315 research outputs found
Ischemic and non-ischemic patterns of late gadolinium enhancement in heart failure with reduced ejection fraction
Background: Late gadolinium enhancement (LGE) by cardiac magnetic resonance (CMR) may revealmyocardial fibrosis which is associated with adverse clinical outcomes in patients undergoing implantablecardioverter-defibrillator (ICD) placement. At the same time, transmural LGE in the posterolateral wall isrelated to nonresponse to conventional cardiac resynchronization therapy (CRT). Herein, the aim was toassess the presence and determinants of LGE in CMR in heart failure (HF) with reduced ejection fraction.Methods: Sixty-seven patients were included (17.9% female, aged 45 [29–60] years), who underwentLGE-CMR and had left ventricular ejection fraction (LVEF) as determined by echocardiography.Results: In HF patients with LVEF ≤ 35% (n = 29), ischemic and non-ischemic patterns of LGE wereobserved in 51.7% and 34.5% of patients, respectively. In controls (n = 38), these patterns were noted in23.7% and 42.1% of patients, respectively. HF patients with LVEF ≤ 35% and transmural LGE in theposterolateral wall (31.0%) were characterized by older age, coronary artery disease (CAD) and previousmyocardial infarction (MI) (61 ± 6 vs. 49 ± 16 years, p = 0.008, 100% vs. 40%, p = 0.003 and 78%vs. 25%, p = 0.014, respectively). In patients with LVEF ≤ 35%, LGE of any type, diagnosed in 86.2%of patients, was associated with CAD (68% vs. 0%, p = 0.02), while only trends were observed for itsassociation with older age and previous MI (p = 0.08 and p = 0.12, respectively).Conclusions: Among HF patients with LVEF ≤ 35%, clinical factors including older age, CAD, andprevious MI are associated with transmural LGE in the posterolateral wall, while CAD is associated with LGE. This data may have potential implications for planning ICD and CRT placement procedures
Near-inertial wave scattering by random flows
The impact of a turbulent flow on wind-driven oceanic near-inertial waves is
examined using a linearised shallow-water model of the mixed layer. Modelling
the flow as a homogeneous and stationary random process with spatial scales
comparable to the wavelengths, we derive a transport (or kinetic) equation
governing wave-energy transfers in both physical and spectral spaces. This
equation describes the scattering of the waves by the flow which results in a
redistribution of energy between waves with the same frequency (or,
equivalently, with the same wavenumber) and, for isotropic flows, in the
isotropisation of the wave field. The time scales for the scattering and
isotropisation are obtained explicitly and found to be of the order of tens of
days for typical oceanic parameters. The predictions inferred from the
transport equation are confirmed by a series of numerical simulations.
Two situations in which near-inertial waves are strongly influenced by flow
scattering are investigated through dedicated nonlinear shallow-water
simulations. In the first, a wavepacket propagating equatorwards as a result
from the -effect is shown to be slowed down and dispersed both zonally
and meridionally by scattering. In the second, waves generated by moving
cyclones are shown to be strongly disturbed by scattering, leading again to an
increased dispersion.Comment: Accepted for publication in Phys. Rev. Fluid
Body weight and the medial longitudinal foot arch : high-arched foot, a hidden problem?
This study had two objectives. First, to determine the prevalence of hollow (high-arched) and flat foot among primary school children in Cracow (Poland). Second, to evaluate the relationship between the type of medial longitudinal arch (MLA; determined by the Clarke’s angle) and degree of fatness. The prevalence of underweight, overweight, and obesity was determined by means of IOTF cut-offs with respect to age and gender. A sample of 1,115 children (564 boys and 551 girls) aged between 3 and 13 years was analyzed. In all age groups, regardless of gender, high-arched foot was diagnosed in the majority of children. A distinct increase in the number of children with high-arched foot was observed between 7- and 8-year olds. Regardless of the gender, high-arched foot was more common among underweight children. In the group of obese children, the biggest differences were attributed to gender. High-arched foot was the most frequently observed among boys. In all gender and obesity level groups, the flat foot was more common among boys than among girls. Conclusions: High-arched foot is the most common foot defect among children 3–13 years old regardless of gender. Flat foot is least frequently observed in children 3–13 years old. A statistic correlation between MLA and adiposity is observed. Stronger correlation is observed among girls
A review and road map of entrepreneurial equity financing research
Equity financing in entrepreneurship primarily includes venture capital, corporate venture capital, angel investment, crowdfunding, and accelerators. We take stock of venture financing research to date with two main objectives: (a) to integrate, organize, and assess the large and disparate literature on venture financing; and (b) to identify key considerations relevant for the domain of venture financing moving forward. The net effect is that organizing and assessing existing research in venture financing will assist in launching meaningful, theory-driven research as existing funding models evolve and emerging funding models forge new frontiers
Jakość badań densytometrycznych w Polsce : wyniki oceny wstępnej
Background: The quality of measurements is the main problem in clinical diagnostics. Only a well-designed and properly implemented quality control system ensures that real and precise measurement results are obtained. The aim of our study was to evaluate the quality of bone mineral density measurements in laboratories in Poland. Material/Methods: 15 laboratories from 9 cities participated in the study. The evaluation was performed on the basis of International Society for Clinical Densitometry recommendations and data from the literature. Part I of the evaluation comprised checking the calibration and stability of the densitometer, the safety of acquisition data, the documentation of services, and the reproducibility of measurements in patients. Part II comprised reproducibility, based on phantom testing, using European spine phantom and anthropomorphic spine phantom. Phantom measurements and analysis were done in a routine manner by native operators. Results: The only activity which was properly and regularly performed in all laboratories was calibration. The other activities were performed properly in less than half of the laboratories, and some of them only in single laboratories. In nearly half of the laboratories the reproducibility error exceeded the tolerance limit. Conclusions: The present study suggests that the quality of bone mineral density measurement in Poland is rather low. Introducing quality control in laboratories and training courses for operators is strongly recommended
A First Order Predicate Logic Formulation of the 3D Reconstruction Problem and its Solution Space
This paper defines the 3D reconstruction problem as the process of reconstructing a 3D scene from numerous 2D visual images of that scene. It is well known that this problem is ill-posed, and numerous constraints and assumptions are used in 3D reconstruction algorithms in order to reduce the solution space. Unfortunately, most constraints only work in a certain range of situations and often constraints are built into the most fundamental methods (e.g. Area Based Matching assumes that all the pixels in the window belong to the same object). This paper presents a novel formulation of the 3D reconstruction problem, using a voxel framework and first order logic equations, which does not contain any additional constraints or assumptions. Solving this formulation for a set of input images gives all the possible solutions for that set, rather than picking a solution that is deemed most likely. Using this formulation, this paper studies the problem of uniqueness in 3D reconstruction and how the solution space changes for different configurations of input images. It is found that it is not possible to guarantee a unique solution, no matter how many images are taken of the scene, their orientation or even how much color variation is in the scene itself. Results of using the formulation to reconstruct a few small voxel spaces are also presented. They show that the number of solutions is extremely large for even very small voxel spaces (5 x 5 voxel space gives 10 to 10(7) solutions). This shows the need for constraints to reduce the solution space to a reasonable size. Finally, it is noted that because of the discrete nature of the formulation, the solution space size can be easily calculated, making the formulation a useful tool to numerically evaluate the usefulness of any constraints that are added
Energy solutions to one-dimensional singular parabolic problems with data are viscosity solutions
We study one-dimensional very singular parabolic equations with periodic
boundary conditions and initial data in , which is the energy space. We
show existence of solutions in this energy space and then we prove that they
are viscosity solutions in the sense of Giga-Giga.Comment: 15 page
Fibrosis of extracellular matrix is related to the duration of the disease but is unrelated to the dynamics of collagen metabolism in dilated cardiomyopathy
Background Fibrosis of extracellular matrix (ECM) in
dilated cardiomyopathy (DCM) corresponds to the
myocardial over-production of various types of collagens.
However, mechanism of this process is poorly understood.
Objective To investigate whether enhanced metabolism of
ECM occur in DCM.
Methods Seventy consecutive DCM patients (pts)
(48 ± 12.1 years, EF 24.4 ± 7.4 %) and 20 healthy volunteers
were studied. Based on symptoms duration, pts
were divided into new-onset (n = 35, 6 months) and
chronic DCM (n = 35, >6 months). Markers of collagen
type I and III synthesis-procollagen type I carboxy- and
amino-terminal peptides (PICP and PINP) and procollagen
type III carboxy- and amino-terminal peptides (PIIICP and
PIIINP), collagen 1 (col-1), ECM metabolism controlling
factors-tumor growth factor beta-1 (TGF1-b), connective
tissue growth factor (CTGF), and ECM degradation
enzymes-matrix metalloproteinases (MMP-2, MMP-9)
and their tissue inhibitor (TIMP-1) were measured in serum. All pts underwent right ventricular endomyocardial
biopsy to study ECM fibrosis.
Results The presence of fibrosis was detected in 24
(34.3 %) pts and was more prevalent in chronic DCM
[17 (48.6 %) vs. 7 (20 %), p\0.01]. The levels of
PIIINP [4.41 (2.17-6.08) vs. 3.32 (1.69-5.02) ng/ml,
p\0.001], CTGF [3.82 (0.48-23.87) vs. 2.37
(0.51-25.32) ng/ml, p\0.01], MMP-2 [6.06 (2.72-14.8)
vs. 4.43 (2.27=7.4) ng/ml, p\0.001], MMP-9 [1.98
(0.28-9.25) vs. 1.01 (0.29-3.59) ng/ml, p\0.002)], and
TIMP-1 [15.29 (1.8-36.17) vs. 2.61 (1.65-24.09) ng/ml,
p\0.004] were significantly higher in DCM, whereas
levels of col-1 [57.7 (23.1-233.4) vs. 159.4 (31.2-512.9)
pg/ml, p\0.001] were significantly lower in DCM
compared to controls. There were no differences in all
measured serum markers of ECM metabolism between
newonset and chronic DCM and as well as fibrosis
positive and negative pts. Fibrosis was weakly correlated
only with the duration of DCM (r = 0.23, p\0.05),
however, not a single serum marker of fibrosis correlated
with fibrosis. Neither unadjusted nor adjusted models,
constructed from serum markers of ECM metabolism,
predicted the probability of myocardial fibrosis.
Conclusions Dynamics of ECM turnover in DCM is high,
which is reflected by the increased levels CTGF and
degradation enzymes. Synthesis of collagen type III prevailed
over collagen type I. ECM metabolism was not
different in DCM regardless of the duration of the disease
and status of myocardial fibrosis. Serum markers of ECM
metabolism were found not to be useful for the prediction
of myocardial fibrosis in DCM
Clinical characteristics, genetic findings and arrhythmic outcomes of patients with catecholaminergic polymorphic ventricular tachycardia from China: A systematic review
Introduction: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited cardiac ion channelopathy. The present study aims to examine the clinical characteristics, genetic basis, and arrhythmic outcomes of CPVT patients from China to elucidate the difference between CPVT patients in Asia and Western countries. Methods: PubMed and Embase were systematically searched for case reports or series reporting on CPVT patients from China until 19 February 2022 using the keyword: “Catecholaminergic Polymorphic Ventricular Tachycardia” or “CPVT”, with the location limited to: “China” or “Hong Kong” or “Macau” in Embase, with no language or publication-type restriction. Articles that did not state a definite diagnosis of CPVT and articles with duplicate cases found in larger cohorts were excluded. All the included publications in this review were critically appraised based on the Joanna Briggs Institute Critical Appraisal Checklist. Clinical characteristics, genetic findings, and the primary outcome of spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF) were analyzed. Results: A total of 58 unique cases from 15 studies (median presentation age: 8 (5.0–11.8) years old) were included. All patients, except one, presented at or before 19 years of age. There were 56 patients (96.6%) who were initially symptomatic. Premature ventricular complexes (PVCs) were present in 44 out of 51 patients (86.3%) and VT in 52 out of 58 patients (89.7%). Genetic tests were performed on 54 patients (93.1%) with a yield of 87%. RyR2, CASQ2, TERCL, and SCN10A mutations were found in 35 (71.4%), 12 (24.5%), 1 (0.02%) patient, and 1 patient (0.02%), respectively. There were 54 patients who were treated with beta-blockers, 8 received flecainide, 5 received amiodarone, 2 received verapamil and 2 received propafenone. Sympathectomy (n = 10), implantable cardioverter-defibrillator implantation (n = 8) and ablation (n = 1) were performed. On follow-up, 13 patients developed VT/VF. Conclusion: This was the first systematic review of CPVT patients from China. Most patients had symptoms on initial presentation, with syncope as the presenting complaint. RyR2 mutation accounts for more than half of the CPVT cases, followed by CASQ2, TERCL and SCN10A mutations
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