固相萃取-HPLC快速测定血清中烟酸及其代谢产物

建立血清中烟酸(NA)、烟酰胺(NM)及其代谢产物N'-甲基尼克酰胺(NMN)、2-吡啶酮(2Py)的测定方法.采用高效液相色谱法(HPLC),以氨基固相柱萃取样品,0.04mol/L KH2PO4提取洗脱,同时测定血清中NMN、NA、2Py、NM的含量.校准曲线线性范围为0.5-30μg/mL,r≥0.9986.检出...     

聚焦核心素养的新型作业——“烃的衍生物”课外作业的设计和研究

从研究对象、问题情境、学科认识、学科能力等4方面聚焦核心素养,确立化学作业设计的目标,编制具有基础性、情境性、开放性、分层性、实践性的化学课外作业。现以“烃的衍生物”的课外作业设计为例,按“感知生活、类比结构、迁移应用、实验探究、情境实践”等5个水平维度进行设计,突出作业的素养培养功能。     

人原发性肝癌中N-ras基因的表达

对9例人原发性肝癌,1例癌旁组织,1例正常肝的poly(A)~ RNA进行了分析。用各种癌基因探针作分子杂交,发现在6例原发性肝癌中,有二条增强表达的区带:2.2kb和5.6kb。肝癌组织较正常肝的mRNA在2.2kb处有明显的增强。提示人N-ras基因的转录产物明显增高。癌旁,正常肝中N-ras基因的专一的mRNA很弱或低于检测水平。由于癌的发生是通过癌基因产物发生作用,因此N-ras基因在多数的人原发性肝癌中的表达明显增强,提示了N-ras基因是人原发性肝癌的重要转化基因之一。     

EXPRESSION OF N-ras GENE IN HUMAN PRIMARY HEPATOCARCINOMA

Poly(A)~+ RNA was isolated from 9 specimens of human primary hepatic carcinoma, 1 non-tumorous liver tissue adjacent to cancer and 1 normal liver tissue samples. The Oligo-dT cellulose-purified poly(A)~+ RNAs were subjected to formaldehyde agarose gel electrophoresis, Northern transfer and hybridization with various ancogene probes. Two RNA species, 5.6 kb and 2.2 kb wore identified by N-ras gone hybridization in 6 out of 9 mRNA samples from primary hepatic carcinoma specimen. N-ras specific mRNA was not detectable in mRNA samples from normal human liver and tumor surrounding cirrhotic tissue. No detectable hybridization of mRNA from hepatoma and normal liver with Ki-ras or Ha-ras was observed.As human N-ras gene has been identified in DNA of mouse transfeetants transformed with PHC DNA, it strongly suggests that N-ras gene might be responsible for the transforming activity of part of cases of human liver cancer.