47 research outputs found
Attracting Manifold for a Viscous Topology Transition
An analytical method is developed describing the approach to a finite-time
singularity associated with collapse of a narrow fluid layer in an unstable
Hele-Shaw flow. Under the separation of time scales near a bifurcation point, a
long-wavelength mode entrains higher-frequency modes, as described by a version
of Hill's equation. In the slaved dynamics, the initial-value problem is solved
explicitly, yielding the time and analytical structure of a singularity which
is associated with the motion of zeroes in the complex plane. This suggests a
general mechanism of singularity formation in this system.Comment: 4 pages, RevTeX, 3 ps figs included with text in uuencoded file,
accepted in Phys. Rev. Let
Assessment of left atrial electro-mechanical delay to predict atrial fibrillation in hypertrophic cardiomyopathy
Aims Atrial fibrillation (AF) is frequently observed in hypertrophic cardiomyopathy (HCM) and is associated with poor clinical outcome. Total atrial conduction time, estimated by tissue Doppler imaging (TDI), the so-called PA-TDI duration, reflects the left atrial (LA) structural and electrical remodelling. The aim of this study was to evaluate the association between PA-TDI and new-onset AF in patients with HCM.Methods and results From a large cohort of patients with HCM, 208 patients (64% male, mean age 53 +/- 14 years) without AF were selected. PA-TDI duration was measured from the onset P wave on electrocardiogram to the peak A' wave of the lateral LA wall using TDI. The incidence of new-onset AF was 20% over a median follow-up of 7.3 (3.5-10.5) years. Patients with incident AF had longer PA-TDI duration when compared with patients without AF (133.7 +/- 23.0 vs. 110.5 +/- 30.0 ms, P < 0.001). PA-TDI duration was independently associated with new-onset AF (hazard ratio: 1.03, 95% confidence interval: 1.01-1.05, P < 0.001).Conclusion Prolonged PA-TDI duration was independently associated with new-onset AF in patients with HCM. This novel parameter could be useful to risk-stratify patients with HCM who are at risk of having AF.Cardiolog
Computed tomography-derived transesophageal echocardiographic views step forward for procedural planning of transcatheter tricuspid valve annuloplasty
Cardiolog
Comparative study of the functional properties of three legume seed isolates: adzuki, pea and soy bean
The aim of this work was to compare functional properties including solubility, emulsifying and foaming properties of native and thermally treated adzuki, soy and pea protein isolates prepared under the same conditions. These functional properties were tested at four pH values: pH 3.0, pH 5.0, pH 7.0 and pH 8.0. The lowest solubility at all pH values were obtained for isolate of adzuki whereas isolates of soybean had the highest values at almost all pHs. Thermal treatment reduced solubility of soy and pea isolates at all pH values, whereas solubility of adzuki isolate was unchanged, except at pH 8. Native isolate of adzuki had the best emulsifying properties at pH 7.0 whereas at the other pH values some of native pea and soybean protein isolates were superior. After thermal treatment, depending on tested pH and selected variety all of three species could be a good emulsifier. Native soy protein isolates formed the most stable foams at all pHs. Thermal treatment significantly improved foaming properties of adzuki isolate, whereas reduced foaming capacity of soy and pea isolates, but could improve foam stability of these isolates at specific pH. Appropriate selection of legume seed as well as variety could have great importance in achievement of desirable functional properties of final products. All three tested species could find specific application in wide range of food products
Adaptive deformation correction of depth from defocus for object reconstruction
The accuracy of three-dimensional object reconstruction using depth from defocus (DfD) can be severely reduced by elliptical lens deformation. This paper presents two correction methods, correction by deformation cancellation (CDC) and correction by least squares fit (CLSF). CDC works by subtracting the current deformed depth value by a prestored deformed value, and CLSF by mapping the deformed values to the expected values. Each method is followed by a smoothing algorithm to address the low-texture problem of DfD. Experiments using four DfD methods on real images show that the proposed methods effectively and efficiently eliminate the deformation
The Impact of Transcoronary Ablation of Septal Hypertrophy on Diastology in Hypertrophic Obstructive Cardiomyopathy
Patterns of cardiac involvement characterized by strain echocardiography in amyloidosis
Cardiolog
Patterns of cardiac involvement characterized by strain echocardiography in amyloidosis
Cardiolog
Prognostic Implications of Right Ventricular Systolic Dysfunction in Cardiac Amyloidosis
Left ventricular (LV) systolic dysfunction in cardiac amyloidosis (CA) is associated with poor prognosis. This study aimed to investigate the prognostic implications of right ventricular (RV) systolic dysfunction in CA. A total of 93 patients diagnosed with CA who underwent standard and speckle-tracking echocardiography were included. During a median follow-up of 17 (5 to 38) months, 42 patients (45%) died. Nonsurvivors were more likely to present with immunoglobulin light-chain amyloidosis and New York Heart Association class III to IV heart failure symptoms. Regarding the echocardiographic characteristics, nonsurvivors had a higher LV apical ratio, worse LV diastolic function, and worse RV systolic function (evaluated with both tricuspid annular plane systolic excursion and RV free wall strain). RV free wall strain was independently associated with all-cause mortality in several multivariable Cox regression models and had incremental prognostic value over conventional parameters of RV function when added to a basal model (including heart failure symptoms, amyloidosis phenotype, and LV global longitudinal strain). Based on spline curve analysis and Youden index, a value of 16% for RV free wall strain was identified as the optimal cutoff to predict outcome and patients with RV free wall strain <16% had a significantly worse short- and long-term survival during follow-up (1- and 3-year cumulative survival: 81% vs 31% and 67% vs 20%, respectively, p <0.001). In conclusion, RV systolic dysfunction is independently associated with poor outcome in patients with CA and the use of advanced echocardiographic parameters, such as RV free wall strain, may be of aid for better risk stratification. (C) 2022 The Author(s). Published by Elsevier Inc
Factors Determining Surgical Approaches to Basilar Bifurcation Aneurysms and Its Surgical Outcomes
ABSTRACT BACKGROUND: The basilar bifurcation aneurysm (BBA) is still considered to be one of the most challenging aneurysms for micro- and endovascular surgery. Classic surgical approaches, such as subtemporal, lateral supraorbital (LSO), and modified presigmoid, are still reliable and effective. OBJECTIVE: To analyze the clinical and radiological factors that affect the selection of these classic surgical approaches and their outcomes. METHODS: A retrospective analysis was conducted on the clinical and radiological data from computed tomographic angiography of BBA that have been clipped in the Department of Neurosurgery of Helsinki University Central Hospital between 2004 and 2014. Statistical analyses were performed using parametric and nonparametric tests where values were considered significant below P = .05. RESULTS: One hundred four patients with BBA underwent surgical clipping in our department between 2004 and 2014. Eight patients were excluded from the study because of incomplete preoperative radiological evaluations, leaving 96 patients for further analysis. Multiple aneurysm clipping, mean basilar bifurcation angle, and aneurysm neck distance from posterior clinoid process were shown to be factors that determine the surgical approach. Unfavorable outcome is strongly associated with poor Hunt-Hess grade on admission, distance from aneurysm neck (the posterior clinoid process), thrombosis, and dome size. CONCLUSION: Microsurgery for BBA clipping can be performed safely with simple surgical approaches: subtemporal and LSO. There are several factors determining the approach selected. Poor patient outcome in BBA was highly associated with poor preoperative clinical grade and large size of aneurysm dome