1,426 research outputs found
Exploring the Design of Pay-Per-Use Objects in the Construction Domain
Equipment used in the construction domain is often hired in order to reduce cost and maintenance overhead. The cost of hire is dependent on the time period involved and does not take into account the actual use equipment has received. This paper presents our initial investigation into how physical objects augmented with sensing and communication technologies can measure use in order to enable new pay-per-use payment models for equipment hire. We also explore user interaction with pay-per-use objects via mobile devices. The user interactions that take place within our prototype scenario range from simple information access to transactions involving multiple users. This paper presents the design, implementation and evaluation of a prototype pay-per-use system motivated by a real world equipment hire scenario. We also provide insights into the various challenges introduced by supporting a pay-per-use model, including data storage and data security in addition to user interaction issues
Ideal isotropic auxetic networks from random networks
Auxetic materials are characterized by a negative Poisson's ratio,
. As the Poisson's ratio becomes negative and approaches the
lower isotropic mechanical limit of , materials show
enhanced resistance to impact and shear, making them suitable for applications
ranging from robotics to impact mitigation. Past experimental efforts aimed at
reaching the limit have resulted in highly anisotropic
materials, which show a negative Poisson's ratio only when subjected to
deformations along specific directions. Isotropic designs have only attained
moderately auxetic behavior, or have led to structures that cannot be
manufactured in 3D. Here, we present a design strategy to create isotropic
structures from disordered networks that leads to Poisson's ratios as low as
. The materials conceived through this approach are
successfully fabricated in the laboratory and behave as predicted. The
Poisson's ratio is found to depend on network structure and bond
strengths; this sheds light on the structural motifs that lead to auxetic
behavior. The ideas introduced here can be generalized to 3D, a wide range of
materials, and a spectrum of length scales, thereby providing a general
platform that could impact technology.Comment: 16 pages, 6 figure
Statistics of heart failure and mechanical circulatory support in 2020
Heart failure is increasing in prevalence, with approximately 26 million patients affected worldwide. This represents a significant cause of morbidity and mortality. Statistics regarding heart failure patient age, hospitalization likelihood, and mortality differ significantly by country. Heart failure patients are typically classified by ejection fraction, with distinct phenotypes associated with reduced ejection fraction (rEF) or preserved ejection fraction (pEF). Heart failure has a significant financial impact related to hospitalization, medication, and procedural expenses. The costs of heart failure also extend to the reduced quality of life conferred by heart failure symptoms. Management of heart failure includes a variety of interventions, including mechanical circulatory support (MCS). MCS, including left ventricular assist devices (LVADs), right ventricular assist devices (RVADs) and extracorporeal membrane oxygenation (ECMO), has been a means of managing end stage heart failure. Given the relative scarcity of transplant organs, the utilization of MCS, particularly as a bridge to transplantation (BTT) has grown significantly. In this review, we discuss statistics related to heart failure and MCS. We evaluate how patients are classified and examine global trends and regional differences. We then address MCS therapies, the costs associated with heart failure, the impact of heart failure on patient quality of life, and data regarding morbidity and mortality
Spectroscopic detection of quasars in the 2dF Galaxy Redshift Survey
The 100,000 spectra from the 2 degree Field Galaxy Redshift Survey (2dFGRS)
in the 100k Public Data Release represent the largest single compilation of
galaxy spectra available. By virtue of its sheer size and the properties of the
photometric catalogue that defines the sample, the 2dFGRS is expected to
contain a number of potentially interesting objects other than galaxies. A
search of the spectra in the 100k Data Release results in a census of 55
candidate high-redshift (z > 0.3) quasars. One additional 2dFGRS spectrum of a
low-redshift galaxy shows an apparent anomalous broad emission feature perhaps
indicating the presence of a gravitationally lensed quasar. These objects have
been identified primarily using two automated routines that we have developed
specifically for this task, one of which uses a matched filter and the other a
wavelet transform. A number of the quasar images possess complicated
morphologies, suggesting the presence of either diffuse foreground objects
along the line-of-sight or very nearby point sources. The quasar catalogue will
form a target list for future absorption and lensing studies, as well as
providing an assessment of the loss of quasars with non-stellar images from the
companion 2dF QSO Redshift Survey.Comment: Latex 13 pages, 8 figures. Accepted for publication in MNRA
Left-ventricular outflow tract acceleration time is associated with symptoms in patients with obstructive hypertrophic cardiomyopathy
AIMS: Not all obstructive hypertrophic cardiomyopathy (HCM) patients are symptomatic. The relation between obstructive HCM and symptoms is not well understood. The hypothesis of this study is that left-ventricular outflow tract (LVOT) acceleration time (AT) is associated with symptoms. METHODS: We included 187 patients (61% men, mean age 55â±â14 years) with obstructive HCM, defined as a maximal wall thicknessââ„â15 mm and a resting or provoked LVOT peak gradientââ„â30 mmHg. Peak velocity (PV), left-ventricular (LV) ejection time (ET), and AT (the time between LVOT flow onset and the moment of PV) were measured on continuous-wave (CW) Doppler tracings. Logistic and Cox proportional hazard regression analyses were used to evaluate the relation between symptoms [New York Heart Association (NYHA) classââ„âII] and echocardiographic measurements, including AT. Reproducibility was assessed using the intraclass correlation coefficient (ICC). RESULTS: Symptomatic patients were more often female and had higher mean AT values. Logistic regression demonstrated a significant association between AT and symptomatic status (odds ratio 1.31 per 10 ms, pâ<â0.01) after adjustment for sex, negative inotropes, PV, LVOT diameter, and diastolic dysfunction. AT was independently associated with symptoms and septal reduction during follow-up (hazard ratio 1.09 per 10 ms, pâ<â0.05). The ICC was 0.98 with a mean difference of 0.28â±â8.4 ms. CONCLUSION: In obstructive HCM patients, increased AT is significantly related to symptoms after adjustment for sex, negative inotropes, PV, LVOT diameter, and diastolic dysfunction, and is associated with the symptomatic status during follow-up. AT represents an easily measured echocardiographic variable with excellent inter-reader reproducibility. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40477-020-00513-3) contains supplementary material, which is available to authorized users
Carburisation of ferritic FeâCr alloys by low carbon activity gases
Model FeâCr alloys were exposed to ArâCO2âH2O gas mixtures at 650 and 800 °C. At equilibrium, these atmospheres are oxidising to the alloys, but decarburising (aC â 10â15 to 10â13). In addition to developing external oxide scales, however, the alloys also carburised. Carbon supersaturation at the scale/alloy interface relative to the gas reflects local equilibrium: a low oxygen potential corresponds to a high pCO/pCO2 ratio, and hence to a high carbon activity. Interfacial carbon activities calculated on the basis of scaleâalloy equilibrium are shown to be in good agreement with measured carburisation rates and precipitate volume fractions, providing support for the validity of the thermodynamic model
How was it for you? Experiences of participatory design in the UK health service
Improving co-design methods implies that we need to understand those methods, paying attention to not only the effect of method choices on design outcomes, but also how methods affect the people involved in co-design. In this article, we explore participants' experiences from a year-long participatory health service design project to develop âBetter Outpatient Services for Older Peopleâ. The project followed a defined method called experience-based design (EBD), which represented the state of the art in participatory service design within the UK National Health Service. A sample of participants in the project took part in semi-structured interviews reflecting on their involvement in and their feelings about the project. Our findings suggest that the EBD method that we employed was successful in establishing positive working relationships among the different groups of stakeholders (staff, patients, carers, advocates and design researchers), although conflicts remained throughout the project. Participants' experiences highlighted issues of wider relevance in such participatory design: cost versus benefit, sense of project momentum, locus of control, and assumptions about how change takes place in a complex environment. We propose tactics for dealing with these issues that inform the future development of techniques in user-centred healthcare design
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Development and Validation of an Electronic Postoperative Morbidity Score.
BACKGROUND: Electronic health records are being adopted due to numerous potential benefits. This requires the development of objective metrics to characterize morbidity, comparable to studies performed in centers without an electronic health record. We outline the development of an electronic version of the postoperative morbidity score for integration into our electronic health record. METHODS: Twohundred and three frail patients who underwent elective surgery were reviewed. We retrospectively defined postoperative morbidity score on postoperative day 3. We also recorded potential electronic surrogates for morbidities that could not be easily extracted in an objective format. We compared discriminative capability (area under the receiver operator curve) for patients having prolonged length of stay or complex discharge requirements. RESULTS: One hundred thirty-nine patients (68%) had morbidity in â„1 postoperative morbidity score domain. Initial electronic surrogates were overly sensitive, identifying 173 patients (84%) as having morbidity. We refined our definitions using backward logistic regression against "gold-standard" postoperative morbidity score. The final electronic postoperative morbidity score differed from the initial version in its definition of cardiac and neurological morbidity. There was no significant difference in the discriminative capability between electronic postoperative morbidity score and postoperative morbidity score for either outcome (area under the receiver operator curve: 0.66 vs 0.66 for complex discharge requirement, area under the receiver operator curve: 0.66 vs 0.67 for a prolonged length of stay; P> .05 for both). Patients with postoperative morbidity score or electronic postoperative morbidity score-defined morbidity on day 3 had increased risk of prolonged length of stay (P < .001 for both). CONCLUSIONS: We present a variant of postoperative morbidity score based on objective electronic metrics. Discriminative performance appeared comparable to gold-standard definitions for discharge outcomes. Electronic postoperative morbidity score may allow characterization of morbidity within our electronic health record, but further study is required to assess external validity
Hexanuclear Ln6L6Â Complex Formation by using an Unsymmetric Ligand
Multinuclear, selfâassembled lanthanide complexes present clear opportunities as sensors and imaging agents. Despite the widely acknowledged potential of this class of supramolecule, synthetic and characterization challenges continue to limit systematic studies into their selfâassembly restricting the number and variety of lanthanide architectures reported relative to their transition metal counterparts. Here we present the first study evaluating the effect of ligand backbone symmetry on multinuclear lanthanide complex selfâassembly. Replacement of a symmetric ethylene linker with an unsymmetric amide at the centre of a homoditopic ligand governs formation of an unusual Ln6L6 complex with coordinatively unsaturated metal centres. The choice of triflate as a counterion, and the effect of ionic radii are shown to be critical for formation of the Ln6L6 complex. The atypical Ln6L6 architecture is characterized using a combination of mass spectrometry, luminescence, DOSY NMR and EPR spectroscopy measurements. Luminescence experiments support clear differences between comparable Eu6L6 and Eu2L3 complexes, with relatively short luminescent lifetimes and low quantum yields observed for the Eu6L6 structure indicative of nonâradiative decay processes. Synthesis of the Gd6L6analogue allows three distinct Gd···Gd distance measurements to be extracted using homoâRIDME EPR experiments
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