Alcohol-assisted low-temperature methanol synthesis was conducted over Cu/ZnO;catalysts while varying the copper content（X）. Unlike conventional methanol synthesis, ethanol acted as both solvent and reaction interme...Alcohol-assisted low-temperature methanol synthesis was conducted over Cu/ZnO;catalysts while varying the copper content（X）. Unlike conventional methanol synthesis, ethanol acted as both solvent and reaction intermediate in this reaction, creating a different reaction pathway. The formation of crystalline phases and characteristic morphology of the co-precipitated precursors during the co-precipitation step were important factors in obtaining an efficient Cu/ZnO catalyst with a high dispersion of metallic copper,which is one of the main active sites for methanol synthesis. The acidic properties of the Cu/ZnO catalyst were also revealed as important factors, since alcohol esterification is considered the rate-limiting step in alcohol-assisted low-temperature methanol synthesis. As a consequence, bifunctionality of the Cu/ZnO catalyst such as metallic copper and acidic properties was required for this reaction. In this respect, the copper content（X） strongly affected the catalytic activity of the Cu/ZnO;catalysts, and accordingly, the Cu/ZnO;.5 catalyst with a high copper dispersion and sufficient acid sites exhibited the best catalytic performance in this reaction.展开更多
Non-alcoholic fatty liver disease(NAFLD)and irritable bowel syndrome(IBS)are two very common diseases in the general population.To date,there are no studies that highlight a direct link between NAFLD and IBS,but some ...Non-alcoholic fatty liver disease(NAFLD)and irritable bowel syndrome(IBS)are two very common diseases in the general population.To date,there are no studies that highlight a direct link between NAFLD and IBS,but some recent reports have found an interesting correlation between obesity and IBS.A systematic PubMed database search was conducted highlighting that common mechanisms are involved in many of the local and systemic manifestations of NAFLD,leading to an increased cardiovascular risk,and IBS,leading to microbial dysbiosis,impaired intestinal barrier and altered intestinal motility.It is not known when considering local and systemic inflammation/immune system activation,which one has greater importance in NAFLD and IBS pathogenesis.Also,the nervous system is implicated.In fact,inflammation participates in the development of mood disorders,such as anxiety and depression,characteristics of obesity and consequently of NAFLD and,on the other hand,in intestinal hypersensitivity and dysmotility.展开更多
Liver is an essential organ that maintains fasting and postprandial blood glucose response via various metabolic pathways. The liver function gradually deteriorates in chronic liver disease (CLD) due to inflammation a...Liver is an essential organ that maintains fasting and postprandial blood glucose response via various metabolic pathways. The liver function gradually deteriorates in chronic liver disease (CLD) due to inflammation and destruction of liver parenchyma. The development of glucose intolerance and hepatogenous diabetes (HD) in patients with CLD is an inevitable event. Diabetes and CLD can coexist, and function synergistically to cause unfavorable clinical consequences, including poor treatment outcomes and frequent hospitalization. The complications associated with liver disease (malnutrition, hypoglycemia, acute kidney injury, lactic acidosis, etc.) and lack of guidelines limit pharmacological management of HD. Dietary recommendations by The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines (2019), suggested weight reducing hypocaloric diet along with adequate branched-chain amino acid (BCAA) and micronutrient consumption to improve steatosis and insulin sensitivity in patients with CLD. Dietary glycemic index controls prognosis of obesity, non-alcoholic fatty liver disease (NAFLD) and diabetes. The importance of low GI diet in reducing fasting blood glucose, hepatic glucose influx and fat accumulation, thereby improving weight loss and NAFLD score, is being published in patients with diabetes or liver disease. Several countries have already incorporated GI into their national health policies, for identification of the nutrient value, resulting in establishment of worldwide GI and glycemic load tables for specific food items. However, the apparent complexity of GI and lack of low GI meal choices need to be resolved in order to enhance patient’s quality of life, health and well-being. Low GI nutritional supplements, comprising of balanced proportion of carbohydrate, protein, BCAAs, fibers and micronutrients, may reduce the complexity related to dietary management of HD. The review summarizes the importance of nutritional management in HD with focus on low GI diet in people with CLD.展开更多
In recent years, the development and application of high performance fiber reinforced concrete or cementitious composites are increasing due to their high ductility and energy absorption characteristics. However, it i...In recent years, the development and application of high performance fiber reinforced concrete or cementitious composites are increasing due to their high ductility and energy absorption characteristics. However, it is difficult to obtain the required properties of the FRCC by simply adding fiber to the concrete matrix. Many researchers are paying attention to fiber reinforced polymers (FRP) for the reinforcement of construction structures because of their significant advantages over high strain rates. However, the actual FRP products are skill-dependent, and the quality may not be uniform. Therefore, in this study, two-way punching tests were carried out to evaluate the performances of FRP strengthened and steel and polyvinyl alcohol (PVA) fiber reinforced concrete specimens for impact and static loads. The FRP reinforced normal concrete (NC), steel fiber reinforced concrete (SFRC), and PVA FRCC specimens showed twice the amount of enhanced dissipated energy (total energy) under impact loadings than the non-retrofitted specimens. In the low-velocity impact test of the two-way NC specimens strengthened by FRPs, the total dissipated energy increased by 4 to 5 times greater than the plain NC series. For the two-way specimens, the total energy increased by 217% between the non-retrofitted SFRC and NC specimens. The total dissipated energy of the CFRP retrofitted SFRC was twice greater than that of the plain SFRC series. The PVA FRCC specimens showed 4 times greater dissipated energy than for the energy of the plain NC specimens. For the penetration of two-way specimens with fibers, the Hughes formula considering the tensile strength of concrete was a better predictor than other empirical formulae.展开更多
基金supported by C1 Gas Refinery Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science,ICT & Future Planning (2015M3D3A1A01064908)
文摘Alcohol-assisted low-temperature methanol synthesis was conducted over Cu/ZnO;catalysts while varying the copper content（X）. Unlike conventional methanol synthesis, ethanol acted as both solvent and reaction intermediate in this reaction, creating a different reaction pathway. The formation of crystalline phases and characteristic morphology of the co-precipitated precursors during the co-precipitation step were important factors in obtaining an efficient Cu/ZnO catalyst with a high dispersion of metallic copper,which is one of the main active sites for methanol synthesis. The acidic properties of the Cu/ZnO catalyst were also revealed as important factors, since alcohol esterification is considered the rate-limiting step in alcohol-assisted low-temperature methanol synthesis. As a consequence, bifunctionality of the Cu/ZnO catalyst such as metallic copper and acidic properties was required for this reaction. In this respect, the copper content（X） strongly affected the catalytic activity of the Cu/ZnO;catalysts, and accordingly, the Cu/ZnO;.5 catalyst with a high copper dispersion and sufficient acid sites exhibited the best catalytic performance in this reaction.
文摘Non-alcoholic fatty liver disease(NAFLD)and irritable bowel syndrome(IBS)are two very common diseases in the general population.To date,there are no studies that highlight a direct link between NAFLD and IBS,but some recent reports have found an interesting correlation between obesity and IBS.A systematic PubMed database search was conducted highlighting that common mechanisms are involved in many of the local and systemic manifestations of NAFLD,leading to an increased cardiovascular risk,and IBS,leading to microbial dysbiosis,impaired intestinal barrier and altered intestinal motility.It is not known when considering local and systemic inflammation/immune system activation,which one has greater importance in NAFLD and IBS pathogenesis.Also,the nervous system is implicated.In fact,inflammation participates in the development of mood disorders,such as anxiety and depression,characteristics of obesity and consequently of NAFLD and,on the other hand,in intestinal hypersensitivity and dysmotility.
文摘Liver is an essential organ that maintains fasting and postprandial blood glucose response via various metabolic pathways. The liver function gradually deteriorates in chronic liver disease (CLD) due to inflammation and destruction of liver parenchyma. The development of glucose intolerance and hepatogenous diabetes (HD) in patients with CLD is an inevitable event. Diabetes and CLD can coexist, and function synergistically to cause unfavorable clinical consequences, including poor treatment outcomes and frequent hospitalization. The complications associated with liver disease (malnutrition, hypoglycemia, acute kidney injury, lactic acidosis, etc.) and lack of guidelines limit pharmacological management of HD. Dietary recommendations by The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines (2019), suggested weight reducing hypocaloric diet along with adequate branched-chain amino acid (BCAA) and micronutrient consumption to improve steatosis and insulin sensitivity in patients with CLD. Dietary glycemic index controls prognosis of obesity, non-alcoholic fatty liver disease (NAFLD) and diabetes. The importance of low GI diet in reducing fasting blood glucose, hepatic glucose influx and fat accumulation, thereby improving weight loss and NAFLD score, is being published in patients with diabetes or liver disease. Several countries have already incorporated GI into their national health policies, for identification of the nutrient value, resulting in establishment of worldwide GI and glycemic load tables for specific food items. However, the apparent complexity of GI and lack of low GI meal choices need to be resolved in order to enhance patient’s quality of life, health and well-being. Low GI nutritional supplements, comprising of balanced proportion of carbohydrate, protein, BCAAs, fibers and micronutrients, may reduce the complexity related to dietary management of HD. The review summarizes the importance of nutritional management in HD with focus on low GI diet in people with CLD.
文摘In recent years, the development and application of high performance fiber reinforced concrete or cementitious composites are increasing due to their high ductility and energy absorption characteristics. However, it is difficult to obtain the required properties of the FRCC by simply adding fiber to the concrete matrix. Many researchers are paying attention to fiber reinforced polymers (FRP) for the reinforcement of construction structures because of their significant advantages over high strain rates. However, the actual FRP products are skill-dependent, and the quality may not be uniform. Therefore, in this study, two-way punching tests were carried out to evaluate the performances of FRP strengthened and steel and polyvinyl alcohol (PVA) fiber reinforced concrete specimens for impact and static loads. The FRP reinforced normal concrete (NC), steel fiber reinforced concrete (SFRC), and PVA FRCC specimens showed twice the amount of enhanced dissipated energy (total energy) under impact loadings than the non-retrofitted specimens. In the low-velocity impact test of the two-way NC specimens strengthened by FRPs, the total dissipated energy increased by 4 to 5 times greater than the plain NC series. For the two-way specimens, the total energy increased by 217% between the non-retrofitted SFRC and NC specimens. The total dissipated energy of the CFRP retrofitted SFRC was twice greater than that of the plain SFRC series. The PVA FRCC specimens showed 4 times greater dissipated energy than for the energy of the plain NC specimens. For the penetration of two-way specimens with fibers, the Hughes formula considering the tensile strength of concrete was a better predictor than other empirical formulae.
