2,915 research outputs found
Validating and comparing stroke prognosis scales
Objective: To compare the prognostic accuracy of various acute stroke prognostic scales using a large, independent, clinical trials dataset.
Methods: We directly compared 8 stroke prognostic scales, chosen based on focused literature review (Acute Stroke Registry and Analysis of Lausanne [ASTRAL]; iSCORE; iSCORE-revised; preadmission comorbidities, level of consciousness, age, and neurologic deficit [PLAN]; stroke subtype, Oxfordshire Community Stroke Project, age, and prestroke modified Rankin Scale [mRS] [SOAR]; modified SOAR; Stroke Prognosis Instrument 2 [SPI2]; and Totaled Health Risks in Vascular Events [THRIVE]) using individual patient-level data from a clinical trials archive (Virtual International Stroke Trials Archive [VISTA]). We calculated area under receiver operating characteristic curves (AUROC) for each scale against 90-day outcomes of mRS (dichotomized atmRS.2), Barthel Index (.85), and mortality. We performed 2 complementary analyses: the first limited to patients with complete data for all components of all scales (simultaneous) and the second using as many patients as possible for each individual scale (separate). We compared AUROCs and performed sensitivity analyses substituting extreme outcome values for missing data.
Results: In total, 10,777 patients contributed to the analyses. Our simultaneous analyses suggested that ASTRAL had greatest prognostic accuracy for mRS, AUROC 0.78 (95% confidence interval [CI] 0.75â0.82), and SPI2 had poorest AUROC, 0.61 (95%CI 0.57â0.66). Our separate analyses confirmed these results: ASTRAL AUROC 0.79 (95% CI 0.78â0.80 and SPI2 AUROC 0.60 (95% CI 0.59â0.61). On formal comparative testing, there was a significant difference in modified Rankin Scale AUROC between ASTRAL and all other scales. Sensitivity analysis identified no evidence of systematic bias from missing data.
Conclusions: Our comparative analyses confirm differences in the prognostic accuracy of stroke scales. However, even the best performing scale had prognostic accuracy that may not be sufficient as a basis for clinical decision-making
The mechanical and microstructural behaviour of calcite-dolomite composites: An experimental investigation
Optical coherence elastography for cellular-scale stiffness imaging of mouse aorta
We have developed a high-resolution optical coherence elastography system capable of estimating Young's modulus in tissue volumes with an isotropic resolution of 15 ÎŒm over a 1 mm lateral field of view and a 100 ÎŒm axial depth of field. We demonstrate our technique on healthy and hypertensive, freshly excised and intact mouse aortas. Our technique has the capacity to delineate the individual mechanics of elastic lamellae and vascular smooth muscle. Further, we observe global and regional vascular stiffening in hypertensive aortas, and note the presence of local micro-mechanical signatures, characteristic of fibrous and lipid-rich regions.Publisher PD
Ingredient Dehydration of Fermented and Flavour-Sensitive Products.
End of Project ReportTraditionally, yoghurt is produced in a hydrated form and, thus, possesses a
limited shelf-life even when refrigerated. Consumption within a short time
of production is advisable, particularly if advantage is to be taken of the
putative benefits associated with the ingestion of live yoghurt cultures.
The production of an instant yoghurt powder would, thus, provide benefits
of shelf-life extension and convenience of preparation and storage.
However, the drying of such products is difficult due to low pH, which
causes stickiness in drier chambers and makes powder recovery difficult.
Furthermore, key flavour components formed by fermentation such as
acetaldehyde and diacetyl which contribute to the unique flavour of natural
yoghurt are sensitive to heat and easily lost during spray-drying.
Hence, a major challenge of this project was to investigate the processing
technologies and conditions necessary for the minimisation of flavour losses
during the spray-drying of acidified/fermented milk bases, to monitor the
effects on drier performance such as powder adhesion to drier walls, and to
develop functional forms of the spray-dried ingredients. The main aims of the project were to:
- improve yoghurt powder spray-drying efficiency through optimisation of
concentrate solids,
- investigate the effect of spray-drying conditions on flavour losses of
sensitive products such as dehydrated yoghurt and fermented creams,- apply technological approaches for the reduction of flavour losses: a)
ingredient formulation, b) modification of fermentation conditions,
- investigate the production of agglomerated forms of spray-dried yoghurt
powders,
- study factors affecting the physical properties such as rheological
characteristics and powder bulk density, and
- adapt technology to ensure greater viability of culture cell numbers at the
end of the drying process.Department of Agriculture, Food and the Marin
Structure and phase transition in BaThO3: A combined neutron and synchrotron X-ray diffraction study
The structure of BaThO3, obtained by solid state synthesis, was refined for the first time by the Rietveld method using a combination of synchrotron X-ray and neutron powder diffraction data. BaThO3 has an orthorhombic structure at room temperature, in space group Pbnm with a = 6.3491(5), b = 6.3796(4) and c = 8.9907(7) Ă
. Heating BaThO3 to above 700 °C results in a continuous transition to a second orthorhombic structure, in space group Ibmm, demonstrated by both in situ neutron and synchrotron X-ray powder diffraction measurements. The coefficient of volumetric thermal expansion for BaThO3 is determined to be 1.04 x 10-5 oC-1 from 50 to 625 oC (Pbnm phase), and 9.43 x 10-6 oC-1 from 800 to 1000 oC (Ibmm phase). BaThO3 was found to decompose upon exposure to atmospheric moisture resulting in the formation of ThO2. The thermal expansion of ThO2, which invariably co-exists with BaThO3, is also described.Australian Synchrotron Australian Research Council2019-12-1
Target Selection for the LBTI Exozodi Key Science Program
The Hunt for Observable Signatures of Terrestrial planetary Systems (HOSTS)
on the Large Binocular Telescope Interferometer will survey nearby stars for
faint emission arising from ~300 K dust (exozodiacal dust), and aims to
determine the exozodiacal dust luminosity function. HOSTS results will enable
planning for future space telescopes aimed at direct spectroscopy of habitable
zone terrestrial planets, as well as greater understanding of the evolution of
exozodiacal disks and planetary systems. We lay out here the considerations
that lead to the final HOSTS target list. Our target selection strategy
maximizes the ability of the survey to constrain the exozodi luminosity
function by selecting a combination of stars selected for suitability as
targets of future missions and as sensitive exozodi probes. With a survey of
approximately 50 stars, we show that HOSTS can enable an understanding of the
statistical distribution of warm dust around various types of stars and is
robust to the effects of varying levels of survey sensitivity induced by
weather conditions.Comment: accepted to ApJ
Structure and phase transition in BaThO3: A combined neutron and synchrotron X-ray diffraction study
The structure of BaThO3, obtained by solid state synthesis, was refined for the first time by the Rietveld method using a combination of synchrotron X-ray and neutron powder diffraction data. BaThO3 has an orthorhombic structure at room temperature, in space group Pbnm with a = 6.3491(5), b = 6.3796(4) and c = 8.9907(7) Ă
. Heating BaThO3 to above 700 °C results in a continuous transition to a second orthorhombic structure, in space group Ibmm, demonstrated by both in situ neutron and synchrotron X-ray powder diffraction measurements. The coefficient of volumetric thermal expansion for BaThO3 is determined to be 1.04 x 10-5 oC-1 from 50 to 625 oC (Pbnm phase), and 9.43 x 10-6 oC-1 from 800 to 1000 oC (Ibmm phase). BaThO3 was found to decompose upon exposure to atmospheric moisture resulting in the formation of ThO2. The thermal expansion of ThO2, which invariably co-exists with BaThO3, is also described.Australian Synchrotron Australian Research Counci
The Life Science Exchange: a case study of a sectoral and sub-sectoral knowledge exchange programme
Background: Local and national governments have implemented sector-specific policies to support economic development through innovation, entrepreneurship and knowledge exchange. Supported by the Welsh Government through the European Regional Development Fund, The Life Science ExchangeÂź project was created with the aim to increase interaction between stakeholders, to develop more effective knowledge exchange mechanisms, and to stimulate the formation and maintenance of long-term collaborative relationships within the Welsh life sciences ecosystem. The Life Science Exchange allowed participants to interact with other stakeholder communities (clinical, academic, business, governmental), exchange perspectives and discover new opportunities.Methods: Six sub-sector focus groups comprising over 200 senior stakeholders from academia, industry, the Welsh Government and National Health Service were established. Over 18 months, each focus group provided input to inform healthcare innovation policy and knowledge mapping exercises of their respective sub-sectors. Collaborative projects identified during the focus groups and stakeholder engagement were further developed through sandpit events and bespoke support.Results: Each sub-sector focus group produced a report outlining the significant strengths and opportunities in their respective areas of focus, made recommendations to overcome any âsystem failuresâ, and identified the stakeholder groups which needed to take action. A second outcome was a stakeholder-driven knowledge mapping exercise for each area of focus. Finally, the sandpit events and bespoke support resulted in participants generating more than ÂŁ1.66 million in grant funding and inward investment. This article outlines four separate outcomes from the Life Science Exchange programme.Conclusions: The Life Science Exchange process has resulted in a multitude of collaborations, projects, inward investment opportunities and special interest group formations, in addition to securing over ten times its own costs in funding for Wales. The Life Science Exchange model is a simple and straightforward mechanism for a regional or national government to adapt and implement in order to improve innovation, skills, networks and knowledge exchange
EnROL: A multicentre randomised trial of conventional versus laparoscopic surgery for colorectal cancer within an enhanced recovery programme
BACKGROUND: During the last two decades the use of laparoscopic resection and a multimodal approach known as an enhanced recovery programme, have been major changes in colorectal perioperative care. Clinical outcome improves using laparoscopic surgery to resect colorectal cancer but until recently no multicentre trial evidence had been reported regarding whether the benefits of laparoscopy still exist when open surgery is optimized within an enhanced recovery programme. The EnROL trial (Enhanced Recovery Open versus Laparoscopic) examines the hypothesis that laparoscopic surgery within an enhanced recovery programme will provide superior postoperative outcomes when compared to conventional open resection of colorectal cancer within the same programme. METHODS/DESIGN: EnROL is a phase III, multicentre, randomised trial of laparoscopic versus open resection of colon and rectal cancer with blinding of patients and outcome observers to the treatment allocation for the first 7âdays post-operatively, or until discharge if earlier. 202 patients will be recruited at approximately 12 UK hospitals and randomised using minimization at a central computer system in a 1:1 ratio. Recruiting surgeons will previously have performed >100 laparoscopic colorectal resections and >50 open total mesorectal excisions to minimize conversion. Eligible patients are those suitable for elective resection using either technique. Excluded patients include: those with acute intestinal obstruction and patients in whom conversion from laparoscopic to open procedure is likely. The primary outcome is physical fatigue as measured by the physical fatigue domain of the multidimensional fatigue inventory 20 (MFI-20) with secondary outcomes including postoperative hospital stay; complications; reoperation and readmission; quality of life indicators; cosmetic assessments; standardized performance indicators; health economic analysis; the other four domains of the MFI-20. Pathological assessment of surgical quality will also be undertaken and compliance with the enhanced recovery programme will be recorded for all patients. DISCUSSION: Should this trial demonstrate that laparoscopic surgery confers a significant clinical and/or health economic benefit this will further support the transition to this type of surgery, with implications for the training of surgeons and resource allocation. TRIAL REGISTRATION: ISRCTN48516968
Autonomous inâsitu calibration of ionâsensitive field effect transistor pH sensors
Ionâsensitive field effect transistorâbased pH sensors have been shown to perform well in high frequency and longâterm ocean sampling regimes. The Honeywell Durafet is widely used due to its stability, fast response, and characterization over a large range of oceanic conditions. However, potentiometric pH monitoring is inherently complicated by the fact that the sensors require careful calibration. Offsets in calibration coefficients have been observed when comparing laboratory to fieldâbased calibrations and prior work has led to the recommendation that an inâsitu calibration be performed based on comparison to discrete samples. Here, we describe our work toward a selfâcalibration apparatus integrated into a SeapHOx pH, dissolved oxygen, and CTD sensor package. This SelfâCalibrating SeapHOx is capable of autonomously recording calibration values from a high quality, traceable, primary reference standard: equimolar tris buffer. The SelfâCalibrating SeapHOx\u27s functionality was demonstrated in a 6âd test in a seawater tank at Scripps Institution of Oceanography (La Jolla, California, U.S.A.) and was successfully deployed for 2âweeks on a shallow, coral reef flat (Lizard Island, Australia). During the latter deployment, the trisâbased selfâcalibration using 15 onâboard samples exhibited superior reproducibility to the standard spectrophotometric pHâbased calibration using \u3eâ100 discrete samples. Standard deviations of calibration pH using tris ranged from 0.002 to 0.005 whereas they ranged from 0.006 to 0.009 for the standard spectrophotometric pHâbased method; the two independent calibration methods resulted in a mean pH difference of 0.008. We anticipate that the SelfâCalibrating SeapHOx will be capable of autonomously providing climate quality pH data, directly linked to a primary seawater pH standard, and with improvements over standard calibration techniques
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