黄芪多糖对大鼠口腔溃疡治疗作用研究

本研究旨在探讨黄芪多糖对患有口腔溃疡大鼠(recurrent aphthous ulcer,RAU)的表皮细胞生长因子(epidermal growth factor,EGF)水平及T淋巴细胞亚群的影响。根据溃疡面的直径计算愈合率及HE染色观察溃疡组织病理学改变,酶联免疫吸附法(ELISA)测定EGF的水平,流式细胞仪检测大鼠外周血CD4+T细胞、CD8+T细胞亚群的百分率。实验结果显示治疗20 d后,黄芪多糖组大鼠溃疡面积减小,愈合率为87.5%～100%。与正常对照组相比,模型对照组大鼠CD4+T细胞数减少、CD8+T细胞数升高,CD4+/CD8+比值降低(P<0.05)。与模型对照组相比,黄芪多糖组大鼠外周血CD4+T细胞数升高、CD8+T细胞数降低,CD4+/CD8+比值回升(P<0.05)。EGF水平在造模后出现明显下降,黄芪多糖灌胃治疗后有升高。提示黄芪多糖能够提高RAU实验性大鼠EGF的水平和改善T细胞亚群的失衡状态,具有明显地促进口腔溃疡愈合的作用。     

Effects of clonal integration,nutrients and cadmium on growth of the aquatic macrophyte Pistia stratiotes

许多湿地同时遭受养分和有毒金属的污染,其植被多数为克隆植物。我们假设,富养化和克隆整合可以通过增加植物的生长来提高对有毒金属污染的植物修复能力,即使在毒性胁迫环境下也是如此。为验证此假说,我们将常见、广布的匍匐茎漂浮植物大薸(Pistia stratiotes L.)的单个分株种植在两种不同的养分条件下和两种镉污染处理(无镉或含0.6 mg L⁻¹ 的镉)中42天。通过保持或切断母株与其后代分株之间的连接来维持或阻止克隆整合,并通过保留或移除切断后的后代分株来控制克隆内竞争的有无。由于高养分条件下克隆后代分株的数量增加了一倍,因此镉处理下大薸的生物量在高养分条件下几乎是在低养分条件下的两倍。切断匍匐茎连接对整个克隆(母株和后代分株的总和)的生物量没有影响。切断连接后去除后代分株对镉污染下母株的生物量没有显著的影响,但却显著增加了无镉污染下母株的生物量。这些研究结果支持富养化可以提高水生植物对有毒金属污染的修复能力这一假说,但并不支持克隆整合有利于植物修复的假说。因此,水生植物(如大薸)可能有助于对同时遭受有毒金属和养分污染的湿地进行修复,但克隆片段化对植物的这种修复能力可能没有显著影响。     

Stem tissue mass density is linked to growth and resistance to a stem‐boring insect in Alternanthera philoxeroides

To investigate how stem anatomical structure is linked to growth and resistance to stem‐boring insects in a herbaceous species, six populations of alligatorweed (Alternanthera philoxeroides) were grown in a common garden. Stem growth rate (GR) of A. philoxeroides and pupation rate as an estimate of resistance to a stem‐boring insect (Agasicles hygrophila) were quantified. Stem tissue mass density (TMD) was measured and stem anatomical traits were analysed on cross‐sectional areas (CSA). Stem TMD was positively correlated with resistance (i.e. negatively correlated with pupation rate) and negatively correlated with GR. Stem cortex CSA (%) and vascular bundle (VB) density (no./mm²) were positively related to stem TMD and negatively related to pupation rate. The GR was positively related to VB CSA (%) and negatively related to VB density. These results suggest that stem TMD, which results from a high fraction in cortex CSA and high VB density, is a key determinant of resistance to a stem‐boring specialist in A. philoxeroides. The high resistance of plants with higher stem TMD may partially impose a cost to plant growth.     

区域气温和降水对关帝山不同海拔华北落叶松径向生长的耦合效应

为揭示区域气温和降水在不同海拔对山地林区林木径向生长的耦合效应,在关帝山林区孝文林场和庞泉沟国家自然保护区外围4个不同海拔选取立地条件相似的华北落叶松(Larix principis-rupprechtii Mayr.)人工林设置调查样地,采集典型样木样芯,采用建立年表的方法,获取年轮宽度指数,结合区域气温和降水进行相关性分析和单年分析。结果表明:在研究地区4个海拔上华北落叶松的径向生长均与区域气温和降水量有密切关系,但不同海拔响应机制不同;在1600 m海拔处,年轮宽度指数与当年4月气温极显著负相关,与当年9月降水量显著正相关;在1800 m海拔处,年轮宽度指数与上年6月气温显著负相关,降水量显著正相关;在2000 m海拔处,年轮宽度指数与当年9月气温和当年3月降水量显著负相关;在海拔2200 m处,年轮宽度指数与上年8月气温显著正相关,降水量显著负相关;随着海拔的升高,气温逐渐降低,降水量增加,两者对华北落叶松径向生长的耦合效应也发生变化,当海拔到达2000 m时,生长季降水量的增加使耦合效应关系发生转换。     

土壤水分对富士苹果果实外观品质的影响

为探究不同果园土壤水分处理对富士苹果果实品质的影响,并重点探究外观品质的差异,筛选出最适宜生产中采用的控水方法,以‘烟富3号’富士苹果品种作为材料,按照土壤相对含水量设置两组水分处理,一组为LT1(55%~65%)、LT2(65%~75%)和LT3(75%~85%),另一组为LT4(前期55%~65%,后期45%~55%)、LT5(前期65%~75%,后期55%~65%)和LT6(前期75%~85%,后期65%~75%),以生理落果为节点,划分处理前期和后期,以普通果园水分管理作为对照处理(LCK),分别测定土壤含水量以及相应果实可溶性固形物含量,计算果实裂纹指数、着色指数和光洁指数,并用扫描电镜观测果皮超微结构。结果表明:(1)LT1、LT4、LT5处理的果实可溶性固形物含量比LCK分别显著提高13.4%、15.2%、13.1%。(2)与LCK相比,LT2、LT3、LT5、LT6处理果实的裂纹指数分别降低了49.8%、19.8%、49.8%、30.1%,LT1、LT2、LT5处理果实的着色指数分别提高了3.4%、14.0%、17.4%,LT1~LT6处理果实的光洁指数分别提高了50.4%、150.4%、125.6%、45.2%、175.9%、100.8%。(3)果皮显微结构观察表明,控制处理前、后期土壤水分不稳定会导致果皮角质层的严重开裂,LT5处理避免了这一情况的发生,而健康果实的果皮角质层厚度大于裂果的果皮。(4)健康果实的水势(-1.22 MPa)明显高于裂果的水势(-1.44 MPa),且果实水势与裂纹发生呈负相关关系。研究认为,适当的土壤水分胁迫(65%~75%)不影响果实食用品质,同时可显著降低果实表面裂纹的发生率,提高果面光洁度;在果实发育后期,适当的轻度控水处理会促进果实的糖积累并减少裂纹的产生;果实裂纹的发生与果皮角质层厚度和果实水势相关,厚度越大、水势越高,裂纹发生越少。土壤相对含水量LT2与LT5处理的苹果果实兼具良好的食用品质与外观品质。     

县域生态资产核算研究——以云南省屏边县为例

生态资产(Eco-Assets)是生产与提供生态产品和服务的自然资源。以国家重点生态功能区县——屏边苗族自治县为例,研究了县域生态资产核算的指标和方法,以生态资产综合指数、负债表和损益表,开展屏边县生态资产实物量核算,以期能够切实反映出生态系统实物量的变化和生态补偿成效,结合生态补偿分析屏边县生态资产变化的原因和趋势,给生态补偿政策和离任干部审计提供技术支撑。结果表明:(1)屏边县生态资产核算可以分为森林、灌丛、草地、湿地自然生态系统和农田、城镇和荒漠人工生态系统实物量的核算。(2)2015年,屏边县生态资产指数为1.09,森林和灌丛占据主要位置,二者总和占当年生态资产的95.48%。15年来,屏边县生态资产综合指数降低了16.48%,其中森林和草地降低明显,分别减少了20.10%和6.67%,湿地指数增长了57.11%。(3)2000年以来,生态保护工程和城镇扩张是生态资产变化的主要原因,生态补偿投入持续增加为生态保护工程顺利建设实施提供了保障。本研究表明,现有的土地利用数据和生态环境监测数据基本可以支撑县域生态资产的核算,同时县域生态资产的变化能够体现出生态保护工程实行成效,并为实...     

面向药物发现和精准医疗的基因表达谱分析

作为功能基因组学中重要的组成部分,基因表达谱在生物学、医学和药物研发等多个领域发挥着重要作用.特别是随着精准医疗概念的提出,整合多组学数据用于个性化医疗是未来的发展趋势.本文从基因表达谱的基本概念出发,重点介绍面向药物发现的基因表达谱分析方法,即基于关联图谱的方法、基于基因调控网络的方法和基于多组学数据整合的方法.系统整理了各种方法的研究进展,特别是在抗癌药物研发领域的最新进展,为利用基因表达谱数据进行药物研发提供方法借鉴.     

Effects of clonal integration on plant plasticity in Fragaria chiloensis

The ability of clonal plants to transport substances between ramets located in different microsites also allows them to modify the plastic responses of individual ramets to local environmental conditions. By equalising concentrations of substances between ramets, physiological integration might decrease responses to local conditions. However, integration has also been observed to increase plasticity and induce novel plastic responses in ramets. To ask how integration modifies plant plasticity in the clonal herb, Fragaria chiloensis, ramets were given either low light and high nitrogen or high light and low nitrogen, simulating a pattern of resource patchiness in their native habitat. Ramets in contrasting light/nitrogen treatments were either connected or single. Effects of light/nitrogen and connection were measured at three levels of morphological organisation, the organ, the ramet, and the clonal fragment. Connection between ramets reduced or had no effect on plastic responses in leaf size at the level of the plant organ. This suggested that integration dampened certain plastic responses. Connection induced a new plastic response at the level of the clonal fragment, an increase in allocation to vegetative reproduction in patches of low light and high nitrogen. It is concluded that clonal integration can have different effects on plant plasticity at different levels of plant organisation. It appears that, at least in this species, integration can increase plasticity at the level of the clonal fragment and concentrate vegetative reproduction in particular microsite types.     

Multifunctionality of prostatic acid phosphatase in prostate cancer pathogenesis

The role of human prostatic acid phosphatase (PAcP, {"type":"entrez-protein","attrs":{"text":"P15309","term_id":"130730"}}P15309|PPAP_HUMAN) in prostate cancer was investigated using a new proteomics tool termed signal sequence swapping (replacement of domains from the native cleaved amino terminal signal sequence of secretory/membrane proteins with corresponding regions of functionally distinct signal sequence subtypes). This manipulation preferentially redirects proteins to different pathways of biogenesis at the endoplasmic reticulum (ER), magnifying normally difficult to detect subsets of the protein of interest. For PAcP, this technique reveals three forms identical in amino acid sequence but profoundly different in physiological functions, subcellular location, and biochemical properties. These three forms of PAcP can also occur with the wildtype PAcP signal sequence. Clinical specimens from patients with prostate cancer demonstrate that one form, termed ^PLPAcP, correlates with early prostate cancer. These findings confirm the analytical power of this method, implicate ^PLPAcP in prostate cancer pathogenesis, and suggest novel anticancer therapeutic strategies.     

Acute toxicity and adverse effects of aqueous and ethanol extracts of Parkia biglobosa pods on biochemical parameters of Clarias gariepinus

The acute toxicity of the aqueous and ethanol extracts of Parkia biglobosa pods against Clarias gariepinus was investigated under laboratory conditions. Agitated behaviours and respiratory distress were also observed during the exposure period. The adverse effects on biochemical parameters were assessed using semi-static bioassays for 28 days. The ethanol extract of P. biglobosa pods was found to be more acutely toxic with a 96 h LC₅₀ value of 13.96 mg l^?1 than the aqueous extracts, with a 96 h LC₅₀ value of 19.95 mg l^?1 against C. gariepinus. Both extracts induced agitated behaviours and respiratory distress in exposed organisms. The activities of superoxide dismutase (SOD), catalase (CAT) and the concentration of malondialdehyde (MDA) were significantly lower (p < 0.05) in groups of organisms exposed to extracts of P. biglobosa when compared with the control group after 14 days. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were also significantly (p < 0.05) lower compared with activities of the enzymes in the control group after 28 days. The current study has shown that the introduction of P. biglobosa pods into aquatic ecosystems is acutely toxic to fish and would possibly be to other non-target aquatic organisms especially invertebrates.