822 research outputs found
Rupture of abdominal aortic aneurysm after spine surgery in the patient with Ehlers-Danlos syndrome -A case report-
Ehlers-Danlos syndrome (EDS) is a rare inherited disorder of the connective tissue that is characterized by hyperextensible skin, hypermobile joints and abnormalities of the cardiovascular system. A 15-year-old girl with Ehlers-Danlos syndrome underwent thoracolumbar surgery for deformity correction. After surgery, an abdominal aortic rupture occurred, and she complained of abdominal distension had an abdominal circumference of 80 cm. Abdominal computed tomography revealed a pseudoaneurysm and a large hematoma at the retroperitoneum. She died of a massive hemorrhage during subsequent abdominal aortic surgery
Influences of excitation-dependent bandstructure changes on InGaN light-emitting diode efficiency
Bandstructure properties in wurtzite quantum wells can change appreciably
with changing carrier density because of screening of quantum-confined Stark
effect. An approach for incorporating these changes in an InGaN
light-emitting-diode model is described. Bandstructure is computed for
different carrier densities by solving Poisson and k\cdotp equations in the
envelop approximation. The information is used as input in a dynamical model
for populations in momentum-resolved electron and hole states. Application of
the approach is illustrated by modeling device internal quantum efficiency as a
function of excitation
Get screened: a pragmatic randomized controlled trial to increase mammography and colorectal cancer screening in a large, safety net practice
Abstract Background Most randomized controlled trials of interventions designed to promote cancer screening, particularly those targeting poor and minority patients, enroll selected patients. Relatively little is known about the benefits of these interventions among unselected patients. Methods/Design "Get Screened" is an American Cancer Society-sponsored randomized controlled trial designed to promote mammography and colorectal cancer screening in a primary care practice serving low-income patients. Eligible patients who are past due for mammography or colorectal cancer screening are entered into a tracking registry and randomly assigned to early or delayed intervention. This 6-month intervention is multimodal, involving patient prompts, clinician prompts, and outreach. At the time of the patient visit, eligible patients receive a low-literacy patient education tool. At the same time, clinicians receive a prompt to remind them to order the test and, when appropriate, a tool designed to simplify colorectal cancer screening decision-making. Patient outreach consists of personalized letters, automated telephone reminders, assistance with scheduling, and linkage of uninsured patients to the local National Breast and Cervical Cancer Early Detection program. Interventions are repeated for patients who fail to respond to early interventions. We will compare rates of screening between randomized groups, as well as planned secondary analyses of minority patients and uninsured patients. Data from the pilot phase show that this multimodal intervention triples rates of cancer screening (adjusted odds ratio 3.63; 95% CI 2.35 - 5.61). Discussion This study protocol is designed to assess a multimodal approach to promotion of breast and colorectal cancer screening among underserved patients. We hypothesize that a multimodal approach will significantly improve cancer screening rates. The trial was registered at Clinical Trials.gov NCT00818857http://deepblue.lib.umich.edu/bitstream/2027.42/78264/1/1472-6963-10-280.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78264/2/1472-6963-10-280.pdfPeer Reviewe
Heterogeneous reaction of ClONO with TiO and SiO aerosol particles: implications for stratospheric particle injection for climate engineering
Deliberate injection of aerosol particles into the stratosphere is a potential climate engineering scheme. Particles injected into the stratosphere would scatter solar radiation back to space, thereby reducing the temperature at the Earth's surface and hence the impacts of global warming. Minerals such as TiO or SiO are among the potentially suitable aerosol materials for stratospheric particle injection due to their greater light-scattering ability than stratospheric sulfuric acid particles. However, the heterogeneous reactivity of mineral particles towards trace gases important for stratospheric chemistry largely remains unknown, precluding reliable assessment of their impacts on stratospheric ozone, which is of key environmental significance. In this work we have investigated for the first time the heterogeneous hydrolysis of ClONO on TiO and SiO aerosol particles at room temperature and at different relative humidities (RHs), using an aerosol flow tube. The uptake coefficient, γ(ClONO), on TiO was ∼ 1.2 × 10 at 7 % RH and remained unchanged at 33 % RH, and increased for SiO from ∼ 2 × 10 at 7 % RH to ∼ 5 × 10 at 35 % RH, reaching a value of ∼ 6 × 10 at 59 % RH. We have also examined the impacts of a hypothetical TiO injection on stratospheric chemistry using the UKCA (United Kingdom Chemistry and Aerosol) chemistry–climate model, in which heterogeneous hydrolysis of NO and ClONO on TiO particles is considered. A TiO injection scenario with a solar-radiation scattering effect very similar to the eruption of Mt Pinatubo was constructed. It is found that, compared to the eruption of Mt Pinatubo, TiO injection causes less ClO activation and less ozone destruction in the lowermost stratosphere, while reduced depletion of NO and NO in the middle stratosphere results in decreased ozone levels. Overall, no significant difference in the vertically integrated ozone abundances is found between TiO injection and the eruption of Mt Pinatubo. Future work required to further assess the impacts of TiO injection on stratospheric chemistry is also discussed.Financial support provided by EPSRC grant EP/I01473X/1 and the Isaac Newton Trust (Trinity College, University of Cambridge, UK) is acknowledged. We thank NCAS-CMS for modelling support. Model integrations have been performed using the ARCHER UK National Supercomputing Service. We acknowledge the ERC for support through the ACCI project (project number: 267760). M. J. Tang would like to thank the CAS Pioneer Hundred Talents programme and State Key Laboratory of Organic Geochemistry for providing starting grants
Informing the design of a national screening and treatment programme for chronic viral hepatitis in primary care: qualitative study of at-risk immigrant communities and healthcare professionals
n Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise statedThis paper presents independent research funded by the National Institute
for Health Research (NIHR) under the Programme Grants for Applied
Research programme (RP-PG-1209-10038).
Long-term residential exposure to PM2.5 constituents and mortality in a Danish cohort
Studies on health effects of long-term exposure to specific PM2.5 constituents are few. Previous studies have reported an association between black carbon (BC) exposure and cardiovascular diseases (CVD) and a few studies have found an association between sulfate exposure and mortality. These studies, however, relied mainly on exposure data from centrally located air-monitoring stations, which is a crude approximation of personal exposure.
We focused on specific chemical constituents of PM2.5, i.e. elemental and primary organic carbonaceous particles (BC/OC), sea salt, secondary inorganic aerosols (SIA, i.e. NO3–, NH4+, and SO42-), and secondary organic aerosols (SOA), in relation to all-cause, CVD and respiratory disease mortality.
We followed a Danish cohort of 49,564 individuals from enrollment in 1993–1997 through 2015. We combined residential address history from 1979 onwards with mean annual air pollution concentrations obtained by the AirGIS air pollution modelling system, lifestyle information from baseline questionnaires and socio-demography obtained by register linkage.
During 895,897 person-years of follow-up, 10,193 deaths from all causes occurred – of which 2319 were CVD-related and 870 were related to respiratory disease. The 15-year time-weighted average concentrations of PM2.5, BC/OC, sea salt, SIA and SOA were 13.8, 2.8, 3.4, 4.9, and 0.3 µg/m3, respectively. For all-cause mortality, a higher risk was observed with higher exposure to PM2.5, BC/OC and SOA with adjusted hazard ratios of 1.03 (95% confidence intervals: 1.01, 1.05), 1.06 (1.03, 1.09), and 1.08 (1.03, 1.13) per interquartile range, respectively. The associations for BC/OC and SOA remained after adjustment for PM2.5 in two-pollutant models. For CVD mortality, we observed elevated risks with higher exposure to PM2.5, BC/OC and SIA. The results showed no clear relationship between sea salt and mortality.
In this study, we observed a relationship between long-term exposure to PM2.5, BC/OC, and SOA and all-cause mortality and between PM2.5, BC/OC, and SIA and CVD mortality.</p
Nonlinear W(infinity) Algebra as Asymptotic Symmetry of Three-Dimensional Higher Spin Anti-de Sitter Gravity
We investigate the asymptotic symmetry algebra of (2+1)-dimensional higher
spin, anti-de Sitter gravity. We use the formulation of the theory as a
Chern-Simons gauge theory based on the higher spin algebra hs(1,1). Expanding
the gauge connection around asymptotically anti-de Sitter spacetime, we specify
consistent boundary conditions on the higher spin gauge fields. We then study
residual gauge transformation, the corresponding surface terms and their
Poisson bracket algebra. We find that the asymptotic symmetry algebra is a
nonlinearly deformed W(infinity) algebra with classical central charges. We
discuss implications of our results to quantum gravity and to various
situations in string theory.Comment: 25 pages, no figure; v2. minor corrections, references added, v3.
JHEP published versio
Recommended from our members
The sensitivity of the tropical circulation and Maritime Continent precipitation to climate model resolution
The dependence of the annual mean tropical precipitation on horizontal resolution is investigated in the atmospheric version of the Hadley Centre General Environment Model (HadGEM1). Reducing the grid spacing from about 350 km to 110 km improves the precipitation distribution in most of the tropics. In particular, characteristic dry biases over South and Southeast Asia including the Maritime Continent as well as wet biases over the western tropical oceans are
reduced. The annual-mean precipitation bias is reduced by about one third over the Maritime Continent and the neighbouring ocean basins associated with it via the Walker circulation. Sensitivity experiments show that much of the improvement with resolution in the Maritime Continent region is due to the specification of better resolved surface boundary conditions (land fraction, soil and vegetation parameters) at the higher resolution.
It is shown that in particular the formulation of the coastal tiling scheme may cause resolution sensitivity of the mean simulated climate. The improvement in the tropical mean precipitation in this region is not primarily associated with the better representation of orography at
the higher resolution, nor with changes in the eddy transport of moisture. Sizeable sensitivity to changes in
the surface fields may be one of the reasons for the large variation of the mean tropical precipitation distribution
seen across climate models
The Seventh Data Release of the Sloan Digital Sky Survey
This paper describes the Seventh Data Release of the Sloan Digital Sky Survey
(SDSS), marking the completion of the original goals of the SDSS and the end of
the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most
of the roughly 2000 deg^2 increment over the previous data release lying in
regions of low Galactic latitude. The catalog contains five-band photometry for
357 million distinct objects. The survey also includes repeat photometry over
250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A
coaddition of these data goes roughly two magnitudes fainter than the main
survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2
in the Northern Galactic Cap, closing the gap that was present in previous data
releases. There are over 1.6 million spectra in total, including 930,000
galaxies, 120,000 quasars, and 460,000 stars. The data release includes
improved stellar photometry at low Galactic latitude. The astrometry has all
been recalibrated with the second version of the USNO CCD Astrograph Catalog
(UCAC-2), reducing the rms statistical errors at the bright end to 45
milli-arcseconds per coordinate. A systematic error in bright galaxy photometr
is less severe than previously reported for the majority of galaxies. Finally,
we describe a series of improvements to the spectroscopic reductions, including
better flat-fielding and improved wavelength calibration at the blue end,
better processing of objects with extremely strong narrow emission lines, and
an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor
correction
- …