Background
How the oncologic outcomes after robotic distal pancreatectomy (RDP) compare to those after laparoscopic distal pancreatectomy (LDP) remains unknown.
Methods
Using the National Cancer ...Database (NCDB), we analyzed all patients undergoing LDP or RDP for resectable pancreatic adenocarcinoma over a 4‐year period (2010‐2013).
Results
Of the 704 eligible patients, 605 (86%) underwent LDP and 99 (14%) underwent RDP. The median follow‐up for patients was 25 months. There were no differences in the two groups with respect to sociodemographic, clinicopathologic, or treatment characteristics. On comparing LDP versus RDP, there was no difference in the margin‐positive rate (15% vs 16%; P = 0.84); lymph nodes examined (12 vs 11; P = 0.67); overall survival (hazard ratio HR, 1.1, 95% confidence intervals CI, 0.7 to 1.7; 28 vs 25 months; P = 0.71); hospital stay (6 vs 5 days; P = 0.14); time to chemotherapy (50 vs 52 days; P = 0.65); 30‐day readmission (9.4% vs 9.1%; P = 0.92); and mortality (1% vs 0%; P = 0.28). Patients undergoing LDP had a significantly higher conversion rate to open or minimally invasive pancreatic cancer resections compared with RDP (27% vs 10%; P < 0.001).
Conclusion
The early national experience with RDP demonstrates similar oncologic outcomes to LDP, with a significantly lower conversion rate.
Abstract
We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV ...Survey (LEGUS)
Hubble
treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes
and a truncation of a few times 10
5
. After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find mass-independent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (≤10
4
) clusters, suggesting that a mass-dependent component is necessary to fully describe the YSC disruption process in NGC 628.
We consider a test particle moving in a random distribution of obstacles in the plane, under the action of a uniform magnetic field, orthogonal to the plane. We show that, in a weak coupling limit, ...the particle distribution behaves according to the linear Landau equation with a magnetic transport term. Moreover, we show that, in a low density regime, when each obstacle generates an inverse power law potential, the particle distribution behaves according to the linear Boltzmann equation with a magnetic transport term. We provide an explicit control of the error in the kinetic limit by estimating the contributions of the configurations which prevent the Markovianity. We compare these results with those ones obtained for a system of hard disks in Bobylev et al. (Phys Rev Lett 75:2,
1995
), which show instead that the memory effects are not negligible in the Boltzmann-Grad limit.
Abstract
The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle 21 Treasury program on the
Hubble Space Telescope
. It studied 50 nearby star-forming galaxies in 5 bands from the ...near-UV to the I-band, combining new Wide Field Camera 3 observations with archival Advanced Camera for Surveys data. LEGUS was designed to investigate how star formation occurs and develops on both small and large scales, and how it relates to the galactic environments. In this paper we present the photometric catalogs for all the apparently single stars identified in the 50 LEGUS galaxies. Photometric catalogs and mosaicked images for all filters are available for download. We present optical and near-UV color–magnitude diagrams for all the galaxies. For each galaxy we derived the distance from the tip of the red giant branch. We then used the NUV color–magnitude diagrams to identify stars more massive than 14
M
⊙
, and compared their number with the number of massive stars expected from the
GALEX
FUV luminosity. Our analysis shows that the fraction of massive stars forming in star clusters and stellar associations is about constant with the star formation rate. This lack of a relation suggests that the timescale for evaporation of unbound structures is comparable or longer than 10 Myr. At low star formation rates this translates to an excess of mass in clustered environments as compared to model predictions of cluster evolution, suggesting that a significant fraction of stars form in unbound systems.
We derive the star formation history (SFH) in four regions of the Small Magellanic Cloud (SMC) using the deepest VI color-magnitude diagrams (CMDs) ever obtained for this galaxy. The images were ...obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope (HST) and are located at projected distances of 0degrees.5-2degrees from the SMC center, probing the main body and the wing of the galaxy. We derived the SFHs of the four fields using two independent procedures to fit synthetic CMDs to the data. We compare the SFHs derived here with our earlier results for the SMC bar to create a deep pencil-beam survey of the global history of the central SMC. We find in all the six fields observed with HST a slow star formation (SF) pace from 13 to 5-7 Gyr ago, followed by a approx =2-3 times higher activity. This is remarkable because dynamical models do not predict a strong influence of either the Large Magellanic Cloud (LMC) or the Milky Way at that time. The level of the intermediate-age SF rate enhancement systematically increases toward the center, resulting in a gradient in the mean age of the population, with the bar fields being systematically younger than the outer ones. SF over the most recent 500 Myr is strongly concentrated in the bar, the only exception being the area of the SMC wing. The strong current activity of the latter is likely driven by interaction with the LMC. At a given age, there is no significant difference in metallicity between the inner and outer fields, implying that metals are well mixed throughout the SMC. The age-metallicity relations we infer from our best-fitting models are monotonically increasing with time, with no evidence of dips. This may argue against the major merger scenario proposed by Tsujimoto and Bekki in 2009, although a minor merger cannot be ruled out.
Abstract
We present the star cluster catalogues for 17 dwarf and irregular galaxies in the HST Treasury Program ‘Legacy ExtraGalactic UV Survey’ (LEGUS). Cluster identification and photometry in this ...sub-sample are similar to that of the entire LEGUS sample, but special methods were developed to provide robust catalogues with accurate fluxes due to low cluster statistics. The colours and ages are largely consistent for two widely used aperture corrections, but a significant fraction of the clusters are more compact than the average training cluster. However, the ensemble luminosity, mass, and age distributions are consistent suggesting that the systematics between the two methods are less than the random errors. When compared with the clusters from previous dwarf galaxy samples, we find that the LEGUS catalogues are more complete and provide more accurate total fluxes. Combining all clusters into a composite dwarf galaxy, we find that the luminosity and mass functions can be described by a power law with the canonical index of −2 independent of age and global SFR binning. The age distribution declines as a power law, with an index of ≈− 0.80 ± 0.15, independent of cluster mass and global SFR binning. This decline of clusters is dominated by cluster disruption since the combined star formation histories and integrated-light SFRs are both approximately constant over the last few hundred Myr. Finally, we find little evidence for an upper-mass cut-off (<2σ) in the composite cluster mass function, and can rule out a truncation mass below ≈104.5M⊙ but cannot rule out the existence of a truncation at higher masses.
Abstract
We investigate the internal kinematics of the young star-forming region NGC 346 in the Small Magellanic Cloud (SMC). We used two epochs of deep F555W and F814W Hubble Space Telescope ...Advanced Camera for Surveys observations with an 11 yr baseline to determine proper motions and study the kinematics of different populations, as identified by their color–magnitude diagram and spatial distribution characteristics. The proper motion field of the young stars shows a complex structure with spatially coherent patterns. NGC 346’s upper main sequence and pre-main sequence stars follow very similar motion patterns, with the outer parts of the cluster being characterized both by outflows and inflows. The proper motion field in the inner ∼10 pc shows a combination of rotation and inflow, indicative of inspiraling motion. The rotation velocity in this regions peaks at ∼3 km s
−1
, whereas the inflow velocity peaks at ∼1 km s
−1
. Subclusters and massive young stellar objects in NGC 346 are found at the interface of significant changes in the coherence of the proper motion field. This suggests that turbulence is the main star formation driver in this region. Similar kinematics observed in the metal-poor NGC 346 and in the Milky Way’s star-forming regions suggest that the differences in the cooling conditions due to different amounts of metallicity and dust density between the SMC and our galaxy are too small to alter significantly the process of star cluster assembly and growth. The main characteristics of our findings are consistent with various proposed star cluster formation models.
Alongside concern about the physical health impacts of the coronavirus disease 2019 (COVID-19) crisis, public health officials have also raised concerns about the potential for massive mental health ...impact. This has led many to wonder, how are individuals with obsessive-compulsive disorder (OCD), and especially those with contamination fears, doing in the era of COVID-19? We present data from eight patients in our residential treatment program for OCD who were admitted prior to any COVID-19 restrictions and continued in treatment at the facility during the pandemic. Much like the general population, our patients varied in the ways they were impacted by COVID-19, yet the majority experienced improvements in OCD symptoms despite the context. This is not to downplay the many ways in which our patients were personally affected by COVID-19. Rather our patients’ relatively resilient responses mirror our program’s treatment model, which emphasizes exposure and response prevention (ERP) within the complementary framework of acceptance and commitment therapy (ACT). The intention of this article is to challenge the notion that by definition this population will fare worse than the general public or that ERP cannot proceed effectively during this time. In contrast, we underscore that effective OCD treatment can and should continue in the era of COVID-19.
The current study aimed to analyse the dentoskeletal effects of the Invisalign mandibular advancement (MA) device in the treatment of skeletal Class II malocclusions.
Pre-treatment and post-treatment ...lateral skull radiographs from patients treated with MA versus TB (Twin-Block Appliance) at the Department of Orthodontics of the University of L'Aquila, Italy, were traced. Eligibility criteria included SNB<78; ANB>4; no previous orthodontic treatments; and vertebral maturation stage (CVM) CS3. Radiographs from patients with craniofacial anomalies, or who underwent extraction treatments, were excluded. Totally, 20 patients were examined, 10 of whom treated with MA and 10 treated with TB. All the radiographs were traced by one expert operator, blind to the groups. A preliminary method error study was performed to exclude intra-operator differences.
Baseline characteristics of the participants were similar between the groups. Both appliances demonstrated a reduction of SNB and ANB angle, and a decrease in overjet. TB demonstrated a higher efficacy in increasing mandibular dimensions. A significant retroinclination of the upper incisive was observed in the TB group, where a decrease of SNA angles was additionally observed. The resulting differences between the two groups could be attributed to the different design of the appliances.
The present data show the effectiveness of both TB and MA in the management of skeletal Class II malocclusions due to mandibular retrusion. But some differences exist in the dentoalveolar effect of the two appliances. MA seems indicated in Class II cases where a control of the upper frontal teeth position is needed.
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