702 research outputs found
A statistical approach to identify superluminous supernovae and probe their diversity
We investigate the identification of hydrogen-poor superluminous supernovae
(SLSNe I) using a photometric analysis, without including an arbitrary
magnitude threshold. We assemble a homogeneous sample of previously classified
SLSNe I from the literature, and fit their light curves using Gaussian
processes. From the fits, we identify four photometric parameters that have a
high statistical significance when correlated, and combine them in a parameter
space that conveys information on their luminosity and color evolution. This
parameter space presents a new definition for SLSNe I, which can be used to
analyse existing and future transient datasets. We find that 90% of previously
classified SLSNe I meet our new definition. We also examine the evidence for
two subclasses of SLSNe I, combining their photometric evolution with
spectroscopic information, namely the photospheric velocity and its gradient. A
cluster analysis reveals the presence of two distinct groups. `Fast' SLSNe show
fast light curves and color evolution, large velocities, and a large velocity
gradient. `Slow' SLSNe show slow light curve and color evolution, small
expansion velocities, and an almost non-existent velocity gradient. Finally, we
discuss the impact of our analyses in the understanding of the powering engine
of SLSNe, and their implementation as cosmological probes in current and future
surveys.Comment: 16 pages, 9 figures, accepted by ApJ on 23/01/201
Challenging the Paradigms on the Origin, Specification and Development of the Female Germ Line in Placental Mammals
Most of our understanding on the origin, specification and development of the female germ line in placental mammals comes from studies in the laboratory mouse. The molecular pathway leading to the development and establishment of the female germ line in mouse has erected as the paradigm for placental mammals. It remains, however, largely unexplored whether the well-established mouse regulatory pathway is a common mechanism to other or all placental mammals. Discrete differences in mammals other than mouse reveal the existence of alternative mechanisms that challenge the currently accepted tenets on the origin and establishment of the mammalian female germinal reserve. Here, we will discuss the mouse framework in the light of emerging discrepancies seen in other placental mammals
Neurotensin localization in adenomatoid cystic malformation versus normal lung: Preliminary report of six consecutive cases
Neuropeptides are considered a new class of neurotransmitters, several of which interact with the immune system as well as the macrophagic activity. Among these, neurotensin (NT) enhances the phagocitic response of macrophages and is the only neuropeptide that can enhance the cytolytic effects of activated macrophages. In this way, it may play a role as an inflammatory mediator. In order to investigate the possible relationship between NT and the defence mechanisms of the lung, we started to localize the presence of NT in pulmonary adenomatoid cystic malformation (CCAM). This series consists of 6 children affected by CCAM. In every case, at operation, we obtained specimens of both normal and pathological lung. Tissue sections from the pathological lung showed a significant increase of NT-like immunoreactivity in respect to sections of normal lung. NT influences and activates the macrophages, thus suggesting that it could represent a defence mechanism in children's lung activated in some malformative conditions. Finally, the increasing evidence of NT immunoreactivity in CCAM could explicate an in utero infectious pathogenesis of this malformation
Minimal invasive technique in mesenchymal hamartoma of the chest wall: use of radiofrequency thermoablation
STAGE-I GOMADAL GERMS CELL TUMORS (GGCT):OUTCOME AFTER THE SURVEILLANCE STRATEGY AS APPLIED IN THE ASSOCIAZIONE ITALIANA EMATOLOGIA ONCOLOGIA PEDIATRICA (AIEOP) 2004 PROTOCOL
SURGERY IN PATIENTS WITH TESTICULAR MALIGNANT GERM CELL TUMORS: COMPLIANCE TO SURGICAL GUIDELINES AND RESULTS IN THE ITALIAN COOPERATIVE STUDY
Purpose:
Surgery represents a main and often the only treatment in patients with testicular Malignant Germ Cell Tumors (MGCT). We analyzed the compliance to surgical guidelines and the results in a series of patients with testicular MGCT -/+ retroperitoneal node involvement, without distant metastases.
Method:
42 patients, observed in 15 Centers were enrolled in the Italian Cooperative Study on MGCT (January2004–December2010). 14/42 were younger than 2 y. of age, 28/42 between 13–18 y. Treatment was delivered according to COG-Staging-System: St.I patients (complete excision with inguinal orchifunicolectomy+decrease of markers, +hemiscrotectomy if scrotal involvement) did not receive further treatment; St.II patients (scrotal involvement after hemiscrotectomy and/or retroperitoneal node (RPN) enlargement:2 cm) had RPN Dissection if residuals were suspected after PEBx3or4.
Results:
St.I: 26 patients. 3/26 had a scrotal approach due to suspected testicular torsion: 1/3 underwent hemiscrotectomy, 2 did not receive further therapy after decrease of alphaFP, due to patient’s or physician’s decision respectively. 3/26 were successfully treated for RPN relapse, occurred at 3,6,9 months after adequate surgery (2 adolescents, 1 infant). St.II: in 4 patients CTwas delivered due to slight enlargement of RPN (+persistent alphaFP in 1). St.III: 12 patients received CT and RPND (bilateral in 1). Histology was negative in 11/12. All patients are alive without disease, 39 in 1stCR, 3 in 2ndCR (f.u 9–86 m.:med.48). 1 St.1 patient suffered from postoperative scrotal hematoma. Among patients younger than 2 y, 10/14 had a pure YST, 12/14 had St.I disease; among those between 13–18 y, 27/28 had a mixed histology, 14/28 were St.II or St.III. In 3 adolescents a testicular prosthesis was positioned during primary operation.
Conclusion:
Outcome was excellent. Regional relapses, observed only in St.I patients, were cured. Surgical guidelines were followed in 40/42 cases. Scrotal approach did not worsen the outcome of patients who did not receive further treatment
Surgery in Malignant Germ Cell Tumors of Childhood. results of the Second Italian Cooperative Study TCG 98.
A young girl with apparent treatment-resistant asthma treated at Bambino Gesù children's hospital
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