共查询到20条相似文献,搜索用时 15 毫秒
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刘坤 《青苹果(高中版)》2008,(1):37-39
<正>自有人类起,人类之间的战争就没有停止。战争离不开武器,从远古时代的石器,到古代的冷兵器,到现在的热兵器,战争中的武器不断升级。那么,未来战争中的武器又将会是什么样的呢?会朝什么方向发展呢? 相似文献
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李佳霖 《小雪花(小学生成长指南)》2006,(5)
人气指数:★★★★★在一个森林里住着一只狗熊,整天吃完就睡,睡完就吃,小动物们都怕它,害怕被它给吃了。有一次,狗熊在森林的草地上,看见一只小羊正在吃草。狗熊假模假样地说:“今天晚上到小河边等着,我有好东西给你。”说完,狗熊就大摇大摆地走了。小羊很害怕,就去找小狗、大 相似文献
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一个寒冷冬天的早晨,狐狸挑着几条鱼走在路上。这时,狗熊从一旁经过。
“早上好,”狗熊说,“你今天早上手气不错啊.钓到了这幺多的鱼。你是怎幺钓到他们的?” 相似文献
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李浩然 《少年天地(小学)》2002,(5)
小狗熊和小猩猩是邻居。小狗熊家在小猩猩家的东南,地势高;小猩猩家在小狗熊家的西北,地势低。一天,小猩猩把一袋花生倒在房顶上晾晒。忽然刮起了西北风,越刮越大,把小猩猩家里的花生卷起来,刮到小狗熊门前的场院上,小狗熊看到有这么多的花生,赶紧把花生拣回家去了。 相似文献
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徐越 《少年文艺(南京)》2008,(12):30-31
今年的冬天特别冷,西北风呼呼地刮着,河面上结了冰。小狗熊心想,河面结了冰,我可以好好地玩一玩。于是,它对爸爸说:"爸爸,我想去溜冰。"爸爸说:"冰面很薄,很危险,不 相似文献
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王子赟 《创新作文(初中版)》2013,(24):9
狗熊想去周游世界,便打算把自己的树卖掉换点盘缠。一群蚂蚁爬上了树,狗熊赶紧推销:"你们是来买树的吧?你们看,这树……"带队的蚂蚁笑了:"我们没有钱!我们是来放牧的。蚜虫就相当于我们的奶牛,我们只要拍拍蚜虫的屁股,它就会产出蜜来给我们吃。""唉!"狗熊叹了口气。突然,他看到一只知了正趴在树干上吮吸树汁,狗熊生气地阻止了他:"知了,你怎么招呼也不打就来了?这可是我的树,要吃就先把树买下 相似文献
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Li D Wang QQ Tang GP Huang HL Shen FP Li JZ Yu H 《Journal of Zhejiang University. Science. B》2006,7(11):906-911
Objective: To construct a novel kind of nonviral gene delivery vector based on polyethylenimine (PEI) conjugated with polypeptides derived from ligand FGF with high transfection efficiency and according to tumor targeting ability. Methods: The synthetic polypeptides CR16 for binding FGF receptors was conjugated to PEI and the characters of the polypeptides including DNA condensing and particle size were determined. Enhanced efficiency and the targeting specificity of the synthesized vector were investigated in vitro and in vivo. Results: The polypeptides were successfully coupled to PEI. The new vectors PEI-CR16 could efficiently condense pDNA into particles with around 200 nm diameter. The PEI-CR16/pDNA polyplexes showed significantly greater transgene activity than PEI/pDNA in FGF receptors positive tumor cells in vitro and in vivo gene transfer, while no difference was observed in FGF receptors negative tumor cells. The enhanced transfection efficiency of PEI-CR 16 could be blocked by excess free polypeptides. Conclusion: The synthesized vector could improve the efficiency of gene transfer and targeting specificity in FGF receptors positive cells. The vector had good prospect for use in cancer gene therapy. 相似文献