浅谈西文图书的主要检索点及其著录

介绍了ISBN(国际标准书号)检索点、责任者检索点、题名检索点、主题词检索点和分类号检索点。     

Effects of Genistein on Cell Cycle and Apoptosis of Two Murine Melanoma Cell Lines

The effects of genistein on several tumor cell lines were investigated to study the effects of gen- istein on cell growth, cell cycle, and apoptosis of two murine melanoma cell lines, B16 and K1735M2. These two closely related murine melanoma cell lines, however, have different responses to the genistein treat- ment. Genistein inhibits the growth of both the B16 and K1735M2 cell lines and arrests the growth at the G2/M phase. After treatment with 60 μmol/L genistein for 72 h, apoptosis and caspase activities were de- tected in B16 cells, while such effects were not found in K1735M2. Further tests showed that after genistein treatment the protein content and mRNA levels of p53 increased in B16, but remained the same in K1735M2. The protein content and mRNA levels of p21WAF1/CIP1 increased in both cell lines after treatment. The results show that genistein might induce apoptosis in B16 cells by damaging the DNA, inhibiting topoi- somerase II, increasing p53 expression, releasing cytochrome c from the mitochondria, and activating the caspases which will lead to apoptosis.     

LF21铝合金薄板搅拌摩擦焊组织与性能

采用搅拌摩擦焊方法对厚度为1.4 mm的LF21铝合金薄板进行单道对接焊实验。实验结果表明:在旋转速度为1 500 r/min,焊接速度为100~180 mm/min时,均可获得较好的焊接性能,焊缝的抗拉强度在125~134 MPa之间,焊接强度系数为基材强度的78%~83%,说明该铝合金薄板采用搅拌摩擦焊方法的焊接适应性好。硬度测试结果表明焊缝发生了软化,其软化区宽度约为25 mm。在焊接热循环的作用下,锰在焊缝区沿轧制方向析出并聚集成较粗大的脆性MnAl6化合物,降低了焊缝的抗拉强度。     

(Ni79Fe21)0.48-(Al2O3)0.52纳米颗粒膜的巨霍尔效应

采用磁控溅射法 ,在玻璃基片上制备了一系列不同Ni79Fe2 1含量的 (Ni79Fe2 1) x (Al2 O3 ) 1-x纳米颗粒膜样品 ,并对样品的巨霍尔效应进行了研究。在 (Ni79Fe2 1) 0 .48 (Al2 O3 ) 0 .52 颗粒膜样品中 ,透射电镜 (TEM )照片清晰地显示出纳米Ni79Fe2 1颗粒包裹于Al2 O3 中 ,且电子间的量子相干效应明显 ,这可能是导致霍尔效应增强的主要原因。室温下测出了最大的巨霍尔效应值达到 4 .5 μΩ·cm。改变基片温度 ,发现巨霍尔效应值变化不大 ,说明该颗粒膜具有良好的热稳定性 ,因而在磁传感器上有良好的应用前景     

Molecular cloning of a full-length cDNA for ECBP21 from Angelica dahurica

ECBP21 is an extracellular calmodulin-binding protein which was first detected and purified from extracellular extracts of suspension-cultured cells of Angelica dahurica. The purified protein was electroblotted onto PVDF membrane and the amino acid sequences from 1 to 20 were determined. Using degenerate oligonucleotides of the sequence, a full-length cDNA coding for ECBP21 was isolated by a combination of RT-PCR and 5′-RACE cloning. The cDNA contains 947 nucleotides and codes for a precursor protein of 216 amino acids. The N-terminal 1-25 amino acid sequence is a predicted signal peptide and the other 26-216 amino acid sequence is a mature peptide. The 26-45 amino acid sequence shows identity with the N-terminal amino acid sequence of purified ECBP21 from Angelica dahurica. The fragment of encoding the mature protein was cloned into pET-28b(+) and transformed into E. coli BL21(DE3). A protein with relative molecular mass 21 ku was expressed in E. coli. Using a biotinylated-CaM gel overlay technique, the expression protein was tested for its ability to bind CaM. The results indicated that the expression protein is a Ca2+- dependent CaM-binding protein. Thus, these results further defined the cDNA clone for ECBP21. This work laid a foundation for elucidating biological functions of ECBP21 by using molecular biological means.     

Characterization and localization of the rat,mouse and human testicular phosphatidylethanolamine binding protein

A cytosolic 23kDa protein was initially puified from bovine brain and shown to bind phosphatidylethanolamine. Later, it was also characterized in rat and human brain, and it is now known to be widespread, having been found in numerous tisues in several species. Here, we report the high level of mRNA and phosphatidyl ethanolamine binding protein expression in rat testis and to a lesser extent mouse testis. In human testis, although it was not detectable by Northern blot analysis, the mRNA was shown be present when PCR amplificatin was performed. Immunohistochemical experiments revealed that the testicular phosphatidylethanolamine binding protein (tPBP) is principally expressed in the elongated spermatids of both rat and mouse testis. This finding, and the association of tPBP with cellular membranes, suggest its possible implication in membrane remodelling during spermatid maturation.     

重组细胞色素P450 BM-3突变酶在大肠杆菌中催化吲哚合成靛蓝

重组细胞色素P450 BM-3突变酶在大肠杆菌（E.coli）BL21得到表达，利用重组菌株细胞催化吲哚合成靛蓝.考察了底物、产物、葡萄糖浓度以及pH值和温度对反应的影响.结果表明：pH 7.0—7.5，温度35℃，底物浓度0.5mmol/L为较好的反应条件.在此条件下，反应进行8h后，靛蓝产率可以达到29.43%.产物靛蓝对合成反应具有一定的抑制作用，在反应体系中加入5g/L葡萄糖，可以将产率提高到44.08%.     

人细胞周期蛋白D1在大肠杆菌BL21中的表达及纯化

将人细胞周期蛋白D1全长cDNA克隆入原核表达载体pET-28c(+)中, 经酶切和测序鉴定正确的重组质粒转化E.coli BL21(DE3)后获得表达菌株. 该菌株经IPTG诱导高效表达出带有组氨酸标签的以包涵体形式存在的融合蛋白, 表达量占菌体总蛋白的23%. 包涵体经洗涤和溶解， 在变性条件下利用Ni²⁺螯合柱纯化、 尿素梯度复性后， 得到纯度达98%以上的纯化蛋白. SDS-PAGE显示纯化蛋白的分子量约为43 ０００， Western-b lot分析表明， 在相应分子量处有一特异性条带， 说明成功表达和纯化重组人细胞周期蛋白D1.     

文化教学与《21世纪大学英语》

通过《21世纪大学英语》的课文实例，分别从文化与语言交际、文化与非语言交际、文化与教学模式、文化与翻译四个方面说明《21世纪大学英语》在选材上独特的文化气息，并结合大学英语教学大纲的要求，对《21世纪大学英语》在文化教学中的新突破作进一步的肯定评价。     

"21世纪大学英语网络课堂"课件的开发

信息技术的迅速发展和应用为大学英语教学提供了新的方法和手段，本文介绍了作者基于现代信息技术和建构主义理论开发的“21世纪大学英语网络课堂”，该课堂以现行大学英语教材为原本。旨在为教师教学提供丰富资源和为学生学习营造相对真实的语言环境。