Hybrid cheetah particle swarm optimization based optimal hierarchical control of multiple microgrids.

The emergence of microgrids arises from the growing integration of Renewable Energy Resources (RES) and Energy Storage Systems (ESSs) into Distribution Networks (DNs). Effective integration, coordination, and control of Multiple Microgrids (MMGs) whereas navigating the complexities of energy transition within this context poses a significant challenge. The dynamic operation of MMGs is a challenge faced by the traditional distributed hierarchical control techniques. The application of Artificial Intelligence (AI) techniques is a promising way to improve the control and dynamic operation of MMGs in future smart DNs. In this paper, an innovative hybrid optimization technique that originates from Cheetah Optimization (CHO) and Particle Swarm Optimization (PSO) techniques is proposed, known as HYCHOPSO. Extensive benchmark testing validates HYCHOPSO's superiority over CHO and PSO in terms of convergence performance. The objective for this hybridization stems from the complementary strengths of CHO and PSO. CHO demonstrates rapid convergence in local search spaces, while PSO excels in global exploration. By combining these techniques, the aim is to leverage their respective advantages and enhance the algorithm's overall performance in addressing complex optimization problems. The contribution of this paper offering a unique approach to addressing optimization challenges in microgrid systems. Through a comprehensive comparative study, HYCHOPSO is evaluated against various metaheuristic optimization approaches, demonstrating superior performance, particularly in optimizing the design parameters of Proportional-Integral (PI) controllers for hierarchical control systems within microgrids. This contribution expands the repertoire of available optimization methodologies and offers practical solutions to critical challenges in microgrid optimization, enhancing the efficiency, reliability, and sustainability of microgrid operations. HYCHOPSO achieves its optimal score within fewer than 50 iterations, unlike CHO, GWO, PSO, Hybrid-GWO-PSO, and SSIA-PSO, which stabilize after around 200 iterations. Across various benchmark functions, HYCHOPSO consistently demonstrates the lowest mean values, attains scores closer to the optimal values of the benchmark functions, underscoring its robust convergence capabilities.the proposed HYCHOPSO algorithm, paired with a PI controller for distributed hierarchical control, minimizes errors and enhances system reliability during dynamic MMG operations. Using HYCHOPSO framework, an accurate power sharing, voltage/frequency stability, seamless grid-to-island transition, and smooth resynchronization are achieved. This enhances the real application's reliability, flexibility, scalability and robustness.

Arthroscopic Saucerization of Discoid Lateral Meniscus, With Meniscus Repair as Indicated, Results in Excellent Outcomes in Pediatric Patients Younger Than 12 Years of Age.

Purpose: To evaluate the experiences and outcomes of arthroscopic partial meniscectomy in symptomatic non-Wrisberg discoid lateral meniscus in children younger than 12 years old at a single center. Methods: We retrospectively reviewed the medical records of all pediatric patients who were treated for non-Wrisberg discoid meniscus at our institute between 2013 and 2021. Patients were separated into 2 groups: Patients who underwent partial resection with saucerization (group A) or patients who underwent saucerization, tear repair, and fixation (group B). Clinical outcomes were compared between the 2 groups. Results: A total of 20 patients (22 knees) were treated for non-Wrisberg discoid meniscus and included in this study. Nine patients underwent partial resection with saucerization (group A) whereas 11 patients underwent saucerization, tear repair, and fixation (group B). The average follow-up was 3 years (range 2-10 years). The results showed that 17 of the 20 patients had excellent outcomes whereas the other 3 had good outcomes after a minimum follow-up of 2 years. The average Knee Injury and Osteoarthritis Outcome Score for Children score was 93. Conclusions: Arthroscopic saucerization of symptomatic non-Wrisberg discoid lateral meniscus, with additional repair as indicated results in excellent or good outcomes in children younger than 12 years of age. Level of Evidence: Level III, case-control study.

Modern PID/FOPID controllers for frequency regulation of interconnected power system by considering different cost functions.

This article presents frequency regulation of an interconnected three-area power system (Thermal + Wind + Hydro). Fractional Order PID (FOPID) and Proportional-Integral-Derivative (PID) controllers are applied as subsidiary regulators to control the electrical power interconnected system at the time of sudden load variation. To accomplish this study, Genetic Algorithm (GA), Grey Wolf Optimizer (GWO), Sine Cosine Inspired Algorithm (SCIA) and Atom Search Inspired Algorithm (ASIA) are implemented to optimize the secondary regulators' gains (PID and FOPID) by considering various cost functions such as Integral Absolute Error (IAE), Integral Time Absolute Error (ITAE), Integral Square Error (ISE), and Integral Time Square Error (ITSE). Performance analysis in this work is conducted using various cost functions based on GA, GWO, SCIA and ASIA. The comparative analysis of the attained results reveals that GWO-PID and ASIA-PID settle at (83.83 s) and (30.31 s), respectively and ASIA-FOPID at (25.12 s). The controllers based on ITSE as a cost function outperform the comptrollers with other cost functions (ISE, IAE and ITAE). In addition, the ISE-based GA-PID and SCIA-PID settle at (113.92 s) and (35.1 s), respectively and SCIA-FOPID at (24.78 s). The ISE-based regulators yield improved response equated to other cost functions (ITSE, IAE and ITAE) optimized controllers. The robustness test also is carried out to validate the effectiveness of the proposed optimization techniques by changing the system parameters within ± 25% and ± 50% from their nominal values as well as changing the load pattern.

Arithmetic optimization algorithm based maximum power point tracking for grid-connected photovoltaic system.

This paper suggests an optimal maximum power point tracking (MPPT) control scheme for a grid-connected photovoltaic (PV) system using the arithmetic optimization algorithm (AOA). The parameters of the proportional-integral (PI) controller-based incremental conductance (IC) MPPT are optimally selected using AOA. To accomplish this study, a 100-kW benchmark PV system connected to a medium distribution utility is constructed and analyzed employing MATLAB/SIMULINK. The optimization framework seeks to minimize four standard benchmark performance indices, then select the best of the best among them. To verify the efficacy of the recommended methodology, a comprehensive comparison is conducted between AOA-based PI-IC-MPPT, modified incremental conductance MPPT (MIC), grey wolf optimization (GWO), genetic algorithm (GA), and particle swarm optimization (PSO)-based MPPT. The proposed control approach has achieved a reduction of 61, 3, 4.5, and 26.9% in the rise time and a decrease of 94, 84.7, 86.6, and 79.3% in the settling time compared with MIC, GWO, GA, and PSO in extracting MPPT of the proposed system, respectively.

Knowledge, attitude and practice of medical students towards COVID19 in Sudan: A cross sectional study among 19 universities.

Background: Since December 2019, an outbreak of severe respiratory infection (COVID-19) emerged in the city of Wuhan in China. The knowledge, awareness and practice of medical students toward COVID-19 pandemic is of most importance as it demonstrates their preparedness to deal with this pandemic. The objective of this study is to assess the knowledge, awareness and practice of medical students in Sudan universities about COVID 19. Methodogy: This is a cross-sectional study conducted on 19 universities that have medical schools in Sudan. Data from at least 100 medical students from each university were included in the study. Data were collected using an online questionnaire in April 2020. Statistical analysis was conducted using the Statistical Package for Social Science software, version 25. Results: About 2603 medical students from 19 universities were included. Overall good knowledge and practice were demonstrated by the medical students (88.9%) and (78.6%), respectively. Respondents who answered that the most common clinical symptoms of COVID-19 were the main combination of dry cough, fatigue and fever were (27.7%), and the first initial symptom was headache were (48.3%.). (60.2%) Wear medical masks, (95%) said that avoiding crowded places protects against the spread of COVID-19, and (50.7%) have confidence that Sudan can win the battle against the COVID-19. Finally, (68.8%) agreed that COVID-19 will finally be successfully controlled. Conclusion: This study has found that medical students in Sudan demonstrated good knowledge and good practice toward Covid19.

Design, synthesis, DNA assessment and molecular docking study of novel 2-(pyridin-2-ylimino)thiazolidin-4-one derivatives as potent antifungal agents.

A series of novel 2-imino-4-thiazolidinone derivatives 4a,b was synthesized through reaction of unsymmetrical thioureas 3a,b with chloroacetic acid. Condensation of 4a,b with aromatic aldehydes 5a-eyielded the corresponding 5-arylidene derivatives 6a-j. In addition, the reaction of 4a,b with 4-arylazo-3-hydroxybenzaldehydes 8a-c furnished the respective mono-arylazo-4-thiazolidinones10a-f. All the newly synthesized compounds were confirmed by their elemental analysis and spectral data. The antifungal activity of the newly synthesized compounds was assessed and the compounds 6d, 6e, 6i, 6j, 9a,b and 10a-frevealedhigher antifungal activity towards Alternaria solani than to the standard Ridomil gold plus. Moreover, the DNA toxicity of 4-thiazolidinone derivatives 6d, 9a, 10b, 10c and 10f on the nucleic acid of Alternaria solani (KT354939) was performed and the results showed qualitatively more than 70% cleavage. Also, compounds 6i, 6j, 9b, 10c and 10f were docked inside the active site of 1ZOYenzyme and suitable binding with the active site of amino acids, were displayed according to their bond lengths, angles and conformational energy.

Assessment of liver fibrosis in Egyptian chronic hepatitis B patients: A comparative study including 5 noninvasive indexes.

Fibrosis assessment in chronic hepatitis B (CHB) is essential for prediction of long-term prognosis and proper treatment decision. This study was conducted to assess predictability of 5 simple noninvasive fibrosis indexes in comparison to liver biopsy in CHB patients.A total of 200 CHB adult Egyptian patients were consecutively included in this study, all were subjected to liver biopsy with staging of fibrosis using METAVIR scoring system. Fibrosis indexes including S-index, red cell distribution width to platelets ratio index (RPR), fibrosis-4 index (Fib-4), AST to platelets ratio index (APRI), and AST/ALT ratio index (AAR) were compared to biopsy result and their predictabilities for the different fibrosis stages were assessed using area under receiver operating characteristic curve (AUROC) analysis.S-index showed the highest AUROCs for predicting fibrosis among the studied indexes. AUROCs of S-index, RPR, Fib-4, APRI, and AAR were: 0.81, 0.67, 0.70, 0.68, and 0.60 for prediction of significant fibrosis (F2-F4), 0.90, 0.66, 0.68, 0.67, and 0.57 for advanced fibrosis (F3-F4), and 0.96, 0.62, 0.61, 0.57, and 0.53 for cirrhosis (F4), respectively. The optimal S-index cutoff for ruling in significant fibrosis was ≥0.3 with 94% specificity, 87% PPV, and 68% accuracy, while that for ruling out significant fibrosis was <0.1 with 96% sensitivity, 91% NPV, and 67% accuracy. Accuracy of S-index was higher for predicting cirrhosis (91%) than that for predicting advanced fibrosis (79%) and significant fibrosis (68%).S-index has the highest predictability for all fibrosis stages among the studied fibrosis indexes in HBeAg-negative CHB patients, with higher accuracy in cirrhosis than in the earlier fibrosis stages.

Butyrate regulates leptin expression through different signaling pathways in adipocytes

Leptin is an adipocytokine that regulates body weight, and maintains energy homeostasis by promoting reduced food intake and increasing energy expenditure. Leptin expression and secretion is regulated by various factors including hormones and fatty acids. Butyrate is a short-chain fatty acid that acts as source of energy in humans. We determined whether this fatty acid can play a role in leptin expression in fully differentiated human adipocytes. Mature differentiated adipocytes were incubated with or without increasing concentrations of butyrate. RNA was extracted and leptin mRNA expression was examined by Northern blot analysis. Moreover, the cells were incubated with regulators that may affect signals which may alter leptin expression and analyzed with Northern blotting. Butyrate stimulated leptin expression, and stimulated mitogen activated protein kinase (MAPK) and phospho-CREB signaling in a time-dependent manner. Prior treatment of the cells with signal transduction inhibitors as pertusis toxin, Gi protein antagonist, PD98059 (a MAPK inhibitor), and wortmannin (a PI3K inhibitor) abolished leptin mRNA expression. These results suggest that butyrate can regulate leptin expression in humans at the transcriptional level. This is accomplished by: 1) Gi protein-coupled receptors specific for short-chain fatty acids, and 2) MAPK and phosphatidylinositol-3-kinase (PI3K) signaling pathways.

Effect of natamycin on the enumeration, genetic structure and composition of bacterial community isolated from soils and soybean rhizosphere.

Natamycin is commonly used to control fungal growth on agar media used for bacterial enumeration or strain isolation. However, there is no conclusive report on the possible effect of this antibiotic on bacterial growth or on the diversity of the recovered soil bacteria. Therefore, the possible effects of natamycin on the numbers of bacteria isolated at 12 degrees C from three different soils and soybean rhizosphere soil were investigated using natamycin concentrations ranging from 0 to 200 mg l(-1). Our results demonstrate that natamycin concentrations, which inhibit the growth of fungi on the media, have a small but significant inhibitory effect on the number of bacterial colony forming units. A natamycin concentration of 50-200 mg l(-1) is required for an efficient control of fungal growth on media in our experimental conditions depending on the soil type. Bacterial community structure was assessed on culturable cells (cells washed from enumeration plates: plate-wash approach) obtained at 12 degrees C from soybean rhizosphere soil by performing Ribosomal Intergenic Spacer Analysis (RISA) fingerprinting. We demonstrate that all natamycin concentrations used alter the structure of the recovered, culturable bacterial community, compared to control without natamycin. Using ARDRA (amplification of the 16S rDNA gene and restriction analysis) genotyping of individual isolates, some differences were observed between the bacterial isolates obtained in the presence or absence of natamycin. Bacterial isolates recovered in the presence of natamycin are more tolerant (maximal growth rate and lag phase) to this compound than those isolated without natamycin, indicating a possible selection of resistant strains. Therefore, high concentration of natamycin cannot be used for isolation of bacterial strains with the aim of studying biodiversity and could bias a selection of strains for practical applications.