X-ray observations of the young open cluster Blanco 1. The XMM-Newton view

2005

We present the analysis of a 50 ks XMM-Newton observation of the young, metal-rich open cluster Blanco 1. In the sum of EPIC MOS 1, MOS 2 and pn data we have detected 190 X-ray sources, 36 of them having as cluster member as optical counterparts. We have analyzed the X-ray spectra and time variability of the light curves of the cluster sources. Coronal spectra of solar mass stars are characterized by two thermal components at 0.3 and 1.0 keV, with comparable emission measure. One late-A type member shows a coronal spectrum remarkably different from that of solar-type members, thus suggesting an intrinsic difference in the corona production mechanism. The X-ray luminosity distribution of M-t…

The Star Formation Region NGC 6530: distance, ages and Initial Mass Function

2005

We present astrometry and $BVI$ photometry, down to $V\simeq22$, of the very young open cluster NGC6530, obtained from observations taken with the Wide Field Imager camera at the MPG/ESO 2.2 m Telescope. Both the $V$ vs. $B-V$ and the $V$ vs. $V-I$ color-magnitude diagrams (CMD) show the upper main sequence dominated by very bright cluster stars, while, due to the high obscuration of the giant molecular cloud surrounding the cluster, the blue envelopes of the diagrams at $V\gtrsim 14$ are limited to the main sequence stars at the distance of NGC6530. This particular structure of the NGC6530 CMD allows us to conclude that its distance is about $d \simeq 1250$ pc, significantly lower than the…

The Gaia-ESO Survey: Dynamics of ionized and neutral gas in the Lagoon nebula (M 8)

2017

Aims. We present a spectroscopic study of the dynamics of the ionized and neutral gas throughout the Lagoon nebula (M 8), using VLT-FLAMES data from the Gaia-ESO Survey. The new data permit exploration of the physical connections between the nebular gas and the stellar population of the associated star cluster NGC 6530. Methods. We characterized through spectral fitting emission lines of Hα, [N II] and [S II] doublets, [O III], and absorption lines of sodium D doublet, using data from the FLAMES-Giraffe and UVES spectrographs, on more than 1000 sightlines toward the entire face of the Lagoon nebula. Gas temperatures are derived from line-width comparisons, densities from the [S II] doublet …

Correlation between the spatial distribution of the circumstellar disks and the massive stars in the open cluster NGC 6611. Compiled catalog and clus…

2006

Context: the observation of young stars with circumstellar disks suggests that the disks are dissipated, starting from the inner region, by the radiation of the central star and eventually by the formation of rocky planetesimals, over a time scale of several million years. It was also shown that strong UV radiation emitted by nearby massive stars can heat a circumstellar disk up to some thousand degrees, inducing the photoevaporation of the gas. This process strongly reduces the dissipation time scale. Aims: we study whether there exists a correlation between the spatial distribution of stars with circumstellar disks and the position of massive stars with spectral class earlier than B5, in …

Gaia -ESO Survey: Analysis of pre-main sequence stellar spectra

2015

This paper describes the analysis of UVES and GIRAFFE spectra acquired by the Gaia-ESO Public Spectroscopic Survey in the fields of young clusters whose population includes pre-main sequence (PMS) stars. Both methods that have been extensively used in the past and new ones developed in the contest of the Gaia-ESO survey enterprise are available and used. The internal precision of these quantities is estimated by inter-comparing the results obtained by such different methods, while the accuracy is estimated by comparison with independent external data, like effective temperature and surface gravity derived from angular diameter measurements, on a sample of benchmarks stars. Specific strategi…

Spectral Variability of the Nucleus of M33 in aChandra/ACIS Observation

2002

We have analyzed a 90 ksec long observation of the bright nucleus of M33 made with Chandra/ACIS. We detected low-amplitude (~sim10%) highly significant variability on timescales of ~5000 sec. We also find associated spectral variability. The two main spectral components (a power-law with \Gamma~2 and a multicolor disk -MCD- with kT~0.9-1.2 keV) vary in relative flux. The MCD temperature also increases with increasing MCD flux. The pattern of variability is reminiscent of (but not identical to) galactic black hole binaries. A ~5 M$_{\odot}$ accreting black hole may explain this source.

Obtaining Mesenchymal Stem Cells From Adipose Tissue Of Murin Origin: Experimental Study

2014

The Chandra COSMOS Survey, I: Overview and Point Source Catalog

2009

The Chandra COSMOS Survey (C-COSMOS) is a large, 1.8 Ms, Chandra} program that has imaged the central 0.5 sq.deg of the COSMOS field (centered at 10h, +02deg) with an effective exposure of ~160ksec, and an outer 0.4sq.deg. area with an effective exposure of ~80ksec. The limiting source detection depths are 1.9e-16 erg cm(-2) s(-1) in the Soft (0.5-2 keV) band, 7.3e(-16) erg cm^-2 s^-1 in the Hard (2-10 keV) band, and 5.7e(-16) erg cm(-2) s(-1) in the Full (0.5-10 keV) band. Here we describe the strategy, design and execution of the C-COSMOS survey, and present the catalog of 1761 point sources detected at a probability of being spurious of <2e(-5) (1655 in the Full, 1340 in the Soft, and…

FLAMES Observations of the Star Forming Region NGC 6530

2006

Context. Mechanisms regulating the evolution of pre-main sequence stars can be understood by studying stellar properties such as rotation, disk accretion, internal mixing and binarity. To investigate such properties, we studied a sample of 332 candidate members of the massive and populous star forming region NGC 6530. Aims. We select cluster members using different membership criteria, to study the properties of pre-main sequence stars with or without circumstellar disks. Methods. We use intermediate resolution spectra including the Li I 6707.8 $\AA$ line to derive radial and rotational velocities, binarity and to measure the Equivalent Width of the lithium line; these results are combined …

ROSAT PSPC/HRI observations of the open cluster NGC 2422

2002

We present the results of a ROSAT study of NGC 2422, a southern open cluster at a distance of about 470 pc, with an age close to the Pleiades. Source detection was performed on two observations, a 10-ks PSPC and a 40-ks HRI pointing, with a detection algorithm based on wavelet transforms, particularly suited to detecting faint sources in crowded fields. We have detected 78 sources, 13 of which were detected only with the HRI, and 37 detected only with the PSPC. For each source, we have computed the 0.2-2.0 keV X-ray flux. Using optical data from the literature and our own low-dispersion spectroscopic observations, we find candidate optical counterparts for 62 X-ray sources, with more than 8…

ChandraX‐Ray Observation of the Orion Nebula Cluster. II. Relationship between X‐Ray Activity Indicators and Stellar Parameters

2002

Using the results of our first paper on the Chandra HRC observation of the Orion Nebula Cluster (ONC), here we explore the relation between the coronal activity of its 1-Myr-old pre-main sequence population and stellar parameters. We find that median X-ray luminosities of low mass stars (M/M_sun < 3) increase with increasing mass and decreasing stellar age. Brown dwarfs (0.03 < M/M_sun < 0.08) follow the same trend with mass. From M~0.1 to M~0.5M_sun, median L_X/L_bol values increase by about half an order of magnitude and then remain constant at ~10^-3.5 for the mass range from 0.5 to 3.0 M/M_sun. In these same two mass ranges, L_X/L_bol remains roughly constant with age, until it…

ChandraX‐Ray Observation of the Orion Nebula Cluster. I. Detection, Identification, and Determination of X‐Ray Luminosities

2002

In this first of two companion papers on the Orion Nebula Cluster (ONC), we present our analysis of a 63 Ksec Chandra HRC-I observation that yielded 742 X-ray detections within the 30'x30' field of view. To facilitate our interpretation of the X-ray image, here we collect a multi-wavelength catalog of nearly 2900 known objects in the region by combining 17 different catalogs from the recent literature. We define two reference groups: an infrared sample, containing all objects detected in the K band, and an optical sample comprising low extinction, well characterized ONC members. We show for both samples that field object contamination is generally low. Our X-ray sources are primarily low ma…

The rich young cluster NGC 6530: a combined X-ray-optical-infrared study

2006

We present a combined X-ray, optical, and IR (2MASS) study of NGC 6530, complementing our previous studies of this cluster. We consider different indicators of IR excesses, which can be taken as an indicator of circumstellar disks and therefore of pre-main-sequence status. We used reddening-free indices to ensure that our results are unaffected by highly irregular, differential reddening. More than the study of the JHK bands alone (33 IR-excess stars found), we found it useful to compare various optical and IR colors, finding overall 333 stars with optical-IR excess. In the field of the previously studied Chandra ACIS-I observation, we found 196 stars with optical-IR excess, of which 120 ha…

Chandra X-ray observations of the stellar group near the Herbig Be star MWC 297

2006

We present a Chandra ACIS-I X-ray observation of the region near the Herbig early-Be star MWC 297, where we detect a tight group of point X-ray sources. These are probably physically associated to MWC 297, because of their obvious clustering with respect to the more scattered field-source population. These data are compared to earlier ASCA data with much poorer spatial resolution, from which the detection of strong quiescent and flaring emission from MWC 297 itself was claimed. We argue that this star, contributing only 5% to the total X-ray emission of the group, was probably not the dominant contributor to the observed ASCA emission, while the X-ray brightest star in the group is a much b…

V4046 Sgr: X-rays from accretion shock

2013

AbstractWe present results of the X-ray monitoring of V4046 Sgr, a close classical T Tauri star binary, with both components accreting material. The 360 ks long XMM observation allowed us to measure the plasma densities at different temperatures, and to check whether and how the density varies with time. We find that plasma at temperatures of 1–4 MK has high densities, and we observe correlated and simultaneous density variations of plasma, probed by O VII and Ne IX triplets. These results strongly indicate that all the inspected He-like triplets are produced by high-density plasma heated in accretion shocks, and located at the base of accretion flows.

The Gaia-ESO Survey: Catalogue of Hα emission stars

2015

We discuss the properties of Hα emission stars across the sample of 22035 spectra from the Gaia-ESO Survey internal data release, observed with the GIRAFFE instrument and largely belonging to stars in young open clusters. Automated fits using two independent Gaussian profiles and a third component that accounts for the nebular emission allow us to discern distinct morphological types of Hα line profiles with the introduction of a simplified classification scheme. All in all, we find 3765 stars with intrinsic emission and sort their spectra into eight distinct morphological categories: single-component emission, emission blend, sharp emission peaks, double emission, P-Cygni, inverted P-Cygni…

The Gaia-ESO survey: Metallicity of the chamaeleon i star-forming region

2014

Context. Recent metallicity determinations in young open clusters and star-forming regions suggest that the latter may be characterized by a slightly lower metallicity than the Sun and older clusters in the solar vicinity. However, these results are based on small statistics and inhomogeneous analyses. The Gaia-ESO Survey is observing and homogeneously analyzing large samples of stars in several young clusters and star-forming regions, hence allowing us to further investigate this issue. Aims. We present a new metallicity determination of the Chamaeleon I star-forming region, based on the products distributed in the first internal release of the Gaia-ESO Survey. Methods. 48 candidate member…

Argentum-quarz solution in the treatment of anorectal fistulas: Is it possible a conservative approach?

2012

Patients suffering from chronic intestinal diseases (Crohn's disease, Ulcerative Colitis, Indeterminate Colitis) are prone to the development of pyogenic complications. These complications are most commonly in the form of perianal or intraabdominal abscesses and/or fistulas. The treatment of these complications are managed differently but, after an initial treatment based on medical or minimally invasive management, the solution of the pathological condition is always achieved by a surgical procedure. In the last few years prospective studies have proposed an alternative conservative therapeutic approach based on application of fibrin glue in the healing of patients with fistulas-in-ano. In…

XMM-Newton observations of the young open cluster Blanco 1

2004

We present an X-ray study of the high metallicity young open cluster Blanco 1 based on XMM--Newton data. X-ray spectroscopy of cluster members is presented for the first time as well as new X-ray distribution functions of late-type stars. We detected all known dF and dG stars in the EPIC field and 80% and 90% of dK and dM stars, respectively. The X-ray spectral analysis of the X-ray brightest cluster stars and X-ray color analysis of a larger sample show that a model with two temperatures (at about 0.3 and 1 keV) explains the quiescent activity phase spectra. We discuss also the nature of unidentified X-ray sources in the observed region and their X-ray spectral properties.

VLT/Flames observations of the star forming region NGC 6530

2006

Mechanisms regulating the evolution of pre-main sequence stars can be understood by studying stellar properties such as rotation, disk accretion, internal mixing and binarity. To investigate such properties, we studied a sample of 332 candidate members of the massive and populous star forming region NGC 6530. We want to select cluster members by using different membership criteria,to study the properties of pre-main sequence stars with or without circumstellar disks. We use intermediate resolution spectra including the Li I 6707.8 Angstroms line to derive radial and rotational velocities, binarity and to measure the Equivalent Width of the lithium line; these results are combined with X-ray…

The Gaia-ESO Survey: evidence of atomic diffusion in M67?

2018

Investigating the chemical homogeneity of stars born from the same molecular cloud at virtually the same time is very important for our understanding of the chemical enrichment of the interstellar medium and with it the chemical evolution of the Galaxy. One major cause of inhomogeneities in the abundances of open clusters is stellar evolution of the cluster members. In this work, we investigate variations in the surface chemical composition of member stars of the old open clusterM67 as a possible consequence of atomic diffusion effects taking place during the main-sequence phase. The abundances used are obtained from high-resolution UVES/FLAMES spectra within the framework of the Gaia-ESO S…

CRT-723 Is the Sporadic Thoracic Aortic Aneurysm the Result of an Inflammatory Process?

2014

Sporadic thoracic aortic aneurysm (S-TAA) is potentially devastating with severe morbidity and mortality. The histopathologic underlying abnormality of both ascending aortic aneurysm and dissection is medial degeneration, a pathological entity initially described as no inflammatory lesions of smooth

RUOLO DELLE CELLULE STAMINALI MESENCHIMALI DA TESSUTO ADIPOSO NELL'ARDS

OBTAINING MESENCHYMAL STEM CELLS FROM ADIPOSE TISSUE OR MURIN ORIGIN: EXPERIMENTAL STUDY.

2014

The aim of this study was to isolate and characterize rat adipose Derived Mesenchymal Stem Cells (AD-MSCs) in order to evaluate their proliferative potential and their ability to different cell types. AD-MSCs and Derived Mesenchymal Stem Cells (BM-MSCs) have the same characteristic in terms of plasticity. The advantage of adipose tissue is that it is an easier accessible source and it offers a large amount of MSCs by less invasive surgical tecniques. MSCs were obtained from subcutaneous adipose tissue of Wistar rats. first of all microbiological controls were made to exclude the presence of bacteria of fungi in then tissue. Adipose tissue was mechanically and enzimatically fragmented and st…

NUTRITION IN IBD PATIENTS

2013

Inflammatory Bowel Disease (IBD) is a chronic disorder characterized by a relapsing-remitting course, which alternates between active and quiescent states, ultimately impairing a patients' quality of life.The two main types of IBD are Crohn's disease (CD) and Ulcerative Colitis (UC). CD Shows a transmural granulomatous inflammation that can involve any segment of the intestine affecting all layers of the intestinal wall, while UC is limited to the mucosa and superficial submucosa of the colon. In physiological conditions the gut is costantly exposed to various antigens, commensal microflora and pathogens and the inflammatory response is finely balanced. Anyhow i some individuals with geneti…

The complex interplay between vitamin D deficiency and diabetes

2015

It has been recently highlighted the link between vitamin D and metabolic and immunological pro- cesses, which established its role as an essential component of human health preservation. Vitamin D has been defined as natural immune modulators, and through the activation of its receptors (VDRs), it regulates calcium metabolism, cellular growth, proliferation and apoptosis, and other immunological functions. In this setting, vita- min D has also been reported to influence glucose regulation via effects on insulin secretion and action. Vitamin D deficiency is strongly associated with obesity mostly due to the storage of vitamin D in adipose tissue because of its lipophilic properties. The dec…

Is the sporadic thoracic aneurysm the result of inflammatory process

2014

DIAGNOSIS-RELATED GROUP ANALYSIS AND STRATEGIC HEALTHCARE BUDGETING

2011

The term Diagnosis-Related Group DRG) refers to a classification system used to assess hospital services with the aim of streamling health care costs and improving performance. The DRG system focuses on the utilization of resources, and is not concerned with the specific type of care provided to the patient. This system highlights any diseconomies and eventual critical aspects of the hospital system. This article examines the variables used to correctly evaluate hospital performance based on the DRG system. These include: Average length of Stay, Average Daily Patients Load, Comparative Performance Index and Case Mix Index.

TOWARDS AN IMPROVEMENT OF HOSPITAL SERVICES AND STREAMLING OF HEALTH CARE COSTS: THE DRG ANALYSIS IN ITALY.

2012

The term Diagnosis-related-Group (DRG) refers to a classification system used to assess hospital services with the aim of a better menagement of a health care costs and improving performance. The DRG system focuses on the utilization of resources, and is not concerned with the specific type of care provided to the patient. This system highlights any diseconomies and eventual critical aspectsof the hospital system. This article, starting from the history of heath care financing in Italy and pointing out the difficulty to define the "quality" of health care services, describes the variables used to evaluated correctly hospital performance based on the DRG system. These include Average Length …

Validation of a modified model of TNBS-induced colitis in rats. How to induce a chemical colitis in rats

2014

Background: there are no standard practice in the induction of colitis by 2,4,6-trinitrobenzene sulfonic (TNBS) acid. Usually, the repeated administration of TNBS is preferred, because it will result in a local Th1 response that has the characteristics of Crohn's disease. material and Methods: A total of 30 rats were randomized into two groups, consisting of a saline control group of ten rats and a TNBS groups of 20 rats. After the animals were anesthesized, 0,5 ml of either 0,9 % saline 8controls) or TNBS 50 mg/Kg dissolved in 50% ethanol were instilled into the colon through a rubber catheter. The experiment was repeated weekly for four weeks, then, the rats were killed at day 40, and the…

NUTRITION IN IBD PATIENT'S: WHAT ARE THE PROSPECTS?

2015

Summary: Inflammatory Bowel Disease (IBD) is a chronic disorder characterized by a relapsing-remitting course, which alternates between active and quiescent states, ultimately impairing a patients quality of life. The two main types of IBD are Crohn's disease (CD) and Ulcerative Colitis (UC). In physiological conditions the gut is costantly exposed to various antigens, commensal microflora and pathogens and the inflammatory response is finely balanced. It is thought that a vast number of environmental risk factors may be implicated in the development of IBD, including smoking factors, dietary factors, psycological stress, use of non-steroidal anti-inflammatory drugs and oral contraceptives,…