4,019 research outputs found
Response to. comment on optic nerve sheath diameter ultrasound evaluation in intensive care unit: possible role and clinical aspects in neurological critical patients' daily monitoring
Comment on "Optic Nerve Sheath Diameter Ultrasound Evaluation in Intensive Care Unit: Possible Role and Clinical Aspects in Neurological Critical Patients' Daily Monitoring"
Kinematic and stellar population properties of the counter-rotating components in the S0 galaxy NGC 1366
Context. Many disk galaxies host two extended stellar components that rotate in opposite directions. The analysis of the stellar populations of the counter-rotating components provides constraints on the environmental and internal processes that drive their formation. Aims. The S0 NGC 1366 in the Fornax cluster is known to host a stellar component that is kinematically decoupled from the main body of the galaxy. Here we successfully separated the two counter-rotating stellar components to independently measure the kinematics and properties of their stellar populations. Methods. We performed a spectroscopic decomposition of the spectrum obtained along the galaxy major axis and separated the relative contribution of the two counter-rotating stellar components and of the ionized-gas component. We measured the line-strength indices of the two counter-rotating stellar components and modeled each of them with single stellar population models that account for the \u3b1/Fe overabundance. Results. We found that the counter-rotating stellar component is younger, has nearly the same metallicity, and is less \u3b1/Fe enhanced than the corotating component. Unlike most of the counter-rotating galaxies, the ionized gas detected in NGC 1366 is neither associated with the counter-rotating stellar component nor with the main galaxy body. On the contrary, it has a disordered distribution and a disturbed kinematics with multiple velocity components observed along the minor axis of the galaxy. Conclusions. The different properties of the counter-rotating stellar components and the kinematic peculiarities of the ionized gas suggest that NGC 1366 is at an intermediate stage of the acquisition process, building the counter-rotating components with some gas clouds still falling onto the galaxy. \ua9 ESO 2017
Second-look turbt: Evaluation of anatomopatological and oncologic results in a single center
Introduction: T1 bladder cancer is associated with a high risk of recurrence and progression; concomitant carcinoma in situ and/or multifocality are negative prognostic factors. Persistent disease after resection of T1 tumours has been observed in 33-55% of patients, and after resection of High-grade (HG) Ta tumour in 41,4%. It has been demonstrated that a second TURB can increase recurrence-free survival and it can make a restaging of the cancer. Patients and methods: From January 2011 to December 2016, 87 patients with superficial bladder tumor (Ta-T1), undergoing TURB and routine repeat TURB (Re-TURB) 4-6 weeks after the initial resection, were included in the study. Re-TURB was applied to the scar of the first resection and other suspicious lesions in the bladder. After the second-look, we studied the follow-up of each patient. Results: Specimens obtained during the second TURBT showed no tumor in 47 (54,02%) patients; 40 (45,98%) patients had residual cancer: 34 of them had cancer of the same stage, 6 patients of pT1 had a lower stage, and 3 had a higher stage. 5 patient underwent radical cistectomy immediatly after re-TURBT. During the first year of follow up, 15 patients had a recurrent bladder cancer; 2 of them underwent radical cistectomy. Conclusions: T1 bladder cancer is an high risk tumor, so that second-look TURBT is a valuable procedure for accurate staging of nonmuscle-invasive bladder cancer and it can guarantee a better eradicationof the neoplasm
Nearly optimal solutions for the Chow Parameters Problem and low-weight approximation of halfspaces
The \emph{Chow parameters} of a Boolean function
are its degree-0 and degree-1 Fourier coefficients. It has been known
since 1961 (Chow, Tannenbaum) that the (exact values of the) Chow parameters of
any linear threshold function uniquely specify within the space of all
Boolean functions, but until recently (O'Donnell and Servedio) nothing was
known about efficient algorithms for \emph{reconstructing} (exactly or
approximately) from exact or approximate values of its Chow parameters. We
refer to this reconstruction problem as the \emph{Chow Parameters Problem.}
Our main result is a new algorithm for the Chow Parameters Problem which,
given (sufficiently accurate approximations to) the Chow parameters of any
linear threshold function , runs in time \tilde{O}(n^2)\cdot
(1/\eps)^{O(\log^2(1/\eps))} and with high probability outputs a
representation of an LTF that is \eps-close to . The only previous
algorithm (O'Donnell and Servedio) had running time \poly(n) \cdot
2^{2^{\tilde{O}(1/\eps^2)}}.
As a byproduct of our approach, we show that for any linear threshold
function over , there is a linear threshold function which
is \eps-close to and has all weights that are integers at most \sqrt{n}
\cdot (1/\eps)^{O(\log^2(1/\eps))}. This significantly improves the best
previous result of Diakonikolas and Servedio which gave a \poly(n) \cdot
2^{\tilde{O}(1/\eps^{2/3})} weight bound, and is close to the known lower
bound of (1/\eps)^{\Omega(\log \log (1/\eps))}\} (Goldberg,
Servedio). Our techniques also yield improved algorithms for related problems
in learning theory
Genetic Features of Metachronous Esophageal Cancer Developed in Hodgkin's Lymphoma or Breast Cancer Long-Term Survivors: An Exploratory Study.
Background
Development of novel therapeutic drugs and regimens for cancer treatment has led to improvements in patient long-term survival. This success has, however, been accompanied by the increased occurrence of second primary cancers. Indeed, patients who received regional radiotherapy for Hodgkin's Lymphoma (HL) or breast cancer may develop, many years later, a solid metachronous tumor in the irradiated field. Despite extensive epidemiological studies, little information is available on the genetic changes involved in the pathogenesis of these solid therapy-related neoplasms.
Methods
Using microsatellite markers located in 7 chromosomal regions frequently deleted in sporadic esophageal cancer, we investigated loss of heterozygosity (LOH) and microsatellite instability (MSI) in 46 paired (normal and tumor) samples. Twenty samples were of esophageal carcinoma developed in HL or breast cancer long-term survivors: 14 squamous cell carcinomas (ESCC) and 6 adenocarcinomas (EADC), while 26 samples, used as control, were of sporadic esophageal cancer (15 ESCC and 11 EADC).
Results
We found that, though the overall LOH frequency at the studied chromosomal regions was similar among metachronous and sporadic tumors, the latter exhibited a statistically different higher LOH frequency at 17q21.31 (p = 0.018). By stratifying for tumor histotype we observed that LOH at 3p24.1, 5q11.2 and 9p21.3 were more frequent in ESCC than in EADC suggesting a different role of the genetic determinants located nearby these regions in the development of the two esophageal cancer histotypes.
Conclusions
Altogether, our results strengthen the genetic diversity among ESCC and EADC whether they occurred spontaneously or after therapeutic treatments. The presence of histotype-specific alterations in esophageal carcinoma arisen in HL or breast cancer long-term survivors suggests that their transformation process, though the putative different etiological origin, may retrace sporadic ESCC and EADC carcinogenesis
Impact of NNLO QED corrections on lepton-proton scattering at MUSE
We present the complete next-to-next-to-leading order (NNLO) pure pointlike
QED corrections to lepton-proton scattering, including three-photon-exchange
contributions, and investigate their impact in the case of the MUSE experiment.
These corrections are computed with no approximation regarding the energy of
the emitted photons and taking into account lepton-mass effects. We contrast
the NNLO QED corrections to known next-to-leading order corrections, where we
include the elastic two-photon exchange (TPE) through a simple hadronic model
calculation with a dipole ansatz for the proton electromagnetic form factors.
We show that, in the low-momentum-transfer region accessed by the MUSE
experiment, the improvement due to more sophisticated treatments of the TPE,
including inelastic TPE, is of similar if not smaller size than some of the
NNLO QED corrections. Hence, the latter have to be included in a precision
determination of the low-energy proton structure from scattering data, in
particular for electron-proton scattering. For muon-proton scattering, the NNLO
QED corrections are considerably smaller.Comment: Article to be submitted to the EPJ A Topical Collection: Radiative
Corrections: From Medium to High Energy Experiments. 23 pages, 9 figure
Impact of NNLO QED corrections on lepton-proton scattering at MUSE
We present the complete next-to-next-to-leading order (NNLO) pure pointlike QED corrections to lepton-proton scattering, including three-photon-exchange contributions, and investigate their impact in the case of the MUSE experiment. These corrections are computed with no approximation regarding the energy of the emitted photons and taking into account lepton-mass effects. We contrast the NNLO QED corrections to known next-to-leading order corrections, where we include the elastic two-photon exchange (TPE) through a simple hadronic model calculation with a dipole ansatz for the proton electromagnetic form factors. We show that, in the low-momentum-transfer region accessed by the MUSE experiment, the improvement due to more sophisticated treatments of the TPE, including inelastic TPE, is of similar if not smaller size than some of the NNLO QED corrections. Hence, the latter have to be included in a precision determination of the low-energy proton structure from scattering data, in particular for electron-proton scattering. For muon-proton scattering, the NNLO QED corrections are considerably smaller
Impact of NNLO QED corrections on lepton-proton scattering at MUSE
We present the complete next-to-next-to-leading order (NNLO) pure pointlike QED corrections to lepton-proton scattering, including three-photon-exchange contributions, and investigate their impact in the case of the MUSE experiment. These corrections are computed with no approximation regarding the energy of the emitted photons and taking into account lepton-mass effects. We contrast the NNLO QED corrections to known next-to-leading order corrections, where we include the elastic two-photon exchange (TPE) through a simple hadronic model calculation with a dipole ansatz for the proton electromagnetic form factors. We show that, in the low-momentum-transfer region accessed by the MUSE experiment, the improvement due to more sophisticated treatments of the TPE, including inelastic TPE, is of similar if not smaller size than some of the NNLO QED corrections. Hence, the latter have to be included in a precision determination of the low-energy proton structure from scattering data, in particular for electron-proton scattering. For muon-proton scattering, the NNLO QED corrections are considerably smaller
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