3,309 research outputs found
3-D Printed Radar Absorber with Meta-material Features for X-band Application
This paper presents a structured radar absorber with metamaterial features based on graphite SLS composite. The unit cell of the proposed design was simulated on COMSOL Multiphysics to determine its frequencydependent absorption characteristics and fabricated using low-cost selective laser sintering 3-D printing technology. The measurement and simulation results showed an effective absorption bandwidth of 1.04 GHz and 2.08 GHz respectively. The optimized structure however, revealed broadband absorption in a frequency range between 8.35 to 12.20 GHz (X band) under normal incidence. Besides, the absorption performance under different polarizations and incident angles were investigated. Results indicated that the absorber exhibits polarization indifference and high absorptivity at a wide angle of incidence. The advantages of low cost, ultra-broad operating band, wide-angle feature, and polarization insensitivity made the proposed absorber a promising candidate in military and civilian applications
Dyslipidemia among Sudanese Children Undergoing Maintenance Dialysis
Introduction: Dyslipidemia is an established risk factor for atherosclerosis and cardiovascular disease. It is common among children undergoing maintenance dialysis. To our knowledge, this is the first report on the lipid profile of children undergoing maintenance hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) in Sudan.
Methods: We studied 17 children on HD, 11 children on CAPD and 28 controls. The levels of total cholesterol (TC), triglycerides (TGD) and high density lipoprotein cholesterol (HDL-C) were measured from fasting serum samples using electrophoresis and low density lipoprotein cholesterol (LDL-C) was then calculated.
Results: End stage renal failure (ESRF) children had higher mean TC (193±36 versus 135±17 mg/dl), higher mean TGD (120±38 versus 90±15 mg/dl), higher mean LDL-C (129±32 versus 69±18 mg/dl), and lower mean HDL-C (39±12 versus 49±4 mg/dl) than controls (P=0.00 for all parameters). CAPD patients had higher mean TC (211±39 versus 181±30 mg/dl) and higher LDL-C (145±35 versus 118±25 mg/dl) than controls (P=0.03 for both parameters). The prevalence of dyslipidemia among ESRF patients was 75% while none of the control group had lipid parameters outside the accepted range. Among ESRF patients, 39.3% had TC > 200 mg/dl, 21.4% had TGD > 150 mg/dl, 42.9% had LDL-C > 130 mg/dl, and 35.7% had HDL-C < 35 mg/dl. Abnormal HDL-C values were more prevalent among CAPD patients compared to HD patients (52.9% versus 9.1%, P=0.02)
Conclusion: Despite the small number of studied children, this study is likely to reflect the high prevalence of dyslipidemia among children undergoing maintenance dialysis treatment in Sudan.
Keywords: Children; Continuous Ambulatory Peritoneal Dialysis; Dyslipidemia; Hemodialysis; Suda
A Dimension-Adaptive Multi-Index Monte Carlo Method Applied to a Model of a Heat Exchanger
We present an adaptive version of the Multi-Index Monte Carlo method,
introduced by Haji-Ali, Nobile and Tempone (2016), for simulating PDEs with
coefficients that are random fields. A classical technique for sampling from
these random fields is the Karhunen-Lo\`eve expansion. Our adaptive algorithm
is based on the adaptive algorithm used in sparse grid cubature as introduced
by Gerstner and Griebel (2003), and automatically chooses the number of terms
needed in this expansion, as well as the required spatial discretizations of
the PDE model. We apply the method to a simplified model of a heat exchanger
with random insulator material, where the stochastic characteristics are
modeled as a lognormal random field, and we show consistent computational
savings
Information Systems Research: Foundations, Design and Theory
This textbook will delve into the philosophical foundation of contemporary IS research design with particular emphasis on the methodological tools that can be applied to conduct effective research in the multidisciplinary area of contemporary IS. What sets the book apart is that it will cover the current social paradigm shift, global changes and the need for new methodological tools, which have revolutionised the way we use IS to support our daily practices. It considers the entire methodological procedures applied to research projects that investigate or explore multifaceted areas of contemporary IS, such as information management, digital business, ICT and information science.
Featuring learning objectives, case studies, assessment questions and exercises, this textbook offers a practical outline for IS research methodology that will be of use to students and researchers. It aims to satisfy researchers who are seeking literature on applying methodological procedures to their research projects that delve into the world of contemporary IS that other titles have only considered in a much broader sense
Production and Evaluation of Nutritional Contents of Traditional Couscous from Sprouted Wheat Fortified with Glycine max (L.) merr (Soya Bean) and Cucurbita pepo (Pumpkin) Seeds
The study was carried to process, produce, and evaluate nutritional contents of traditional couscous from sprouted wheat (Triticum aestivum), fortified with Soya bean (Glycine max) and Pumpkin (Cucurbita pepo) seeds. The composite couscous blends were traditionally produced and compared with commercial couscous. The sprouted wheat couscous blends were blended in different ratios, they include; unprocessed (Raw wheat, 100), blend 1 (sprouted wheat mixed with soya bean and pumpkin seeds, 70:20:10), blend 2 (sprouted wheat mixed with soya bean, 60:40) and blend 3 (sprouted wheat mixed with pumpkin seeds, 60:40). Traditional wheat couscous blends were fed to experimental albino rats of wister strain weighing between (35 g and 45 g) for a period of 28 days. The nutritional and physiochemical analysis were determined using standard laboratory methods. The Statistical Package for Social Sciences (SPSS), version 20.0 was used to analyze the data collected which were expressed as means ± SE. One way analysis of variance (ANOVA) and Duncan’s multiple range tests were used to compare the means obtained after each experiment. Differences were considered significant at p < 0.05. Processing (Sprouting) decreases the levels of anti-nutrients, mineral elements and vitamins. Supplementation with soya bean and pumpkin seeds increased the nutritional composition of the sprouted wheat couscous blends. Results of chemical composition showed that blend 2, recorded high protein (29.95%), fat (8.95%) and low carbohydrate content (49.56%), followed by blend 1 and then blend 3, while commercial couscous crude protein, fat and carbohydrate were 12.53%, 1.42% and 75.10% respectively. There was improved level of in vitro protein digestibility at 1 hour (76.64% to 98.59%) and at 6 hours (96.80% to 99.33%). Results of in vivo studies showed that raw wheat couscous recorded protein quality when compared with spouted wheat couscous blends produced. The biological values of the composite couscous blends range from 95.04% to 95.73% and blend 2, recorded high net protein utilization (98.57%). In terms of sensory evaluation using hedonic method, blend 2 was most acceptable and differ significantly (p < 0.05) with other sprouted wheat couscous blends and commercial couscous. The cost of producing sprouted wheat couscous blends is cheaper than the commercial couscous. The study has therefore, revealed that with proper selection of locally available cereal, it is possible to produce nutritious complementary couscous blends that would be acceptable and nutritionally adequate to meet up the nutritional requirement for both children and adults. It also compares favourably with the commercial couscous in terms of nutrient contents
Digital entrepreneurship and co-creating value through digital encounters
Digital technologies have enabled certain opportunities for industries, societies, and companies to change for the better. The service sector has essentially evolved through signi� cant developments in recent decades, such as the increasing adoption of arti� cial intelligence (AI) applications and automated technologies, including service robots, chatbots, and virtual assistants. Both digital transformation and digital entrepreneurship are multifaceted areas that relate to varied emerging technologies that have recently dominated the current service industry. These technologies serve to enhance various sociotechnical areas, including communication and collaboration, as well as co-creating business value and promoting service automatio
Congenital dysplastic hips, spinal column abnormalities, fractures and progressive neurological manifestations in Tunisian family with cockayne syndrome
We report an inbred, Tunisian family in which cousins have the definite diagnosis of Cockayne syndrome. Intervening members in this family, who are intellectually normal, though, most are manifesting complications of hip dysplasia (development of dysplastic arthrosis) and various vertebral abnormalities. We presume that these are carriers who manifest dreadful bone features rather than the clinical phenotype of Cockayne syndrome, the mode of inheritance of the abnormal gene in this family is suggesting autosomal dominant, to our knowledge the family reported with such skeletal abnormalities in association to Cockayne syndrome is the largest in comparison to the international literatures.Keywords: cockayne syndrome, skeletal abnormalitiesRésuméNous faisons un rapport sur un cas résultant de croisements entre animaux de même souche, une famille tunisiene chez laquelle les cousins avaient un diagnostic précis du syndrome de cockaye. Les membres de cette famille qui interviennent et qui sont sains intellectuellement bien que la plupart des patients manifestaient des complications de la hanche dysplasie (devéloppement d\'arthrose dysplastique) et des anomalies vertébrales. Nous supposons qu\'elles sont des porteuses qui manifestent des traits épouvantables d\'os plutôt que le phénotype clinique de syndrone de cockaye, la méthode d\'héritage de ce gêne anomalie chez cette famille pourrait être autosome dominant. Pour autant que nous sachons, la famille s\'est présentée atteinte d\'une telle anomalité squelettique en association avec le syndrome de cockaye est le plus grand par rapport à la littérature internationale.Mots clés: syndrome de cockaye, anomalité squelettiqueAnnals of African Medicine Vol. 4(2) 2005: 83–8
SUSCEPTIBILITY PATTERN OF PSEUDOMONAS AERUGINOSA PRODUCING ENZYMES AGAINST ANTIMICROBIAL AGENT CELL FREE SUPERNATANT OF LACTOCOCCUS WITH THE FOCUS ON ITS DETERMINING QUANTITATIVELY BY OD (ENZYME LINKED IMMUNE SORBENT ASSAY)
ABSTRACTObjective: The present work was conducted to explore the prevalence of Pseudomonas aeruginosa that produce lipase and protease enzymes in40 samples, as well as detection of quality and quantity production and determine its susceptibility to antimicrobial.Methods: The antimicrobial activity of Lactococcus cell free supernatant (CFS) on P. aeruginosa growth and quantity production of enzymes by twomethods (special media and OD) were also studied.Results: A total of 8(20%) and 13(32%) isolates were found to be positive to P. aeruginosa producing lipase and protease, respectively. The in vitroantimicrobial activity results revealed that all isolates producing enzymes showed sensitive to CFS of Lactococcus, only one isolate exhibited lowsensitivity to CFS 4 mm, however, these isolates varied in their sensitivity to CFS ranged 4-15 mm.Conclusion: Results of the quantity production of P. aeruginosa enzymes with CFS of Lactococcus showed and exerts growth inhibitory activity andreduce the production of enzymes. We could be concluded that CFS of Lactococcus has great potential antimicrobial activity against P. aeruginosagrowth and its ability on enzymes production.Keywords: Pseudomonas aeruginosa, Lactococcus, Cell-free supernatant, Optical density, Lipase, Protease
Diverticule de Zenker à propos de 6 observations
Introduction : Le diverticule de Zenker est une pathologie acquise rare qui touche surtout le sujet âgé. Il peut être à l’origine de sérieuses complications pulmonaires.Matériel et méthodes : il s’agit d’une étude rétrospective à propos de 6 patients opérés pour diverticule de Zenker au service d’ORL Farhat Hached de Sousse sur une période de 15 ans (1996-2010).Résultats : Le symptôme majeur était la dysphagie. L’âge moyen était de 64 ans. Les six patients étaient opérés par voie de cervicotomie. Les suites opératoires immédiates étaient bonnes. Un seul patient a développé une sténose oesophagienne.Conclusion : Le diverticule de Zenker est une pathologie rare qui touche le sujet âgé. Le tableau clinique est peu spécifique. Son diagnostic positif est confirmé par le transit pharyngo-oesophagien. La cervicotomie ainsi que l’endoscopie représentent les deux modalités thérapeutiques possibles. La diverticulectomie avec myotomie trans-muqueuse reste le traitement de choix pour le sujet jeune. Cependant le traitement endoscopique reste une bonne alternative chez le sujet âgé à haut risque chirurgical.Mots clés : diverticule de Zenker, dysphagie, myotomie
Les pseudo nodules thyroidiens
Buts : Rappeler les particularités cliniques et paracliniques des différentes étiologies des pseudonodules thyroïdiens et discuter les moyens de diagnostic positif et de prise en charge thérapeutique.Matériels et méthodes : il s'agit de 5 observations de patientes porteuses de pseudo-nodules thyroïdiens colligées au service d'oRL et de CCF du ChU Farhat hached de Sousse. L'âge variait entre 21 et 52 ans. dans tous les cas, le motif de consultation était une tuméfaction basicervicale associée à des signes de compression (dysphagie, dyspnée et/ou dysphonie). Une échographie et une scintigraphie thyroïdiennes ont été réalisées dans tous les cas. La cytoponction n'a été pratiquée que dans trois cas.Résultats : La tuméfaction basicervicale était mobile à la déglutition dans tous les cas. L'échographie et la scintigraphie ont évoqué une lésion thyroïdienne dans tous les cas. La cytoponction n'a été contributive dans aucun des trois cas. Après cervicotomie exploratrice et étude histologique, le diagnostic était, selon les cas, un kyste hydatique, un schwannome,un adénome parathyroïdien, un kyste du tractus thyréoglosse et un chondrosarcome cricoïdien.Conclusion: Les pseudo- nodules thyroïdiens sont des nodules cervicaux péri-thyroïdiens qui constituent des situations cliniques exceptionnelles voire anecdotiques que le chirurgien doit savoir évoquer. L'examen cytologique fait par une personne entraînée peut être contributif au diagnostic différentiel. Cependant, le diagnostic se fait souvent après cervicotomie exploratrice.Mots clés : pseudo- nodule, thyroïde, kyste hydatique, schwannome, adénome parathyroïdien, kyste du tractus thyréoglosse, chondrosarcom
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