牛膝多糖抑制大肠埃希菌细胞粘附的实验研究

目的 :研究牛膝多糖能否影响大肠埃希菌对细胞的粘附。方法 :使用 Hela细胞进行了粘附试验及粘附抑制试验。结果 :发现牛膝多糖浓度为 0 .8mg/ml时 ,对细菌的细胞粘附抑制最为明显 ,粘附率由(2 5 7.0± 5 .2 )个细菌 /细胞 降低到 (63 .6± 3 .6)个细菌 /细胞 。结论 :牛膝多糖对大肠埃希菌的细胞粘附具有抑制作用 ,提示该多糖具有调节肠道微生态的潜在应用价值     

Molecular phylogeny of the Western Palaearctic Cordulegaster taxa (Odonata: Anisoptera: Cordulegastridae)

Although Odonata are a key component of many freshwater ecosystems, their taxonomy and evolutionary history is still far from being well resolved. In the present study, we report the first molecular phylogeny for the Western Palaearctic Cordulegaster genus (Odonata: Anisoptera: Cordulegastridae). We sequenced fragments of both mitochondrial and nuclear genes [cytochrome c oxidase I (COI) and Internal Transcribed Spacer‐1 (ITS‐1)] from eight species and 13 subspecies, from western, southern and central Europe, Turkey, and Morocco. Our data support the existence of two major groups corresponding to the traditional boltonii‐ and bidentata‐groups. Both groups are monophyletic based on COI sequences and the distinctiveness of Cordulegaster princeps, Cordulegaster trinacriae, Cordulegaster picta and Cordulegaster heros relative to Cordulegaster boltonii, and Cordulegaster helladica and Cordulegaster insignis relative to Cordulegaster bidentata, is confirmed. All species are also monophyletic for ITS‐1, with the exception of Cordulegaster helladica buchholzi, which shares the haplotype with C. insignis. Although moderate levels of genetic diversity were found within C. boltonii, there was no clear separation among the four subspecies, with the exception of the populations of Cordulegaster boltonii algirica from North Africa. Similarly, no genetic differentiation was found between the two subspecies of C. bidentata, Cordulegaster bidentata bidentata and Cordulegaster bidenta sicilica. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 49–57.     

Fitness of insularia morphs of the peppered moth Biston betularia

In recent years the industrial melanic carbonaria morph in the moth Biston betularia (L.) has decreased rapidly in frequency in Britain as air pollution has decreased. The intermediate melanic insularia has shown a variable response. We have estimated the fitness of insularia, compared with the other two morphs, for several data sets. As a rule its fitness lies between that of carbonaria and typical, but nearer to typical and sometimes very close to it. The intermediate position is expected if fitness relates directly to phenotype. The results suggest that insularia may continue polymorphic while carbonaria is likely to disappear. The past high frequency of insularia in South Wales may have been due to an initial increase in insularia frequency before carbonaria reached the region. Differences in dynamics of frequency change in insularia and carbonaria are evidence against induction, which has sometimes been invoked to explain the spread of melanism in this species.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 82 , 359–366.     

云南西双版纳植物区系新资料

<正> 多年生草本,茎细长而匍匐,节上生根。叶片膜质,近圆形或肾形,长0.5—1.5厘米,宽0.7—2.5厘米,基部心形,5—7裂,裂片阔倒卵形,边缘有钝齿,掌状脉6—8,上面疏生明显的刺状毛,下面光滑;叶柄长0.7—3厘米,无毛;托叶小,薄膜质,近肾形,具不规则的浅裂。聚伞状伞形花序通常顶生,与叶对生,有花序2—3,花序梗纤细,两侧的花序梗长达1厘米,中间的花序梗仅长1—2毫米,小总苞披针形,长约1毫米,膜质,小伞形花宇有花2—5,花无柄,花瓣卵形,长约0.5     

Chronic photoinhibition in seedlings of tropical trees

Seedlings of five canopy species of tropical trees from Costa Rica and Puerto Rico were grown in full shade (midday range of photosynthetic photon flux density [PPFD], 100–140 μmol m^?2 s^?1), partial shade (midday PPFD, 400–600 μmol m^?2 s^?1) and full sun (midday PPFD, 1 500–1 800 μmol m^?2 s^?1) for 3 months. The species were Ochroma lagopus (Bombacaceae), a pioneer species; Inga edulis (Fabaceae), found in secondary forest; and Dipteryx panamensis (Fabaceae), Hampea appendiculata (Malvaceae), and Manilkara bidentata (Sapotaceae), three species characteristic of primary forest. After the plants were placed in the dark overnight, chlorophyll fluorescence characteristics were measured for recently expanded and mature leaves. The ratio of variable fluorescence to maximum fluorescence (F_v/F_m) was used to estimate the degree of chronic photoinhibition. Only individuals of one species, Dipteryx panamensis, showed significant depression of F_v/F_m after long-term exposure to full sun. The depression was highly correlated with quantum yield of O₂ evolution which also declined after exposure to full sun. The decline may have been related to foliar N concentration. Although all plants were supplied with ample nutrients, foliar N did not increase significantly for Dipteryx seedlings in full sun, whereas it did for Ochroma and Inga. Leaf age affected F_v/F_m only in the cases of Manilkara, where it was slightly lower in recently expanded leaves, and of Dipteryx where it interacted with the effects of light regime. We conclude that chronic photoinhibition is not common in seedlings of canopy trees of tropical rain forests except when availability of mineral nutrients may be limiting.     

土牛膝碱（abidenine）的分离及结构测定

从土牛膝(Achyraanthes bidentata Bl.)的根中分离到一种新的生物碱——土牛膝碱(ubidenine),通过波谱方法测定出土牛膝碱的化学结构为5,6—二氢化—2,3,10,11—四甲氧基—二苯并[a,g]—喹嗪盐(1)。     

ABPS诱导单核细胞HLA-DR表达

目的研究牛膝多糖(ABPS)在体外激活单核细胞的效应.方法采集健康成人抗凝血,用贴壁法分离单核细胞,调节细胞数接种到24孔板.在370 C,5%CO2条件下,以同一时间不同ABPS浓度或同一ABPS浓度不同时间培养,用流式细胞术和电镜检测单核细胞的激活.结果 ABPS诱导单核细胞超微结构和HLA-DR的改变.结论 ABPS上调HLA-DR表达并能激活单核细胞.     

牛膝不同密度群体光合速率与干物质积累和品质的关系

在大田条件下,探讨不同种植密度(A,500 000;B,330 000;C,250 000;D 200 000株/hm2)与牛膝的群体光合速率、干物质积累、产量及多糖含量之间的关系.结果表明:群体光合速率B处理较高,各群体日变化在开花期均呈双峰型,籽盛期均为单峰型;单株根干重和单位面积根产量的拟合均呈Logistic曲线变化;不同密度处理单株根干重增加速率为D>C>B>A,而单位面积根产量增加速率为B>C>D>A;密度与产量呈负相关,与多糖呈正相关;各处理群体光合速率与产量呈显著正相关,与多糖含量在开花和籽末期呈负相关.综合分析显示,330 000株/hm2为牛膝最佳种植密度;密度对牛膝产量和多糖含量影响较大,适当地提高籽粒期群体光合速率有利于提高牛膝产量和质量.     

怀牛膝细胞悬浮培养条件的优化

为进一步优化怀牛膝(Achyranthes bidentata)细胞悬浮培养条件,对接种量、继代周期、pH、光照及Cu2+等多种影响因子的作用效果进行了研究,以提高怀牛膝细胞生长量及牛膝多糖含量。结果显示,接种量50 g·L^–1、继代周期14天,pH5–6和光照培养可以使细胞保持良好的生长状态及多糖合成能力;添加50μmol·L^–1 Cu^2+,细胞的干重最大,可达44.63 g·L^–1,多糖含量也最高,为4.02 mg·g^–1。     

Distribution and Biosynthesis of 20-Hydroxyecdysone in Plants of Achyranthes japonica Nakai

There is increasing interest in phytoecdysteroids (PEs) because of their potential role in plant defense against insects. To understand the mechanism regulating their levels in plants, the fluctuation, distribution, and biosynthesis of PE 20-hydroxyecdysone (20E) examined in Achyranthes japonica. The total amount of 20E per individual plant initially remained at a constant level, and increased markedly after the first leaf pair (LP) stage, while the concentration of 20E in a given plant decreased rapidly during vegetative growth. In addition, the incorporation of [2-¹⁴C]-mevalonic acid into 20E did not differ significantly depending on plant organs and developmental stages, suggesting that biosynthesis of 20E is not restricted to particular organs or growth stages.