The synthesis process of N-acetyl-aspartyl-glutamate (NAAG) was studied, in which L-aspartic acid was used as the raw material, and the dipeptide was first prepared by esterification,acylation and the reaction with L-...The synthesis process of N-acetyl-aspartyl-glutamate (NAAG) was studied, in which L-aspartic acid was used as the raw material, and the dipeptide was first prepared by esterification,acylation and the reaction with L-glutamic acid, and then the product NAAG was finally obtained by hydrolyzation and purification.The product and the intermediate were analyzed and identified by melting point measuring, elemental analysis, polarimeter and IR analysis.The effects of mixture ratio of raw materials, reaction temperature and reaction time were investigated.The results showed that the total yield was 50.02% when the esterification temperature was controlled at 20℃, esterification time 10 h, acylation temperature 70℃, acylation time 2 h, and DCC was used as the addition reagent to synthesize dipeptide.The hydrolization temperature was 60℃, the hydrolization time was 4 h.The product was purified by ion-exchange resin.The purity detected by HPLC was 97.5%.展开更多
目的评价磁共振多体素波谱扫描技术对颞叶癫痫的定位诊断价值。方法选择具有明显颞叶癫痫表现,并经脑电图检查定位诊断明确的单侧颞叶癫痫患者30例作为研究对象;排除M R I检查存在颅脑肿瘤、脑血管畸形等症状性癫痫患者。患者均行常规M...目的评价磁共振多体素波谱扫描技术对颞叶癫痫的定位诊断价值。方法选择具有明显颞叶癫痫表现,并经脑电图检查定位诊断明确的单侧颞叶癫痫患者30例作为研究对象;排除M R I检查存在颅脑肿瘤、脑血管畸形等症状性癫痫患者。患者均行常规M RI及双侧海马区多体素波谱扫描,完成检查后将以代谢物峰值含量为灰阶的伪彩图与倾斜冠状重度T2W I图像进行融合,测量双侧海马区N-乙酰天冬氨酸、胆碱峰值含量和胆碱/N-酰天冬氨酸比值,并直观分析双侧海马区两代谢物的分布情乙况。结果患侧N-乙酰天冬氨酸峰值含量为(13587.61±3913.99)M R units,健侧为(17683.10±5610.61)M R units,患侧低于健侧差异有显著性意义(t=6.728,P<0.001);患侧胆碱/N-乙酰天冬氨酸比值为(1.26±0.11),健侧比值为(1.01±0.14),患侧高于健侧差异亦有显著性意义(t=7.883,P<0.001)。将两代谢物含量及比值伪彩图与常规M RI图像进行融合,可直观发现双侧海马区N-乙酰天冬氨酸峰值含量及胆碱/N-酰天冬氨酸比值存在明显差异。结论磁共振多体素波谱技术不仅可以通过对某些代谢物含量乙的定量分析进行癫痫灶的定位、定侧诊断,还可通过常规M RI图像与多体素磁共振波谱图像的融合图像直观评价代谢物分布状态,描记癫痫灶的大致轮廓,为制定手术方案提供依据。展开更多
文摘The synthesis process of N-acetyl-aspartyl-glutamate (NAAG) was studied, in which L-aspartic acid was used as the raw material, and the dipeptide was first prepared by esterification,acylation and the reaction with L-glutamic acid, and then the product NAAG was finally obtained by hydrolyzation and purification.The product and the intermediate were analyzed and identified by melting point measuring, elemental analysis, polarimeter and IR analysis.The effects of mixture ratio of raw materials, reaction temperature and reaction time were investigated.The results showed that the total yield was 50.02% when the esterification temperature was controlled at 20℃, esterification time 10 h, acylation temperature 70℃, acylation time 2 h, and DCC was used as the addition reagent to synthesize dipeptide.The hydrolization temperature was 60℃, the hydrolization time was 4 h.The product was purified by ion-exchange resin.The purity detected by HPLC was 97.5%.
文摘目的评价磁共振多体素波谱扫描技术对颞叶癫痫的定位诊断价值。方法选择具有明显颞叶癫痫表现,并经脑电图检查定位诊断明确的单侧颞叶癫痫患者30例作为研究对象;排除M R I检查存在颅脑肿瘤、脑血管畸形等症状性癫痫患者。患者均行常规M RI及双侧海马区多体素波谱扫描,完成检查后将以代谢物峰值含量为灰阶的伪彩图与倾斜冠状重度T2W I图像进行融合,测量双侧海马区N-乙酰天冬氨酸、胆碱峰值含量和胆碱/N-酰天冬氨酸比值,并直观分析双侧海马区两代谢物的分布情乙况。结果患侧N-乙酰天冬氨酸峰值含量为(13587.61±3913.99)M R units,健侧为(17683.10±5610.61)M R units,患侧低于健侧差异有显著性意义(t=6.728,P<0.001);患侧胆碱/N-乙酰天冬氨酸比值为(1.26±0.11),健侧比值为(1.01±0.14),患侧高于健侧差异亦有显著性意义(t=7.883,P<0.001)。将两代谢物含量及比值伪彩图与常规M RI图像进行融合,可直观发现双侧海马区N-乙酰天冬氨酸峰值含量及胆碱/N-酰天冬氨酸比值存在明显差异。结论磁共振多体素波谱技术不仅可以通过对某些代谢物含量乙的定量分析进行癫痫灶的定位、定侧诊断,还可通过常规M RI图像与多体素磁共振波谱图像的融合图像直观评价代谢物分布状态,描记癫痫灶的大致轮廓,为制定手术方案提供依据。
