68 research outputs found

    Official Knowledge and the Relations of Ruling

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    Intramural haematoma of the thoracic aorta: who's to be alerted the cardiologist or the cardiac surgeon?

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    This review article is written so as to present the pathophysiology, the symptomatology and the ways of diagnosis and treatment of a rather rare aortic disease called Intra-Mural Haematoma (IMH). Intramural haematoma is a quite uncommon but potentially lethal aortic disease that can strike as a primary occurrence in hypertensive and atherosclerotic patients to whom there is spontaneous bleeding from vasa vasorum into the aortic wall (media) or less frequently, as the evolution of a penetrating atherosclerotic ulcer (PAU). IMH displays a typical of dissection progress, and could be considered as a precursor of classic aortic dissection. IMH enfeebles the aortic wall and may progress to either outward rupture of the aorta or inward disruption of the intima layer, which ultimately results in aortic dissection. Chest and back acute penetrating pain is the most commonly noticed symptom at patients with IMH. Apart from a transesophageal echocardiography (TEE), a tomographic imaging such as a chest computed tomography (CT), a magnetic resonance (MRI) and most lately a multy detector computed tomography (MDCT) can ensure a quick and accurate diagnosis of IMH. Similar to type A and B aortic dissection, surgery is indicated at patients with type-A IMH, as well as at patients with a persistent and/or recurrent pain. For any other patient (with type-B IMH without an incessant pain and/or without complications), medical treatment is suggested, as applied in the case of aortic dissection. The outcome of IMH in ascending aorta (type A) appears favourable after immediate (emergent or urgent) surgical intervention, but according to international bibliography patients with IMH of the descending aorta (type B) show similar mortality rates to those being subjected to conservative medical or surgical treatment. Endovascular surgery and stent-graft placement is currently indicated in type B IMH

    Action Without Awareness: Reaching to an Object You Do Not Remember Seeing

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    BACKGROUND: Previous work by our group has shown that the scaling of reach trajectories to target size is independent of obligatory awareness of that target property and that "action without awareness" can persist for up to 2000 ms of visual delay. In the present investigation we sought to determine if the ability to scale reaching trajectories to target size following a delay is related to the pre-computing of movement parameters during initial stimulus presentation or the maintenance of a sensory (i.e., visual) representation for on-demand response parameterization. METHODOLOGY/PRINCIPAL FINDINGS: Participants completed immediate or delayed (i.e., 2000 ms) perceptual reports and reaching responses to different sized targets under non-masked and masked target conditions. For the reaching task, the limb associated with a trial (i.e., left or right) was not specified until the time of response cuing: a manipulation that prevented participants from pre-computing the effector-related parameters of their response. In terms of the immediate and delayed perceptual tasks, target size was accurately reported during non-masked trials; however, for masked trials only a chance level of accuracy was observed. For the immediate and delayed reaching tasks, movement time as well as other temporal kinematic measures (e.g., times to peak acceleration, velocity and deceleration) increased in relation to decreasing target size across non-masked and masked trials. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that speed-accuracy relations were observed regardless of whether participants were aware (i.e., non-masked trials) or unaware (i.e., masked trials) of target size. Moreover, the equivalent scaling of immediate and delayed reaches during masked trials indicates that a persistent sensory-based representation supports the unconscious and metrical scaling of memory-guided reaching

    Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

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    [This corrects the article DOI: 10.1186/s13054-016-1208-6.]

    Combined impact of viscosity variation and Lorentz force on slip flow of radiative nanofluid towards a vertical stretching surface with convective heat and mass transfer

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    This study is conducted to examine the influence of temperature dependent viscosity on slip flow over a convective sheet. Brownian motion and thermophoresis effects are taken into consideration in the presence of applied magnetic field and Joule heating. The emerging nonlinear problem is presented and tackled numerically using Runge–Kutta Fehlberg method coupled with shooting scheme. Graphical results for velocity, temperature, concentration field and skin friction are obtained and analyzed in a physical manner. Skin friction at the wall enhances with increasing magnetic field parameter. Local heat flux is found to be an increasing function of thermal radiation and Biot number. The model is valid in nano-material industrial developments containing extruding sheets. Keywords: MHD, Thermophoresis and Brownian motion, Variable viscosity, Joule heating, Viscous dissipation, Thermal radiatio

    Thermal stratification effect on gravity driven transport of hybrid CNTs down a stretched surface through porous medium

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    The purpose of the current article is to explore the impact of thermal stratification and medium porosity on gravity-coerced transport of hybrid carbon nanotubes down an upright extending sheet inspired by a constant applied magnetic field along with heat transfer investigation in existence of thermal radiation, viscous dispersal, and joule heating effect. Rectangular coordinates are chosen for the mathematical interpretation of the governing flow problem. Homothetic analysis is employed for the sake of simplification process. The reduced system of coupled nonlinear differential equations is dealt numerically by dint of computational software MATLAB inbuilt routine function Bvp4c. The numerical investigation is carried out for the distinct scenarios namely, (i) Presence of favorable buoyancy force, (ii) Case of purely forced convection and (iii) Presence of opposing buoyancy force. Significant Findings: The key findings include that the presence of hybrid carbon nanotubes and medium porosity contributes significantly to upsurging surface shear stress magnitude whereas, external magnetic field and velocity slip effects in an altered manner. The present study may be a benchmark in study of fueling process in space vehicles and space technology

    Evaluation of hemolysis in patients with prosthetic heart valves.

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    The primary mechanism and most common cause of hemolytic disease in patients with prosthetic heart valves are mechanical trauma to red blood cells and paraprosthetic valvular regurgitation, respectively. Presenting features in patients with this condition include anemia, congestive heart failure, fatigue, jaundice, dark urine, and a regurgitant murmur. Various laboratory studies can be utilized to diagnose hemolytic anemia and to assess the severity of hemolysis. Transthoracic echocardiography, transesophageal echocardiography, and Doppler studies including color Doppler are useful imaging methods to assess valve function. Treatment is usually medical (oral iron); however, in patients with paravalvular regurgitation, surgery is often required to correct the anemia

    Meta-analysis of 143 reported cases of aortic intramural hematoma.

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    Aortic intramural hematoma (IMH) is a clinical condition that has still not been completely defined. We conducted a meta-analysis of reported cases and analyzed the demographic profiles, imaging modalities, pathologic sites, and treatment strategies in relation to outcome in 143 patients with IMH. We performed an English language search of Medline for manuscripts with the keywords aortic diseases, aorta AND hematoma, and intramural hematoma. Data from 143 reported cases were extracted. IMH of the aorta has a reported incidence of 5% to 20% among patients with acute aortic syndromes and a mortality rate of 21%. Most patients were men (61%) and median age was 68 years (range 15 to 88). Hypertension was a predisposing factor in 53% of the patients. Most patients had chest and/or back pain (80%). Transesophageal echocardiography, computer tomographic scan, or magnetic resonance imaging may be effectively used to diagnose this condition. There is no difference in the overall mortality rates in Stanford type A versus type B patients. Patients with Stanford type A IMH who underwent surgery, compared with those who underwent medical management, had a significantly better prognosis (14% vs 36% mortality, respectively, p \u3c 0.02). Patients in Stanford group A who received medical treatment had a higher mortality rate than those in group B who received medical treatment (36% vs 14% mortality respectively, p \u3c 0.02). In type B patients, medical and surgical outcomes were similar

    Haptoglobin 2-2 genotype is associated with presence and progression of MRI depicted atherosclerotic intraplaque hemorrhage

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    Background: Atherosclerotic intraplaque hemorrhage (IPH) is a source of free hemoglobin that binds the haptoglobin protein and forms a complex cleared by CD163 macrophages. Compared to the other common haptoglobin genotypes, hemoglobin-haptoglobin2-2 complex has the lowest affinity for tissue macrophages resulting in lower rate of hemoglobin uptake and increased oxidative burden. We hypothesized that haptoglobin2-2 patients' failure to clear hemoglobin results in a greater prevalence and progression of IPH. Methods: Prevalence and volume of IPH were measured in eighty patients with advanced vascular disease using MRI. Haptoglobin was genotyped using PCR. Mixed Models Repeated Measures Analyses were performed to detect any differences in prevalence and volume of IPH between the haptoglobin genotypes. Results: Haptoglobin2-2 patients had a statistically significant higher prevalence of baseline IPH (OR = 4.34, p-value: 0.01, 95% CI: 1.31–14.35). Longitudinal analysis of 48 IPH positive carotids indicated a statistically significant progression of IPH volume over time in haptoglobin2-2 patients (Type 3 test for fixed effect p-value = 0.0106; baseline vs. year 3: β = 0.11, SE = 0.05, p-value = 0.03; year 2 vs. year 3: β = 0.05, SE = 0.02, p-value = 0.03). Conclusions: Patients with the Hp2-2 genotype had a significantly higher prevalence of carotid baseline IPH, which progressed over a two year follow up period. Detection of pre-symptomatic vascular disease using haptoglobin genotyping may allow for better risk stratification of populations at risk of stroke and in need of more targeted imaging investigations. Keywords: Vascular intraplaque hemorrhage, Biomarkers, Haptoglobin genotype, Magnetic resonance imaging, Strok
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