5,191 research outputs found
Multiwavelength study of the starburst galaxy NGC7714. I: Ultraviolet-Optical spectroscopy
We have studied the physical conditions in the central 300 pc of the
proto-typical starburst galaxy NGC 7714. Our analysis is based on ultraviolet
spectroscopy with the HST+GHRS and ground-based optical observations.The data
are interpreted using evolutionary models optimized for young starburst
regions. The massive stellar population is derived in a self-consistent way
using the continuum and stellar absorption lines in the ultraviolet and the
nebular emission line optical spectrum.
The central starburst has an age of about 4.5 Myr, with little evidence for
an age spread. Wolf-Rayet features at the ultraviolet indicates a stellar
population of 2000 Wolf-Rayet stars. The overall properties of the newly
formed stars are quite similar to those derived, e.g., in 30 Doradus. A
standard Salpeter IMF is consistent with all observational constraints. We find
evidence for spatial structure within the central 300 pc sampled. Therefore it
is unlikely that the nucleus of NGC 7714 hosts a single star cluster exceeding
the properties of other known clusters. Contrary to previous suggestions, we
find no evidence for a nuclear supernova rate that would significantly exceed
the total disk-integrated rate. About one supernova event per century is
predicted.Comment: 19 pages, 9 figures in a tar file. Accepted for publication in ApJ,
1999, March, issue 51
Experiencia en reconstrucción mamaria inmediata con prótesis pre pectoral post mastectomía con conservación de complejo areola pezón
El cáncer de mama es el tipo de cáncer más frecuente en el mundo y en mujeres en el Perú. Actualmente, la reconstrucción mamaria es una parte importante del tratamiento integral del cáncer de mama ya que tiene gran impacto en la calidad de vida de la paciente. Existen diversos tipos de reconstrucción mamaria, la cual se adecuada a las características de cada paciente como estadio de enfermedad, comorbilidades, preferencias de la paciente, etc. La reconstrucción aloplástica es la que se realiza más frecuentemente a nivel mundial debido a que no ocasiona morbilidad de otras zonas donantes, requiere un menor tiempo operatorio, menor estancia hospitalaria y tiene un tiempo de recuperación más corto. La reconstrucción mamaria con prótesis pre pectoral está teniendo cada más adeptos debido a que es una técnica que respeta los planos anatómicos, sin afectar el músculo pectoral, permitiendo que la reconstrucción sea inmediata y en un solo tiempo operatorio. El objetivo del trabajo es presentar una serie de casos de pacientes que fueron sometidas a reconstrucción mamaria inmediata con prótesis pre pectoral. Los criterios de inclusión fueron: localización de tumor a más de 3cm del complejo areola pezón, ausencia de compromiso del complejo areola pezón, mamas mediana o pequeñas con ptosis leve o moderada, adecuado grosor del colgajo graso evidenciado en la mamografía y pacientes no fumadoras. Se obtuvo mamas reconstruidas con resultados estéticamente adecuados Breast cancer is the most common cancer in the world and among Peruvian women. At the moment, breast reconstruction is an important part of the integral treatment of breast cancer because of its impact in the patient´s quality of life. There are many types of breast reconstruction to be chosen according to the characteristics of the patient, such as the disease stage, comorbidities, preferences of the patient, etc. Alloplastic reconstruction is the most common worldwide because it doesn´t generate morbidity in other parts of the body, it requires less time in the operating room, shorter hospital stay and a quicker recuperation period. Nowadays, the pre pectoral breast reconstruction with implants is a technique used frequently because it respects the anatomical planes, without affecting the pectoralis muscle and it is done just after the mastectomy and in just one time. The objective of this work is to present a case series of patients with immediate breast reconstruction pre pectoral with implants. The inclusion criteria were location of the tumor more than 3 cm from the nipple areola complex, no disease in the nipple areola complex, small or medium breasts with mild or moderate ptosis, adequate thickness of the fat flap evidenced on mammography and non-smokers patients. The results were aesthetically good, and in addition patients reported minimal post operative pain and shorter recovery time
The AMS-02 RICH Imager Prototype - In-Beam Tests with 20 GeV/c per Nucleon Ions -
A prototype of the AMS Cherenkov imager (RICH) has been tested at CERN by
means of a low intensity 20 GeV/c per nucleon ion beam obtained by
fragmentation of a primary beam of Pb ions. Data have been collected with a
single beam setting, over the range of nuclear charges 2<Z<~45 in various beam
conditions and using different radiators. The charge Z and velocity beta
resolutions have been measured.Comment: 4 pages, contribution to the ICRC 200
Preventing and addressing the stress reactions of health care workers caring for patients with COVID-19: Development of a digital platform (Be + against COVID)
Background: COVID-19 became a major public health concern in March 2020. Due to the high rate of hospitalizations for COVID-19 in a short time, health care workers and other involved staff are subjected to a large workload and high emotional distress.
Objective: The objective of this study is to develop a digital tool to provide support resources that might prevent and consider acute stress reactions in health care workers and other support staff due to the COVID-19 pandemic.
Methods: The contents of the digital platform were created through an evidence-based review and consensus conference. The website was built using the Google Blogger tool. The Android version of the app was developed in the Java and XML languages using Android Studio version 3.6, and the iOS version was developed in the Swift language using Xcode version 11.5. The app was evaluated externally by the Andalusian Agency for Healthcare Quality.
Results: We detected the needs and pressing situations of frontline health care workers, and then, we proposed a serial of recommendations and support resources to address them. These resources were redesigned using the feedback received. A website in three different languages (Spanish, English, and Portuguese) and a mobile app were developed with these contents, and the AppSaludable Quality Seal was granted to the app. A specific self-report scale to measure acute stress and additional tools were included to support the health care workforce. This instrument has been used in several Latin American countries and has been adapted considering cultural differences. The resources section of the website was the most visited with 18, 516 out of 68, 913 (26.9%) visits, and the “Self-Report Acute Stress Scale” was the most visited resource with 6468 out of 18, 516 (34.9%) visits.
Conclusions: The Be + against COVID platform (website and app) was developed and launched to offer a pool of recommendations and support resources, which were specifically designed to protect the psychological well-being and the work morale of health care workers. This is an original initiative different from the usual psychological assistance hotlines
The AMS-RICH velocity and charge reconstruction
The AMS detector, to be installed on the International Space Station,
includes a Ring Imaging Cerenkov detector with two different radiators, silica
aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to
provide very precise measurements of velocity and electric charge in a wide
range of cosmic nuclei energies and atomic numbers. The detector geometry, in
particular the presence of a reflector for acceptance purposes, leads to
complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The
results of different reconstruction methods applied to test beam data as well
as to simulated samples are presented. To ensure nominal performances
throughout the flight, several detector parameters have to be carefully
monitored. The algorithms developed to fulfill these requirements are
presented. The velocity and charge measurements provided by the RICH detector
endow the AMS spectrometer with precise particle identification capabilities in
a wide energy range. The expected performances on light isotope separation are
discussed.Comment: Contribution to the ICRC07, Merida, Mexico (2007); Presenter: F.
Bara
Ultraviolet-Optical observations of the Seyfert 2 Galaxies NGC 7130, NGC 5135 and IC 3639: Implications for the Starburst-AGN Connection
We present and discuss HST (WFPC2 and FOC) images and UV GHRS spectra plus
ground-based near UV through to near IR spectra of three Seyfert 2 nuclei (NGC
7130, NGC 5135 and IC 3639). These galaxies, together to Mrk 477, were selected
from a bigger sample that comprises the 20 brightest Seyfert 2 nuclei, with the
goal to study the origin of the UV-optical-near IR featureless continuum in
Seyfert 2 nuclei. These four galaxies have bolometric luminosities, as computed
with the four IRAS bands, of 10^11 Lsol. They are close enough to be resolved
with HST the nuclear zone. This makes these Seyfert 2 galaxies benchmarks to
study the Starburst-AGN connection in more distant galaxies.
The data provide direct evidence of the existence of a central nuclear
starburst that dominates the UV light, and that seem to be responsible for the
origin of the so called featureless continuum. These starbursts are dusty and
compact. They have sizes (from less than 100 pc to a few hundred pc) much
smaller and closer to the nucleus than that seen in the prototype Seyfert 2
galaxy NGC 1068. The bolometric luminosity of these starbursts is similar to
the estimated bolometric luminosities of their obscured Seyfert 1 nuclei, and
thus they contribute in the same amount to the overall energetics of these
galaxies.Comment: to be published in ApJ 505, September issue. The figures are in a tar
files at: http://www.iaa.es/~rosa/Seyfert
The RICH detector of the AMS-02 experiment: status and physics prospects
The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be
installed on the International Space Station (ISS) for at least 3 years, is a
detector designed to measure charged cosmic ray spectra with energies up to the
TeV region and with high energy photon detection capability up to a few hundred
GeV. It is equipped with several subsystems, one of which is a proximity
focusing RICH detector with a dual radiator (aerogel+NaF) that provides
reliable measurements for particle velocity and charge. The assembly and
testing of the AMS RICH is currently being finished and the full AMS detector
is expected to be ready by the end of 2008. The RICH detector of AMS-02 is
presented. Physics prospects are briefly discussed.Comment: 5 pages. Contribution to the 10th ICATPP Conference on Astroparticle,
Particle, Space Physics, Detectors and Medical Physics Applications (Como
2007). Presenter: Rui Pereir
Multidrug resistant pulmonary tuberculosis treatment regimens and patient outcomes: an individual patient data meta-analysis of 9,153 patients.
Treatment of multidrug resistant tuberculosis (MDR-TB) is lengthy, toxic, expensive, and has generally poor outcomes. We undertook an individual patient data meta-analysis to assess the impact on outcomes of the type, number, and duration of drugs used to treat MDR-TB
Fecal microbiota composition is related to brown adipose tissue F-18-fluorodeoxyglucose uptake in young adults
Objective Human brown adipose tissue (BAT) has gained considerable attention as a potential therapeutic target for obesity and its related cardiometabolic diseases; however, whether the gut microbiota might be an efficient stimulus to activate BAT metabolism remains to be ascertained. We aimed to investigate the association of fecal microbiota composition with BAT volume and activity and mean radiodensity in young adults. Methods 82 young adults (58 women, 21.8 +/- 2.2 years old) participated in this cross-sectional study. DNA was extracted from fecal samples and 16S rRNA sequencing was performed to analyse the fecal microbiota composition. BAT was determined via a static F-18-fluorodeoxyglucose (F-18-FDG) positron emission tomography-computed tomography scan (PET/CT) after a 2 h personalized cooling protocol. F-18-FDG uptake was also quantified in white adipose tissue (WAT) and skeletal muscles. Results The relative abundance of Akkermansia, Lachnospiraceae sp. and Ruminococcus genera was negatively correlated with BAT volume, BAT SUVmean and BAT SUVpeak (all rho = 0.262, P = 0.213, P Conclusion Our results suggest that fecal microbiota composition is involved in the regulation of BAT and glucose uptake by other tissues in young adults. Further studies are needed to confirm these findings.</p
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