406 research outputs found

    Thermosolutal Marangoni boundary layer magnetohydrodynamic flow with the Soret and Dufour effects past a vertical flat plate

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    AbstractA numerical study of laminar magnetohydrodynamic thermosolutal Marangoni convection along a vertical surface in the presence of the Soret and Dufour effects has been performed. The diffusion-thermo implies that the heat transfer is induced by concentration gradient, and thermo-diffusion implies that the mass diffusion is induced by thermal gradient. In conformity to actuality, it is assumed that the surface tension varies linearly with both the temperature and concentration and that both interface temperature and concentration are quadratic functions of the interface arc length x. The general governing partial differential equations are converted into nonlinear ordinary differential equations using unique similarity transformations. The aim of this study is to investigate the effects of Hartmann number (0 ≤ M ≤ 5), thermosolutal surface tension ratio (0 ≤ R ≤ 5), Soret parameter (0.1 ≤ Sr ≤ 2), Dufour parameter (0.03 ≤ Du ≤ 0.6), Prandtl number (0.72 ≤ Pr ≤ 10) and Schmidt number (0.3 ≤ Sc ≤ 3) on the fluid velocity heat and mass transfer. It is found that, both of temperature and concentration gradient at the wall increases as the thermosolutal surface tension ratio increases. Also, the increase in Prandtl number results in an enhancement in the heat transfer at the wall

    Cattaneo–Christov heat flux impacts on MHD radiative natural convection of Al2O3-Cu-H2O hybrid nanofluid in wavy porous containers using LTNE

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    This paper aims to examine impacts of Cattaneo–Christov heat flux on the magnetohydrodynamic convective transport within irregular containers in the presence of the thermal radiation. Both of the magnetic field and flow domain are slant with the inclination angles Ω and γ, respectively. The worked fluid is consisting of water (H2O) and Al2O3-Cu hybrid nanoparticles. The enclosures are filled with a porous medium, and the local thermal nonequilibrium (LTNE) model between the hybrid nanofluids and the porous elements are considered. Influences of various types of the obstacles are examined, namely, horizontal cold elliptic, vertical elliptic and cross section ellipsis. The solution methodology is depending on the finite volume method with nonorthogonal grids. The major outcomes revealed that the location (0.75, 0.5) is better for the rate of the flow and temperature gradients. The higher values of H* causes that the solid phase temperature has a similar behavior of the fluid phase temperature indicating to the thermal equilibrium state. Also, the fluid-phase average Nusselt number is maximizing by increasing Cattaneo–Christov heat flux factor

    Autofluorescence of routinely hematoxylin and eosinstained sections without exogenous markers

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    Hematoxylin and eosin stained paraffin section was examined by fluorescence microscopy to study the pattern and distribution of fluorescence. Autofluorescence was sensitive and specific for detection ofelastic and collagen fibers. It was concluded that analytical morphological techniques based on autofluorescence can obtain information about morphological and pathological state of tissue and cells

    DETECTION OF CHRONIC TYPHOID CARRIERS AMONG FOOD HANDLERS IN WAD MEDANI , GEZIRA STATE , SUDAN

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    Typhoid fever remains a disease of major public health importance in the tropics. This cross sectional prospective descriptive study was carried out between July 2005 to July 2008 in Wad Medani Town. The objective of the study was to identify chronic typhoid carriers among food handlers in Wad Medani. To achieve this objective, Vi agglutination test was used to determine suggested typhoid carriers among food handlers then stool culture was performed on those with a positive Vi agglutination test. A questionnaire was designed to collect data from suggested typhoid carriers about hygienic practices during food handling and processing .  The collected data were reviewed and coded. Data were analyzed using SPSS versions 10.0 software for tabulation and statistical analysis. The results showed that, ten percent of the examined food handlers were found positive typhoid carriers by Vi agglutination test, 48.5% of the suspected of typhoid carriers were found positive by stool culture, street vendors were more common among suspected typhoid carriers, all of whom had not received any health education about typhoid disease. The study suggested the following recommendations: Regular health authority inspection visitor food handling personnel specially street vendors to exclude typhoid carriers among them, education and training course in good hygienic practices should be provided to all food handlers specially typhoid carriers by Food Control Department, Ministry of Health, Gezira State

    Vitamin D and IL28B genotyping as predictors for antiviral therapy: a retrospective study in Egyptian HCV genotype 4a

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    Purpose: To evaluate the role of pre-treatment vitamin D serum level and interleukin28B (IL28B) (rs 12979860) polymorphism in chronic hepatitis C (CHC) genotype 4a patients treated with pegylated interferon α2-A and ribavirin (peg IFN+RBV) as predictors of response.Methods: A retrospective study of clinical and pathological data and stored blood samples of 150 naïve chronic hepatitis C (CHC) genotype 4a patients, treated with pegylated interferon and ribavirin for 48 weeks. Follow-up to detect sustained virological response (SVR) was carried out. Based on SVR, two groups were studied; group 1 consisted of 75 responder patients to pegylated IFN + RBV therapy while group 2 comprised of 75 non-responder patients to standard hepatitis C virus (HCV) therapy. Vitamin D serum levels were assessed using Enzyme Linked Immunoassay (ELISA), quantitative reverse transcriptase- polymerase chain reaction (qRT-PCR for HCV RNA ), and IL28B gene polymorphism by Restriction Fragment Length Polymorphism Polymerase Cchain Reaction (RFLP-PCR).Results: Pretreatment vitamin D level was significantly higher in group 1 than in group 2 (p < 0.001). The sensitivity and specificity of vitamin D level for prediction of SVR at a cutoff value of 29.75 ng/ml were 100 and 96 %, respectively, with area under the curve (AUC) of 0.995 (p < 0.001). A significant difference was detected between baseline vitamin D level for early versus advanced fibrosis stage (p = 0.01) in group 1.Conclusion: Pretreatment vitamin D serum level (at a cutoff value of 29.75 ng/ml), IL28B gene polymorphism and quantitative HCV RNA are independent trait predictors of SVR.Keywords: Vitamin D, Interleukin 28B, Chronic hepatitis C, Sustained virological response (SVR), Antiviral, Genotypin

    Detection of Insulin Resistance in Obese young men and its association with metabolic abnormalities in Najran, Saudi Arabia

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    Abstract: The association between obesity and type 2 diabetes mellitus (T2DM) has been recognized for decades. The major basis for this link is the ability of obesity to engender insulin resistance (IR). Homeostasis Model Assessment-Insulin Resistance (HOMA-IR) is an indirect marker of IR. The present study evaluated the usefulness of HOMA-IR in the prediction of the risk of the development of T2DM among overweight and obese individuals in Najran, Saudi Arabia. This study was carried out on 116 male individuals divided into 3 groups. Of these, 20 healthy control (GI), 44 prediabetic overweight and obese individuals with high normal serum glucose levels (GII) and 52 diabetic overweight and obese individuals with high serum glucose levels (GIII). Body mass index (BMI) was calculated for all individuals. In addition, fasting serum glucose and insulin levels, lipid profile and liver and kidney function tests were estimated for all individuals. The mean BMI was 21.84±1.28 kg/m 2 in GI, 28.68±2.42 kg/m 2 in GII and 33.82±2.78 kg/m 2 in GIII. The mean fasting serum glucose was 128.29±27.92 mg/dl in GII and 159.46±44.86 mg/dl in GIII. Such findings were correlated with increased fasting serum insulin levels (21.57±2.58 µU/ml in GII and 37.28±6.15 µU/ml in GIII) compared to GI (16.22±6.23 µU/ml). The mean HOMA-IR was 5.77±1.71 in GII and 12.67±4.07 in GIII compared to GI (4.07±1.04). We conclude that, increased BMI was associated with increased incidence of Insulin Resistance, dyslipidaemia and hyperuricaemia among overweight and obese individuals in Najran, Saudi Arabia.

    Evaluation of the Efficacy of Single Anastomosis Sleeve Ileal (SASI) Bypass for Patients with Morbid Obesity: a Multicenter Study

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    Background: Single anastomosis sleeve ileal (SASI) bypass is a newly introduced bariatric and metabolic procedure. The present multicenter study aimed to evaluate the efficacy of the SASI bypass in the treatment of patients with morbid obesity and the metabolic syndrome. Methods: This is a retrospective, seven-country, multicenter study on patients with morbid obesity who underwent the SASI bypass. Data regarding patients' demographics, body mass index (BMI), percentage of total weight loss (%TWL), percentage of excess weight loss (%EWL), and improvement in comorbidities at 12 months postoperatively and postoperative complications were collected. Results: Among 605 patients who underwent the SASI, 54 were excluded and 551 (390; 70.8% female) were included. At 12 months after the SASI, a significant decrease in the BMI was observed (43.2 ± 12.5 to 31.2 ± 9.7 kg/m2; p < 0.0001). The %TWL was 27.4 ± 13.4 and the %EWL was 63.9 ± 29.5. Among the 279 patients with type 2 diabetes mellitus (T2DM), complete remission was recorded in 234 (83.9%) patients and partial improvement in 43 (15.4%) patients. Eighty-six (36.1%) patients with hypertension, 104 (65%) patients with hyperlipidemia, 37 (57.8%) patients with sleep apnea, and 70 (92.1%) patients with GERD achieved remission. Fifty-six (10.1%) complications and 2 (0.3%) mortalities were recorded. Most complications were minor. All patients had 12 months follow-up. Conclusions: The SASI bypass is an effective bariatric and metabolic surgery that achieved satisfactory weight loss and improvement in medical comorbidities, including T2DM, hypertension, sleep apnea, and GERD, with a low complication rate.info:eu-repo/semantics/publishedVersio

    Liposome co-incubation with cancer cells secreted exosomes (extracellular vesicles) with different proteins expressions and different uptake pathways

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    We recently showed that in vitro incubation of cells with liposomes of varying compositions can increase exosome secretion and increase the yield of harvested exosomes (extracellular vesicles, EVs). This might foster their potential therapeutic implementations. In the current study, we investigated the surface proteins and the uptake of the harvested exosomes (EVs) to see if the incubation of cells with liposomes would change the biological properties of these exosomes (EVs). Interestingly, exosomes (EVs) induced by solid cationic liposomes lacked some major exosome marker proteins such as CD9, flotillin-1, annexin-A2 and EGF, and subsequently had lower levels of cellular uptake upon re-incubation with donor cancer cells. However, exosomes (EVs) induced under normal condition and by fluid cationic liposomes, displayed the entire spectrum of proteins, and exhibited higher uptake by the donor cancer cells. Although endocytosis was the major uptake pathway of exosomes (EVs) by tumor cells, endocytosis could occur via more than one mechanism. Higher exosome uptake was observed in donor B16BL6 cells than in allogeneic C26 cells, indicating that donor cells might interact specifically with their exosomes (EVs) and avidly internalize them. Taken together, these results suggest a technique for controlling the characteristics of secreted exosomes (EVs) by incubating donor cancer cells with liposomes of varying physiochemical properties

    A Comparative Study of Prediction Techniques for Supersonic Missile Aerodynamic Coefficients / Loai A. El-Mahdy … [et al.]

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    Evaluating the aerodynamic coefficients of flying vehicles such as missiles is a key step in their design and development procedures. In practice, the aerodynamic coefficients can be estimated using experimental measurements, numerical simulations, or using empirical and semi-empirical engineering tools. In the present paper, these three approaches are compared in the context of examining the aerodynamic coefficients of a fin-stabilized tactical missile. Supersonic flight conditions up to Mach 4 at incidence up to 18 degrees are considered. Lift and drag coefficients as well as the centre of pressure locations based on the three approaches are compared. The flow features around the missile are explored based on the numerical simulations

    Impact of nutrients and water level changes on submerged macrophytes along a temperature gradient: A pan-European mesocosm experiment

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    Submerged macrophytes are of key importance for the structure and functioning of shallow lakes and can be decisive for maintaining them in a clear water state. The ongoing climate change affects the macrophytes through changes in temperature and precipitation, causing variations in nutrient load, water level and light availability. To investigate how these factors jointly determine macrophyte dominance and growth, we conducted a highly standardized pan-European experiment involving the installation of mesocosms in lakes. The experimental design consisted of mesotrophic and eutrophic nutrient conditions at 1 m (shallow) and 2 m (deep) depth along a latitudinal temperature gradient with average water temperatures ranging from 14.9 to 23.9 degrees C (Sweden to Greece) and a natural drop in water levels in the warmest countries (Greece and Turkey). We determined percent plant volume inhabited (PVI) of submerged macrophytes on a monthly basis for 5 months and dry weight at the end of the experiment. Over the temperature gradient, PVI was highest in the shallow mesotrophic mesocosms followed by intermediate levels in the shallow eutrophic and deep mesotrophic mesocosms, and lowest levels in the deep eutrophic mesocosms. We identified three pathways along which water temperature likely affected PVI, exhibiting (a) a direct positive effect if light was not limiting; (b) an indirect positive effect due to an evaporation-driven water level reduction, causing a nonlinear increase in mean available light; and (c) an indirect negative effect through algal growth and, thus, high light attenuation under eutrophic conditions. We conclude that high temperatures combined with a temperature-mediated water level decrease can counterbalance the negative effects of eutrophic conditions on macrophytes by enhancing the light availability. While a water level reduction can promote macrophyte dominance, an extreme reduction will likely decrease macrophyte biomass and, consequently, their capacity to function as a carbon store and food source
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