180 research outputs found

    Review of Heterotopic Thyroid Autotransplantation

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    Total thyroidectomy is increasingly accepted for the management of bilateral benign thyroid disorders. Postoperatively, patients require lifelong levothyroxine replacement therapy to avoid postoperative hypothyroidism, which besides the burden of compliance, has been proven to be associated with several long-term side effects. Heterotopic thyroid autotransplantation was proposed several decades ago to avoid the need for life-long postoperative replacement therapy with maintaining the autoregulatory mechanism of thyroxin production inside the body according to its needs. Available data regarding this topic in literature is relatively poor. Before applying thyroid autotransplantation on humans, several studies have been done on animals, where the autologous transplantations were found to be successful in almost all the cases, proved by follow up postoperative 8-week measurements of thyroid hormones and histopathological examination of the removed autografts. Regarding the clinical application, few trials have been done using cryopreserved in vivo, in vitro or immediately autotransplanted thyroid autografts. Satisfactory results were obtained, however, the number of these studies and the number of patients per each study was very low. Besides the study methodologies were not so consistent

    Interaction diagram for RC column strengthened by steel angles and strips

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    This paper presents an analytical model to construct the interaction diagrams (normal force and moment) for the RC column strengthened using the steel jacket technique. The proposed model is defined using the strain distribution block by determining the location of the neutral axis in the concrete section. The proposed analytical formulation is verified by experimental results performed by previous researches and numerical models using the nonlinear program ANSYS. The factors affecting the capacity of the strengthened column are taken into consideration, such as the amount of loads resisted by the steel cage, steel strips spacing, and the effect of concrete confinement. The results of the proposed model are in good agreement with the results from the experimental and numerical work used in verification. A practical design formula has been presented for strengthened columns

    Slotted Reinforced Concrete Beam-Column Connection: State-of-the-Art Review

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    Research on reinforced concrete (RC) beam-column connections has significantly increased during the past few decades. Interest in this topic is related to the importance of beam-column connections in maintaining the integrity of the whole structure. The slotted RC beam-column connection was investigated as promising low damage beam-column connection replacement for conventional design. A slotted RC beam consists of a conventional RC beam, modified with a narrow vertical slot adjacent to the face of the column that runs approximately three-quarters of the beam depth. This study reviews the literature on the mechanics and design of slotted beams, illustrating the works of various researchers on developing and modifying this innovative system. Then, the research progress in the behavior of slotted RC beams is briefly described, in chronological order, to place each contribution in a wider context. Extremely promising structural performance was observed due to minimum beam elongation, non-tearing action, minimum cracks, high energy dissipation, and stable hysteresis response. At the end of the study, a list of the main gaps that need further investigation and recommendations to fill out these gaps are provided

    Foresight for sustainable energy policy in Egypt: results from a Delphi survey

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    International audienceThis paper presents energy opportunities, particular areas of high potential and reflections on energy challenges in Egypt by the year 2040. Energy foresight significantly contributes in the effective review and formulation of national energy policies and strategies. In this work, 350 experts participated in real-time Delphi survey and responded to a set of structured and cross-linked questionnaires that aim to assess and provide future dimension to the energy sector in Egypt. Priorities are presented across 14 energy cluster-areas with 180 identified topics. The two-round Delphi study with an iterative process was performed to determine and measure the expectations of the different stakeholders with specific emphasis on the prospects of renewable energy and energy efficiency. The designed cross-linkages between survey components allowed the systematic pooling and convergence of knowledge in addition to the technical insights and different perspectives. About 50% of Egypt's energy demand was foresighted to be met by renewable energies around 2030. The results showed that all types of energy would not only provide economic and environmental benefits but also improve living standards. This work demonstrates that involving large diversity of expertise and different stakeholders, comprising heterogeneous groups, in foresight studies would potentiate the forecasting power, reduce the polarization effect, and enhance the reliability of the foresight exercise

    Co-administration of Vitamins E and C protects against stress-induced hepatorenal oxidative damage and effectively improves lipid profile at both low and high altitude

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    The aim of this study was to evaluate the effect of co- administration of vitamins E and C on exhaustive exercise induced-stress in regards to hepatorenal function in rats native to low altitude (LA) and high altitude (HA). In both LA and HA areas, native wistar rats of each area were divided into three groups of 6 rats each, which include stress-free control, forced swimming-induced experimental stress and experimental stress plus vitamins E and C treatment. Lipid profile and Liver and kidney functions were assessed in both groups. HA and LA rats exhibit similar baseline levels of liver and kidney function as well as lipid metabolism profiles. However, HA rats showed decreased levels of antioxidant markers with an increased level of lipid peroxidation. Exhaustive swimming exercise induced a significant increase in the liver and kidney function of rats at both altitudes accompanied with a decrease in antioxidants levels. However, the magnitude of change observed in HA rats was more profound. Also at LA, forced swimming exercise resulted in a significant increase in serum total cholesterol (TChol), triacylglycerides (TAG) and high-density lipoprotein cholesterol (HDL). However, in HA rats, forced swimming exercise caused a significant decrease in serum TChol and low-density lipoprotein (LDL), except for HDL levels which were significantly elevated. Pre- and co-administration of vitamins E and C counteracted the induction of liver and/or kidney function by exhaustive exercise, and lowered TChol and LDL levels in rats at either altitude. In conclusion, at native high altitude: kidney and liver function essentially remained stable; response to stress included more profound oxidative damage to liver and kidney tissues as well as augmented deterioration in lipid metabolism compared to low altitude; and combined administration of vitamins E and C protected against observed oxidative stress damage to liver and kidney tissues and preserved lipid metabolism. At low altitude, combined administration of vitamin E and C protected against stress-induced oxidative damage to the liver and kidney and did preserve normal lipid metabolism, except for HDL. These novel findings reveal the pathophysiological changes in the liver function, kidney function and lipid metabolism occurring at high altitude specifically under stress, and demonstrate the efficacy of combined supplementation of vitamins E and C to normalize these changes.Key words: Exercise, oxidative stress, vitamin E, vitamin C, altitude, rats

    The Efficacy of Specific Essential Oils on Yeasts Isolated from the Royal Tomb Paintings at Tanis, Egypt

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    Yeast strains play an important role in the biodeterioration and biodegradation of paintings in ancient Egyptian tombs. Thirteen yeast were isolated from the royal tombs at Tanis (Oserkon II, Psunes and Shashanq), Sharkia Governorate, Egypt, dated back to 840 B.C., by using a sterile cotton swab. Those strains were identified as Saccharomyces cerevisiae, Candida albicans, C. lipolytica and Lodderomyces elongspous. The S. cerevisiae strains were halotolerant for sodium chloride, up to 10 %. Moreover, they caused a fading for the azurite blue color in laboratory cultures and S. cerevisiae was the most potent agent in fading the color. Five essential oils (lemon, spearmint, fennel, marjonam and rosemary) were used to control their growth. Spearmint and lemon oils were the most effective oils in inhibiting the growth of those strains, whereas marjonam, fennel and rosemary had no effect on their growth

    Derangement of hemopoiesis and hematological indices in Khat (Catha edulis) - treated rats

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    The purpose of this study was to identify the sub-acute toxic effects of Khat (Catha edulis) on hemopoiesis and hematological indices of white albino rats. Two groups, each of 10 rats, were used. In the experimental group, a hydro-ethanol extract of C. edulis was administered orally to rats, daily, in single doses of 500 mg/kg body weight, for for weeks. The control group received equivalent amounts of normal saline. Our results show, for the first time, that oral administration of C. edulis hydro-ethanol extract caused significant derangement in hemopoiesis and in gross hematological indices in rats, characterized by macrocytic anemia and leucopenia. Our data show statistically significant decreases in total leukocytes count (TLC) in which, hemoglobin concentration (Hb. conc.), packed cell volume (PCV), and red cell count (RCC), accompanied by significant increases in mean cell volume (MCV), red blood cell distribution width (RDW) and platelets count with no change in mean hemoglobin concentration (MHC). In peripheral blood smears (PBS) of treated rats, there were evidences of dyserythropoiesis- impaired hemoglobinization, macrocytosis, poikilocytosis and anisocytosis, and dysgranulopoiesis- giant forms, hypersegmented neutrophils and bizarre nuclear shapes. In conclusion, our results indicate that oral administration of a hydro-ethanol extract of C. edulis adversely affected blood cell formation and induced macrocytic anemia and leukopenia in rats. However, the exact mechanisms of these hematological changes produced by Khat are still in need for further studies.Keywords:Catha edulis, hemopoiesis, anemia, leukopenia, ratsAfrican Journal of Biotechnology, Vol. 13(2), pp. 349-355, 8 January, 201

    FK 506 pre-treatment is associated with reduced levels of tumor necrosis factor and interleukin 6 following hepatic ischemia/reperfusion

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    Using a rat model, the effect of pre-treatment with FK 506 on hepatic ischemia/reperfusion injury was investigated. All control animals died within 72 h of the ischemia/reperfusion injury. Pre-treatment of the animals with FK 506 (0.3 mg/kg in 0.5 ml saline) administered intravenously improved survival. The most striking protection against fatal ischemia/reperfusion injury was achieved in rats that were given FK 506 6 and 24 h prior to the induction of the hepatic ischemic insult (70% and 80% 10-day survival rates, respectively). The hepatoprotective effect of FK 506 was assessed further in a second experiment in which the serum levels of tumor necrosis factor (TNF) and interleukin 6 (IL-6) were measured. These results suggest that a 60-min period of hepatic ischemia and subsequent reperfusion triggers the release of both TNF and IL-6, and that FK 506 pre-treatment (6 h before the ischemic episode) significantly inhibits the production and/or release of these two cytokines compared to untreated controls. These data provide additional information concerning the immunosuppressive and hepatoprotective activities of FK 506. Based upon these data, it is probable that FK 506 attenuates hepatic ischemia/reperfusion injury, at least in part, by reducing TNF and IL-6 levels. © 1993 Elsevier Scientific Publishers Ireland Ltd. All rights reserved
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