176 research outputs found

    Recommendation of RILEM TC 271-ASC: New accelerated test procedure for the assessment of resistance of natural stone and fired-clay brick units against salt crystallization

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    This recommendation is devoted to testing the resistance of natural stone and fired-clay brick units against salt crystallization. The procedure was developed by the RILEM TC 271-ASC to evaluate the durability of porous building materials against salt crystallization through a laboratory method that allows for accelerated testing without compromising the reliability of the results. The new procedure is designed to replicate salt damage caused by crystallization near the surface of materials as a result of capillary transport and evaporation. A new approach is proposed that considers the presence of two stages in the salt crystallization test. In the first, the accumulation stage, salts gradually accumulate on or near the surface of the material due to evaporation. In the second, the propagation stage, damage initiates and develops due to changes in moisture content and relative humidity that trigger salt dissolution and crystallization cycles. To achieve this, two types of salt were tested, namely sodium chloride and sodium sulphate, with each salt tested separately. A methodology for assessing the salt-induced damage is proposed, which includes visual and photographical observations and measurement of material loss. The procedure has been preliminarily validated in round robin tests

    Long-term, hormone-responsive organoid cultures of human endometrium in a chemically defined medium

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    In humans, the endometrium, the uterine mucosal lining, undergoes dynamic changes throughout the menstrual cycle and pregnancy. Despite the importance of the endometrium as the site of implantation and nutritional support for the conceptus, there are no long-term culture systems that recapitulate endometrial function in vitro. We adapted conditions used to establish human adult stem-cell-derived organoid cultures to generate three-dimensional cultures of normal and decidualized human endometrium. These organoids expand long-term, are genetically stable and differentiate following treatment with reproductive hormones. Single cells from both endometrium and decidua can generate a fully functional organoid. Transcript analysis confirmed great similarity between organoids and the primary tissue of origin. On exposure to pregnancy signals, endometrial organoids develop characteristics of early pregnancy. We also derived organoids from malignant endometrium, and so provide a foundation to study common diseases, such as endometriosis and endometrial cancer, as well as the physiology of early gestation.</p

    Recommendation of RILEM TC 271-ASC: New accelerated test procedure for the assessment of resistance of natural stone and fired-clay brick units against salt crystallization

    Get PDF
    This recommendation is devoted to testing the resistance of natural stone and fired-clay brick units against salt crystallization. The procedure was developed by the RILEM TC 271-ASC to evaluate the durability of porous building materials against salt crystallization through a laboratory method that allows for accelerated testing without compromising the reliability of the results. The new procedure is designed to replicate salt damage caused by crystallization near the surface of materials as a result of capillary transport and evaporation. A new approach is proposed that considers the presence of two stages in the salt crystallization test. In the first, the accumulation stage, salts gradually accumulate on or near the surface of the material due to evaporation. In the second, the propagation stage, damage initiates and develops due to changes in moisture content and relative humidity that trigger salt dissolution and crystallization cycles. To achieve this, two types of salt were tested, namely sodium chloride and sodium sulphate, with each salt tested separately. A methodology for assessing the salt-induced damage is proposed, which includes visual and photographical observations and measurement of material loss. The procedure has been preliminarily validated in round robin tests

    Chromophores in Photomorphogenesis

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    MULTILINE MODEL FOR THE E-BEAM PUMPED XeF(B-X) LASER

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