Induced BVOC emissions from pyrolyzed plants that may accumulate in confined topographies have been a controversy for their role in wildfire eruptions or flashovers. α-pinene (C<sub>10</sub>H<sub>16...Induced BVOC emissions from pyrolyzed plants that may accumulate in confined topographies have been a controversy for their role in wildfire eruptions or flashovers. α-pinene (C<sub>10</sub>H<sub>16</sub>) is one of the most abundant monoterpenes emitted from pyrolyzed Mediterranean vegetation in wildfires. Its thermal degradation under fire thermal stresses produces a range of highly flammable gases. In order to identify these products, thermal degradation experiments were performed on α-pinene in a tubular furnace in an inert atmosphere and a high-temperature range (300°C - 900°C). The pyrolysis products were identified using gas chromatography (GC) linked to a tubular furnace outlet by which their retention times were compared with those of reference standards. The degradation products were mainly terpenoids, aliphatic hydrocarbons (methane, ethane, ethene, propane, propene, 1,3-butadiene, isoprene), and aromatics (benzene, toluene) in addition to hydrogen. The radical mechanisms of the chemical reactions associated with the formation of the products at different experimental temperatures were addressed and compared with the literature. Monoterpenes, butadiene, isoprene, aliphatic hydrocarbons, and aromatics formations from α-pinene were consistent with the literature. However, even if benzene has been identified in our experiments, we cannot support with certainty the mechanisms of its formation described in the literature since acetylene was not observed.展开更多
目的探讨孕中期合并胎盘前置状态患者采用利凡诺引产的临床效果。方法选取我院2010年1月至2015年12月孕中期合并胎盘前置状态进行利凡诺引产患者16例作为观察组,同期胎盘位置正常引产患者22例作为对照组,比较2组患者产程时间、产后24 h...目的探讨孕中期合并胎盘前置状态患者采用利凡诺引产的临床效果。方法选取我院2010年1月至2015年12月孕中期合并胎盘前置状态进行利凡诺引产患者16例作为观察组,同期胎盘位置正常引产患者22例作为对照组,比较2组患者产程时间、产后24 h出血量、一次引产成功率、大出血需剖宫取胎及术后感染等探讨利凡诺引产的临床效果。结果观察组患者的引产成功率、产程时间、大出血需剖宫取胎与对照组比较,差异无统计学意义(P>0.05);产时及产后出血量多于对照组,差异有统计学意义(P<0.05),但小于500 m L,未明显增加患者相关风险。结论孕中期胎盘前置状态行利凡诺引产安全、有效,副作用少、创伤小,是孕中期胎盘前置状态患者首选的引产方法。展开更多
文摘Induced BVOC emissions from pyrolyzed plants that may accumulate in confined topographies have been a controversy for their role in wildfire eruptions or flashovers. α-pinene (C<sub>10</sub>H<sub>16</sub>) is one of the most abundant monoterpenes emitted from pyrolyzed Mediterranean vegetation in wildfires. Its thermal degradation under fire thermal stresses produces a range of highly flammable gases. In order to identify these products, thermal degradation experiments were performed on α-pinene in a tubular furnace in an inert atmosphere and a high-temperature range (300°C - 900°C). The pyrolysis products were identified using gas chromatography (GC) linked to a tubular furnace outlet by which their retention times were compared with those of reference standards. The degradation products were mainly terpenoids, aliphatic hydrocarbons (methane, ethane, ethene, propane, propene, 1,3-butadiene, isoprene), and aromatics (benzene, toluene) in addition to hydrogen. The radical mechanisms of the chemical reactions associated with the formation of the products at different experimental temperatures were addressed and compared with the literature. Monoterpenes, butadiene, isoprene, aliphatic hydrocarbons, and aromatics formations from α-pinene were consistent with the literature. However, even if benzene has been identified in our experiments, we cannot support with certainty the mechanisms of its formation described in the literature since acetylene was not observed.
文摘目的探讨孕中期合并胎盘前置状态患者采用利凡诺引产的临床效果。方法选取我院2010年1月至2015年12月孕中期合并胎盘前置状态进行利凡诺引产患者16例作为观察组,同期胎盘位置正常引产患者22例作为对照组,比较2组患者产程时间、产后24 h出血量、一次引产成功率、大出血需剖宫取胎及术后感染等探讨利凡诺引产的临床效果。结果观察组患者的引产成功率、产程时间、大出血需剖宫取胎与对照组比较,差异无统计学意义(P>0.05);产时及产后出血量多于对照组,差异有统计学意义(P<0.05),但小于500 m L,未明显增加患者相关风险。结论孕中期胎盘前置状态行利凡诺引产安全、有效,副作用少、创伤小,是孕中期胎盘前置状态患者首选的引产方法。
