11 research outputs found

    Incentives for privacy-concerned mobile sensing systems

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    To gather meaningful data about individuals and other environments, wireless sensor focuses on inputs posted by customers via their Smartphone (e.g., smart phone). Consumers, on the other hand, might well be hesitant to participate leading to a shortage of incentive as well as concern about probable privacy breaches. Both motivation and security challenges must be resolved in order to successfully stimulate public participation. [2] Although motivations as well as security have already been tackled independently in sensing system, addressing both concurrently remains an outstanding challenge. We introduce two resource private information additional incentives in mobile wearable sensors throughout this research, with the concentrate on data protection rather than incentives mechanism design [12]. Our methods allow Smartphone members to earn rewards by providing information without revealing what data they've supplied, and they prevent bad users from abusing the system to gain a limitless number of credits. The first approach takes into account instances in which an internet intermediary (TTP) is provided and depends just on TTP to preserve consumer privacy and avoid abusive threats [5]. The second strategy examines cases in which there is no online TTP

    Proximal false lumen thrombosis is associated with low false lumen pressure and fewer complications in type B aortic dissection

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    BACKGROUND Improved risk stratification is a key priority for type B aortic dissection (TBAD). Partial false lumen thrombus morphology is an emerging predictor of complications. However, partial thrombosis is poorly defined, and its evaluation in clinical studies has been inconsistent. Thus, we aimed to characterize the hemodynamic pressure in TBAD and determine how the pressure relates to the false lumen thrombus morphology and clinical events. METHODS The retrospective admission computed tomography angiograms of 69 patients with acute TBAD were used to construct three-dimensional computational models for simulation of cyclical blood flow and calculation of pressure. The patients were categorized by the false lumen thrombus morphology as minimal, extensive, proximal or distal thrombosis. Linear regression analysis was used to compare the luminal pressure difference between the true and false lumen for each morphology group. The effect of morphology classification on the incidence of acute complications within 14 days was studied using logistic regression adjusted for clinical parameters. A survival analysis for adverse aortic events at 1 year was also performed using Cox regression. RESULTS Of the 69 patients, 44 had experienced acute complications and 45 had had an adverse aortic event at 1 year. The mean ± standard deviation age was 62.6 ± 12.6 years, and 75.4% were men. Compared with the patients with minimal thrombosis, those with proximal thrombosis had a reduced false lumen pressure by 10.1 mm Hg (95% confidence interval [CI], 4.3-15.9 mm Hg; P = .001). The patients who had not experienced an acute complication had had a reduced relative false lumen pressure (-6.35 mm Hg vs -0.62 mm Hg; P = .03). Proximal thrombosis was associated with fewer acute complications (odds ratio, 0.17; 95% CI, 0.04-0.60; P = .01) and 1-year adverse aortic events (hazard ratio, 0.36; 95% CI, 0.16-0.80; P = .01). CONCLUSIONS We found that proximal false lumen thrombosis was a marker of reduced false lumen pressure. This might explain how proximal false lumen thrombosis appears to be protective of acute complications (eg, refractory hypertension or pain, aortic rupture, visceral or limb malperfusion, acute expansion) and adverse aortic events within the first year

    Low Shear Stress at Baseline Predicts Expansion and Aneurysm-Related Events in Patients With Abdominal Aortic Aneurysm

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    Background Low shear stress has been implicated in abdominal aortic aneurysm (AAA) expansion and clinical events. We tested the hypothesis that low shear stress in AAA at baseline is a marker of expansion rate and future aneurysm-related events. Methods Patients were imaged with computed tomography angiography (CTA) at baseline and followed up every six months >24 months with ultrasound measurements of maximum diameter. From baseline CTA, we reconstructed three dimensional models for automated computational fluid dynamics simulations and computed luminal shear stress. The primary composite endpoint was aneurysm repair and/or rupture, and the secondary endpoint was aneurysm expansion rate. Results We included 295 patients with median AAA diameter of 49mm (IQR 43-54mm) and median follow-up of 914 (IQR 670-1112) days. There were 114 (39%) aneurysm-related events, with 13 AAA ruptures and 98 repairs (one rupture was repaired). Patients with low shear stress (0.6 Pa; 29%) shear stress groups (p=0.010). This association was independent of known risk factors (adjusted HR 1.72; 95% CI [1.08, 2.73]; p=0.023). Low shear stress was also independently associated with AAA expansion rate (ÎČ=+0.28mm/y; 95% CI [0.02, 0.53]; p=0.037). Conclusions We show for the first time that low shear stress (<0.4 Pa) at baseline is associated with both AAA expansion and future aneurysm-related events. Aneurysms within the lowest tertile of shear stress, versus those with higher shear stress, were more likely to rupture or reach thresholds for elective repair. Larger prospective validation trials are needed to confirm these findings and translate them into clinical management

    First-in-human controlled inhalation of thin graphene oxide nanosheets to study acute cardiorespiratory responses

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    Graphene oxide nanomaterials are being developed for wide-ranging applications but are associated with potential safety concerns for human health. We conducted a double-blind randomized controlled study to determine how the inhalation of graphene oxide nanosheets affects acute pulmonary and cardiovascular function. Small and ultrasmall graphene oxide nanosheets at a concentration of 200 ÎŒg m or filtered air were inhaled for 2 h by 14 young healthy volunteers in repeated visits. Overall, graphene oxide nanosheet exposure was well tolerated with no adverse effects. Heart rate, blood pressure, lung function and inflammatory markers were unaffected irrespective of graphene oxide particle size. Highly enriched blood proteomics analysis revealed very few differential plasma proteins and thrombus formation was mildly increased in an ex vivo model of arterial injury. Overall, acute inhalation of highly purified and thin nanometre-sized graphene oxide nanosheets was not associated with overt detrimental effects in healthy humans. These findings demonstrate the feasibility of carefully controlled human exposures at a clinical setting for risk assessment of graphene oxide, and lay the foundations for investigating the effects of other two-dimensional nanomaterials in humans. Clinicaltrials.gov ref: NCT03659864

    First-in-human controlled inhalation of thin graphene oxide nanosheets to study acute cardiorespiratory responses

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    Graphene oxide nanomaterials have been developed for wide-ranging applications, but has potential safety concerns for human health. Controlled inhalation exposures in human volunteers have been a vital means to determine the effects and mechanisms of ultrafine particles in air pollution, however, few studies have used this approach to explore the effects of nanomaterials. We conducted a double-blind randomised controlled study to determine whether inhalation of graphene oxide affects pulmonary or cardiovascular function. A high purity graphene oxide was synthesised with a thickness of 1-2 layers in two sizes: ‘small’ (lateral dimensions: 100-1700 nm) and ‘ultrasmall’ (30-500 nm). Graphene oxide particles at 200 ”g/m3, or filtered air, were inhaled for 2 hours by 14 young healthy volunteers on repeated visits, with measurement of cardiorespiratory parameters before and across 4 hours after exposure. Graphene oxide exposure was well-tolerated with no adverse effects. Heart rate, blood pressure, lung function and inflammatory markers were unaffected by graphene oxide irrespective of particle size. GO did not change blood biomarkers of coagulation, however, there was a mild increase in thrombus formation in an ex vivo model of arterial injury. Proteomics revealed very few differential plasma proteins. Overall, acute inhalation of graphene oxide was not associated with overt detrimental effects in healthy humans. These findings demonstrate the feasibility of carefully controlled human exposures for risk assessment of graphene nanomaterials

    Thoracic Aortic 18F-Sodium Fluoride Activity and Ischemic Stroke in Patients With Established Cardiovascular Disease

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    Objectives: The purpose of this study was to investigate whether thoracic 18F-sodium fluoride positron emission tomography (PET) could improve the identification of patients at the highest risk of ischemic stroke. Background: Aortic atherosclerosis represents an important contributor to ischemic stroke risk. Identifying patients with high-risk aortic atheroma could improve preventative treatment strategies for future ischemic stroke. Methods: In a post hoc observational cohort study, we quantified thoracic aortic and coronary 18F-sodium fluoride activity in 461 patients with stable cardiovascular disease undergoing PET combined with computed tomography (CT). Progression of atherosclerosis was assessed by change in aortic and coronary CT calcium volume. Clinical outcomes were determined by the occurrence of ischemic stroke and myocardial infarction. We compared the prognostic utility of 18F-sodium fluoride activity for predicting stroke to clinical risk scores and CT calcium quantification using survival analysis and multivariable Cox regression. Results: After 12.7 ± 2.7 months, progression of thoracic aortic calcium volume correlated with baseline thoracic aortic 18F-sodium fluoride activity (n = 140; r = 0.31; P = 0.00016). In 461 patients, 23 (5%) patients experienced an ischemic stroke and 32 (7%) a myocardial infarction after 6.1 ± 2.3 years of follow-up. High thoracic aortic 18F-sodium fluoride activity was strongly associated with ischemic stroke (HR: 10.3 [3.1 to 34.8]; P = 0.00017), but not myocardial infarction (P = 0.40). Conversely, high coronary 18F-sodium fluoride activity was associated with myocardial infarction (HR: 4.8 [1.9 to 12.2]; P = 0.00095) but not ischemic stroke (P = 0.39). In a multivariable Cox regression model including imaging and clinical risk factors, thoracic aortic 18F-sodium fluoride activity was the only variable associated with ischemic stroke (HR: 8.19 (2.33 to 28.7), P = 0.0010). Conclusions: In patients with established cardiovascular disease, thoracic aortic 18F-sodium fluoride activity is associated with the progression of atherosclerosis and future ischemic stroke. Arterial 18F-sodium fluoride activity identifies localized areas of atherosclerotic disease activity that are directly linked to disease progression and downstream regional clinical atherothrombotic events. (DIAMOND - Dual Antiplatelet Therapy to Reduce Myocardial Injury [DIAMOND], NCT02110303; Study Investigating the Effect of Drugs Used to Treat Osteoporosis on the Progression of Calcific Aortic Stenosis [SALTIRE II], NCT02132026; Novel Imaging Approaches To Identify Unstable Coronary Plaques, NCT01749254; and Role of Active Valvular Calcification and Inflammation in Patients With Aortic Stenosis, NCT01358513)

    First-in-human controlled inhalation of thin graphene oxide nanosheets to study acute cardiorespiratory responses

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    Datasets for manuscript published in Nature Nanotechnology. Graphene oxide nanomaterials are being developed for wide-ranging applications, but have potential safety concerns for human health. We conducted a double-blind randomised controlled study to determine how inhalation of graphene oxide nanosheets affects acute pulmonary and cardiovascular function. Small and ultrasmall graphene oxide nanosheets at ”g/m3 or filtered air were inhaled for 2 hours by 14 young healthy volunteers on repeated visits. Overall, graphene oxide nanosheet exposure was well-tolerated with no adverse effects. Heart rate, blood pressure, lung function and inflammatory markers were unaffected irrespective of graphene oxide particle size. Highly enriched blood proteomics analysis revealed very few differential plasma proteins and thrombus formation was mildly increased in an ex vivo model of arterial injury. Overall, acute inhalation of such highly purified and thin graphene oxide nanosheets of nanometre dimensions was not associated with overt detrimental effects in healthy humans. These findings demonstrate the feasibility of carefully controlled human exposures for risk assessment of graphene oxide, and lay the foundations for investigating the effects of other two dimensional nanomaterials in humans
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