汉源金花梨果园土壤和果实中重金属元素含量的测定分析

采用原子吸收法测定了汉源县7个地点的金花梨果园土壤和果实中重金属元素Cu、Cd、Cr、Pb的含量.将测定结果与中华人民共和国农业行业标准中的相关标准值进行分析比较.结果表明:7个采样地点中土壤重金属元素Cu、Cd、Cr、Pb的含量均小于标准值,果实中只有2个地点的Cd元素含量略微高于国家标准值,分别为标准值上限的165.67%和160.33%.相关性分析则表明土壤和果实中重金属元素之间并没有太大的相关性.     

江西峡江成功引种早熟青花菜中青8 号

近年来,江西省峡江县青花菜生产发展较快,年生产面积逾33.3 hm 2,主栽品种为优秀,一般每667m 2 产量950 kg 左右,产值4 000～4 500 元。为提高青花菜产量,增加农民收入,2009 年笔者从中国农业科学院蔬菜花卉研究所引进早熟青花菜品种中青8 号进行试种,试种面积10.13 hm 2,其中秋栽面积7.20 hm 2,每667 m 2 产量为1 126～1 183 kg,产值为4 640～6 110元;春栽面积2.93 hm 2,每667 m 2 产量936～964 kg,产值4 773～5 013 元。中青8 号比优秀平均每667 m 2 增加产量100～150 kg,增加产值800～1 000 元。与优秀相比,中青8 号株型更紧凑,叶片宽大,茎粗大,花球大,田间保持性好,市场价格高,但生育期迟2～3 d（天）。目前,中青8 号已是峡江县青花菜主栽品种,年栽培面积逾13.3 hm 2。     

试论美语和英语的差异及其由来与发展

简明而又系统地论述美国英语同英国英语在读音、拼写、用词和语法方面的差异,并从社会和时代发展的观点及美国历史变迁和经济发展的视角,分析了产生这些差异的主要原因,展望了两种英语相互弥补、融为一体、形成一种标准英语的乐观前景.     

Effect of oncogenic microRNA-106a on growth of normal gastric mucous epithelial cells and gastric cancer cells

AIM: To investigate the oncogenic effect of microRNA-106a (miR-106a) on normal gastric mucous epithelial cells and gastric cancer cells.METHODS: The miR-106a mimic was transfected into normal gastric mucous epithelial cell line GES-1 using liposome. The change of cell growth was measured by MTT assay. The miR-106a inhibitor was transfected into gastric cancer cell lines MGC-803 and SGC-7901 using liposome, and the changes of cell cycle distribution and cell cycle-related protein expression were measured by flow cytometry and Western blotting,respectively. The growth of gastric cancer was also observed using nude mouse xenograft model. RESULTS: The miR-106a mimic increased the growth of GES-1 cells in a dose-dependent manner. By decreasing the expression of cyclin-dependent kinase (CDK) 1 and CDK2, the miR-106a inhibitor arrested MGC-803 cells at G₀/G₁ and G₂/M phases. The miR-106a inhibitor also arrested SGC-7901 cells at G₂/M phase by decreasing the expression of CDK1. The results of animal experiments showed that the miR-106a inhibitor significantly suppressed the tumor growth in a dose-dependent manner.CONCLUSION: miR-106a may play an important role in the development of gastric cancer.     

华南蚕区蚕沙产地无害化和肥料化处理技术体系构建思路

调查华南蚕区现有的蚕沙处理主要有分散简易堆肥、沼气发酵和集中资源化利用处理3种模式。针对该蚕区高温多湿的环境,以及一年多次养蚕,蚕沙生产量大的情况,提出因地制宜,采用简易蚕沙池改造升级、小型设施堆肥处理、小规模集约化堆肥处理等多种模式相结合的蚕沙好氧堆肥处理技术,并通过蚕沙堆肥过程与条件的控制,达到蚕沙病原菌灭活无害化、蚕沙堆肥发酵完全熟化和蚕沙作为桑园肥料应用无风险的目的,构建蚕沙产地无害化和肥料化处理技术体系。     

抑制瘤胃甲烷排放的酵母菌的筛选及培养条件优化

减少瘤胃甲烷排放措施的研究已成为当前的研究热点之一。本研究以酒、面包和畜禽专用酿酒酵母产品为原材料,从中分离到三株酵母菌,将其制成冻干粉,通过体外产气试验,筛选出了一株抑制瘤胃甲烷排放效果最为显著的酵母菌株。然后以该酵母菌株作为研究对象,进行分子生物学鉴定;采用分光光度计比浊法测定该酵母菌株的生长曲线,确定菌体生长规律;并以此为依据,设计单因素试验考察该酵母菌株最适宜的生长条件。结果表明,分离得到的酵母菌株均为酿酒酵母saccharomyces cerevisiae;抑制瘤胃体外甲烷排放效果最显著的1株酵母菌分离自面包中;该酿酒酵母菌株的对数生长期为8～24h,其最佳培养条件为:生长温度30℃,pH 5.5,培养基中葡萄糖的浓度4.0%。     

Role of voltage-dependent anion channel in cardiomyocytes subjected to anoxia/reoxygenation

AIM: To investigate the role of voltage-dependent anion channel (VDAC) in H9c2 cardiomyocytes subjected to anoxia/reoxygenation (A/R).METHODS: The shRNAs targeting VDAC1 mRNA were inserted into pSUPER plasmid.H9c2 cells were randomly divided into 5 groups as follows: control group, A/R group, anoxia preconditioning (APC) group, pSUPER-VDAC1-A/R group and pSUPER-A/R group. The expression of VDAC1 was detected by Western blotting. Cellular injury was evaluated by measuring the cell viability and the release of lactate dehydrogenase (LDH) and creatine phosphokinase (CPK). The mitochondria membrane potential was determined by flow cytometry.RESULTS: VDAC1 expression was up-regulated in A/R group and was inhibited in APC group. Similarly, down-regulation of VDAC1 expression by shRNA protected H9c2 cells from A/R injury. Moreover, we found that, with silencing VDAC1 expression, mitochondrial membrane potential was well preserved in H9c2 cells subjected to A/R.CONCLUSION: Down-regulation of VDAC1 protects H9c2 cells against A/R injury and its possible mechanism appears to be related to the regulation of mitochondial permeability transition pore opening.     

丙酮溶物对天然橡胶臭氧老化性能影响

天然橡胶中的非胶物质种类和含量影响橡胶的质量和应用性能。本文通过硫化性能、交联密度、耐臭氧老化 性能测试和热重分析研究丙酮溶物含量对天然橡胶臭氧老化性能的影响。结果表明,丙酮溶物可以改善天然橡胶的硫 化性能,提高其交联密度。随着丙酮溶物添加量的增加,天然橡胶的热稳定性、臭氧裂纹显现时间、拉伸强度保持率 逐渐提高并达到最大值。采用衰减全反射傅里叶红外光谱分析仪（ATR-FTIR）分析了天然橡胶臭氧老化前后分子结构 变化,可知橡胶在臭氧老化后出现了氧化官能团。     

基于有效积温的NFT栽培生菜生长模型

以3种生菜品种为试材,在福建省海峡现代农业示范园温室内开展了3次栽培试验,每隔1～3 d,采集生菜的生长指标.根据生菜对温度的响应,以有效积温为自变量,采用Logistic方程构建生菜NFT栽培生长模型.建立了生菜地上部鲜质量、地上部干质量、地下部鲜质量、地下部干质量、株高、叶片数、总叶面积等模型,以期探明营养液膜栽培技术(NFT)栽培的生菜生长模型.结果 表明:模拟模型的曲线决定系数范围在0.869～0.984,模型的预测值与实际值之间基于1∶1直线的决定系数范围在0.965～0.992,地上部鲜质量、地上部干质量、地下部鲜质量、地下部干质量、株高、叶片数、总叶面积的RMSE最大值分别为6.52 g、0.66 g、6.50g、0.16 g、2.13 cm、1.11叶、200.09 cm2,模型预测效果较好.最后,用最大叶叶长和叶宽的乘积为自变量,建立了最大叶叶面积及单株总叶面积非破坏性估测模型,模型精度也较高.     

杀菌剂丙环唑对斜纹夜蛾的生物活性

为从现有农药中寻找杀虫剂先导化合物，研究了11种农药对斜纹夜蛾细胞的毒杀活性。结果表明，杀菌剂丙环唑的活性最高，处理后24h和48h，丙环唑对斜纹夜蛾细胞的LC50值分别为23．89μg／mL和13．62μg／mL。在活体试验中，以0．5μg／头剂量的丙环唑注射斜纹夜蛾4龄幼虫，处理后24h和48h，试虫血淋巴中血细胞数分别下降了19．67％、21．38％，血淋巴含量分别下降了20．42％、23．87％。以0．5μg／头和1．0μg／头剂量的丙环唑注射处理后，斜纹夜蛾幼虫体重显著降低。在注射处理后48h和72h，丙环唑对斜纹夜蛾4龄幼虫的LD50值分别为0．91μg/头和0．63μg/头。丙环唑对斜纹夜蛾细胞和斜纹夜蛾幼虫均具有较好的毒杀活性，显示出杀菌剂丙环唑衍生物控制害虫的可能性。