13 research outputs found

    MHD squeezing flow of nanoliquid on a porous stretched surface: numerical study

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    This work is aimed at conducting a comparative study between two base fluids water as well as ethylene glycol along with nanoparticle (oxide aluminium). Analysis is done for determining unsteadiness between two parallel walls, wherein squeezing of upper wall towards lower is done, while porous stretching surface is lower. The mathematical formulation uses constitutive expression pertaining to viscous nanoliquids. By keeping a variable magnetic field, conduction of nanoliquid is done electrically. The partial differential equations concerning the issue were resolved after transforming to ordinary differential equations by employing forth-fifth Runge-Kutta Fehlberg method. The effect of disparity in various parameters pertaining to temperature, velocity and concentration profile of nanoparticle is first plotted and then tabulated. Based on the obtained results, the velocity field was seen to enhance with rise in squeezing parameter values. Squeezing parameters that possess larger values result in decrease in temperature and concentration profiles of nanoparticles. The heat transfer of nanoliquids was seen to improve with squeezing flow, magnetic field parameter and nanoparticle volume fraction. For the rate of skin friction pertaining to ethylene glycol and water, dominance was seen for magnetic parameter M, suction parameter S and nanoparticle volume fraction parameter

    A review on femoropopliteal arterial deformation during daily lives and nickel-titanium stent properties

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    The increasing number of studies on the behaviour of stent placement in recent decades provides a clear understanding of peripheral artery disease (PAD). The severe mechanical loads (axial ten�sion and compression, bending, radial compression and torsion) deformation of the femoropopli�teal artery (FPA) is responsible for the highest failure rate of permanent nickel-titanium (Nitinol) stents. Therefore, the purpose of this article is to review research papers that examined the deformation of the natural load environment of FPA, the properties of Nitinol and mechanical considerations. In conclusion, a better understanding of mechanical behaviour for FPA Nitinol stents contributes to increased mechanical performance and fatigue-life

    Relationship of Oxidant and Antioxidant Markers to Asthma Severity in Egyptian Asthmatic Children

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    BACKGROUND: Asthma is a chronic airway disease which is characterized by oxidant antioxidant imbalance with the generation of oxidative stress related mediators.AIM: The study aimed to evaluate the role of asymmetric dimethylarginine, and malondialdehyde as oxidant markers and serum paraoxonase activity as an antioxidant marker in asthma, and to determine their relationship to the asthma severity and lung function among asthmatic children in Egypt.PATIENTS AND METHODS: This case control study was conducted on sixty patients with asthma compared with sixty apparently healthy children of matched age and sex.RESULTS: Serum concentrations of oxidant markers as asymmetric dimethylarginine and malondialdehyde were significantly increased in asthmatic patients while anti-oxidant marker as paraoxonase activity was significantly decreased compared to healthy controls (P < 0.05). ANOVA test revealed highly significant elevation of the serum concentrations of oxidant markers while anti-oxidant marker was significantly decreased in severe asthmatic patients (P < 0.001) compared to the patients with moderate and mild asthma respectively. Serum malondialdehyde concentration was a strong predictor of asthma severity by multiple regression analysis (P < 0.05).CONCLUSION: The study revealed an imbalance between oxidative and antioxidant defence systems in asthmatic children. Serum concentration of malondialdehyde was the most predictive biomarker having a significant association with asthma severity

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    The regulatory effects of interleukin-12 on interleukin-18 and interferon-γ production in Egyptian breast cancer patients

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    Background: Breast cancer is the commonest form of cancer in women throughout the world. The outcome of malignant neoplasia in human is often accompanied by defective cellular immunity. Objective: To investigate the regulatory effects of IL-12 on IL-18 and IFN-γ production in patients with breast cancer. In addition, the correlations between IL-18 and IFN-γ levels with different prognostic factors. Methods: This study included 40 female patients with histologically proved breast cancer. They were divided into two groups metastatic and non-metastatic. Peripheral blood mononuclear cells were isolated from freshly drawn heparinized blood of each subject and cultured with and without recombinant IL-12 supplementation. IL-18 and IFN-γ levels assessed using ELISA before and after the addition of IL-12. Results: The level of IL-18 in culture supernatants ranged from 0.69 to 0.95 ng/ml with mean value of 0.8 ng/ml in non-metastatic patients, whereas IL-18 in metastatic patients levels varied from 0.5 to 0.7 ng/ml with a mean value of 0.6 ng/ml after supplementation with IL-12. In non-metastatic patients the levels of IFN-γ ranged from 1.2 to 1.9 ng/ml with mean value 1.4 ng/ml while in metastatic patients the levels ranged from 0.7 to 1.2 ng/ml. Statistical analysis of data revealed that the supplementation of culture with IL-12 significantly increased the mean values of IL-18 IFN-γ in different clinicopathological parameters.Univariate analysis by age, tumor size, grade, number of lymph nodes, ER-PR, IL-18 level, and HER2 neu. Indicated that patients with IL-18 level higher than the median at the diagnosis had higher survival results than those with lower IL-18 concentration. In multivariate analysis IL-18 did not have an independent influence on the survival. Conclusion: Findings provide insights that interleukin-12 may be a potent stimulant of the immune response by enhancing the production of IL-18 and IFN-γ. We can suggest that, IL-12 could be used as a therapeutic agent for improving prognosis associated with breast cancer. Keywords: Interleukin, Interferon-

    Oropharyngeal Candidiasis among Egyptian COVID-19 Patients: Clinical Characteristics, Species Identification, and Antifungal Susceptibility, with Disease Severity and Fungal Coinfection Prediction Models

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    The study aimed to investigate the causative species, antifungal susceptibility, and factors associated with oropharyngeal candidiasis (OPC) among Egyptian COVID-19 patients. This is an observational, case-controlled, single-center study that included three groups: COVID-19 patients (30), COVID-19 patients with OPC (39), and healthy individuals (31). Patients’ demographic data (age, sex), laboratory tests, comorbidities, treatment, and outcomes were included. Candida species were isolated from COVID-OPC patient’s oropharyngeal swabs by convenient microbiological methods. Isolated strains were tested for antimicrobial susceptibility, biofilm production, aspartyl protease, and phospholipase activities. The most common respiratory symptoms reported were dyspnea (36/39; 92.4%) and cough (33/39; 84.7%). Candida albicans was the most common isolated species, accounting for 74.36% (29/39), followed by Candida tropicalis and Candida glabrata (15.38% and 10.26%, respectively). Amphotericin was effective against all isolates, while fluconazole was effective against 61.5%. A total of 53.8% of the isolates were biofilm producers. The phospholipase activity of C. albicans was detected among 58.6% (17/29) of the isolates. Significant variables from this study were used to create two equations from a regression model that can predict the severity of disease course and liability to fungal infection, with a stativity of 87% and 91%, respectively. According to our findings, COVID-19 patients with moderate to severe infection under prolonged use of broad-spectrum antibiotics and corticosteroids should be considered a high-risk group for developing OPC, and prophylactic measures are recommended to be included in the treatment protocols. In addition, due to the increased rate of fluconazole resistance, other new antifungals should be considered

    Determinants of COVID-19 Vaccine Acceptance among Dental Professionals: A Multi-Country Survey

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    Purpose: This study sought to investigate the acceptance rate and associated factors of COVID-19 vaccines among dentists and dental students in seven countries. Material and Methods: A structured questionnaire prepared and guided by the report of the SAGE Working Group on Vaccine Hesitancy was distributed among groups of dentists and dental students in seven countries across four continents. Results: A total of 1527 subjects (850 dentists and 677 dental students) participated in this survey. Although 72.5% of the respondents reported their intention to accept COVID-19 vaccines (dentists: 74.4%, dental students: 70.2%), there was a significant difference in agreement between dentists/dental students across countries; generally, respondents in upper-middle-, and high-income countries (UM-HICs) showed significantly higher acceptance rates compared to those in low- and lower-middle income countries (L-LMICs). Potential predictors of higher vaccine acceptance included being a dentist, being free of comorbidity, being well-informed about COVID-19 vaccines, having better knowledge about COVID-19 complications, having anxiety about COVID-19 infection, having no concerns about the side effects of the produced vaccines and being a resident of an UM-HIC. Conclusion: The results of our survey indicate a relatively good acceptance rate of COVID-19 among the surveyed dentists and dental students. However, dentists and dental students in L-LMICs showed significantly lower vaccine acceptance rates and trust in COVID-19 vaccines compared to their counterparts in UM-HICs. Our results provide important information to policymakers, highlighting the need for implementation of country-specific vaccine promotion strategies, with special focus on L-LMICs

    Parametricism vs Materialism : Evolution of digital technologies for development

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    We build on previous technological developments in CAAD by looking into parametric design exploration and the development of the concept of parametricism. We use the phenomenological backdrop to account for our physical experiences and encounters as well as our mental ones; both evident in the link between parametric design as a process and an outcome. In specific, we previously examined two particular metaphors. The first metaphor addressed aspects of virtual environments that resemble our physical world; In other words, computer model as physical model and digital world as material world. In this volume, we extend the exploration into aspects of virtual environments and their resemblance to physical environments by looking at ‘performance’ aspects: the way in which environments are sensed, measured, tracked and visualised. Moreover, we reflect on matters and materiality in both virtual and physical space philosophically, theoretically, practically and reflectively. The second metaphor looked into the modes and means of interaction between our bodies and such virtual environment. Here we extend the investigation to look at the ways in which measures of environmental performance influence human interaction in real environments. The exploration takes us further to look into the area of design fabrication of the built environment, and methods in which developed processes meet environmental performance requirements, and the innovative outcomes that lead to disruptive technologies getting introduced into design and we revisit parametric design under this focus area
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