85 research outputs found

    Age- and region-specific hepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review

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    Toy M, Önder FO, Wörmann T, et al. Age- and region-specific hepatitis B prevalence in Turkey estimated using generalized linear mixed models: a systematic review. BMC infectious diseases. 2011;11(1): 337.BACKGROUND: To provide a clear picture of the current hepatitis B situation, the authors performed a systematic review to estimate the age- and region-specific prevalence of chronic hepatitis B (CHB) in Turkey. METHODS: A total of 339 studies with original data on the prevalence of hepatitis B surface antigen (HBsAg) in Turkey and published between 1999 and 2009 were identified through a search of electronic databases, by reviewing citations, and by writing to authors. After a critical assessment, the authors included 129 studies, divided into categories: 'age-specific'; 'region-specific'; and 'specific population group'. To account for the differences among the studies, a generalized linear mixed model was used to estimate the overall prevalence across all age groups and regions. For specific population groups, the authors calculated the weighted mean prevalence. RESULTS: The estimated overall population prevalence was 4.57, 95% confidence interval (CI): 3.58, 5.76, and the estimated total number of CHB cases was about 3.3 million. The outcomes of the age-specific groups varied from 2.84, (95% CI: 2.60, 3.10) for the 0-14-year olds to 6.36 (95% CI: 5.83, 6.90) in the 25-34-year-old group. CONCLUSION: There are large age-group and regional differences in CHB prevalence in Turkey, where CHB remains a serious health problem

    SIMULTANEOUS DEEP AND INTERMEDIATE DEPTH CONVECTION IN THE NORTHERN LEVANTINE SEA, WINTER 1992

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    The northern Levantine Sea is the primary source region for the Levantine Intermediate Water (LIW) in the Mediterranean Sea. The Deep Water (DW) of the Eastern Mediterranean mainly originates in the Adriatic basin, but local contributions from the Levantine Sea have also been suspected in the past. Observations in the northern Levantine Sea during March 1992 shed new light on the above processes, showing simultaneous formation of DW in the cyclonic Rhodes Gyre (Rhodes Gyre) area, and of LIW in the adjacent regions. The deep convection region coincides with the permanent dome structure of the Rhodes Gyre, where overturning of the water is generated by cooling during sufficiently severe winters. The LIW is produced in a much larger area of the northern Levantine Sea than previously thought, by direct surface cooling and mixing of the near-surface stratified waters

    BOUNDARY CURRENT INSTABILITIES, UPWELLING, SHELF MIXING AND EUTROPHICATION PROCESSES IN THE BLACK-SEA

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    Satellite and in situ data are utilized to investigate the mesoscale dynamics of the Black Sea boundary current system with special emphasis on aspects of transport and productivity. The satellite data are especially helpful in capturing rapid sub-mesoscale motions insufficiently resolved by the in situ measurements

    Microstructural Characterization and Thermal Properties of Aluminium Titanate/Talc Ceramic Matrix Composites

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    Talc (3MgO·4SiO₂·H₂O) has excellent mechanical properties, shock and abrasion resistance, good electrical and thermal shock resistance, softness, isolation, chemical activity, heat resistance and oil absorption properties. Aluminium titanate (Al₂TiO₅) exhibit extremely good thermal shock resistance and low thermal conductivity coupled with good chemical resistance in molten metals. In the present work, Aluminium titanate/talc ceramics composites with different percentages of Al₂TiO₅ was prepared using powder metallurgy techniques. The microstructural, mechanical and thermal properties were characterized using XRD, SEM, dilatometer and hardness. Thermal shock resistance behaviour under water quenching of the as-prepared ceramics was also evaluated. Results, revealed that the addition of aluminium titanate to talc matrix improves the properties of the aluminium titanate/talc ceramics
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