2,520 research outputs found

    Biological explorations of Sinai: flora and fauna of Wadi Isla and Hebran, St Katherine Protectorate, Egypt

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    A comprehensive survey was accomplished for two of the most important and beautiful wadis in the Sinai, Wadi Isla & Hebran. The biodiversity of the two wadis are surveyed including plant species and their associated insects, spiders and scorpions. The list includes 20 plant families with 51 species, 8 insect orders with 54 families and 138 species, and 4 arachnid orders with 17 families and 23 species. The highest number of species recorded were Coleoptera and Hymenoptera.Keywords: Biodiversity, checklist, plants, insects, spider

    Live Imaging of Type I Collagen Assembly Dynamics in Osteoblasts Stably Expressing GFP and mCherry-Tagged Collagen Constructs

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    Type I collagen is the most abundant extracellular matrix protein in bone and other connective tissues and plays key roles in normal and pathological bone formation as well as in connective tissue disorders and fibrosis. Although much is known about the collagen biosynthetic pathway and its regulatory steps, the mechanisms by which it is assembled extracellularly are less clear. We have generated GFPtpz and mCherry-tagged collagen fusion constructs for live imaging of type I collagen assembly by replacing the α2(I)-procollagen N-terminal propeptide with GFPtpz or mCherry. These novel imaging probes were stably transfected into MLO-A5 osteoblast-like cells and fibronectin-null mouse embryonic fibroblasts (FN-null-MEFs) and used for imaging type I collagen assembly dynamics and its dependence on fibronectin. Both fusion proteins co-precipitated with α1(I)-collagen and remained intracellular without ascorbate but were assembled into α1(I) collagen-containing extracellular fibrils in the presence of ascorbate. Immunogold-EM confirmed their ultrastuctural localization in banded collagen fibrils. Live cell imaging in stably transfected MLO-A5 cells revealed the highly dynamic nature of collagen assembly and showed that during assembly the fibril networks are continually stretched and contracted due to the underlying cell motion. We also observed that cell-generated forces can physically reshape the collagen fibrils. Using co-cultures of mCherry- and GFPtpz-collagen expressing cells, we show that multiple cells contribute collagen to form collagen fiber bundles. Immuno-EM further showed that individual collagen fibrils can receive contributions of collagen from more than one cell. Live cell imaging in FN-null-MEFs expressing GFPtpz-collagen showed that collagen assembly was both dependent upon and dynamically integrated with fibronectin assembly. These GFP-collagen fusion constructs provide a powerful tool for imaging collagen in living cells and have revealed novel and fundamental insights into the dynamic mechanisms for the extracellular assembly of collagen

    Bioactive Metabolites from Propolis Inhibit Superoxide Anion Radical, Acetylcholinesterase and Phosphodiesterase (PDE4)

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    Cycloartane-triterpenes (cycloartenol, 3α-cycloartenol-26-oic acid and 3β-cycloartenol-26-oic acid) together with α-amyrin acetate and flavonoids (pinostrobin, tectochrysin and chrysin) were isolated from Egyptian propolis for the first time. Their antioxidant activity was evaluated with DPPH and superoxide anion radical (O2.-). All compounds possessed both (O2.-) scavenging as well as XOD inhibitory activity in the range of 50 – 75 %. With DPPH, only the flavonoids showed scavenging activity (48 – 83 %). Acetylcholinesterase (AChE) and phosphodiesterase type 4 (PDE4) inhibitors are currently considered as intracellular targets for treatment of Alzheimer’s disease and Chronic obstructive pulmonary disease (COPD). 3β-cycloartenol-26-oic acid moderately inhibited AChE and PDE4 activities in vitro with IC50 values of 0.8±0.2 and 1.9±0.4 μM, respectively, while 3-cycloartenol-26-oic acid inhibited AChE activity with an IC50 value of 2.1±0.1 μM. The flavonoids pinostrobin and chrysin reduced PDE4 activity by 43 and 40 %, respectively (10 μM) as well as moderately inhibited the growth of the HepG2 cell line, whereas chrysin reduced proliferation of NIH-3T3 cells at 50 μM. Therefore, our results with 3β- and 3-cycloartenol-26-oic acids can contribute to further research on alternative drugs for the treatment of neurological and neurodegenerative diseases, as well as asthma and COPD

    Do renewable energy consumption and financial development contribute to environmental quality in MINT nations? Implications for sustainable development

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    Maintaining a balance between the well-being of the economy and the environment has become a top priority for governments globally. In the contemporary age, world economies, particularly the emerging ones like MINT nations, highlight the need for eco-friendly economic expansion. The MINT nations are thriving economically but are having difficulty reducing their Ecological footprint (EF). This paper aimed to determine if factors such as population density, renewable energy, foreign direct investment, economic growth, and financial development impact ecological footprint in the MINT countries between 1990 and 2018. The study applied ample advanced econometrics such as method of moments quantile regression (MMQR), augmented mean group (AMG) and Common Correlated Effects Mean Group (CCEMG). The overall results indicated that the variables are integrated at the first difference and are cointegrated. The AMG, CCEMG and MMQR results reveal that economic growth deteriorates ecological well-being by promoting the EF while foreign direct investment, population density and renewable energy assists in enhancing it by mitigating the EF in the MINT nations. In addition, financial development does not exert a significant effect on EF. The Dumitrescu Hurlin Panel Causality results show unidirectional causality from economic growth, financial development, population density, and renewable energy to EF. Based on these results policy recommendations are suggested

    Natural Radioactivity of Ground Water in Some Areas in Aden Governorate South of Yemen Region

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    This paper presents the concentrations of naturally occurring radionuclides 226Ra, 232Th and 40K measured in Groundwater collected from Aden Governorate South of Yemen Region using gamma spectroscopy. Thirty-seven Groundwater samples were collected from four areas in Aden Governorate. The average activity concentrations for groundwater from Beer Ahmed area were 1.60 Bql−1, 1.25 Bql−and 16.90Bql−1 for 226Ra, 232Th and40K respectively and from Beer Fadle area were 1.45Bql−1, 0.87Bql−1 and 19.8Bql−1 for 226Ra, 232Th and 40 K, respectively, while that for groundwater samples from Daar-saad area were 1.27 Bql−1, 1.18Bql−1 and 18.28 Bql−1 for 226Ra, 232Th and 40 K, respectively and Al-Masabian area were 1.55Bql−1, 1.421Bql−1 and 19.03Bql−1 for 226Ra, 232Th and 40K respectively. Also, annual effective dose equivalent of ingestion of these waters was calculated. The results showed that the annual dose equivalent obtained in the present study was much higher than the recommended value (0.1mSv year−1) as reported by WHO. The results were compared with those for drinking water

    ASSESSMENT OF CYTOTOXIC AND ANTICANCER ACTIVITY OF Zygophyllum album AND Suaeda palastina EXTRACTS ON HUMAN LIVER CANCER CELL LINES

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    In this study, anticancer activity of Zygophyllum album and Suaeda palastina extracts was evaluated. Dichloromethane, methanol and hot water were used as solvents for extraction. Results indicated that the highest half-maximal inhibitory concentration (IC50) on human lung carcinoma (A549) cell lines was achieved by dichloromethane extracts of Z. album and S. palastina (70.48 μg/ml and 34.82 μg/ml respectively) compared to methanolic and hot water extracts. Furthermore, dichloromethane extracts of both plants had antiproliferative effect and highly cytotoxicity on human cancer cells. IC50 of Z. album was 27.74 μg/ml in the human hepatocellular carcinoma (HepG2), while IC50 of S. palaestina was 30.76 μg/ml with no cytotoxic activity on normal cell lines. In conclusion, these results suggest that Z. album and S. palaestina could be a good candidate species as a natural source of anticancer agents

    Archaeometric Study of the Historic Terrazzo Pavement of Prince Mohamed Ali Museum, Cairo, Egypt

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    This research will shed light on studying a terrazzo pavement in Prince Mohamed Ali Museum (the case study). The authors used visual inspection, stereo microscope, USB microscope, XRPD analysis, and SEM.EDX to identify its components, deterioration aspects and execution techniques. The XRPD and SEM.EDX results revealed that Portland cement was used in the three layers of terrazzo because of the detection of Hatrurite, Alite, Anorthite, Albite, Aragonite, etc. Many pigments were used in the topping terrazzo layer as; Goethite, Greenalite, Hematite, Azurite and Magnetite. The divider strips were made of brass alloy and the topping layer chips were prepared from basalt, marble and sea shells
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