Functionalized organozinc reagents can easily under 1, 4-addition reaction withunsaturated esters in the presence of catalytic amount of Ni (acac)_2 and tertiary ammes under verymild conditions to give the products in...Functionalized organozinc reagents can easily under 1, 4-addition reaction withunsaturated esters in the presence of catalytic amount of Ni (acac)_2 and tertiary ammes under verymild conditions to give the products in excellent yields.展开更多
Lipophilic complexes of macrocyclic 12-membered dioxotetraamine ligand bearing bis-hydroxy groups as functional pendants are effective catalysts for the hydrolysis of amino acid esters in micellar media, and the rate ...Lipophilic complexes of macrocyclic 12-membered dioxotetraamine ligand bearing bis-hydroxy groups as functional pendants are effective catalysts for the hydrolysis of amino acid esters in micellar media, and the rate enhancement of more than 10-fold were observed.展开更多
The main objective is to study the role or nitric oxide (NO) in small Intestinal migratingmotor complex (MMC). Rats were implanted with strain gauges in the duobenum and jejunum forrecording the motor action of the sm...The main objective is to study the role or nitric oxide (NO) in small Intestinal migratingmotor complex (MMC). Rats were implanted with strain gauges in the duobenum and jejunum forrecording the motor action of the small intestine in fasting and red states arter intravenous infusionof N'-nitro-L-arginine methyl ester (L-NAME ), L-arginin., D-arglnine, sodium nitropusside(NaNP) and angiotensin 1 respectively. The results showed that intravenous inrusion or L-NAME,a NO synthase inhibitor, induced a fasting-like MMC motor pattern in fed rats. Infusion of NaNP, aNO donor, disrupted small intestinal MMC in fasting rats, inducing a postprandial-like motor pattern. Both fasting and postprandial, infusion of L-NAME shortened the duration or Phase I andphase Ⅱ,but didn't chang. the duration, frequency, amplitude and s,eed or Propogatiou of thephaSe, Ⅲ-argining, not D-arginine infused together with L-NAME, prevented the effect of LNAME infusion. Infusion of L-arginine, D-arginine or angioteusin Ⅰ alone didn't modify the smallintestinal motor pattern. It suggests that an inhibition of NO synthesis may be involved in the initiation of the MMC motor pattern during fasting, whereas an increase of NO output relates to the occurrence of the fed motor pattern展开更多
对不同类型复杂基质样品中邻苯二甲酸酯（PAEs）测定的前处理方法进行了研究。待测样品类型包括沉积物、土壤、悬浮颗粒物、地表灰尘、生物组织、化妆品、皮革、塑料以及近岸/河口海水等复杂基质样品。这些样品中PAEs 测定的最常用方法...对不同类型复杂基质样品中邻苯二甲酸酯（PAEs）测定的前处理方法进行了研究。待测样品类型包括沉积物、土壤、悬浮颗粒物、地表灰尘、生物组织、化妆品、皮革、塑料以及近岸/河口海水等复杂基质样品。这些样品中PAEs 测定的最常用方法为气相色谱-质谱法（GC-MS），针对该测定方法所需的样品前处理研究集中于待测 PAEs的萃取、净化等步骤操作条件的确定。对各种样品基质前处理方法的研究结果表明，二氯甲烷是进行固液萃取时最佳的超声振荡提取溶剂；而对各种复杂基质样品的净化，硅胶则是经济、实用的固相萃取填料；C18是最常用的近岸/河口海水样品中PAEs的预富集填料；一定比例的正己烷与乙酸乙酯混合溶液是适宜的固相萃取洗脱液。优化实验条件下，各种样品基质中 PAEs 的加标回收率高于58％，方法相对标准偏差（RSD）小于10.5％（ n =6）；方法对沉积物样品中 PAEs 的检出限（DL，3σ）最低，在0.3μg / kg（邻苯二甲酸二丁酯）-5.2μg / kg（邻苯二甲酸二异壬酯）之间；对近岸/河口海水样品的检出限（DL，3σ）在6 ng / L（邻苯二甲酸二丙酯）-67 ng / L（邻苯二甲酸二异癸酯）之间，能满足上述各类复杂基质样品中16种 PAEs 测定的需要。展开更多
文摘Functionalized organozinc reagents can easily under 1, 4-addition reaction withunsaturated esters in the presence of catalytic amount of Ni (acac)_2 and tertiary ammes under verymild conditions to give the products in excellent yields.
文摘Lipophilic complexes of macrocyclic 12-membered dioxotetraamine ligand bearing bis-hydroxy groups as functional pendants are effective catalysts for the hydrolysis of amino acid esters in micellar media, and the rate enhancement of more than 10-fold were observed.
文摘The main objective is to study the role or nitric oxide (NO) in small Intestinal migratingmotor complex (MMC). Rats were implanted with strain gauges in the duobenum and jejunum forrecording the motor action of the small intestine in fasting and red states arter intravenous infusionof N'-nitro-L-arginine methyl ester (L-NAME ), L-arginin., D-arglnine, sodium nitropusside(NaNP) and angiotensin 1 respectively. The results showed that intravenous inrusion or L-NAME,a NO synthase inhibitor, induced a fasting-like MMC motor pattern in fed rats. Infusion of NaNP, aNO donor, disrupted small intestinal MMC in fasting rats, inducing a postprandial-like motor pattern. Both fasting and postprandial, infusion of L-NAME shortened the duration or Phase I andphase Ⅱ,but didn't chang. the duration, frequency, amplitude and s,eed or Propogatiou of thephaSe, Ⅲ-argining, not D-arginine infused together with L-NAME, prevented the effect of LNAME infusion. Infusion of L-arginine, D-arginine or angioteusin Ⅰ alone didn't modify the smallintestinal motor pattern. It suggests that an inhibition of NO synthesis may be involved in the initiation of the MMC motor pattern during fasting, whereas an increase of NO output relates to the occurrence of the fed motor pattern
文摘对不同类型复杂基质样品中邻苯二甲酸酯（PAEs）测定的前处理方法进行了研究。待测样品类型包括沉积物、土壤、悬浮颗粒物、地表灰尘、生物组织、化妆品、皮革、塑料以及近岸/河口海水等复杂基质样品。这些样品中PAEs 测定的最常用方法为气相色谱-质谱法（GC-MS），针对该测定方法所需的样品前处理研究集中于待测 PAEs的萃取、净化等步骤操作条件的确定。对各种样品基质前处理方法的研究结果表明，二氯甲烷是进行固液萃取时最佳的超声振荡提取溶剂；而对各种复杂基质样品的净化，硅胶则是经济、实用的固相萃取填料；C18是最常用的近岸/河口海水样品中PAEs的预富集填料；一定比例的正己烷与乙酸乙酯混合溶液是适宜的固相萃取洗脱液。优化实验条件下，各种样品基质中 PAEs 的加标回收率高于58％，方法相对标准偏差（RSD）小于10.5％（ n =6）；方法对沉积物样品中 PAEs 的检出限（DL，3σ）最低，在0.3μg / kg（邻苯二甲酸二丁酯）-5.2μg / kg（邻苯二甲酸二异壬酯）之间；对近岸/河口海水样品的检出限（DL，3σ）在6 ng / L（邻苯二甲酸二丙酯）-67 ng / L（邻苯二甲酸二异癸酯）之间，能满足上述各类复杂基质样品中16种 PAEs 测定的需要。
