不同类型水稻土微生物群落结构特征及其影响因素

选取基于我国土壤地理发生分类的不同类型土壤发育的四种水稻土,利用15N2气体示踪法测定生物固氮速率,采用实时荧光定量PCR(Real-time PCR)技术测定细菌丰度,通过16S rRNA基因高通量测序分析微生物群落组成和多样性.结果表明:变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria...     

Effect of trastuzumab (herceptin) on the apoptosis induced by ZD1839 (iressa) in lung cancer A549 cells

AIM: ZD1839 and trastuzumab are reported to improve the therapeutic efficacy of treatment for non-smallcell lung cancer (NSCLC) and breast cancer, respectively, although the effectiveness of either drug alone is not satisfactory. NSCLC cells often express both EGFR and HER2. We therefore investigated whether a combination of ZD1839 and trastuzumab had an additive or synergistic antitumor effect. METHODS: MTT was used to measure the inhibitory effects of ZD1839 (iressa) and trastuzumab (herceptin) on the growth of A549 cells. The cell apoptosis was studied by DAPI staining, and Annexin V/PI double labeling. RESULTS: The inhibitory action of cell growth was seen in A549 cells dealing with ZD1839 and trastuzumab. They inhibited the growth of the human lung cancer cell line A549 in a concentration and time dependent manners. Compared with either ZD1839 or trastuzumab alone, combination with curcumin respectively increased the growth inhibition rate and increased apoptosis of A549 cells (P<0.05) significantly, suggesting the synergistic actions of the two drugs. CONCLUSION: The results suggest that combination treatment with ZD1839 and trastuzumab might have improved therapeutic efficacy against NSCLC cells expressing both EGFR and HER2.     

鲆鲽鱼类维生素及微量元素营养需求研究进展

随着海水鱼养殖规模的不断扩大,对鲆鲽鱼类养殖以及其饲料开发的研究也随之增多.对国内外维生素和微量元素研究进展做了系统性的综述,以期为开展鲆鲽鱼类健康养殖和其饲料开发提供借鉴。     

中国杂交粳稻研究现状与对策

系统回顾了中国杂交粳稻发展的历程和取得的成就,综述了其研究现状及存在的问题,分析了这些问题产生的原因,提出了解决这些问题的方法和技术策略,以促进中国杂交粳稻的发展。     

壳聚糖对Cd2+和Pb2+的吸附作用

为开发新型吸附剂,降低重金属对水体的污染,研究了壳聚糖对Cd²⁺和Pb²⁺的吸附条件,探讨了pH、温度、反应时间、壳聚糖添加量和金属离子初始浓度等因素对壳聚糖吸附性能的影响。结果表明,pH 7~8和pH 5~6条件下壳聚糖对Cd²⁺和Pb²⁺的吸附能力最强;低温有利于壳聚糖的吸附;在8 h时壳聚糖对Cd²⁺的吸附容量达到最大,而对Pb²⁺的吸附在实验时间内是随着吸附时间的延长而增大;随着壳聚糖添加量的增加,其对Cd²⁺和Pb²⁺的吸附能力也增强;初始金属离子浓度的变化对Cd²⁺的影响不大,而在高的金属浓度下对Pb²⁺的吸附率显著降低。壳聚糖对Cd²⁺、Pb²⁺的吸附动力学和热力学分别符合Lagergren方程二级吸附模型和Langmuir吸附方程。研究表明,壳聚糖对不同金属离子的吸附能力不同,在单一金属溶液中,壳聚糖对Cd²⁺的吸附能力要强于对Pb²⁺的吸附能力。系统地研究了壳聚糖对Cd²⁺和Pb²⁺的吸附条件及性能,为壳聚糖作为重金属吸附剂的应用提供理论依据。     

我国人寿保险收入的时间序列分析

本文选用我国人寿保险公司2005.01 - 2010.12期间的月度原保险收入为样本,采用ARIMA模型和Auto -Regressive模型进行了时间序列分析,结果显示模型具有较好的预测效果,可为我国人寿保险的监管和决策提供参考.     

Research Progress on Technique of Frozen Embryo Transfer in Sheep

The paper introduced the research progress on the technique of frozen embryo transfer in sheep,illustrated selection of donors and receptors,superovulation,synchronization of estrus,embryo cryopreservation and embryo transplantation. Frozen embryo transfer in sheep is another breakthrough in the high-quality sheep raising,and this technique in China is in its infancy recommendation stage,but it will be comprehensively popularized in the future.     

磁处理水对两种十字花科植物种子发芽生长的影响

为了观察磁处理水培养液对2种十字花科植物莱菔与白芥种子发芽生长的影响．使用不同强度的磁处理水培养液对莱菔种子和白芥种子进行处理，设置对照组，7d统计发芽率、根长、根重，测相对电导率。结果表明：0．08T、0．10T强度磁处理水培养液处理的莱菔子与白芥子发芽和根生长情况均好于对照组（P〈O．05）．0．08T、0．10T磁处理水培养液处理的两种幼株的电导率均低于对照组。说明磁处理水培养液对两种十字花科植物莱菔与白芥种子发芽生长有影响，其生长情况与磁场强度有关。     

浅析现代城市景观设计

探讨现代城市景观设计的概念、内容、特点及现状,并提出现代城市景观设计的发展趋势。     

图表法在农学生物化学教学中的应用

对图表法在农学生物化学教学中的应用做了探讨,证明这种方法有助于调动学生学习的积极性、改善教学效果和提高教学质量,值得更多教师在教学实践中进行尝试。