迷失的世界(20)

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CD20F(ab'''')2抗体的发酵与纯化

转化了质粒PYZcpp^3的16C9大肠杆菌可高水平地分泌表达可溶性CD20 F(ab’)2抗体;采用经优化的培养条件,在发酵罐上进行高密度培养OD550值达140;每升湿菌菌重200g;抗体的产量每升为241mg,其中F(ab’)2片段达50％,F(ab‘)2可以特异性的识别CD20^ 细胞并与CD20相结合;F(ab‘)2对Raji细胞的IC50值为22.8μg／mL;而Fab’对Raji细胞的IC50值为45．9μg／mL。     

Novel taxa-4(20),12-diene and 2(3→20)abeotaxane from needles of Taxus canadensis

A novel 6/8/6-membered taxane with a rare C-12(13)-double bond and rare 2(3→20)abeotaxane were isolated from the needles of Taxus canadensis. Their structures were characterized as 7β,9α,10β-triacetoxytaxa-4(20),12-diene-2α,5α,11β-triol (1) and 2α,7β,10β-triacetoxy-5α-hydroxy-2(3→20)abeotaxa-4(20),11-diene-9,13-dione (2) on the basis of 1D and 2D spectroscopic data. 1 is the first example of a natural taxane without substitution at both C-13 and C-14.     

每期20题(初中用)

1.螂鱼的消化系统中,不与食物接触的器官是 )。A.肠B.食管c.气管D.肝胰脏2.有关鱼类特征的描述哪项正确()。A.心脏二腔,二腔中都为动脉血B.附月支骨与脊柱不相连C.软骨鱼的鳃有鳃盖保护D.唾液腺发达,与水生习性有关3.「列在一生的某时期里形成脊索的动物是 A. 4.位是( A. I今 C. D.海胆B.章鱼c.鸽子D义昌鱼在显微镜卜观察活金负尾部毛细血管,最好的部有血液流动的小血管血液流动尾部的血管红细胞成单行通过的血管血液;友向头部的血管卜列不属一f同一门的动物是()。大麻哈鱼B.海琢C.马面纯D.海参大多数海产鱼类不能在淡水中生存,因为…     

Novel Taxa-4(20),12-diene and 2(3→20)Abeotaxane from Needles of Taxus canadensis

A novel 6/8/6-membered taxane with a rare C-12(13)-double bond and rare 2(3→20)abeotaxane were isolated from the needles of Taxus canadensis. Their structures were characterized as 7β,9α,10β-triacetoxytaxa-4(20),12-diene-2α,5α,11β-triol (1) and 2α,7β,10β-triacetoxy-5α-hydroxy-2(3→20)abeotaxa-4(20),11-diene-9,13-dione (2) on the basis of 1D and 2D spectroscopic data. 1 is the first example of a natural taxane without substitution at both C-13 and C-14.     

每期20题(高中用)

1.预防小儿麻痹症的糖丸(疫苗),必须在一定的较低温度下保存。其原因是()。 A.防止环境污染,以免病菌随疫苗服入 B.防止蛋白质变性,以免疫苗死亡失效 c.防止疫苗大量繁殖,以免服入剂量失控 D.防止蛋白质脱水分解,以免疫苗溶解失效2.与植物体中的豆固醇属于同类的物质是(). A.纤维素B.胰岛素C.叶绿素.D.性激素3.人和动物乳汁中特有的二精水解后产物是()。 A一分子葡萄糖和一分子果精 B一分子果糖和一分子半乳糖 C一分子半乳糖和一分子葡萄搪 D.二分子葡萄糖4.以下四种物质中,能构成蛋白质的物质是()。N。:_止_达一(。H {!CH之SH }NH:…