1,257 research outputs found

    Ultrasound-detected pathologies cluster into groups with different clinical outcomes: data from 3000 community referrals for shoulder pain

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    Background Ultrasound is increasingly used to evaluate shoulder pain but the benefits of this are unclear. This study examined whether ultrasound-defined pathologies have implications for clinical outcomes. Methods We extracted reported pathologies from 3000 ultrasound scans of people with shoulder pain referred from primary care. Latent class analysis (LCA) identified whether individual pathologies clustered in groups. Optimal group number was determined by the minimum Bayesian information criterion. A questionnaire was sent to all patients scanned over a 12-month period (n=2322). Data collected included demographics, treatments received, current pain and function. The relationship between pathology-defined groups and clinical outcomes was examined. Results LCA revealed four groups: 1. bursitis with limited inflammation elsewhere (n=1280); 2. bursitis with extensive inflammation (n=595); 3. rotator cuff tears (n=558); 4. limited pathology (n=567). 777 (33%) completed questionnaires; median (IQR) duration post-ultrasound scan was 25 (22, 29) months. Subsequent injections were most common in groups 1 & 2 (groups 1-4: 76%; 67%; 48%; 61%); surgery was most common in group 3 (23%; 21%; 28%; 16%). Shoulder Pain and Disability Index scores were highest in group 3 (median 48 and 30 respectively) and lowest in group 4 (32 and 9). Patients in group 4 who had surgery reported poor outcomes. Conclusion In a community-based population, ultrasound identified clusters of pathologies. Our retrospective data suggests these groups have different treatment pathways and outcomes. This requires replication in a prospective study to determine the value of a pathology-based classification in people with shoulder pain

    A proper understanding of Millikan

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    Ruth Millikan’s teleological theory of mental content is complex and often misunderstood. This paper motivates and clarifies some of the complexities of the theory, and shows that paying careful attention to its details yields answers to a number of common objections to teleological theories, in particular, the problem of novel mental states, the problem of functionally false beliefs, and problems about indeterminacy or multiplicity of function

    Experimental Determination of Load Carrying Capacity of Point Contacts at Zero Entrainment Velocity

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    A capacitance technique was used to monitor the film thickness separating two steel balls of a unique tribometer while subjecting the ball-ball contact to highly stressed, zero entrainment velocity (ZEV) conditions. All tests were performed under a N2 purge (R.H. < 1.0%) and utilized 52100 steel balls (R(sub a) = 0.02 mm). Tribometer operations and capacitance-to-film-thickness accuracy were verified by comparing the film thickness approximations to established theoretical predictions for test conditions involving pure rolling. Pure rolling experiments were performed under maximum contact stresses and entrainment velocities of 1.0 GPa and 1.0 m/s to 3.0 m/s, respectively. All data from these baseline tests conformed to theory. ZEV tests were initiated after calibration of the tribometer and verification of film thickness approximation accuracy. Maximum contact stresses up to 0.57 GPa were supported at zero entrainment velocity with sliding speeds from 6.0 to 10.0 m/s for sustained amounts of time up to 28.8 minutes. The protective lubricating film separating the specimens at ZEV had a thickness between 0.10 and 0.14 mm (4 to 6 min), which corresponds to an approximate L-value of 4. The film thickness did not have a strong dependence upon variations of load or speed. Decreasing the sliding speed from 10.0 m/s to 1 m/s revealed a rapid loss in load support between 3.0 and 1.0 m/s. The formation of an immobile film formed by lubricant entrapment is discussed as an explanation of the load carrying capacity at these zero entrainment velocity conditions, relevant to the ball-ball contact application in retainerless ball bearings

    Experimental Study of Load Carrying Capacity of Point Contacts at Zero Entrainment Velocity

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    A capacitance technique was used to monitor the film thickness separating two steel balls while subjecting the ball-ball contact to highly stressed, zero entrainment velocity conditions. Tests were performed in a nitrogen atmosphere and utilized 52100 steel balls and a polyalphaolefin lubricant. Capacitance to film thickness accuracy was verified under pure rolling conditions using established EHL theory. Zero entrainment velocity tests were performed at sliding speeds from 6.0 to 10.0 m/s and for sustained amounts of time to 28.8 min. The protective lubricant film separating the specimens at zero entrainment velocity had a film thickness between 0.10 to 0.14 microns (4 to 6 micro in.), which corresponded to a k value of 4. The formation of an immobile surface film formed by lubricant entrapment is discussed as an explanation of the load carrying capacity at zero entrainment velocity conditions, relevant to the ball-ball contacts occurring in retainerless ball bearings

    The Use of Intraosseous Needles for Injection of Contrast Media for Computed Tomographic Angiography of the Thoracic Aorta

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    Background The objective of this study is to evaluate the safety and quality of computed tomographic angiography of the thoracic aorta (CTA-TA) exams performed using intraosseous needle intravenous access (ION-IVA) for contrast media injection (CMI). Methods All CTA-TA exams at the study institution performed between 1/1/2013 and 8/14/2015 were reviewed retrospectively to identify those exams which had been performed using ION-IVA (ION-exams). ION-exams were then analyzed to determine aortic attenuation and contrast-to-noise ratio (CNR). Linear regression was used to determine how injection rate and other variables affected image quality for ION-exams. Patient electronic medical records were reviewed to identify any adverse events related to CTA-TA or ION-IVA. Results 17 (∼0.2%) of 7401 exams were ION-exams. ION-exam CMI rates varied between 2.5 and 4 ml/s. Mean attenuation was 312 HU (SD 88 HU) and mean CNR was 25 (SD 9.9). A strong positive linear association between attenuation and injection rate was found. No immediate or delayed complications related to the ION-exams, or intraosseous needle use in general, occurred. Conclusion For CTA-TA, ION-IVA appears to be a safe and effective route for CMI at rates up to 4 ml/s

    Bonding in Functionalized Aziridines: Nitrogen-15 and Carbon-13 Studies

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    Two isomeric pairs of cis- and trans-1-cyclohexyl-2-phenyl-3-benzoylaziridines have been synthesized: (1) with a nitrogen-15 labelled nitrogen, and (2) with carbon-13 labelled ring carbons. The carbon-13 to X (where X=nitrogen-15, carbon-13 or hydrogen-I) spin-spin coupling constants were measured and interpreted in terms of stereoelectronic effects. X-ray crystallographic data (earlier determined for cisand trans-1-cyclohexyl-2-phenyl-3-(p-toluyl)aziridines)1 appear in good agreement with the NMR data. Bonding is discussed for the three-ring itself (NMR studies) and for its substituents (X-ray studies). It is concluded that stereochemical interaction of the Van der Waals type is an important determinant of aziridine bond length. Three-ring to carbonyl hyperconjugation is correlated with stereoelectronic interactions in the trans isomer

    Bonding in Functionalized Aziridines: Nitrogen-15 and Carbon-13 Studies

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    Two isomeric pairs of cis- and trans-1-cyclohexyl-2-phenyl-3-benzoylaziridines have been synthesized: (1) with a nitrogen-15 labelled nitrogen, and (2) with carbon-13 labelled ring carbons. The carbon-13 to X (where X=nitrogen-15, carbon-13 or hydrogen-I) spin-spin coupling constants were measured and interpreted in terms of stereoelectronic effects. X-ray crystallographic data (earlier determined for cisand trans-1-cyclohexyl-2-phenyl-3-(p-toluyl)aziridines)1 appear in good agreement with the NMR data. Bonding is discussed for the three-ring itself (NMR studies) and for its substituents (X-ray studies). It is concluded that stereochemical interaction of the Van der Waals type is an important determinant of aziridine bond length. Three-ring to carbonyl hyperconjugation is correlated with stereoelectronic interactions in the trans isomer

    Cost-effectiveness of hydroxychloroquine versus placebo for hand osteoarthritis: economic evaluation of the HERO trial

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    Background: An economic evaluation alongside the Hydroxychloroquine Effectiveness in Reducing symptoms of hand Osteoarthritis (HERO) trial was undertaken to assess the cost-effectiveness of hydroxychloroquine compared with placebo for symptomatic treatment of hand osteoarthritis for patients with at least moderate hand pain and inadequate response to current therapies. Methods: A trial-based cost–utility analysis was undertaken from the perspective of the UK National Health Service and Personal Social Services over a 12-month time horizon, using evidence from 248 participants included in the HERO trial, conducted in England. Patient-level data were collected prospectively over a 12-month period, using participant-completed questionnaires and investigator forms, to collect healthcare utilisation, costs and quality-adjusted life years (QALYs) using the EQ-5D-5L. The base-case analysis was conducted on an intention-to-treat basis and used multiple imputation methods to deal with missing data. Results were presented in terms of incremental cost-effectiveness ratios (incremental cost per QALY) and net health benefit, with uncertainty surrounding the findings explored using cost-effectiveness acceptability curves. Results: The base-case analysis estimated slightly lower costs on average (−£11.80; 95% confidence interval (CI) −£15.60 to −£8.00) and marginally fewer QALYs (−0.0052; 95% CI −0.0057 to −0.0047) for participants in the hydroxychloroquine group versus placebo group at 12 months. The resulting incremental cost-effectiveness ratio of £2,267 per QALY lost indicated that although costs were saved, health-related quality of life was lost. Even assuming symmetrical preferences regarding losses and gains for health benefits, the findings do not fall within the cost-effective region. Similar findings arose for analyses conducted from the societal perspective and using complete cases only. Conclusions: This economic evaluation indicates that hydroxychloroquine is unlikely to provide a cost-effective pain relief option for improving health-related quality of life in adult patients with moderate-to-severe hand osteoarthritis

    Toward a simulation approach for alkene ring-closing metathesis : scope and limitations of a model for RCM

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    A published model for revealing solvent effects on the ring-closing metathesis (RCM) reaction of di-Et diallylmalonate 7 has been evaluated over a wider range of conditions, to assess its suitability for new applications. Unfortunately, the model is too flexible and the published rate consts. do not agree with exptl. studies in the literature. However, by fixing the values of important rate consts. and restricting the concn. ranges studied, useful conclusions can be drawn about the relative rates of RCM of different substrates, precatalyst concn. can be simulated accurately and the effect of precatalyst loading can be anticipated. Progress has also been made toward applying the model to precatalyst evaluation, but further modifications to the model are necessary to achieve much broader aims

    Multilingual representations for low resource speech recognition and keyword search

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    © 2015 IEEE. This paper examines the impact of multilingual (ML) acoustic representations on Automatic Speech Recognition (ASR) and keyword search (KWS) for low resource languages in the context of the OpenKWS15 evaluation of the IARPA Babel program. The task is to develop Swahili ASR and KWS systems within two weeks using as little as 3 hours of transcribed data. Multilingual acoustic representations proved to be crucial for building these systems under strict time constraints. The paper discusses several key insights on how these representations are derived and used. First, we present a data sampling strategy that can speed up the training of multilingual representations without appreciable loss in ASR performance. Second, we show that fusion of diverse multilingual representations developed at different LORELEI sites yields substantial ASR and KWS gains. Speaker adaptation and data augmentation of these representations improves both ASR and KWS performance (up to 8.7% relative). Third, incorporating un-transcribed data through semi-supervised learning, improves WER and KWS performance. Finally, we show that these multilingual representations significantly improve ASR and KWS performance (relative 9% for WER and 5% for MTWV) even when forty hours of transcribed audio in the target language is available. Multilingual representations significantly contributed to the LORELEI KWS systems winning the OpenKWS15 evaluation
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