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硫酸雌酮浓度作为妊娠马胎儿死亡的一项指标
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作者 lonnie 朱璧科 《国外兽医学(畜禽疾病)》 CSCD 1989年第3期26-28,共3页
测定了用PGF_(2a)引产(n=4)和手术摘除胎儿(n=3)前后的7匹母马血清和尿中硫酸雌酮浓度,以确定早孕雌激素来源[妊娠天数(GD)44到89天]。也测定了在妊娠51和58天之间切除卵巢的3匹母马血清硫酸雌酮浓度(冷藏2年)。硫酸雌酮浓度在胎儿排出... 测定了用PGF_(2a)引产(n=4)和手术摘除胎儿(n=3)前后的7匹母马血清和尿中硫酸雌酮浓度,以确定早孕雌激素来源[妊娠天数(GD)44到89天]。也测定了在妊娠51和58天之间切除卵巢的3匹母马血清硫酸雌酮浓度(冷藏2年)。硫酸雌酮浓度在胎儿排出后的血清和尿中降低(尿中浓度范型比血清浓度范型更明显)。而卵巢切除的母马血清硫酸雌酮浓度短暂降低。虽然早孕时硫酸雌酮部分来自卵巢,但主要来自孕体。血清和尿中硫酸雌酮的测定为妊娠44天后的母马胎儿存活提供了一种简便而准确的诊断方法。 展开更多
关键词 硫酸雌酮 胎儿 死亡 指标 妊娠
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Synthesis and Surface Tension Properties of Polyethyleneimine-Polyethylene Oxide Block Copolymers 被引量:1
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作者 张剑 lonnie Bryant 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2003年第4期460-465,共6页
This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. Thes... This paper describes the synthesis, surface tension and dispersancy properties of block copolymer nonionic surfactants comprised of polyethyleneimine (PEI) and polyethylene oxide (PEO) blocks of selected lengths. These block copolymers were prepared by a three step synthetic sequence. Firstly, PEO glycol was converted to its dimethanesulphonylester (dimesyl) derivative by reacting with methanesulphonyl chloride. Then a tri block polymer was prepared by the ring opening polymerization of 2 methyl 2 oxazoline (MeOZO) with the dimesyl PEO derivative. Lastly, linear PEI blocks were obtained by subsequent hydrolysis and purification. 1H NMR spectra confirmed the structures of the intermediate, final products and their purities (>99%). The utility of these block copolymers is described in terms of their surface tension and clay dispersancy measurements as a function of copolymer chain and block length. 展开更多
关键词 block copolymer polyethylene oxide poly^ethyle^nei^mine surface tension clay dispersancy
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