A pareto strategy based on multi-objective optimal integration of distributed generation and compensation devices regarding weather and load fluctuations.

In this study, we present a comprehensive optimization framework employing the Multi-Objective Multi-Verse Optimization (MOMVO) algorithm for the optimal integration of Distributed Generations (DGs) and Capacitor Banks (CBs) into electrical distribution networks. Designed with the dual objectives of minimizing energy losses and voltage deviations, this framework significantly enhances the operational efficiency and reliability of the network. Rigorous simulations on the standard IEEE 33-bus and IEEE 69-bus test systems underscore the effectiveness of the MOMVO algorithm, demonstrating up to a 47% reduction in energy losses and up to a 55% improvement in voltage stability. Comparative analysis highlights MOMVO's superiority in terms of convergence speed and solution quality over leading algorithms such as the Multi-Objective Jellyfish Search (MOJS), Multi-Objective Flower Pollination Algorithm (MOFPA), and Multi-Objective Lichtenberg Algorithm (MOLA). The efficacy of the study is particularly evident in the identification of the best compromise solutions using MOMVO. For the IEEE 33 network, the application of MOMVO led to a significant 47.58% reduction in daily energy loss and enhanced voltage profile stability from 0.89 to 0.94 pu. Additionally, it realized a 36.97% decrease in the annual cost of energy losses, highlighting substantial economic benefits. For the larger IEEE 69 network, MOMVO achieved a remarkable 50.15% reduction in energy loss and improved voltage profiles from 0.89 to 0.93 pu, accompanied by a 47.59% reduction in the annual cost of energy losses. These results not only confirm the robustness of the MOMVO algorithm in optimizing technical and economic efficiencies but also underline the potential of advanced optimization techniques in facilitating the sustainable integration of renewable energy resources into existing power infrastructures. This research significantly contributes to the field of electrical distribution network optimization, paving the way for future advancements in renewable energy integration and optimization techniques for enhanced system efficiency, reliability, and sustainability.

Strain predicts left ventricular functional recovery after acute myocardial infarction with systolic dysfunction.

OBJECTIVE: Regional and global longitudinal strain (RLS-GLS) are considered reliable indexes of myocardial viability in chronic ischemic patients and prediction of left ventricular (LV) functional recovery after acute myocardial infarction (MI) with preserved left ventricular ejection fraction (LVEF). We tested in the present study whether RLS and GLS could also identify transmural extent of myocardial scar and predict LV functional recovery and remodeling in patients with reduced LVEF after acute MI. METHODS: Echocardiography and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) were performed in 71 patients with reduced LVEF (≤45%) after acute MI treated with acute percutaneous coronary intervention. At 8-month follow-up, echocardiography was repeated to determine global LV functional recovery and remodeling. RESULTS: RLS was worse in transmural than in non-transmural infarcted segments (-6.6 ± 6.1% vs -10.3 ± 5.9%, p < 0.0001) and in non-transmural than in normal segments (-10.3 ± 5.9% vs -14.5 ± 6.4%, p < 0.0001). RLS > -12% had sensitivity of 78% and specificity of 69% to identify transmural infarcted segments (AUC = 0.79; 95% CI, 0.77-0.81, p < 0.0001). GLS > -11.3% had sensitivity of 53% and specificity of 100% to predict the absence of LV global functional improvement (AUC = 0.73, CI, 0.55-0.87, p = 0.01) at 8-month follow-up. GLS < -12.5% predicted the absence of adverse LV remodeling with sensitivity of 100% and specificity of 54% (AUC = 0.83; CI, 0.66-0.94, p < 0.0001). GLS > -11.5% was associated with a poor prognosis. CONCLUSIONS: In patients with reduced LVEF after acute MI, RLS and GLS allow: (1) identification of transmural extent of myocardial scar and (2) predict LV global functional recovery and remodeling at 8-month follow-up.

The subxiphoid view cannot replace the apical view for transthoracic echocardiographic assessment of hemodynamic status.

INTRODUCTION: This prospective study aimed to assess whether use of the subxiphoid acoustic window in transthoracic echocardiography (TTE) can be an accurate alternative in the absence of an apical view to assess hemodynamic parameters. METHODS: This prospective study took place in a teaching hospital medical ICU. Over a 4-month period, TTE was performed in patients admitted for more than 24 hours. Two operators rated the quality of parasternal, apical, and subxiphoid acoustic windows as Excellent, Good, Acceptable, Poor, or No image. In the subpopulation presenting adequate (rated as acceptable or higher) apical and subxiphoid views, we compared the left ventricular ejection fraction (LVEF), the ratio between right and left ventricular end-diastolic areas (RVEDA/LVEDA), the ratio between early and late mitral inflow on pulsed Doppler (E/A ratio), the aortic velocity time integral (Ao VTI), and the ratio between early mitral inflow and displacement of the mitral annulus on tissue Doppler imaging (E/Ea ratio). RESULTS: An adequate apical view was obtained in 80%, and an adequate subxiphoid view was obtained in 63% of the 107 patients included. Only 5% of patients presented an adequate subxiphoid view without an adequate apical view. In the subpopulation of patients with adequate apical and subxiphoid windows (n = 65), LVEF, E/A, and RVEDA/LVEDA were comparable on both views, and were strongly correlated (r > 0.80) with acceptable biases and precision. However, the Ao VTI and the E/Ea ratio were lower on the subxiphoid view than on the apical view (18 ± 5 versus 16 ± 5 cm and 9.6 ± 4.6 versus 7.6 ± 4 cm, respectively, P = 0.001 for both). CONCLUSIONS: An adequate TTE subxiphoid window was obtained in fewer than two thirds of ICU patients. In addition to the classic indication for the subxiphoid window to study the vena cava and pericardium, this view can be used to study right and left ventricular morphology and function, but does not provide accurate hemodynamic Doppler information. ICU echocardiographers should therefore record both apical and subxiphoid views to assess comprehensively the cardiac function and hemodynamic status.

Endocardial electrogram analysis after intramyocardial injection of mesenchymal stem cells in the chronic ischemic myocardium.

BACKGROUND: Cell injection therapies have been introduced for the treatment of patients with coronary heart disease. However, intramyocardial injection of bone marrow (BM)-derived cells may generate proarrhythmogenicity. METHODS: Two weeks after the placement of a circumflex artery-ameroid constrictor, 21 pigs received mesenchymal stem cells (MSC, n = 9), mononuclear (BM)-derived stem cells (MNC, n = 6), and placebo (n = 6) using a electromechanical mapping (EMM)-guided percutaneous transendocardial injection catheter. At week 6, EMM was repeated and the injected areas were analyzed in detail to evaluate local bipolar electrogram fragmentation, duration, and amplitude. Myocardial fibrosis was evaluated by a quantitative histological analysis. RESULTS: At week 6, the injection of MSC or MNC did not increase local electrogram fragmentation (MSC group: 1.4 +/- 0.3 vs. 1.3 +/- 0.2; MNC group: 1.4 +/- 0.2 vs. 1.3 +/- 0.2; P = NS), prolong electrogram duration (MSC group: 27.1 +/- 7.8 ms vs. 23.7 +/- 2.0 ms; MNC group: 27.8 +/- 3.5 ms vs. 26.8 +/- 5.6 ms; P = NS), or decrease bipolar voltages (MSC group 2.7 +/- 0.9 mV vs. 2.8 +/- 1.0 mV; MNC group 2.0 +/- 1.0 mV vs. 1.7 +/- 0.4 mV). From week 2 to week 6, mean left ventricular ejection fraction increased in the MSC group (37.9 +/- 4.2% vs. 45.9 +/- 2.2%; P = 0.039) only. Histological analysis of the ischemic regions revealed 17.6 +/- 5% myocardial fibrosis in the MNC group vs. 13.6 +/- 3.4% MSC vs. 28.7 +/- 8.7% in the control group (P = 0.038 and P = 0.013). No death occurred in any animal after the injection procedure. CONCLUSION: Intramyocardial injection of MSC or MNC do not increase fragmentation and duration of endocardial electrograms in the injected ischemic myocardium but attenuate ischemic damage and therefore may not create an electrophysiological substrate for reentry tachycardias.