88 research outputs found
Dual weighted residual error estimation for the finite cell method
The paper presents a goal-oriented error control based on the dual weighted residual method (DWR) for the ïŹnite cell method (FCM), which is characterized by an enclosing domain covering the domain of the problem. The error identity derived by the DWR method allows for a combined treatment of the discretization and quadrature error introduced by the FCM. We present an adaptive strategy with the aim to balance these two error contributions. Its performance is demonstrated for some two-dimensional examples
Model-Based Analysis of Flow-Mediated Dilation and Intima-Media Thickness
We present an end-to-end system for the automatic measurement of flow-mediated dilation (FMD) and intima-media thickness (IMT) for the assessment of the arterial function.
The video sequences are acquired from a B-mode echographic
scanner. A spline model (deformable template) is fitted to the
data to detect the artery boundaries and track them all along
the video sequence. The a priori knowledge about the image
features and its content is exploited. Preprocessing is performed
to improve both the visual quality of video frames for visual
inspection and the performance of the segmentation algorithm
without affecting the accuracy of the measurements. The system
allows real-time processing as well as a high level of interactivity
with the user. This is obtained by a graphical user interface
(GUI) enabling the cardiologist to supervise the whole process
and to eventually reset the contour extraction at any point in time.
The system was validated and the accuracy, reproducibility, and
repeatability of the measurements were assessed with extensive
in vivo experiments. Jointly with the user friendliness, low cost,
and robustness, this makes the system suitable for both research
and daily clinical use
Coadministration of Atorvastatin Prevents Nitroglycerin-Induced Endothelial Dysfunction and Nitrate Tolerance in Healthy Humans
ObjectivesWe aimed to assess whether concurrent administration of atorvastatin would modify the development of tolerance and endothelial dysfunction associated with sustained nitroglycerin (GTN) therapy in humans.BackgroundAnimal studies have demonstrated that administration of 3-hydroxy-3 methylglutaryl coenzyme A reductase inhibitors can protect against GTN-induced endothelial dysfunction and tolerance, likely through an antioxidant mechanism.MethodsThirty-six healthy male volunteers were randomized to receive continuous transdermal GTN (0.6 mg/h) and placebo, atorvastatin (80 mg/day) alone, or continuous transdermal GTN (0.6 mg/h) with concurrent atorvastatin (80 mg/day), all for 7 days. On the second visit, forearm blood flow was measured with venous-occlusion strain gauge plethysmography in response to incremental infusions of acetylcholine (7.5, 15, and 30 ÎŒg/min). Acetylcholine infusions were coinfused first with saline, and repeated during the coinfusion of vitamin C (24 mg/min). Blood pressure responses to sublingual GTN (400 ÎŒg) were assessed on both visits.ResultsAcetylcholine responses in the GTN plus placebo group were significantly attenuated versus those in the GTN plus atorvastatin and atorvastatin groups (p < 0.01). Coinfusion of vitamin C completely restored acetylcholine responses in the GTN plus placebo group (p < 0.01 vs. saline coinfusion), but caused no change in either the atorvastatin or the GTN plus atorvastatin groups. Blood pressure responses to sublingual GTN did not significantly change between visits in subjects receiving GTN plus atorvastatin and atorvastatin alone, but were significantly blunted in the GTN plus placebo group (p < 0.05).ConclusionsThe present findings demonstrate, for the first time in humans, that atorvastatin prevents both GTN-induced endothelial dysfunction and nitrate tolerance, likely by counteracting the GTN-induced increase in oxidative stress
Persistent recovery of normal left ventricular function and dimension in idiopathic dilated cardiomyopathy during long\u2010term follow\u2010up: does real healing exist?
BACKGROUND:
An important number of patients with idiopathic dilated cardiomyopathy have dramatically improved left ventricular function with optimal treatment; however, little is known about the evolution and long-term outcome of this subgroup, which shows apparent healing. This study assesses whether real healing actually exists in dilated cardiomyopathy.
METHODS AND RESULTS:
Persistent apparent healing was evaluated among 408 patients with dilated cardiomyopathy receiving tailored medical treatment and followed over the very long-term. Persistent apparent healing was defined as left ventricular ejection fraction 6550% and indexed left ventricular end-diastolic diameter 6433 mm/m(2) at both mid-term (19\ub14 months) and long-term (103\ub19 months) follow-up. At mid-term, 63 of 408 patients (15%) were apparently healed; 38 (60%; 9%of the whole population) showed persistent apparent healing at long-term evaluation. No predictors of persistent apparent healing were found. Patients with persistent apparent healing showed better heart transplant\u2013free survival at very long-term follow-up (95% versus 71%; P=0.014) compared with nonpersistently normalized patients. Nevertheless, in the very longterm, 37% of this subgroup experienced deterioration of left ventricular systolic function, and 5% died or had heart transplantation.
CONCLUSIONS:
Persistent long-term apparent healing was evident in a remarkable proportion of dilated cardiomyopathy patients receiving optimal medical treatment and was associated with stable normalization of main clinical and laboratory features. This condition can be characterized by a decline of left ventricular function over the very long term, highlighting the relevance of serial nd individualized follow-up in all patients with dilated cardiomyopathy, especially considering the absence of predictors for longterm apparent healing
Natural History of Dilated Cardiomyopathy in Children
The long-term progression of idiopathic dilated cardiomyopathy (DCM) in pediatric patients compared with adult patients has not been previously characterized. In this study, we compared outcome and long-term progression of pediatric and adult DCM populations
Model Numerikal Reservoir Sistem Panasbumi Pada Daerah Topografi Relatif Datar Untuk Mencari Kondisi Natural State Dan Menganalisa Sensitivitas Panas Pada Reservoir Menggunakan Software Tough2
Telah dilakukan pemodelan reservoir menggunakan software Tough2 dengan data sintetik, berupa data permeabilitas dan pororsitas. Dimana terdiri dari 4 lapisan, yaitu lapisan overburden, lapisan clay caps, lapisan recharge area + lapisan reservoir (berada pada lapisan yang sama), dan lapisan basement dengan tujuan untuk menganalisa sensitivitas panas, serta untuk mencari kondisi natural state (natural state merupakan kondisi setimbang, yaitu dimana kondisi tekanan, temperatur dan kondisi reservoirnya tidak berubah terhadap waktu).Dari hasil pemodelan reservoir oleh Tough2 didapat bahwa kondisi natural state selama 2,20857E+4 tahun, dimana terjadi penurunan suhu dari kondisi natural state tanpa sumur produksi berbanding kondisi natural state dengan sumur produksi, dimana suhu pada saat kondisi natural state tanpa sumur produksi sebesar 245OC dan suhu pada saat kondisi natural state dengan sumur produksi sebesar 235OC pada kedalaman 1350 m. Sedangkan untuk penggunaan rate 20 kg/s, 25 kg/s, 30 kg/s dan 35 kg/s untuk melihat sensitivitas heat nya, didapatkan bahwa semakin besar nilai rate yang dipakai dalam suatu sumur produksi, maka akan menurunnya nilai temperatur di sumur produksi tersebut
Xanthine oxidase inhibition for the treatment of cardiovascular disease: an updated systematic review and meta-analysis
Background:
Previous studies have shown that xanthine oxidase inhibitors (XOI) might improve outcome for patients with cardiovascular disease. However, more evidence is required.
Methods and results:
We published a metaâanalysis of trials conducted before 2014 examining the effects of XOI on mortality in patients with cardiovascular disease. At least two further trials (Nâ=â323 patients) have since been published. Accordingly, we repeated our analysis after a further search for randomized controlled trials of XOI in PubMed/MEDLINE, EMBASE, and Cochrane Databases. We identified eight relevant trials with 1031 patients. The average age of the patients was 61âyears and 68% were men (one study did not report gender). There were 57 deaths in these eight trials, 26 in those assigned to XOI, and 31 in those assigned to the control. The updated metaâanalysis could not confirm a reduction in mortality for patients assigned to XOI compared with placebo (odds ratio 0.84) but 95% confidence intervals were wide (0.48â1.47).
Conclusions:
This updated metaâanalysis does not suggest that XOI exert a large reduction in mortality but also cannot exclude the possibility of substantial harm or benefit
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The ENPP1 Q121 Variant Predicts Major Cardiovascular Events in High-Risk Individuals: Evidence for Interaction With Obesity in Diabetic Patients
Insulin resistance (IR) and cardiovascular disease may share a common genetic background. We investigated the role of IR-associated ENPP1 K121Q polymorphism (rs1044498) on cardiovascular disease in high-risk individuals
UGRâ16: A New Dataset for the Evaluation of Cyclostationarity-Based Network IDSs
The evaluation of algorithms and techniques to implement intrusion detection systems heavily rely on the existence
of well designed datasets. In the last years, a lot of efforts
have been done towards building these datasets. Yet, there is
still room to improve. In this paper, a comprehensive review of
existing datasets is first done, making emphasis on their main
shortcomings. Then, we present a new dataset that is built with
real traffic and up-to-date attacks. The main advantage of this
dataset over previous ones is its usefulness for evaluating IDSs
that consider long-term evolution and traffic periodicity. Models
that consider differences in daytime/night or weekdays/weekends
can also be trained and evaluated with it. We discuss all the
requirements for a modern IDS evaluation dataset and analyze
how the one presented here meets the different needs
Integration of a palliative approach into heart failure care: a European Society of Cardiology Heart Failure Association position paper
The Heart Failure Association of the European Society of Cardiology has published a previous position paper and various guidelines over the past decade recognizing the value of palliative care for those affected by this burdensome condition. Integrating palliative care into evidence-based heart failure management remains challenging for many professionals, as it includes the identification of palliative care needs, symptom control, adjustment of drug and device therapy, advance care planning, family and informal caregiver support, and trying to ensure a 'good death'. This new position paper aims to provide day-to-day practical clinical guidance on these topics, supporting the coordinated provision of palliation strategies as goals of care fluctuate along the heart failure disease trajectory. The specific components of palliative care for symptom alleviation, spiritual and psychosocial support, and the appropriate modification of guideline-directed treatment protocols, including drug deprescription and device deactivation, are described for the chronic, crisis and terminal phases of heart failure
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