3,240 research outputs found
Atrial fibrillation and survival in colorectal cancer
BACKGROUND: Survival in colorectal cancer may correlate with the degree of systemic inflammatory response to the tumour. Atrial fibrillation may be regarded as an inflammatory complication. We aimed to determine if atrial fibrillation is a prognostic factor in colorectal cancer. PATIENTS AND METHODS: A prospective colorectal cancer patient database was cross-referenced with the hospital clinical-coding database to identify patients who had underwent colorectal cancer surgery and were in atrial fibrillation pre- or postoperatively. RESULTS: A total of 175 patients underwent surgery for colorectal cancer over a two-year period. Of these, 13 patients had atrial fibrillation pre- or postoperatively. Atrial fibrillation correlated with worse two-year survival (p = 0.04; log-rank test). However, in a Cox regression analysis, atrial fibrillation was not significantly associated with survival. CONCLUSION: The presence or development of atrial fibrillation in patients undergoing surgery for colorectal cancer is associated with worse overall survival, however it was not found to be an independent factor in multivariate analysis
One-step volumetric additive manufacturing of complex polymer structures.
Two limitations of additive manufacturing methods that arise from layer-based fabrication are slow speed and geometric constraints (which include poor surface quality). Both limitations are overcome in the work reported here, introducing a new volumetric additive fabrication paradigm that produces photopolymer structures with complex nonperiodic three-dimensional geometries on a time scale of seconds. We implement this approach using holographic patterning of light fields, demonstrate the fabrication of a variety of structures, and study the properties of the light patterns and photosensitive resins required for this fabrication approach. The results indicate that low-absorbing resins containing ~0.1% photoinitiator, illuminated at modest powers (~10 to 100 mW), may be successfully used to build full structures in ~1 to 10 s
A Smooth Representation of Belief over SO(3) for Deep Rotation Learning with Uncertainty
Accurate rotation estimation is at the heart of robot perception tasks such
as visual odometry and object pose estimation. Deep neural networks have
provided a new way to perform these tasks, and the choice of rotation
representation is an important part of network design. In this work, we present
a novel symmetric matrix representation of the 3D rotation group, SO(3), with
two important properties that make it particularly suitable for learned models:
(1) it satisfies a smoothness property that improves convergence and
generalization when regressing large rotation targets, and (2) it encodes a
symmetric Bingham belief over the space of unit quaternions, permitting the
training of uncertainty-aware models. We empirically validate the benefits of
our formulation by training deep neural rotation regressors on two data
modalities. First, we use synthetic point-cloud data to show that our
representation leads to superior predictive accuracy over existing
representations for arbitrary rotation targets. Second, we use image data
collected onboard ground and aerial vehicles to demonstrate that our
representation is amenable to an effective out-of-distribution (OOD) rejection
technique that significantly improves the robustness of rotation estimates to
unseen environmental effects and corrupted input images, without requiring the
use of an explicit likelihood loss, stochastic sampling, or an auxiliary
classifier. This capability is key for safety-critical applications where
detecting novel inputs can prevent catastrophic failure of learned models.Comment: In Proceedings of Robotics: Science and Systems (RSS'20), Corvallis ,
Oregon, USA, Jul. 12-16, 202
An interaction of β-amyloid with aluminium in vitro
AbstractWe have used circular dichroism spectroscopy to confirm that, in a membrane-mimicking solvent, AβP(1–40) adopts a partially helical conformation and we have demonstrated the loss of this structure in the presence of physiologically relevant concentrations of aluminium. This is the first evidence of a direct biochemical interaction between aluminium and β-amyloid and may have important implications for the pathogenesis of Alzheimer's disease
High Morbidity during Treatment and Residual Pulmonary Disability in Pulmonary Tuberculosis: Under-Recognised Phenomena
BACKGROUND In pulmonary tuberculosis (PTB), morbidity during treatment and residual pulmonary disability can be under-estimated. METHODS Among adults with smear-positive PTB at an outpatient clinic in Papua, Indonesia, we assessed morbidity at baseline and during treatment, and 6-month residual disability, by measuring functional capacity (six-minute walk test [6MWT] and pulmonary function), quality of life (St George's Respiratory Questionnaire [SGRQ]) and Adverse Events ([AE]: new symptoms not present at outset). Results were compared with findings in locally-recruited volunteers. RESULTS 200 PTB patients and 40 volunteers were enrolled. 6WMT was 497m (interquartile range 460-529) in controls versus 408m (IQR 346-450) in PTB patients at baseline (p<0.0001) and 470m (IQR 418-515) in PTB patients after 6 months (p=0.02 versus controls). SGRQ total score was 0 units (IQR 0-2.9) in controls, versus 36.9 (27.4-52.8) in PTB patients at baseline (p<0.0001) and 4.3 (1.7-8.8) by 6 months (p<0.0001). Mean percentage of predicted FEV1 was 92% (standard deviation 19.9) in controls, versus 63% (19.4) in PTB patients at baseline (p<0.0001) and 71% (17.5) by 6 months (p<0.0001). After 6 months, 27% of TB patients still had at least moderate-severe pulmonary function impairment, and 57% still had respiratory symptoms, despite most achieving 'successful' treatment outcomes, and reporting good quality of life. More-advanced disease at baseline (longer illness duration, worse baseline X-ray) and HIV positivity predicted residual disability. AE at any time during treatment were common: itch 59%, arthralgia 58%, headache 40%, nausea 33%, vomiting 16%. CONCLUSION We found high 6-month residual pulmonary disability and high AE rates. Although PTB treatment is highly successful, the extent of morbidity during treatment and residual impairment could be overlooked if not specifically sought. Calculations of PTB-related burden of disease should acknowledge that TB-related morbidity does not stop at 6 months. Early case detection and treatment are key in minimising residual impairment.The study received funding from the Australian Respiratory Council, Royal Australasian College of Physicians (Covance Award to APR), National
Health and Medical Research Council (NHMRC) of Australia (Grants 605806 and 496600, a scholarship to APR, and fellowships to APR, TWY, PMK,
NMA). Graeme Maguire is supported by an NHMRC Practitioner Fellowship and the Margaret Ross Chair in Indigenous Health. Views expressed in this
publication are those of the authors and do not reflect the views of NHMRC. The funders had no role in study design, data collection and analysis, decision
to publish, or preparation of the manuscript
The glacial geomorphology of upper Godthåbsfjord (Nuup Kangerlua) in south-west Greenland
© 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group on behalf of Journal of Maps. This is an 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 cited.The Greenland Ice Sheet (GrIS) is known to have experienced widespread retreat over the last century. Information on outlet glacier dynamics, prior to this, are limited due to both a lack of observations and a paucity of mapped or mappable deglacial evidence which restricts our understanding of centennial to millennial timescale dynamics of the GrIS. Here we present glacial geomorphological mapping, for upper Godthåbsfjord, covering 5800 km 2 at a scale of 1:92,000, using a combination of ASTER GDEM V2, a medium-resolution DEM (error < 10 m horizontal and < 6 m vertical accuracy), panchromatic orthophotographs and ground truthing. This work provides a detailed geomorphological assessment for the area, compiled as a single map, comprising of moraines, meltwater channels, streamlined bedrock, sediment lineations, ice-dammed lakes, trimlines, terraces, gullied sediment and marine limits. Whilst some of the landforms have been previously identified, the new information presented here improves our understanding of ice margin behaviour and can be used for future numerical modelling and landform dating programmes. Data also form the basis for palaeoglaciological reconstructions and contribute towards understanding of the centennial to millennial timescale record of this sector of the GrIS.Peer reviewedFinal Published versio
Can manipulation of differentiation conditions eliminate proliferative cells from a population of ES cell-derived forebrain cells?
There is preliminary evidence that implantation of primary fetal striatal cells provides functional
benefit in patients with Huntington’s disease, a neurodegenerative condition resulting in loss of
medium-sized spiny neurons (MSN) of the striatum. Scarcity of primary fetal tissue means it is
important to identify a renewable source of cells from which to derive donor MSNs. Embryonic stem
(ES) cells, which predominantly default to telencephalic-like precursors in chemically defined
medium (CDM), offer a potentially inexhaustible supply of cells capable of generating the desired
neurons. Using an ES cell line, with the forebrain marker FoxG1 tagged to the LacZ reporter, we
assessed effects of known developmental factors on the yield of forebrain-like precursor cells in
CDM suspension culture. Addition of FGF2, but not DKK1, increased the proportion of FoxG1-
expressing cells at day 8 of neural induction. Oct4 was expressed at day 8, but was undetectable by
day 16. Differentiation of day 16 precursors generated GABA-expressing neurons, with few
DARPP32 positive MSNs. Transplantation of day 8 precursor cells into quinolinic acid-lesioned striata
resulted in generation of teratomas. However, transplantation of day 16 precursors yielded grafts
expressing neuronal markers including NeuN, calbindin and parvalbumin, but no DARPP32 6 weeks
post-transplantation. Manipulation of fate of ES cells requires optimization of both concentration
and timing of addition of factors to culture systems to generate the desired phenotypes.
Furthermore, we highlight the value of increasing the precursor phase of ES cell suspension culture
when directing differentiation toward forebrain fate, so as to dramatically reduce the risk of
teratoma formation
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