The Experts below are selected from a list of 91560 Experts worldwide ranked by ideXlab platform
Julang Li - One of the best experts on this subject based on the ideXlab platform.
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protective effects of protegrin in dextran Sodium Sulfate induced murine colitis
Frontiers in Pharmacology, 2019Co-Authors: Evanna Huynh, Julang Li, Jenna Penney, Jeff L CaswellAbstract:Cathelicidins, a class of antimicrobial peptides, have been widely studied for their antimicrobial role in innate immune responses during infection and inflammation. At sub-antimicrobial concentrations, various cathelicidins from different species have been reported to exert chemotactic activity on neutrophils, monocytes, dendritic cells and T-cells, and also enhance angiogenesis and wound healing. To date, the role of the pig cathelicidin, protegrin-1 (PG-1), in immune modulation and tissue repair in the intestinal tract has not been investigated. The aim of the present study was to examine the potential protective effects of recombinant PG-1 in a mouse dextran Sulfate Sodium (DSS)-induced colitis inflammation model. This is the first report showing the protective effects of PG-1 in its various forms (pro-, cathelin-, and mature- form) in attenuating significant body weight loss associated with DSS-induced colitis (p<0.05). PG-1 treatment improved histological scores (P<0.05) and influenced the gene expression of inflammatory mediators and tissue repair factors such as trefoil factor (TFF3) and mucin (MUC-2). Protegrin treatment also altered the metabolite profile, returning the metabolite levels back closer to untreated control levels. These findings lay the foundation for future oral application of recombinant PG-1 to potentially treat intestinal damage and inflammation.
Yulong Ding - One of the best experts on this subject based on the ideXlab platform.
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Sodium Sulfate diatomite composite materials for high temperature thermal energy storage
Powder Technology, 2015Co-Authors: Guanghui Leng, Hui Cao, Geng Qiao, Yunfeng Dai, Yelong Zhang, Yulong DingAbstract:This work explores the use of Sodium Sulfate and diatomite to formulate composite materials for high temperature thermal energy storage applications. Sodium Sulfate in the composite functions as a phase change material (PCM) and diatomite as a structural skeleton for shape stabilization. It is found that Sodium Sulfate and diatomite have an excellent chemical compatibility with the PCM melting temperature at around 880 degrees C It is shown that the composite containing 45% diatomite gives an optimal formulation in terms of energy density, salt leakage and mechanical strength. The results also suggest that the composite with the optimal formulation has an application window of 890-980 degrees C Failures occur to the composite materials at temperatures above 1000 degrees C. (C) 2014 Elsevier B.V. All rights reserved.
R N Swamy - One of the best experts on this subject based on the ideXlab platform.
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Sulfate attack and role of silica fume in resisting strength loss
Cement & Concrete Composites, 2005Co-Authors: S T Lee, H Y Moo, R N SwamyAbstract:Abstract This paper presents a detailed experimental study on the Sulfate attack of Portland cement mortars, and the effectiveness of silica fume in controlling the damage arising from such attack. The test solutions used to supply the Sulfate ions and cations were 5% Sodium Sulfate solution and 5% magnesium Sulfate solution. Tap water was used as the reference solution. The main variables investigated in the study were the water/cementitious materials ratio, and the level of cement replacement. Compressive strength measured on 50 mm cubes was used to assess the changes in the mechanical properties of mortar specimens exposed to Sulfate attack for 510 days. X-ray diffraction and differential scanning calorimetry were used to evaluate the microstructural nature of the Sulfate attack. The test results showed that the presence of silica fume had a beneficial effect on the strength loss due to Sodium Sulfate attack. The best resistance to Sodium Sulfate attack was obtained with a SF replacement of 5–10%, but even then, a strength loss of 15–20% can be expected. On the other hand, mortars with silica fume were severely damaged in the magnesium Sulfate environment. Further, the compressive strength loss actually increased with increasing SF content. The test results thus showed clearly that the use of SF in concrete exposed to magnesium Sulfate solution is not recommended. The test results also showed that the w/cm ratio is the most critical parameter influencing the resistance of concrete to Sulfate attack. All the tests reported in the study were carried out at 20 ± 1 °C.
Mohammed K Ibrahim - One of the best experts on this subject based on the ideXlab platform.
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Sulfate resistance of plain and blended cements exposed to varying concentrations of Sodium Sulfate
Cement & Concrete Composites, 2003Co-Authors: Salah U Aldulaija, Mohammed Maslehuddi, M M Alzahrani, A M Sharif, M Shameem, Mohammed K IbrahimAbstract:Concrete deterioration due to Sulfate attack is the second major durability problem, after reinforcement corrosion. This type of deterioration is noted in the structures exposed to Sulfate-bearing soils and groundwater. Though concrete deterioration due to Sulfate attack is reported from many countries, the mechanisms of Sulfate attack have not been thoroughly investigated, particularly the effect of Sulfate concentration and the cation type associated with the Sulfate ions on concrete deterioration. This study was conducted to evaluate the performance of plain and blended cements exposed to varying concentrations of Sodium Sulfate for up to 24 months. Four types of cements, namely Type I, Type V, Type I plus silica fume and Type I plus fly ash, were exposed to five Sodium Sulfate solutions with Sulfate concentrations of 1%, 1.5%, 2%, 2.5% and 4%. These concentrations are representative of the Sulfate concentration in highly saline soils. The Sulfate resistance was evaluated by visual examination and measuring the and reduction in compressive strength. The maximum deterioration, due to Sulfate attack, was noted in Type I cement followed by silica fume and Type V cements. The performance of Type V, Type I plus silica fume and Type I plus fly ash was not significantly different from each other. The enhanced Sulfate resistance noted in the Type I cement blended with either silica fume or fly ash indicates the usefulness of these cements in both Sulfate and Sulfate plus chloride environments.
Nabi Yuzer - One of the best experts on this subject based on the ideXlab platform.
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effects of magnesium Sulfate concentration on the Sulfate resistance of mortars with and without silica fume
Cement and Concrete Research, 1995Co-Authors: Fikret Turker, Fevziye Akoz, Sema Koral, Nabi YuzerAbstract:Abstract An investigation was carried out on the effect of Sodium Sulfate concentration on the Sulfate resistance of mortars. Experiments were carried out on the RILEM portland cement standard mortars and portland cement-silica fume mortars. Sulfate exposure of mortars were initiated after 28 days of lime saturated water curing. Some physical and mechanical properties were determined periodically up to 300 days of exposure. Low concentrations of Sodium Sulfate not exceeding 18000 mg/L had not any significant effect on the compressive and flexural strength of mortars. However, at a concentration of 18000 mg/L some of the properties i.e. volume density, volumetric water absorption, indicated beginning of rapid deterioration of mortar structure at an exposure time which could be called critical time. Concentration of 72000 mg/L caused sharp strength reduction between 90 and 180 days for both compressive and flexural strengths. Silica fume replacement caused significant increase in Sulfate resistance of mortar even at highest Sulfate concentration.