5,850 research outputs found
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Pathological margins and advanced cutaneous squamous cell carcinoma of the head and neck.
OBJECTIVE:The recommended treatment for cutaneous squamous cell cancer (CuSCC) of the head and neck is Mohs surgical excision or wide local excision. Excision is recommended to a gross surgical margin of 4-6 mm however this is based on limited evidence and specify a goal histologic margin. The objective of this study was therefore to examine the reported histological margin distance following WLE of advanced CuSCC and its association with recurrence and survival. STUDY DESIGN:Retrospective database review. SETTING:All patients included received treatment at UC Davis Department of Otolaryngology-Head and Neck Surgery and/or Radiation Oncology in Sacramento, California. SUBJECTS AND METHODS:The patients included were treated for advanced CuSCC with primary surgery with or without adjuvant therapy. Kaplan Meier survival curves with log rank analysis were then performed to compare 5-year recurrence free survival, and disease-specific survival for patients with different margin distances. RESULTS:Total number of subjects was 92. The overall 5-year DSS and RFS was 68.8 and 51.0% respectively. When the pathological margin distance was ≥5 mm, 5-year disease specific survival was improved when compared to margin distance less than 5 mm (94.7 vs 60.7 p = 0.034). CONCLUSION:The findings of this study suggest that a histologic margin of at least 5 mm may increase survival in advanced head and neck CuSCC patients
A systematic search for massive young stars in the Galaxy - the RMS survey
We have selected red MSX sources (RMS) that have the colours of massive young
stellar objects (MYSOs). Our aim is to generate a large, systematically
selected sample to address questions such as their luminosity function,
lifetimes, clustering and triggering. Other objects such as UCHIIs, PN, PPN and
AGB stars have similar IR colours and a large programme of ground-based
follow-up observations is underway to identify and eliminate these from the
sample of the red MSX sources. These include radio continuum observations,
kinematic distances, ground-based mid-IR imaging, near-IR imaging and
spectroscopy to distinguish. We report the progress of these campaigns on the
3000 candidates, with initial indications showing that a substantial fraction
are indeed massive YSOs.Comment: 3 pages, 4 figures Talk in conference: Milky Way surveys, the
structure and evolution of our Galaxy, Boston 200
Spatial variability in the diversity and structure of faunal assemblages associated with kelp holdfasts (<i>Laminaria hyperborea</i>) in the northeast Atlantic
<p>Map indicating the locations of the four study regions in the UK, northeast Atlantic: (A) northern Scotland, (B) western Scotland, (C) southwest Wales and (D) southwest England. Smaller panels show the positions of the 3 study sites within each region.</p
Josephson effects in MgB2 meta masked ion damage junctions
Ion beam damage combined with nanoscale focused ion beam direct milling was
used to create manufacturable SNS type Josephson junctions in 100 nm thick
MgB with T of 38 K. The junctions show non-hysteretic current -
voltage characteristics between 36 and 4.2 K. Experimental evidence for the dc
and ac Josephson effects in MgB metal masked ion damage junctions are
presented. This technique is particularly useful for prototyping devices due to
its simplicity and flexibility of fabrication and has a great potential for
high-density integration.Comment: 12 pages, 4 figures, RevTeX4, submitted to AP
A distance-limited sample of massive molecular outflows
We have observed 99 mid-infrared-bright, massive young stellar objects and compact H ii regions drawn from the Red MSX source survey in the J = 3−2 transition of 12CO and 13CO, using the James Clerk Maxwell Telescope. 89 targets are within 6 kpc of the Sun, covering a representative range of luminosities and core masses. These constitute a relatively unbiased sample of bipolar molecular outflows associated with massive star formation. Of these, 59, 17 and 13 sources (66, 19 and 15 per cent) are found to have outflows, show some evidence of outflow, and have no evidence of outflow, respectively. The time-dependent parameters of the high-velocity molecular flows are calculated using a spatially variable dynamic time-scale. The canonical correlations between the outflow parameters and source luminosity are recovered and shown to scale with those of low-mass sources. For coeval star formation, we find the scaling is consistent with all the protostars in an embedded cluster providing the outflow force, with massive stars up to ∼30 M⊙ generating outflows. Taken at face value, the results support the model of a scaled-up version of the accretion-related outflow-generation mechanism associated with discs and jets in low-mass objects with time-averaged accretion rates of ∼10−3 M⊙ yr−1 on to the cores. However, we also suggest an alternative model, in which the molecular outflow dynamics are dominated by the entrained mass and are unrelated to the details of the acceleration mechanism. We find no evidence that outflows contribute significantly to the turbulent kinetic energy of the surrounding dense cores
Compact High-Velocity Clouds at High Resolution
Six examples of the compact, isolated high-velocity clouds catalogued by
Braun & Burton (1999) and identified with a dynamically cold ensemble of
primitive objects falling towards the barycenter of the Local Group have been
imaged with the Westerbork Synthesis Radio Telescope; an additional ten have
been imaged with the Arecibo telescope. The imaging reveals a characteristic
core/halo morphology: one or several cores of cool, relatively
high-column-density material, are embedded in an extended halo of warmer,
lower-density material. Several of the cores show kinematic gradients
consistent with rotation; these CHVCs are evidently rotationally supported and
dark-matter dominated. The imaging data allows several independent estimates of
the distances to these objects, which lie in the range 0.3 to 1.0 Mpc. The CHVC
properties resemble what might be expected from very dark dwarf irregular
galaxies.Comment: 12 pages, 7 figures, to appear in "The Chemical Evolution of the
Milky Way: Stars versus Clusters", eds. F. Matteuchi and F. Giovannelli,
Kluwer Academic Publisher
Cavity QED with a Bose-Einstein condensate
Cavity quantum electrodynamics (cavity QED) describes the coherent
interaction between matter and an electromagnetic field confined within a
resonator structure, and is providing a useful platform for developing concepts
in quantum information processing. By using high-quality resonators, a strong
coupling regime can be reached experimentally in which atoms coherently
exchange a photon with a single light-field mode many times before dissipation
sets in. This has led to fundamental studies with both microwave and optical
resonators. To meet the challenges posed by quantum state engineering and
quantum information processing, recent experiments have focused on laser
cooling and trapping of atoms inside an optical cavity. However, the tremendous
degree of control over atomic gases achieved with Bose-Einstein condensation
has so far not been used for cavity QED. Here we achieve the strong coupling of
a Bose-Einstein condensate to the quantized field of an ultrahigh-finesse
optical cavity and present a measurement of its eigenenergy spectrum. This is a
conceptually new regime of cavity QED, in which all atoms occupy a single mode
of a matter-wave field and couple identically to the light field, sharing a
single excitation. This opens possibilities ranging from quantum communication
to a wealth of new phenomena that can be expected in the many-body physics of
quantum gases with cavity-mediated interactions.Comment: 6 pages, 4 figures; version accepted for publication in Nature;
updated Fig. 4; changed atom numbers due to new calibratio
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Variation in excess all-cause mortality by age, sex, and province during the first wave of the COVID-19 pandemic in Italy.
Although previous evidence suggests that the infection fatality rate from COVID-19 varies by age and sex, and that transmission intensity varies geographically within countries, no study has yet explored the age-sex-space distribution of excess mortality associated with the COVID pandemic. By applying the principles of small-area estimation to existing model formulations for excess mortality, this study develops a novel method for assessing excess mortality across small populations and assesses the pattern of COVID excess mortality by province, year, week, age group, and sex in Italy from March through May 2020. We estimate that 53,200 excess deaths occurred across Italy during this time period, compared to just 35,500 deaths where COVID-19 was registered as the underlying cause of death. Out of the total excess mortality burden, 97% of excess deaths occurred among adults over age 60, and 68% of excess deaths were concentrated among adults over age 80. The burden of excess mortality was unevenly distributed across the country, with just three of Italy's 107 provinces accounting for 32% of all excess mortality. This method for estimating excess mortality can be adapted to other countries where COVID-19 diagnostic capacity is still insufficient, and could be incorporated into public health rapid response systems
The interface between silicon and a high-k oxide
The ability to follow Moore's Law has been the basis of the tremendous
success of the semiconductor industry in the past decades. To date, the
greatest challenge for device scaling is the required replacement of silicon
dioxide-based gate oxides by high-k oxides in transistors. Around 2010 high-k
oxides are required to have an atomically defined interface with silicon
without any interfacial SiO2 layer. The first clean interface between silicon
and a high-K oxide has been demonstrated by McKee et al. Nevertheless, the
interfacial structure is still under debate. Here we report on first-principles
calculations of the formation of the interface between silicon and SrTiO3 and
its atomic structure. Based on insights into how the chemical environment
affects the interface, a way to engineer seemingly intangible electrical
properties to meet technological requirements is outlined. The interface
structure and its chemistry provide guidance for the selection process of other
high-k gate oxides and for controlling their growth. Our study also shows that
atomic control of the interfacial structure can dramatically improve the
electronic properties of the interface. The interface presented here serves as
a model for a variety of other interfaces between high-k oxides and silicon.Comment: 10 pages, 2 figures (one color
An exploratory cluster randomised trial of a university halls of residence based social norms marketing campaign to reduce alcohol consumption among 1st year students
<p>Aims: This exploratory trial examines the feasibility of implementing a social norms marketing campaign to reduce student drinking in universities in Wales, and evaluating it using cluster randomised trial methodology.</p>
<p>Methods: Fifty residence halls in 4 universities in Wales were randomly assigned to intervention or control arms. Web and paper surveys were distributed to students within these halls (n = 3800), assessing exposure/contamination, recall of and evaluative responses to intervention messages, perceived drinking norms and personal drinking behaviour. Measures included the Drinking Norms Rating Form, the Daily Drinking Questionnaire and AUDIT-C.</p>
<p>Results: A response rate of 15% (n = 554) was achieved, varying substantially between sites. Intervention posters were seen by 80% and 43% of students in intervention and control halls respectively, with most remaining materials seen by a minority in both groups. Intervention messages were rated as credible and relevant by little more than half of students, though fewer felt they would influence their behaviour, with lighter drinkers more likely to perceive messages as credible. No differences in perceived norms were observed between intervention and control groups. Students reporting having seen intervention materials reported lower descriptive and injunctive norms than those who did not.</p>
<p>Conclusions: Attention is needed to enhancing exposure, credibility and perceived relevance of intervention messages, particularly among heavier drinkers, before definitive evaluation can be recommended. A definitive evaluation would need to consider how it would achieve sufficient response rates, whilst hall-level cluster randomisation appears subject to a significant degree of contamination.</p>
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