25 research outputs found

    Performance Improvement of Hybrid System Based DFIG-Wind/PV/Batteries Connected To DC And AC Grid By Applying Intelligent Control

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    One of the main causes of CO2 emissions is the production of electrical energy. Therefore, many researchers goal’s is to develop renewable power systems. This paper proposes a new intelligent control development of hybrid PV–Wind-Batteries. Neuro-Fuzzy Direct Power Control (NF-DPC) is invested in order to enhance system performance and generated currents quality. An improved MPPT algorithm based on Fuzzy Controller (FC) is invested for PV power optimization. In addition, a new Modified Fuzzy Direct Power Control (MF-DPC) is developed and applied to the grid side converter to control the active and reactive power by monitoring the involved active power flow and providing a unit power factor by imposing a zero reactive power. An Energy Management Algorithm (EMA) is developed to maintain energy balance, meet the DC load demand, mitigate fluctuations caused by weather condition variations (wind speed and solar irradiance), and minimize battery overcharge and deep discharge. To test the proposed hybrid microgrid system operation, the different parts of the system are modeled, the wind turbine associated to the DFIG, the photovoltaic system as well as the battery storage system. Furthermore, the associated power converters with their control strategies are also presented. Global system simulation, using MATLAB/Simulink, is carried out to validate the effectiveness of both EMA and control techniques. The obtained results show significant reduction of active/reactive power ripples and THD by about 64%, 72%, and 50%, respectively. The EMA ability to manage the energy flow, produced and requested by the load. The THD rate of all injected currents is less than 4%, meaning that the proposed controls will increase the used equipments’ life span, minimize their maintenance and then reduce the hybrid power system cost

    Role of Imaging and AI in the Evaluation of COVID-19 Infection: A Comprehensive Survey

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    Coronavirus disease 2019 (COVID-19) is a respiratory illness that started and rapidly became the pandemic of the century, as the number of people infected with it globally exceeded 253.4 million. Since the beginning of the pandemic of COVID-19, over two years have passed. During this hard period, several defies have been coped by the scientific society to know this novel disease, evaluate it, and treat affected patients. All these efforts are done to push back the spread of the virus. This article provides a comprehensive review to learn about the COVID-19 virus and its entry mechanism, its main repercussions on many organs and tissues of the body, identify its symptoms in the short and long terms, in addition to recognize the role of diagnosis imaging in COVID-19. Principally, the quick evolution of active vaccines act an exceptional accomplishment where leaded to decrease rate of death worldwide. However, some hurdels still have to be overcome. Many proof referrers that infection with CoV-19 causes neurological dis function in a substantial ratio of influenced patients, where these symptoms appear severely during the infection and still less is known about the potential long term consequences for the brain, where Loss of smell is a neurological sign and rudimentary symptom of COVID-19. Hence, we review the causes of olfactory bulb dysfunction and Anosmia associated with COVID-19, the latest appropriate therapeutic strategies for the COVID-19 treatment (e.g., the ACE2 strategy and the Ang II receptor), and the tests through the follow-up phases. Additionally, we discuss the long-term complications of the virus and thus the possibility of improving therapeutic strategies. Moreover, the main steps of artificial intelligence that have been used to foretell and early diagnose COVID-19 are presented, where Artificial intelligence, especially machine learning is emerging as an effective approach for diagnostic image analysis with performance in the discriminate diagnosis of injuries of COVID-19 on multiple organs, comparable to that of human practitioners. The followed methodology to prepare the current survey is to search the related work concerning the mentioned topic from different journals, such as Springer, Wiley, and Elsevier. Additionally, different studies have been compared, the results are collected and then reported as shown. The articles are selected based on the year (i.e., the last three years). Also, different keywords were checked (e.g., COVID-19, COVID-19 Treatment, COVID-19 Symptoms, and COVID-19 and Anosmia)

    Flavonoid-coated gold nanoparticles as efficient antibiotics against gram-negative bacteria—evidence from in silico-supported in vitro studies

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    Flavonoids are a class of bioactive plant-derived natural products that exhibit a broad range of biological activities, including antibacterial ones. Their inhibitory activity toward Gram-positive bacterial was found to be superior to that against Gram-negative ones. In the present study, a number of flavonoid-coated gold nanoparticles (GNPs) were designed to enhance the antibacterial effects of chrysin, kaempferol, and quercetin against a number of Gram-negative bacteria. The prepared GNPs were able to conjugate to these three flavonoids with conjugation efficiency ranging from 41% to 80%. Additionally, they were able to exert an enhanced antibacterial activity in comparison with the free flavonoids and the unconjugated GNPs. Quercetin-coated GNPs were the most active nano-conjugates and were able to penetrate the cell wall of E. coli. A number of in silico experiments were carried out to explain the conjugation efficiency and the antibacterial mechanisms of these flavonoids as follows: (i) these flavonoids can efficiently bind to the glutathione linker on the surface of GNPs via H-bonding; (ii) these flavonoids, particularly quercetin, were able to increase the bacterial membrane rigidity, and hence decrease its functionality; (iii) these flavonoids can inhibit E. coli’s DNA gyrase (Gyr-B) with IC(50) values ranging from 0.9 to 3.9 µM. In conclusion, these bioactive flavonoid-based GNPs are considered to be very promising antibiotic candidates for further development and evaluation

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    Safety and consumption of sevoflurane versus desflurane using target controlled anesthesia in children

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    Background: Recently a concept of target controlled inhalational anesthesia (TCA) is introduced in which the fresh gas flow and its composition are automatically delivered to the patients with the least possible flow. The aim of this study is to compare safety, consumption and cost of both sevoflurane and desflurane when delivered by target controlled anesthesia (TCA) using fully closed circuit conditions. Patient and method: After approval of the hospital review board and obtaining parental informed consent, 60 pediatric patients aged 2–12 were selected. The patients were classified into two groups according to the anesthetic used S Group (n = 30) in which sevoflurane D Group (n = 30): in which desflurane was used. Both were delivered by auto control mode of Zeus machine. Anesthetic agent and O2 consumption, cost and number of adjustments were assessed. Blood samples were obtained preoperatively and at 24, 48 and 72 h after the end of surgery for measuring serum creatinine, BUN, AST and ALT. Twenty-four hour urine samples were collected for 3 consecutive days to measure glucose, microprotein and creatinine for the estimation of creatinine clearance. Results: This study revealed that sevoflurane group had a lower O2, anesthetic consumption and cost than desflurane group. Also both groups had higher levels of serum urea and creatinine together with urinary microproteins and glucose in the first three post-operative days compared to preoperative values which indicates minor tubular insult. However there was no statistically significant difference between the two groups. Conclusion: Sevoflurane is as safe as desflurane when delivered by auto control mode of Zeus machine with decreased anesthetic consumption and cost

    Efficient Artificial Neural Network for Smart Grid Stability Prediction

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    According to the stability process of smart grids, which starts by gathering information of consumers, and then evaluating this information based on specifications of a power supply, and finally, information of a price is sent to the consumers as a report about the utilization. From this perspective, this process is too much time consuming, thus it should predict a smart grid stability via artificial intelligence (e.g., neural networks). Recent advances in the accuracy of neural network have effective solutions to solving the smart grid stability prediction issues, but it remains necessary to develop high performance neural networks that give higher accuracy. In this paper, an artificial neural network (ANN) is proposed to predict a smart grid stability for Decentral Smart Grid Control (DSGC) systems. This neural network is applied to a dataset aggregated from simulations of grid stability, executed on a four-node network with star topology, and engaged in two classes of grid stability–stable and unstable. Keras framework is used to train the proposed neural network, and a hyperparameter tuning method is utilized to achieve high accuracy. Receiver operating characteristic (ROC) curves and confusion matrices are experimentally utilized to evaluate the performance of the proposed neural network. The neural network provides high performance, with a testing loss rate of 0.0619, and a testing accuracy of 97.36%. The weighted average recall, precision, and F1-score for the proposed neural network are 98.02%, 98.03%, and 98.02%, respectively, while the area under the ROC curves (AUCs) is 100%. This neural network with the utilized dataset indeed provides an accurate and quick approach of predicting grid stability to analyze DSGC systems

    Effect of ultra violet irradiation on the interplay between Th1 and Th2 lymphocytes

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    Although UV radiation is used to treat several diseases, including rickets, psoriasis, eczema and jaundice, prolonged human exposure to UV radiation may result in acute and chronic health effects on the skin, eye and immune system. Aim: this study is carried out to show the effect of UV on both splenocyte lymphoproliferative response and their capacity to produce IL-12 and IL-10 in mice. Methods: mice were exposed to whole body UVB and tested for the effect of recovery times on splenocyte proliferation and cytokine production. In addition, direct irradiation of spleens and lymphocyte suspension was done. Basal and mitogen-stimulated splenocyte proliferation was assessed by MTT assay while IL-10 and IL-12 were measured using ELISA. Results showed significant suppression in splenocyte proliferation in comparison with control. IL-12 levels were significantly reduced while IL-10 was increased. ConA and PWM had no significant changes in IL-10 while Con A caused a highly significant increase in IL-12 at day six recovery in UVB body irradiation. Conclusion: Exposure to UVB radiation could cause a state of immune suppression and shifts Th1/Th2 cell response. This effect is closely associated with the reduction of Th1 cytokines' expression and increase in Th2 cytokines' levels

    Effect of murine exposure to gamma rays on the interplay between Th1 and Th2 lymphocytes

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    Background: Gamma radiation or radiotherapy is one of the most widely used treatments for cancer. There is accumulating evidence that adaptive immunity significantly contributes to the efficacy of radiotherapy. Aim: This study is carried out to show the effect of gamma rays on the interplay between Th1/Th2 response, splenocyte lymphoproliferative response to polyclonal mitogenic activators and lymphocytic capacity to produce IL-12 and IL-10 in mice. Methods: mice were exposed to whole body gamma irradiation and tested for the effect of recovery times on splenocyte proliferation and cytokine production. In addition, direct irradiation of spleens and lymphocyte suspension was done. Basal and mitogen-stimulated splenocyte proliferation was assessed by MTT assay while IL-10 and IL-12 were measured using ELISA. Results showed that exposure of intact spleens to different doses of γ-rays (5, 10, 20 gray) caused spontaneous and dose dependent immune stimulation manifested by enhanced cell proliferation and elevated IL-12 production with decreased IL-10 release (i.e. Th1 bias). While exposure of splenocytes suspension to different doses of γ-rays (5, 10, 20 gray) showed activation in splenocytes stimulated by PWM at 5 grays then a state of conventional immune suppression that is characterized by being dose-dependent and is manifested by decreased cell proliferation and IL-12 release accompanied by increase in IL-10 production (i.e. Th2 bias). In addition, we investigated exposure of the whole murine bodies to different doses of γ-rays and found that exposure to low dose γ-rays (0.2 gray) caused a state of immune stimulation terminated by a remarkable tendency for immune suppression. Exposure to 5 or 10 gray of γ-rays resulted in a state of immune stimulation (Th1 bias), but exposure to 20 gray showed a standard state of immune suppression (Th2 bias). Conclusion: Exposure to gamma radiation could cause a state of immune stimulation or suppression via controlling Th1/Th2 cel

    Prognostic value of FOXP3 and TGF-β expression in both peripheral blood and lymph nodes in patients with B-Non Hodgkin’s lymphoma

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    Foxp3 has been studied as a biomarker of Treg cells in many solid malignant diseases, although its role as an immunomodulator in B-NHL remain poorly understood and the effect of traditional chemotherapy on its expression remains unclear. In this study the role of circulating and intra-tumoral Treg and TGF-β in patients with B-NHL before and after chemotherapy was evaluated. Enumeration of Treg cells was carried out by flow cytometric staining of their cell surface markers CD4 and CD25 as well as by molecular analysis of its signature transcription factor FoxP3. Expression of FoxP3 was done using quantitative real-time PCR while TGF-β mRNA expression was semi-quantitatively assayed by the conventional reverse transcription-PCR. In addition, spontaneous versus mitogen-induced release of TGF-β by PBMCs was assessed by a short term cell culture followed by ELISA. This was done before and after six cycles of CHOP chemotherapy. The results were evaluated in relation to the clinicopathological data. A significant increase in mRNA transcripts of both Fox P3 and TGF-β as well as the percentage of CD4+/CD25+ in B-NHL patients before receiving the chemotherapy were recorded, when compared either to healthy controls or to patients after completion the treatment regimen. Interestingly 6 cycles of CHOP treatment caused significant reduction in all parameters under study, relative to the situation before treatment. A significant enhancement in spontaneous TGF-β release in B-NHL patient either before or after chemotherapy was obtained. These results strongly confirm the possible involvement of Treg cells and TGF-β in orienting the clinical course of the disease as well as the ability of targeting them in immunotherapeutic approaches
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