1,613 research outputs found
Brown dwarf disks with ALMA
We present ALMA continuum and spectral line data at 0.89 mm and 3.2 mm for
three disks surrounding young brown dwarfs and very low mass stars in the
Taurus star forming region. Dust thermal emission is detected and spatially
resolved for all the three disks, while CO(J=3-2) emission is seen in two
disks. We analyze the continuum visibilities and constrain the disks physical
structure in dust. The results of our analysis show that the disks are
relatively large, the smallest one with an outer radius of about 70 AU. The
inferred disk radii, radial profiles of the dust surface density and disk to
central object mass ratios lie within the ranges found for disks around more
massive young stars. We derive from our observations the wavelength dependence
of the millimeter dust opacity. In all the three disks data are consistent with
the presence of grains with at least millimeter sizes, as also found for disks
around young stars, and confirm that the early stages of the solid growth
toward planetesimals occur also around very low mass objects. We discuss the
implications of our findings on models of solids evolution in protoplanetary
disks, on the main mechanisms proposed for the formation of brown dwarfs and
very low mass stars, as well as on the potential of finding rocky and giant
planets around very low mass objects.Comment: 15 pages, 10 figures, accepted for publication in Ap
Lumir: The EHR-S In The Basilicata Region
The Lucania â Medici in Rete (LuMiR) project aims to support the changing environment in the Italian National Health Systems, embodying a shift from organisation-centric to patient-centric healthcare service delivery in the Basilicata Region. The project main objective is to foster collaborative, cross-organizational and patient-centric healthcare processes, with a suite of shared e-services supporting the interoperability of active stakeholdersâ IT applications and the exchange of patient related clinical information. In the paper the LuMiR project approach and its aim to overcome some limitations of the EHR-S national recommendation are discussed. The methodology adopted in the design and development of the LuMiR system to comply with institutional constraints and to better support a gradual change in the daily working practice of healthcare professionals is described, together with details on the LuMiR system architecture and remarks on the interventions scheduled to cope with possible hindrances for the large scale adoption of the LuMiR system itself
Nucleolus vs nucleus count for identifying spiral ganglion in human temporal bone
OBJECTIVES: Spiral ganglion (SG) counting is used in experimental studies conducted on age-, noise-, and drug-induced sensorineural hearing loss, as well as in the assessment of cochlear implant performances. Different methods of counting have been reported, but no definite standardization of such procedure has been published. The aim of our study is to identify the best method to count human spiral ganglions (SGs).
MATERIAL and METHODS: By identification of nuclei or nucleoli as described by Schucknect, seven researchers with different experience levels counted SGs in 123 human temporal bones (TBs). Data on time of post-mortem bone removal post-mortem, methods of specimenâs fixation, decalcification, and coloration were collected to test their possible influence on human tissue. Percentage, two-tailed t-test, Spearmanâs test, and one-way ANOVA were used to analyze the data.
RESULTS: Nucleoli were identified in 61% of cases, whereas nuclei were recognized in 100% of cases (p<0.005). Nucleoli presence in all four segments in the same temporal bone (TB) was observed in 69 cases (92%), whereas nuclei were identified in all four segments in 103 cases (83.7%) (p<0.001). The junior investigators requested a double check by the seniors in 25 (20.3%) cases for identifying and counting nucleoli, whereas the senior researchers showed no doubts in their identification and count. The only parameter positively affecting nucleoli identification in tissue preparation was bone removal for <12 h with respect to longer post-mortem time (p<0.001). CONCLUSION: We suggest counting nuclei, rather than nucleoli, for spiral ganglion computation because of easier recognition of nuclei, especially in case of investigatorâs limited experience
A medical device domain analysis model based on HL7 RIM
Clinical investigations (CIs) are carried out to demonstrate safety and efficacy of new Medical Devices (MDs). The presence of many stakeholders participating in CIs makes it necessary to develop a common standard language to achieve semantic interoperability among systems and organizations. In Italy the National Research Council is carrying out a project supported by Ministry of Health aiming to develop an information system (MEDIS) that manages MD clinical investigations. In order to develop a flexible and interoperable system, MEDIS design has been based on the application of HL7 (Health Level 7) v.3 standards. This paper presents the results of the MEDIS design: the MD DAM based on HL7 RIM
ALMA Observations of Ï-Oph 102: Grain Growth and Molecular Gas in the Disk around a Young Brown Dwarf
We present ALMA continuum and spectral line observations of the young brown dwarf Ï-Oph 102 at about 0.89 mm and 3.2 mm. We detect dust emission from the disk at these wavelengths and derive an upper limit on the radius of the dusty disk of ~40 AU. The derived variation of the dust opacity with frequency in the millimeter (mm) provides evidence for the presence of mm-sized grains in the disk's outer regions. This result demonstrates that mm-sized grains are found even in the low-density environments of brown dwarf disks and challenges our current understanding of dust evolution in disks. The CO map at 345 GHz clearly reveals molecular gas emission at the location of the brown dwarf, indicating a gas-rich disk as typically found for disks surrounding young pre-main-sequence stars. We derive a disk mass of ~0.3%-1% of the mass of the central brown dwarf, similar to the typical values found for disks around more massive young stars
<b><i>Topoisomerase 1</i></b> Promoter Variants and Benefit from Irinotecan in Metastatic Colorectal Cancer Patients
Objective: Topoisomerase 1 (topo-1) is an important target for the treatment of metastatic colorectal cancer (CRC). The aim of the present study was to evaluate the correlation between topo-1 single-nucleotide polymorphisms (SNPs) and clinical outcome in metastatic CRC (mCRC) patients.
Methods: With the use of specific software (PROMO 3.0), we performed an in silico analysis of topo-1 promoter SNPs; the rs6072249 and rs34282819 SNPs were included in the study. DNA was extracted from 105 mCRC patients treated with FOLFIRI ± bevacizumab in the first line. SNP genotyping was performed by real-time PCR. Genotypes were correlated with clinical parameters (objective response rate, progression-free survival, and overall survival).
Results: No single genotype was significantly associated with clinical variables. The G allelic variant of rs6072249 topo-1 SNP is responsible for GC factor and X-box-binding protein transcription factor binding. The same allelic variant showed a nonsignificant trend toward a shorter progression-free survival (GG, 7.5 months; other genotypes, 9.3 months; HR 1.823, 95% CI 0.8904-3.734; p = 0.1).
Conclusion: Further analyses are needed to confirm that the topo-1 SNP rs6072249 and transcription factor interaction could be a part of tools to predict clinical outcome in mCRC patients treated with irinotecan-based regimens
Brown Dwarf Disks with ALMA
15 pages, 10 figures, accepted for publication in ApJWe present Atacama Large Millimeter/submillimeter Array continuum and spectral line data at 0.89 mm and 3.2 mm for three disks surrounding young brown dwarfs and very low mass stars in the Taurus star forming region. Dust thermal emission is detected and spatially resolved for all the three disks, while CO(J = 3-2) emission is seen in two disks. We analyze the continuum visibilities and constrain the disks' physical structure in dust. The results of our analysis show that the disks are relatively large; the smallest one has an outer radius of about 70 AU. The inferred disk radii, radial profiles of the dust surface density, and disk to central object mass ratios lie within the ranges found for disks around more massive young stars. We derive from our observations the wavelength dependence of the millimeter dust opacity. In all the three disks, data are consistent with the presence of grains with at least millimeter sizes, as also found for disks around young stars, and confirm that the early stages of the solid growth toward planetesimals occur also around very low-mass objects. We discuss the implications of our findings on models of solids evolution in protoplanetary disks, the main mechanisms proposed for the formation of brown dwarfs and very low-mass stars, as well as the potential of finding rocky and giant planets around very low-mass objects.PostprintPeer reviewe
Brown dwarf disks with ALMA: Evidence for truncated dust disks in Ophiuchus
The study of the properties of disks around young brown dwarfs can provide
important clues on the formation of these very low-mass objects and on the
possibility of forming planetary systems around them. The presence of warm
dusty disks around brown dwarfs is well known, based on near- and mid-infrared
studies. High angular resolution observations of the cold outer disk are
limited; we used ALMA to attempt a first survey of young brown dwarfs in the
-Oph star-forming region. All 17 young brown dwarfs in our sample were
observed at 890 m in the continuum at \sim0.\!^{\prime\prime}5 angular
resolution. The sensitivity of our observations was chosen to detect
M of dust. We detect continuum emission in 11 disks (\%\ of
the total), and the estimated mass of dust in the detected disks ranges from
to M. These disk masses imply that planet formation
around brown dwarfs may be relatively rare and that the supra-Jupiter mass
companions found around some brown dwarfs are probably the result of a binary
system formation. We find evidence that the two brightest disks in -Oph
have sharp outer edges at R<~25 AU, in contrast to disks around Taurus brown
dwarfs. This difference may suggest that the different environment in
-Oph may lead to significant differences in disk properties. A comparison
of the M/M ratio for brown dwarf and solar-mass systems also
shows a possible deficit of mass in brown dwarfs, which could support the
evidence for dynamical truncation of disks in the substellar regime. These
findings are still tentative and need to be put on firmer grounds by studying
the gaseous disks around brown dwarfs and by performing a more systematic and
unbiased survey of the disk population around the more massive stars
Ringed Structures of the HD 163296 Protoplanetary Disk Revealed by ALMA
We present Atacama Large Millimeter and Submillimeter Array observations of the protoplanetary disk around the Herbig Ae star HD 163296 that trace the spatial distribution of millimeter-sized particles and cold molecular gas on spatial scales as small as 25 astronomical units (A.U.). The image of the disk recorded in the 1.3 mm continuum emission reveals three dark concentric rings that indicate the presence of dust depleted gaps at about 60, 100, and 160 A.U. from the central star. The maps of the ^(12)CO, ^(13)CO, and C^(18)O J=2â1 emission do not show such structures but reveal a change in the slope of the radial intensity profile across the positions of the dark rings in the continuum image. By comparing the observations with theoretical models for the disk emission, we find that the density of CO molecules is reduced inside the middle and outer dust gaps. However, in the inner ring there is no evidence of CO depletion. From the measurements of the dust and gas densities, we deduce that the gas-to-dust ratio varies across the disk and, in particular, it increases by at least a factor 5 within the inner dust gap compared to adjacent regions of the disk. The depletion of both dust and gas suggests that the middle and outer rings could be due to the gravitational torque exerted by two Saturn-mass planets orbiting at 100 and 160 A.U. from the star. On the other hand, the inner dust gap could result from dust accumulation at the edge of a magnetorotational instability dead zone, or from dust opacity variations at the edge of the CO frost line. Observations of the dust emission at higher angular resolution and of molecules that probe dense gas are required to establish more precisely the origins of the dark rings observed in the HD 163296 disk
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