城市道路绿化树种综合评价

本文对包头市常见的道路绿化树种综合性状进行评价,依据综合评价的结果,为道路绿化树种选择与配置及提高生态效益提出建议,并提出基调树种和骨干树种。       

鲜食糯玉米高密度制种试验研究

试验设5000,5500,6000,6500,7000,7500株／666．7m^2共6个密度,研究鲜食玉米沪玉糯1号在西北地区高产制种的合理密度。结果表明,不同密度处理制种产量问差异达极显著水平,在一定范围内,制种产量随密度增加而增加,呈二次曲线变化。由回归模型得出沪玉糯1号最佳制种密度为7415株／666．7m^2。株高和穗位高随密度增加而上升,茎粗则略有下降,果穗变化较小,未有倒伏现象,表明沪玉糯1号母本申W22耐密植性好,合理高密度制种能获得高产量。     

混种非洲狗尾草对紫茎泽兰表型特征的影响

紫茎泽兰是我国最具入侵性的外来杂草之一,现已在西南大部分地区造成危害。研究了紫茎泽兰和非洲狗尾草在重度、中度和轻度3个不同入侵程度的土壤和未入侵土壤中单种和混合种植时的表型特征差异。结果表明,混合种植时非洲狗尾草的长势明显强于紫茎泽兰,混种非洲狗尾草可明显降低紫茎泽兰的生长势。混种区的紫茎泽兰株高、节间距、节数、单株叶片数、绿叶率、叶绿素含量和根长均小于单种区,其中株高、节间距和叶绿素含量差异达到显著水平(P0.05);非洲狗尾草对紫茎泽兰生长的抑制作用随其密度的增加而增强,在非洲狗尾草植株数量3倍于紫茎泽兰时抑制效果最大,紫茎泽兰株高只有其单种的1/3,节间距只有单种的1/2,叶绿素含量不足单种的1/2。对不同入侵类型土壤中的替代效果进行比较研究表明,在相同种植比例下,随着入侵程度的增加,非洲狗尾草对紫茎泽兰的抑制作用呈现逐渐减弱的趋势。在紫茎泽兰与非洲狗尾草等比种植时,重度入侵土壤中的紫茎泽兰节间距和单株叶片数与轻度和中度入侵土壤中的紫茎泽兰节间距和单株叶片数差异达显著水平(P0.05),在轻度入侵土壤中开展紫茎泽兰的牧草替代控制效果最为显著。     

Notch1 regulates stemness and chemotherapeutic sensitivity of human glioma U251 cells

AIM: To investigate whether Notch1 changes stemness and chemotherapeutic sensitivity in human glioma U251 cells. METHODS: The lentiviral vectors, which expressed Notch1-shRNA or Notch1 intracellular domain (NICD), were transfected into U251 cells. Western blot and immunofluorescence staining were applied to monitor the validity of the cells, down-regulation of Notch1 expression or over-expression of NICD. The proportion of CD133⁺ cells was analyzed by flow cytometry. The expression of nestin and GFAP was identified by immunofluorescence staining. The formation rate of tumor cell spheres and the implanted tumor growth in SCID mice were observed. MTT assay was performed to evaluate the chemotherapeutic sensitivity to VM-26 and BCNU of the cells with different treatments. RESULTS: Stemness was significantly enhanced in the cells over-expressing NICD. For example, the proportion of CD133⁺ cells was increased, the expression of nestin was up-regulated, the expression of GFAP was down-regulated, and the formation rate of tumor cell spheres and implanted tumor growth were increased. The chemotherapeutic sensitivity to VM-26 and BCNU of the cells was decreased. In the cells with Notch1 gene down-regulation by RNAi, the stemness was inhibited and chemotherapeutic sensitivity was increased. CONCLUSION: Notch1, which leads to the change of stemness and chemotherapeutic sensitivity in human glioma U251 cells, is likely to be a potential molecular target for treatment of glioma.     

菠萝PEPC基因家族生物信息学分析

磷酸烯醇式丙酮酸羧化酶（phosphoenolpyruvate carboxylase, PEPC）在C₄和景天酸代谢（CAM）光合途径吸收CO₂过程中发挥重要作用,并参与各种非光合作用过程,包括果实成熟、气孔开放、碳氮相互作用、种子形成和萌发以及调节植物对逆境胁迫的耐受性。菠萝为典型的景天酸代谢途径（CAM）植物,为了解磷酸烯醇式丙酮酸羧化酶（PEPC）在菠萝景天酸代谢途径（CAM）中的作用,本研究鉴定到3个菠萝PEPC基因,按照基因描述命名为AcPEPC1、AcPEPC3和AcPEPC4,进化树分析结果AcPEPC1和AcPEPC3为植物型PEPC（PTPCs）蛋白,序列同源性较高且基因结构、保守结构域及保守基序均一致。AcPEPC4为细菌型PEPC（BTPCs）蛋白,与AcPEPC1/AcPEPC3间的序列同源性低。组织表达分析表明AcPEPC1菠萝叶片表达量较高,而AcPEPC3和AcPEPC4在菠萝花和果实表达量较高。     

Kinetics Characteristics of Resolving of Rock Salt of Changshan in Dynamic State

Kinetics characteristics of resolving of rock salt of Changshan in dynamic state have been studied by using conductance method and equipment made by ourself. The results show that the quantitative relationship between conductance(L) or concentration (c) of resolving solution in the process of resolving of rock salt and time t ( kinetics equation )is analogous to Langmuir equation for different flows in ambient temperature.Constant E or a increases with the increase of the flow( V ), whereas constant F or b constant decreases. The above 4 constants in dynamic state are smaller than those in static state.     

美洲斑潜蝇在豇豆上发生为害规律及药剂防治技术研究

本研究较系统地调查、考查了美洲斑潜蝇在豇豆上的生物学特发表主发生为害规律,初步确此虫在南宁豇豆上一年可发生１０￣１２代,世代历期１６￣２２ｄ;此虫从３月开始为害春植豇豆苗,至１２月初仍可为害秋植的残留豆株,在田间豇豆株 上的种群密度以９￣１０月间最大;豇豆苗期前期及结荚后期受此虫为害较重,秋植豆受害较春夏植豆重。常见的豇豆品种均受此虫为害,但”美国冠军豆“品种受害相对较轻;与豇豆不同属的”四棱豆“     

Effect of the Circulate Loading on the Deformation of Sanjome Andesite

By the experimental study about the effect of a circulate loading on the deformation and the Young's model of Sanjome andesite at the distinct strain rate in a low stress state, the viscoelasticity of Sanjome andesite in a low stress state is researched by means of the effect of the circulate loading on the deformation of rocks. It is found that the natural material such as rocks has obvious viscoelasticity, and the mechanical property of rocks has a direct bearing on the size, direction and loading rate, but also on the way of loading and the organization attribute of rocks.     

少花桂组织培养离体繁殖初步研究

少花桂(Cinnamomum pauciflorum Nees),俗称岩桂、香桂等,属樟科(Lauraceae)樟属小乔木,高达3～10 m,花期3～5(或6)个月,果期6～9(或10)个月.产于我国四川、云南、贵州、湖北、湖南、广西、广东等省区,印度也有分布[1,2].从少花桂中提取的黄樟油素是很重要的化工原料[3,4].