tracking data and their impact on planetary ephemeris construction. We
show that the use of future BC range observations should improve these
estimates, in particular . Finally, interesting perspectives for the
detection of the Sun core rotation seem to be reachable thanks to the BC
mission and its accurate range measurements in the GRT frame.Comment: Proceedings of the IAU Symposium 364 "Multi-scale dynamics of space
objects
The fundamental parameters of the roAp star 10 Aql
Due to the strong magnetic field and related abnormal surface layers existing
in rapidly oscillating Ap stars, systematic errors are likely to be present
when determining their effective temperatures, which potentially compromises
asteroseismic studies of these pulsators. Using long-baseline interferometry,
our goal is to determine accurate angular diameters of a number of roAp targets
to provide a temperature calibration for these stars. We obtained
interferometric observations of 10 Aql with the visible spectrograph VEGA at
the CHARA array. We determined a limb-darkened angular diameter of
0.275+/-0.009 mas and deduced a linear radius of 2.32+/-0.09 R_sun. We
estimated the star's bolometric flux and used it, in combination with its
parallax and angular diameter, to determine the star's luminosity and effective
temperature. For two data sets of bolometric flux we derived an effective
temperature of 7800+/-170 K and a luminosity of 18+/-1 L_sun or of 8000+/-210 K
and 19+/-2 L_sun. We used these fundamental parameters together with the large
frequency separation to constrain the mass and the age of 10 Aql, using the
CESAM stellar evolution code. Assuming a solar chemical composition and
ignoring all kinds of diffusion and settling of elements, we obtained a mass of
1.92 M_sun and an age of 780 Gy or a mass of 1.95 M_sun and an age of 740 Gy,
depending on the considered bolometric flux. For the first time, we managed to
determine an accurate angular diameter for a star smaller than 0.3 mas and to
derive its fundamental parameters. In particular, by only combining our
interferometric data and the bolometric flux, we derived an effective
temperature that can be compared to those derived from atmosphere models. Such
fundamental parameters can help for testing the mechanism responsible for the
excitation of the oscillations observed in the magnetic pulsating stars
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