13,826 research outputs found

    Investigating IoT Middleware Platforms for Smart Application Development

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    With the growing number of Internet of Things (IoT) devices, the data generated through these devices is also increasing. By 2030, it is been predicted that the number of IoT devices will exceed the number of human beings on earth. This gives rise to the requirement of middleware platform that can manage IoT devices, intelligently store and process gigantic data generated for building smart applications such as Smart Cities, Smart Healthcare, Smart Industry, and others. At present, market is overwhelming with the number of IoT middleware platforms with specific features. This raises one of the most serious and least discussed challenge for application developer to choose suitable platform for their application development. Across the literature, very little attempt is done in classifying or comparing IoT middleware platforms for the applications. This paper categorizes IoT platforms into four categories namely-publicly traded, open source, developer friendly and end-to-end connectivity. Some of the popular middleware platforms in each category are investigated based on general IoT architecture. Comparison of IoT middleware platforms in each category, based on basic, sensing, communication and application development features is presented. This study can be useful for IoT application developers to select the most appropriate platform according to their application requirement

    Prognostic Impact of Admission Blood Glucose for All-Cause Mortality in Patients with Acute Coronary Syndromes: Added Value on Top of GRACE Risk Score

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    BACKGROUND: Abnormal glucose metabolism is a predictor of worse outcome after acute coronary syndrome (ACS). However, this parameter is not included in risk prediction scores, including GRACE risk score. We sought to evaluate whether the inclusion of blood glucose at admission in a model with GRACE risk score improves risk stratification. METHODS: Study of consecutive patients included in a single centre registry of ACS. Our primary endpoint was the occurrence of all-cause mortality at one-year follow-up. The ability of the two logistic regression models (GRACE risk score alone and in combination with blood glucose) to predict death was analysed. Continuous net reclassification improvement (NRI) and integrated discrimination improvement (IDI), with corresponding 95% confidence intervals (CIs), were also calculated. RESULTS: We included 2099 patients, with a mean age of 64 (SD=13) years, 69% males. In our sample, 55.1% presented with ST-segment elevation ACS and 13.1% in Killip class ≥ 2. Only 25% were known diabetic at admission. In-hospital mortality was 5.8% and 9.7% at one-year follow-up. The best cut-point for blood glucose was 160 mg/dl (sensitivity 62% and specificity 68%), and 35.2% of the patients had increased levels. This group was elderly, had more prevalence of cardiovascular risk factors, worse renal function and GRACE score as well as more frequently Killip class ≥2. Treatment was similar in both groups besides less frequent use of clopidogrel in high glycaemic patients. The hyperglycaemia group had higher one-year mortality (17.2% vs. 5.6%, p<0.001). Moreover, binary blood glucose remained a predictor of death independently of the GRACE risk score and the presence of diabetes (odds ratio (OR) 1.99, 95% CI 1.40-2.84, p<0.001). The inclusion of blood glucose, as a continuous variable, in a logistic regression model with GRACE score, increased the area under the ROC curve from 0.80 to 0.82 (p=0.018) as well as the goodness-of-fit and was associated with an improvement in both the NRI (37%) and the IDI (0.021), suggesting effective reclassification. CONCLUSIONS: A blood glucose level on admission ≥ 160 mg/dl is an independent predictor of mortality in medium-term follow-up. It offers an incremental predictive value when added to the GRACE risk score, although with a modest magnitude of improvement, probably due to the high predictive performance of the GRACE risk score alone.info:eu-repo/semantics/publishedVersio

    Is It Possible to Simplify Risk Stratification Scores for Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Angioplasty?

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    INTRODUCTION: There are several risk scores for stratification of patients with ST-segment elevation myocardial infarction (STEMI), the most widely used of which are the TIMI and GRACE scores. However, these are complex and require several variables. The aim of this study was to obtain a reduced model with fewer variables and similar predictive and discriminative ability. METHODS: We studied 607 patients (age 62 years, SD=13; 76% male) who were admitted with STEMI and underwent successful primary angioplasty. Our endpoints were all-cause in-hospital and 30-day mortality. Considering all variables from the TIMI and GRACE risk scores, multivariate logistic regression models were fitted to the data to identify the variables that best predicted death. RESULTS: Compared to the TIMI score, the GRACE score had better predictive and discriminative performance for in-hospital mortality, with similar results for 30-day mortality. After data modeling, the variables with highest predictive ability were age, serum creatinine, heart failure and the occurrence of cardiac arrest. The new predictive model was compared with the GRACE risk score, after internal validation using 10-fold cross validation. A similar discriminative performance was obtained and some improvement was achieved in estimates of probabilities of death (increased for patients who died and decreased for those who did not). CONCLUSION: It is possible to simplify risk stratification scores for STEMI and primary angioplasty using only four variables (age, serum creatinine, heart failure and cardiac arrest). This simplified model maintained a good predictive and discriminative performance for short-term mortality

    Predictive Impact on Medium-Term Mortality of Hematological Parameters in Acute Coronary Syndromes: Added Value on Top of GRACE Risk Score

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    BACKGROUND: Red Cell Distribution Width (RDW) prognostic value in patients with Acute Coronary Syndrome (ACS) has been well validated whereas that of Platelet Distribution Width (PDW) is less well known. OBJECTIVES: Investigate the incremental prognostic value, on top of GRACE risk score, of a new variable resulting from the combination of RDW and PDW. METHODS: Consecutive patients with ACS. Complete blood count, with RDW and PDW, was obtained. Primary endpoint was one-year all-cause mortality and Cox regression models were used to measure the influence of RDW and PDW on patients' survival time. A new combination categorical variable (RDW/PDW) was created with both discretized RDW and PDW and logistic regression models were used. Predictive value and discriminative ability of the model with GRACE risk score alone and of the model with inclusion of RDW/PDW was assessed. RESULTS: We included 787 patients. Hospital and one-year mortality rates were 5.1% and 7.8%, respectively. Both continuous RDW and PDW were independent predictors of death. The best cut-off for RDW was 13.9%, and 14.5% for PDW. Inclusion of RDW/PDW in a model with GRACE risk score improved the AUC from 0.81 (95% CI 0.75-0.86) to 0.84 (95% CI 0.79-0.90) (p=0.024) with an improvement in total NRI (56%) and IDI (0.048). CONCLUSIONS: Simple markers such as RDW and PDW can be useful in risk stratification of death after ACS. Combining both markers with GRACE risk score improved the predictive value for all-cause mortality and reduced the estimated risk of those who did not die.info:eu-repo/semantics/publishedVersio

    Determination of phase wetting in oil-water pipe flows

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    Oil-water two-phase flow is often a problem in transportation since the corrosion rate is closely related to which phase wets the pipe. The problem has been investigated on a large scale, in a 60 meter-long flow loop with Saudi Arabian crude oils. In this paper extensive experimental studies of flow pattern as well as phase wetting determination have been carried out for different crude oils and different pipe inclinations. Four experimental techniques have been applied to determine which phase, either water or oil, wets the pipe inner wall at different flowing conditions: wall conductance probes, wall sampling, flow visualization, and corrosion monitoring by electric resistance probes. Based on the overlapping information from these techniques, comprehensive phase wetting maps as a function of water cut and flow velocities were obtained. Three flow patterns were observed: stratified flow, stratified flow with mixed layer, and dispersed flows. The comparison of flow pattern and wetting regimes gives good understanding of the water wetting mechanism. Moreover, the phase wetting maps produced are a precious tool which can be used as a useful reference for corrosion engineers and pipeline operators to manipulate oil-water two-phase flow systems under corrosion free conditions

    Sensory Electrical Stimulation Improves Foot Placement during Targeted Stepping Post-Stroke

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    Proper foot placement is vital for maintaining balance during walking, requiring the integration of multiple sensory signals with motor commands. Disruption of brain structures post-stroke likely alters the processing of sensory information by motor centers, interfering with precision control of foot placement and walking function for stroke survivors. In this study, we examined whether somatosensory stimulation, which improves functional movements of the paretic hand, could be used to improve foot placement of the paretic limb. Foot placement was evaluated before, during, and after application of somatosensory electrical stimulation to the paretic foot during a targeted stepping task. Starting from standing, twelve chronic stroke participants initiated movement with the non-paretic limb and stepped to one of five target locations projected onto the floor with distances normalized to the paretic stride length. Targeting error and lower extremity kinematics were used to assess changes in foot placement and limb control due to somatosensory stimulation. Significant reductions in placement error in the medial–lateral direction (p = 0.008) were observed during the stimulation and post-stimulation blocks. Seven participants, presenting with a hip circumduction walking pattern, had reductions (p = 0.008) in the magnitude and duration of hip abduction during swing with somatosensory stimulation. Reductions in circumduction correlated with both functional and clinical measures, with larger improvements observed in participants with greater impairment. The results of this study suggest that somatosensory stimulation of the paretic foot applied during movement can improve the precision control of foot placement

    High resolution Compton scattering as a Probe of the Fermi surface in the Iron-based superconductor LaO1xFxFeAsLaO_{1-x}F_xFeAs

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    We have carried out first principles all-electron calculations of the (001)-projected 2D electron momentum density and the directional Compton profiles along the [100], [001] and [110] directions in the Fe-based superconductor LaOFeAs within the framework of the local density approximation. We identify Fermi surface features in the 2D electron momentum density and the directional Compton profiles, and discuss issues related to the observation of these features via Compton scattering experiments.Comment: 4 pages, 3 figure

    Prognostic Value of Left Atrial Volume in Patients with Dilated Cardiomyopathy

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    Introdução: O aumento da aurícula esquerda (AE) é um marcador de mortalidade na população geral. Os doentes com miocardiopatia dilatada (MCD) têm um amplo espetro de tamanhos deAE, mas a importância clínica desta observação tem sido pouco estudada. Objectivo: Avaliar a importância prognóstica a longo prazo do volume da AE (VAE) em doentes com MCD. Métodos: Estudo prospetivo de doentes admitidos durante o ano de 2004 com o diagnóstico deMCD, em ritmo sinusal. Foi realizado estudo ecocardiográfico completo em repouso e após stress farmacológico. O endpoint composto considerou a assistência ventricular mecânica (AVM), a transplantação cardíaca ou a morte. Resultados: Foram incluídos 35 doentes (68,6% sexo masculino, idade média 52,0), 82,9% etiologia não isquémica. Fração ejeção em repouso 31,1 ± 9,4%.Durante o seguimento, oito doentes morreram, um foi colocado em AVM e um foi transplantado. A análise de Cox univariável revelou potenciais marcadores ecocardiográficos de prognóstico na amostra tais como a dimensão da AE em modo M (HR-1,12; IC: 0,99-1,26;p = 0,067); VAE (HR-1,02; IC: 1,00-1,04; p = 0,046); VAE ajustado à superfície corporal (HR-1,03;IC: 1,00-1,07; p = 0,049); E/A (HR-0,99; IC: 0,99-1,81; p = 0,060); E/A > 2 (HR-7,00; IC:1,48-32,43; p = 0,014) e E/E’ mitral (HR-1,04; IC: 1,00-1,09; p = 0,074). Na análise multivariável a única variável que permaneceu no modelo foi o VAE com o ponto de corte de 63 ml (HR-7,7, IC:0,97-60,61, p = 0,05).Conclusão: Nesta amostra, o VAE foi o único parâmetro ecocardiográfico determinante de AVM,transplantação cardíaca ou morte. Os parâmetros ecocardiográficos habitualmente utilizadospara estratificação de risco, tais como a fração ejeção do ventrículo esquerdo, a dimensão do ventrículo esquerdo e a reserva contrátil não tiveram valor prognóstico na nossa amostra
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