3,283 research outputs found
Current status of laboratory and imaging diagnosis of neonatal necrotizing enterocolitis
Necrotizing enterocolitis continues to be a devastating disease process for very low birth weight infants in Neonatal Intensive Care Units. The aetiology and pathogenesis of necrotizing enterocolitis are not definitively understood. It is known that necrotizing enterocolitis is secondary to a complex interaction of multiple factors that results in mucosal damage, which leads to intestinal ischemia and necrosis. Advances in neonatal care, including resuscitation and ventilation support technology, have seen increased survival rates among premature neonates and a concomitant detection in the incidence of this intestinal disease.Diagnosis can be difficult, and identifying infants at the onset of disease remains a challenge. Early diagnosis, which relies on imaging findings, and initiation of prompt therapy are essential to limit morbidity and mortality. Moreover, early management is critical and life-saving.This review summarizes what is known on the laboratory and instrumental diagnostic strategies needed to improve neonatal outcomes and, possibily, to prevent the onset of an overt necrotizing enterocolitis
Global Calculations of Density Waves and Gap Formation in Protoplanetary Disks using a Moving Mesh
We calculate the global quasi-steady state of a thin disk perturbed by a
low-mass protoplanet orbiting at a fixed radius using extremely high-resolution
numerical integrations of Euler's equations in two dimensions. The calculations
are carried out using a moving computational domain, which greatly reduces
advection errors and allows for much longer time-steps than a fixed grid. We
calculate the angular momentum flux and the torque density as a function of
radius and compare them with analytical predictions. We discuss the
quasi-steady state after 100 orbits and the prospects for gap formation by low
mass planets.Comment: Accepted to Ap
Final results of an experiment to search for 2beta processes in zinc and tungsten with the help of radiopure ZnWO4 crystal scintillators
A search for the double beta decay of zinc and tungsten isotopes has been
performed with the help of radiopure ZnWO4 crystal scintillators (0.1-0.7 kg)
at the Gran Sasso National Laboratories of the INFN. The total exposure of the
low background measurements is 0.529 kg yr. New improved half-life limits on
the double beta decay modes of 64Zn, 70Zn, 180W, and 186W have been established
at the level of 10^{18}-10^{21} yr. In particular, limits on double electron
capture and electron capture with positron emission in 64Zn have been set:
T_{1/2}(2\nu 2K) > 1.1 10^{19} yr, T_{1/2} (0\nu 2\epsilon) > 3.2 10^{20} yr,
T_{1/2} (2\nu \epsilon \beta^+) > 9.4 10^{20} yr, and T_{1/2} (0\nu \epsilon
\beta^+) > 8.5 10^{20} yr, all at 90% C.L. Resonant neutrinoless double
electron capture in 180W has been restricted on the level of T_{1/2} (0\nu
2\epsilon) > 1.3 10^{18} yr. A new half-life limit on alpha transition of 183W
to the metastable excited level 1/2^- 375 keV of 179Hf has been established:
T_{1/2} > 6.7 10^{20} yr.Comment: This is an author-created, un-copyedited version of an article
published in J. Phys. G: Nucl. Part. Phys. IOP Publishing Ltd is not
responsible for any errors or omissions in this version of the manuscript or
any version derived from it. The definitive publisher authenticated version
is available online at doi: 10.1088/0954-3899/38/11/11510
Comments on Experimental Studies of Electrostatic Fluctuations in a Turbulently Heated Plasma
Search for long-lived superheavy eka-tungsten with radiopure ZnWO crystal scintillator
The data collected with a radioactively pure ZnWO crystal scintillator
(699 g) in low background measurements during 2130 h at the underground (3600 m
w.e.) Laboratori Nazionali del Gran Sasso (INFN, Italy) were used to set a
limit on possible concentration of superheavy eka-W (seaborgium Sg, Z = 106) in
the crystal. Assuming that one of the daughters in a chain of decays of the
initial Sg nucleus decays with emission of high energy particle
( MeV) and analyzing the high energy part of the measured
spectrum, the limit N(Sg)/N(W) < 5.5 10 atoms/atom at
90% C.L. was obtained (for Sg half-life of 10 yr). In addition, a limit on
the concentration of eka-Bi was set by analysing the data collected with a
large BGO scintillation bolometer in an experiment performed by another group
[L. Cardani et al., JINST 7 (2012) P10022]: N(eka-Bi)/N(Bi) < 1.1
10 atoms/atom with 90% C.L. Both the limits are comparable with those
obtained in recent experiments which instead look for spontaneous fission of
superheavy elements or use the accelerator mass spectrometry.Comment: 9 pages, 2 figures; in press on Physica Script
First evaluation of neutron induced single event effects on the CMS barrel muon electronics
Neutron irradiation tests of the currently available electronics for the CMS barrel muon detector were performed using Thermal and fast neutrons at E< 11MeV. The Single Event Upset rate on the Static RAM was measured, while upper limits are derived for events having experienced no failure. The results are used to guess the upper limits on the mean time between failures in the whole barrel muon detector
First search for double-beta decay of 184Os and 192Os
A search for double-beta decay of osmium has been realized for the first time
with the help of an ultra-low background HPGe gamma detector at the underground
Gran Sasso National Laboratories of the INFN (Italy). After 2741 h of data
taking with a 173 g ultra-pure osmium sample limits on double-beta processes in
184Os have been established at the level of T_{1/2} about 10^{14}-10^{17} yr.
Possible resonant double-electron captures in 184Os were searched for with a
sensitivity T_{1/2} about 10^{16} yr. A half-life limit T_{1/2} > 5.3 10^{19}
yr was set for the double-beta decay of 192Os to the first excited level of
192Pt. The radiopurity of the osmium sample has been investigated and
radionuclides 137Cs, 185Os and 207Bi were detected in the sample, while
activities of 40K, 60Co, 226Ra and 232Th were limited at the mBq/kg level.Comment: 12 pages, 7 figures, 2 table
Search for 2\beta\ decays of 96Ru and 104Ru by ultra-low background HPGe gamma spectrometry at LNGS: final results
An experiment to search for double beta decay processes in 96Ru and 104Ru,
which are accompanied by gamma rays, has been realized in the underground Gran
Sasso National Laboratories of the I.N.F.N. (Italy). Ruthenium samples with
masses of about (0.5-0.7) kg were measured with the help of ultra-low
background high purity Ge gamma ray spectrometry. After 2162 h of data taking
the samples were deeply purified to reduce the internal contamination of 40K.
The last part of the data has been accumulated over 5479 h. New improved half
life limits on 2\beta+/\epsilon \beta+/2\epsilon\ processes in 96Ru have been
established on the level of 10^{20} yr, in particular for decays to the ground
state of 96Mo: T1/2(2\nu 2\beta+) > 1.4 10^{20} yr, T1/2(2\nu \epsilon\beta+) >
8.0 10^{19} yr and T1/2(0\nu 2K) > 1.0 10^{21} yr (all limits are at 90% C.L.).
The resonant neutrinoless double electron captures to the 2700.2 keV and 2712.7
keV excited states of 96Mo are restricted as: T1/2(0\nu KL) > 2.0 10^{20} yr
and T1/2(0\nu 2L) > 3.6 10^{20} yr, respectively. Various two neutrino and
neutrinoless 2\beta\ half lives of 96Ru have been estimated in the framework of
the QRPA approach. In addition, the T1/2 limit for 0\nu 2\beta- transitions of
104Ru to the first excited state of 104Pd has been set as > 6.5 10^{20} yr.Comment: 14 pages, 5 figures, 2 tables; version accepted for publication on
Phys. Rev.
Ofd1 Controls Dorso-Ventral Patterning and Axoneme Elongation during Embryonic Brain Development.
Oral-facial-digital type I syndrome (OFDI) is a human X-linked dominant-male-lethal developmental disorder caused by mutations in the OFD1 gene. Similar to other inherited disorders associated to ciliary dysfunction OFD type I patients display neurological abnormalities. We characterized the neuronal phenotype that results from Ofd1 inactivation in early phases of mouse embryonic development and at post-natal stages. We determined that Ofd1 plays a crucial role in forebrain development, and in particular, in the control of dorso-ventral patterning and early corticogenesis. We observed abnormal activation of Sonic hedgehog (Shh), a major pathway modulating brain development. Ultrastructural studies demonstrated that early Ofd1 inactivation results in the absence of ciliary axonemes despite the presence of mature basal bodies that are correctly orientated and docked. Ofd1 inducible-mediated inactivation at birth does not affect ciliogenesis in the cortex, suggesting a developmental stage-dependent role for a basal body protein in ciliogenesis. Moreover, we showed defects in cytoskeletal organization and apical-basal polarity in Ofd1 mutant embryos, most likely due to lack of ciliary axonemes. Thus, the present study identifies Ofd1 as a developmental disease gene that is critical for forebrain development and ciliogenesis in embryonic life, and indicates that Ofd1 functions after docking and before elaboration of the axoneme in vivo
Radioactive contamination of ZnWO4 crystal scintillators
The radioactive contamination of ZnWO4 crystal scintillators has been
measured deep underground at the Gran Sasso National Laboratory (LNGS) of the
INFN in Italy with a total exposure 3197 kg x h. Monte Carlo simulation,
time-amplitude and pulse-shape analyses of the data have been applied to
estimate the radioactive contamination of the ZnWO4 samples. One of the ZnWO4
crystals has also been tested by ultra-low background gamma spectrometry. The
radioactive contaminations of the ZnWO4 samples do not exceed 0.002 -- 0.8
mBq/kg (depending on the radionuclide), the total alpha activity is in the
range: 0.2 - 2 mBq/kg. Particular radioactivity, beta active 65Zn and alpha
active 180W, has been detected. The effect of the re-crystallization on the
radiopurity of the ZnWO4 crystal has been studied. The radioactive
contamination of samples of the ceramic details of the set-ups used in the
crystals growth has been checked by low background gamma spectrometry. A
project scheme on further improvement of the radiopurity level of the ZnWO4
crystal scintillators is briefly addressed.Comment: 15 pages, 8 figures, 6 tables, submitted for publicatio
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