22 research outputs found
Massive hydrothorax following subclavian vein catheterization
Since the introduction of central venous catheterization for monitoring of the venous pressure, fluid infusion and hyperalimentation, the literature has been full of serious life-threatening complications. Of these complications is the false positioning of the central venous catheter and subsequent development of pleural effusion. In this report we are describing a case of iatrogenic massive pleural effusion following subclavian vein catheterization necessitating intercostal tube drainage and mechanical ventilation. The case highlights the importance of ensuring adequate positioning of the catheter after insertion through aspiration of venous blood, immediate post insertion X-ray and the utilization of ultrasound guidance in cases with expected difficult catheterization
Using Spiritual Connections to Cope With Stress and Anxiety During the COVID-19 Pandemic
During the initial phases of the COVID-19 pandemic, stress and anxiety were pervasive among the masses due to high morbidity and mortality. Besides the fear of coronavirus was also particularly driven by social media. Many people started to look for faith and spiritual connections to gain comfort. The role of spiritual ties and religious beliefs in relation to coping with pandemic stress has acquired the attention of researchers in some parts of the world. This cross-sectional survey aimed at assessing the intensity of stress and anxiety symptoms experienced by people and how much they were alleviated by employing spiritual connections. The study sample comprises 795 respondents with 52% males and 48% females living in Saudi Arabia. The brief online study questionnaire collected data about background variables, anxiety and stress scale from DASS-21, and items from the WHOQOL (SRBP) instrument assessed the use of spiritual beliefs to cope. Multiple regression models were tested to determine the role of spiritual connections after adjusting demographic variables. Results illustrated that after adjusting for gender and age, participantsā anxiety symptoms decreased by (Ī² = ā0.27; p = 0.000) units with each unit increase in the use of spiritual connections, and participantsā stress symptoms reduce by (Ī² = ā0.36; p = 0.000) units with each unit increase in coping with spirituality. Additionally, femalesā risk to experience anxiety and stress symptoms was more than males [(Ī² = 0.88; p = 0.01) and (Ī² = 0.92; p = 0.000)], respectively. An increase in age decreases the likelihood of experiencing anxiety symptoms and stress symptoms by (Ī² = ā0.75; p = 0.02) and (Ī² = ā0.11; p = 0.000) units, respectively. Findings support the protective role of spiritual connections despite small beta coefficients. The social and cultural context in Saudi Arabia favors deep-rooted connections with spirituality and faith. Our findings support the fact that the reliance on spiritual connections helped older people to deal with exaggerated fear during the initial phase of the COVID-19 pandemic and reduces the risk of experiencing anxiety and stress symptoms. Females and younger participants were relatively vulnerable to developing these symptoms. We discussed these findings considering some recent studies that reported similar relationships and made recommendations for future research
Role of Silver Nanoparticles Synthetized by Marine Red Algae, Acanthophora spicifera, Against Saprolegniosis in Oreochromis niloticus
The anti-fungal activity of Acanthophora spicifera-synthetized silver nanoparticles (AS-AgNPs) was tested in vitro against S. australis. In vivo, 160 Oreochromis niloticus (25 Ā± 0.57 grams) were separated into 4 groups; group 1 and group 2 received 0 mg/L and 0.9 mg/L AS-AgNPs, respectively, and were not exposed to S. australis. Group 3 and group 4 were experimentally infected with S. australis and imperiled to 0 and 0.9 mg/L AS-AgNPs for 96 hours, respectively. At all levels, survival rates, non-specific immune indices, antioxidant activities, and expression analysis of IL-8 and TNF-Ī±Ā genes in the anterior kidneys were estimated. Moreover, histopathological pictures of the skin and underlying musculature were investigated. Results showed that AS-AgNPs produced an inhibitory zone with a diameter of around 12 millimeters. A significant survival rate (72.50%) accompanied by marked non-specific immune responses and antioxidant activities was recorded in the infected-treated group. The histopathological picture of the skin and underlying musculature of diseased fish (group 3) exhibited degenerative changes in the dermal and epidermal layers of the skin and the myocytes. Intriguingly, infected fish treated with AS-AgNPs (group 4) showed normal histological structures of the skin and underlying musculature. Based on these findings, AS-AgNPs have a curative outcome against the destructive effects of S. australis infection and are a potential option for the control of S. australis infection in aquaculture
Pathological findings of cutaneous periocular habronemiasis in a horse in Egypt
A 14 years old horse was admitted in June 2014 with an unhealed ulcer near to the medial canthus of the left eye. The ulcerated skin lesion was 3 cm in diameter reddish in color with hazy irregular borders and containing grayish and yellowish necrotic tissues with offensive odor. Histopathological examination of tissue sections showed parasitic elements embedded in multiple granulomas with caseated centers with degenerated habronema larvae containing masses from granulated eosinophil in the center followed by eosinophilic and basophilic necrotic debris beside numerous macrophage and giant cells followed by fibrous capsule. The covering skin revealed large deep cutaneous ulcer containing purulent or serous exudate with living and degenerated neutrophils. The inflammatory process was extended into deeper area forming pyogranuloma containing multinucleated giant cells and fibrous tissues. Alsothe adjacent tissues revealed aggregations of microfilaria in dermis (Onchocerciasis), and in other section from behind the granuloma we saw nonseptated mycelium (Cutaneous Phaeohyphomycosis) within the purulent exudate as an opportunistic infection.It could be concluded that complicated cutaneous Habronemiasis consider one of the parasitic cutaneous lesions which is rare among horses in Egypt. Immunological reactions of the parasitic element may be one of the etiological agents of skin ulcers and fungal invasions
Acute perimyocarditis mimicking transmural myocardial infarction
<p>Abstract</p> <p>Although acute pericarditis has charachteristic electrocardiographic (ECG) findings that differentiate it from acute ST segment elevation myocardial infarction (MI); in certain cases diagnosis is somewhat difficult especially when the ECG reveals focal instead of diffuse changes and moreover when pericarditis is associated with an underlying myocarditis causing elevation of the cardiac biomarkers therefore increasing the difficulty in differentiating between both enteties. This is especially important because adverse lethal side effect can occur if thrombolytic therapy is administered for a patient with acute pericarditis, or if a diagnosis of transmural MI is missed. In this case report we are describing an 18 year old male patient who presented with an acute onset of severe chest pain associated with focal ECG changes and elevated cardiac enzymes mimicking transmural MI. This report aims to sensitize readers to this debate and create awareness among cardiologists and intensivists with both presentations and how to reach an accurate diagnosis.</p
Robust Parameter Identification Strategy for Lead Acid Battery Model
The most popular approach for smoothing renewable power generation fluctuations is to use a battery energy storage system. The lead-acid battery is one of the most used types, due to several advantages, such as its low cost. However, the precision of the model parameters is crucial to a reliable and accurate model. Therefore, determining actual battery storage model parameters is required. This paper proposes an optimal identification strategy for extracting the parameters of a lead-acid battery. The proposed identification strategy-based metaheuristic optimization algorithm is applied to a Shepherd model. The bald eagle search algorithm (BES) based identification strategy provided excellent performance in extracting the battery’s unknown parameters. As a result, the proposed identification strategy’s total voltage error has been reduced to 2.182 × 10−3, where the root mean square error (RMSE) between the model and the data is 6.26 × 10−5. In addition, the optimization efficiency achieved 85.32% using the BES algorithm, which approved its efficiency
A New Fractional-Order Load Frequency Control for Multi-Renewable Energy Interconnected Plants Using Skill Optimization Algorithm
Connection between electric power networks is essential to cover any deficit in the generation of power from any of them. The exchange powers of the plants during load disturbance should not be violated beyond their specified values. This can be achieved by installing load frequency control (LFC); therefore, this paper proposes a new metaheuristic-based approach using a skill optimization algorithm (SOA) to design a fractional-order proportional integral derivative (FOPID)-LFC approach with multi-interconnected systems. The target is minimizing the integral time absolute error (ITAE) of frequency and exchange power violations. Two power systems are investigated. The first one has two connected plants of photovoltaic (PV) and thermal units. The second system contains four plants, namely, PV, wind turbine, and two thermal plants, with governor dead-band (GDB) and generation rate constraints (GRC). Different load disturbances are analyzed in both considered systems. Extensive comparisons to the use of chef-based optimization algorithm (CBOA), jumping spider optimization algorithm (JSOA), Bonobo optimization (BO), Tasmanian devil optimization (TDO), and Atomic orbital search (AOS) are conducted. Moreover, statistical tests of Friedman ANOVA table, Wilcoxon rank test, Friedman rank test, and Kruskal Wallis test are implemented. Regarding the two interconnected areas, the proposed SOA achieved the minimum fitness value of 1.8779 pu during 10% disturbance on thermal plant. In addition, it outperformed all other approaches in the case of 1% disturbance on the first area as it achieved ITAE of 0.0327 pu. The obtained results proved the competence and reliability of the proposed SOA in designing an efficient FOPID-LFC in multi-interconnected power systems with multiple sources
A Comparison of Different Renewable-Based DC Microgrid Energy Management Strategies for Commercial Buildings Applications
DC microgrid systems allow commercial buildings to use locally generated energy and achieve an optimal economy efficiently. Economical and eco-friendly energy can be achieved by employing renewable energy sources. However, additional controllable sources, such as fuel cells, are required because of their reduced efficiency and fluctuated nature. This microgrid can use energy storage systems to supply transient power and enhance stability. The functioning of the microgrid and its efficiency are related to the implemented energy management strategy. In this paper, a comparison of several reported energy management strategies is fulfilled. The considered EMSs include the fuzzy logic control (FLC) strategy, the state machine control (SMC) strategy, the equivalent consumption minimization strategy (ECMS), and external energy maximization strategy (EEMS). These strategies are compared in terms of power-saving, system efficiency, and power quality specifications. The overall results confirm the ability of EEMS (high efficiency of 84.91% and economic power-saving 6.11%) and SMC (efficiency of 84.18% with high power-saving 5.07%) for stationary applications, such as building commercial applications. These strategies provide other advantages, which are discussed in detail in this paper
Optimal Energy Management for Hydrogen Economy in a Hybrid Electric Vehicle
Fuel cell hybrid electric vehicles (FCEVs) are mainly electrified by the fuel cell (FC) system. As a supplementary power source, a battery or supercapacitor (SC) is employed (besides the FC) to enhance the power response due to the slow dynamics of the FC. Indeed, the performance of the hybrid power system mainly depends on the required power distribution manner among the sources, which is managed by the energy management strategy (EMS). This paper considers an FCEV based on the proton exchange membrane FC (PEMFC)/battery/SC. The energy management strategy is designed to ensure optimum power distribution between the sources considering hydrogen consumption. Its main objective is to meet the electric motorās required power with economic hydrogen consumption and better electrical efficiency. The proposed EMS combines the external energy maximization strategy (EEMS) and the bald eagle search algorithm (BES). Simulation tests for the Extra-Urban Driving Cycle (EUDC) and New European Driving Cycle (NEDC) profiles were performed. The test is supposed to be performed in typical conditions t = 25 Ā°C on a flat road without no wind effect. In addition, this strategy was compared with the state machine control strategy, classic PI, and equivalent consumption minimization strategy. In terms of optimization, the proposed approach was compared with the original EEMS, particle swarm optimization (PSO)-based EEMS, and equilibrium optimizer (EO)-based EEMS. The results confirm the ability of the proposed strategy to reduce fuel consumption and enhance system efficiency. This strategy provides 26.36% for NEDC and 11.35% for EUDC fuel-saving and efficiency enhancement by 6.74% for NEDC and 36.19% for EUDC