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  • Open Access

    ARTICLE

    A Genetic Algorithm to Solve Capacity Assignment Problem in a Flow Network

    Ahmed Y. Hamed1, Monagi H. Alkinani2, M. R. Hassan3, *

    CMC-Computers, Materials & Continua, Vol.64, No.3, pp. 1579-1586, 2020, DOI:10.32604/cmc.2020.010881

    Abstract Computer networks and power transmission networks are treated as capacitated flow networks. A capacitated flow network may partially fail due to maintenance. Therefore, the capacity of each edge should be optimally assigned to face critical situations—i.e., to keep the network functioning normally in the case of failure at one or more edges. The robust design problem (RDP) in a capacitated flow network is to search for the minimum capacity assignment of each edge such that the network still survived even under the edge’s failure. The RDP is known as NP-hard. Thus, capacity assignment problem subject to system reliability and total… More >

  • Open Access

    ARTICLE

    Differential Effects of Ammonium and Nitrate on Growth Performance of Glechoma longituba under Heterogeneous Cd Stress

    Yanwei Feng1, Wen Lei2, Rui Gu3, Ping Zhao4, Shijun Ni1,*, Ningfei Lei3,*

    Phyton-International Journal of Experimental Botany, Vol.89, No.3, pp. 667-679, 2020, DOI:10.32604/phyton.2020.010160

    Abstract Water, minerals, nutrients, etc., can be shared by physiological integration among inter-connected ramets of clonal plants. Nitrogen plays an important role in alleviating cadmium (Cd) stress for clonal plants. But how different forms of nitrogen affect growth performance of clonal plants subjected to heterogeneous Cd stress still remains poorly understood. A pot experiment was conducted to investigate the differential effects of ammonium and nitrate on growth performance of Glechoma longituba under heterogeneous Cd stress. In the experiment, parent ramets of Glechoma longituba clonal fragments were respectively supplied with modified Hoagland solution containing 7.5 mM ammonium, 7.5 mM nitrate or the… More >

  • Open Access

    ARTICLE

    Right ventricular and pulmonary vascular function indices for risk stratification of patients with pulmonary regurgitation

    Alexander C. Egbe, William R. Miranda, Patricia A. Pellikka, Sorin V. Pislaru, Barry A. Borlaug, Srikanth Kothapalli, Sindhura Ananthaneni, Harigopal Sandhyavenu, Maria Najam, Mohamed Farouk Abdelsamid, Heidi M. Connolly

    Congenital Heart Disease, Vol.14, No.4, pp. 657-664, 2019, DOI:10.1111/chd.12768

    Abstract Background: We hypothesized that echocardiographic indices of right ventricular to pulmonary artery (RV‐PA) coupling were comparable to cardiac magnetic resonance imaging (CMRI)‐derived RV volumetric indices in predicting disease severity in chronic pulmonary regurgitation (PR).
    Methods: Patients with ≥ moderate PR (2003‐2015) with and without prior CMRI scans were enrolled into the study cohort and validation cohort, respectively. Endpoint was to determine the association between noninvasive RV‐PA coupling in‐ dices (tricuspid annular plane systolic excursion/right ventricular systolic pressure [TAPSE/RVSP] and fractional area change [FAC]/RVSP ratio) and markers of disease severity, and compared this association to that of CMRI‐derived RV volumetric indi‐… More >

  • Open Access

    Experimental Analysis of the Performances of Unit Refrigeration Systems Based on Parallel Compressors with Consideration of the Volumetric and Isentropic Efficiency

    Daoming Shen1,2,*, Chao Gui1, Jinhong Xia1, Songtao Xue2,3

    FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.3, pp. 489-500, 2020, DOI:10.32604/fdmp.2020.08969

    Abstract The performances of a refrigeration unit relying on compressors working in parallel have been investigated considering the influence of the compressor volumetric efficiency and isentropic efficiency on the compression ratio. Moreover, the following influential factors have been taken into account: evaporation temperature, condensation temperature and compressor suction-exhaust pressure ratio for different opening conditions of the compressor. The following quantities have been selected as the unit performance measurement indicators: refrigeration capacity, energy efficiency ratio (COP), compressor power consumption, and refrigerant flow rate. The experimental results indicate that the system refrigeration capacity and COP decrease with a decrease in evaporation temperature, increase… More >

  • Open Access

    ARTICLE

    Forced vital capacity predicts morbidity and mortality in adults with repaired tetralogy of Fallot

    Katie E. Cohen1, Matthew W. Buelow1, Jennifer Dixon1, Ruta Brazauskas2, Scott B. Cohen3, Michael G. Earing1,3, Salil Ginde1

    Congenital Heart Disease, Vol.12, No.4, pp. 435-440, 2017, DOI:10.1111/chd.12470

    Abstract Objective: Abnormal lung function characterized by a reduced forced vital capacity (FVC) is common in adults with repaired tetralogy of Fallot (TOF) and is associated with previous thoracotomies and sternotomies. The impact of abnormal lung function on clinical outcomes in adult patients with repaired TOF is unclear. The aim of this study was to determine the impact of abnormal lung function on the outcome of hospitalization and death in adults with repaired TOF when analyzed with other traditional cardiac risk factors.
    Design: Retrospective study of adults with repaired TOF, who underwent spirometry between 2000 and 2014. FVC < 60% of… More >

  • Open Access

    ARTICLE

    Physical activity modulates arterial stiffness in children with congenital heart disease: A CHAMPS cohort study*

    Natasha G. Boyes1, Michael K. Stickland2, Stephanie Fusnik1, Elizabeth Hogeweide1, Josie T.J. Fries1, Mark J. Haykowsky3, Chantelle L. Baril1, Shonah Runalls1, Ashok Kakadekar4, Scott Pharis4, Charissa Pockett4, Timothy J. Bradley4, Kristi D. Wright5, Marta Erlandson1, Corey R. Tomczak1

    Congenital Heart Disease, Vol.13, No.4, pp. 578-583, 2018, DOI:10.1111/chd.12614

    Abstract Children with congenital heart disease are at risk for developing increased arterial stiffness and this may be modulated by physical activity. Objective: To compare arterial stiffness in high- and low-physically active children with congenital heart disease and healthy age- and sex-matched controls.
    Patients: Seventeen children with congenital heart disease (12 ± 2 years; females = 9), grouped by low- and high-physical activity levels from accelerometry step count values, and 20 matched controls (11 ± 3 years; females = 9) were studied.
    Outcome Measures: Carotid-radial pulse wave velocity was assessed with applanation tonometry to determine arterial stiffness. Body composition and 6-min… More >

  • Open Access

    ARTICLE

    Intrauterine growth restriction is not associated with decreased exercise capacity in adolescents with congenital heart disease

    Andrew D. Spearman1, Rohit S. Loomba2, Michael Danduran1, Joshua Kovach1

    Congenital Heart Disease, Vol.13, No.3, pp. 369-376, 2018, DOI:10.1111/chd.12577

    Abstract Objective: Multiple studies demonstrate the association of intrauterine growth restriction (IUGR) with impaired aerobic fitness in adolescents and adults. To our knowledge, there are no studies including individuals with the history of both IUGR and congenital heart disease (CHD). Thus, we sought to evaluate the impact of IUGR on exercise capacity in adolescents with CHD.
    Study Design: We conducted a retrospective chart review of patients <18 years of age who underwent cardiopulmonary exercise testing (CPET) between August 1, 2003 and July 1, 2016. Individuals with birth weight <10th percentile for gestational age were defined as IUGR. Patients with IUGR were… More >

  • Open Access

    ARTICLE

    Home-based interval training increases endurance capacity in adults with complex congenital heart disease

    Camilla Sandberg1,2, Magnus Hedström1, Karin Wadell2, Mikael Dellborg3, Anders Ahnfelt3, Anna-Klara Zetterström4, Amanda Öhrn4, Bengt Johansson1

    Congenital Heart Disease, Vol.13, No.2, pp. 254-262, 2018, DOI:10.1111/chd.12562

    Abstract Objective: The beneficial effects of exercise training in acquired heart failure and coronary artery disease are well known and have been implemented in current treatment guidelines. Knowledge on appropriate exercise training regimes for adults with congenital heart disease is limited, thus further studies are needed. The aim of this study was to examine the effect of home-based interval exercise training on maximal endurance capacity and peak exercise capacity.
    Design: Randomized controlled trial.
    Methods: Twenty-six adults with complex congenital heart disease were recruited from specialized units for adult congenital heart disease. Patients were randomized to either an intervention group—12 weeks of… More >

  • Open Access

    ARTICLE

    Small unrepaired atrial septal defects display impaired exercise capacity compared with healthy peers

    Sebastian Udholm, Christian Rex, Filip Eckerström, Mine Onat, Camilla Nyboe, Vibeke E. Hjortdal

    Congenital Heart Disease, Vol.14, No.3, pp. 372-379, 2019, DOI:10.1111/chd.12740

    Abstract Objective: Adult patients with small, unrepaired atrial septal defects have an in‐ creased risk of pneumonia, atrial fibrillation, and stroke. Furthermore, they have higher late mortality than the background population. The functional capacity is un‐ known in these patients. Therefore, our objective was to determine exercise capacity in adult patients diagnosed with an unrepaired atrial septal defect compared to healthy controls. Design: A cross‐sectional study. Patients: Adult patients with small, unrepaired atrial septal defects, aged 18‐65, di‐ agnosed between 1953 and 2011. Interventions: Cardiopulmonary exercise test was performed using an incremental bicycle test and gas exchange was measured using breath‐by‐breath… More >

  • Open Access

    ARTICLE

    A restrictive ventilatory pattern is common in patients with univentricular heart after Fontan palliation and associated with a reduced exercise capacity and quality of life

    Alessia Callegari1,2,4, Rhoia Neidenbach2, Ornella Milanesi1, Biagio Castaldi1, Martin Christmann4, Masamichi Ono3, Jan Müller2, Peter Ewert2, Alfred Hager2

    Congenital Heart Disease, Vol.14, No.2, pp. 147-155, 2019, DOI:10.1111/chd.12694

    Abstract Aim: The Fontan circulation is highly dependent on ventilation, improving pulmonary blood flow and cardiac output. A reduced ventilatory function is reported in these patients. The extent of this impairment and its relation to exercise capacity and qual‐ ity of life is unknown and objective of this study.
    Methods: This multicenter retrospective/cross‐sectional study included 232 patients (140 females, age 25.6 ± 10.8 years) after Fontan palliation (19.8% atrioventricular connection; 20.3% atriopulmonary connection; 59.9% total cavopulmonary connec‐ tion). Resting spirometry, cardiopulmonary exercise tests, and quality‐of‐life assess‐ ment (SF‐36 questionnaire) were performed between 2003 and 2015.
    Results: Overall, mean forced expiratory volume… More >

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