基于氧化石墨烯的磺胺嘧啶核酸适配体的筛选与鉴定

[目的]利用GO-SELEX方法对磺胺嘧啶(Sulfadiazine)核酸适配体进行筛选与鉴定.[方法]基于氧化石墨烯(Graphene oxide)与ssDNA的π-π堆积作用,将氧化石墨烯作为结合ssDNA与分离的介质,以磺胺嘧啶为靶标分子,利用指数富集的配体系统进化技术(SELEX)和磁分离技术建立了基于氧化石墨...     

大肠杆菌核酸适配体筛选的研究

由于传统微生物检测存在步骤繁琐、耗费时间、成本较高等缺点,因此研发快速有效检测微生物的新技术新方法显得尤为必要.本文利用whole-cell SELEX技术,进行了大肠杆菌活细胞核酸适配体的筛选,对单链DNA的制备鉴定、每轮筛选核酸文库的检测、核酸适配体的扩增克隆等内容进行了研究,在筛选过程中成功制备了单链DNA,并对整个筛选过程的核酸适配体库进行监测,保证了筛选的顺利进行,并对核酸适配体库进行了扩增和克隆,最终获得靶向大肠杆菌的核酸适配体序列,这将有助于基于核酸适配体的微生物检测新方法的建立.     

农药分子核酸适体筛选研究进展及其在生物传感器中的应用

核酸适体作为一类通过体外筛选指数富集配体系统进化技术(SELEX)得到的单链DNA或RNA,具有特异性强、稳定性好和靶分子广等特点,被广泛用于生化传感检测领域.总结了近年来筛选的农药分子核酸适体及其筛选方法,综述了农药分子核酸适体在生物传感检测中的应用,并探讨了农药分子核酸适体筛选的问题和未来发展的趋势.     

P-糖蛋白的核酸适配体筛选及应用研究

基于SELEX技术筛选P-糖蛋白（permeability glycoprotein,P-gp）的特异性核酸适配体（aptamer,Apt）,并用酶联免疫吸附测定（ELISA）法、表面等离子体共振（SPR）法表征了Apt与P-gp的结合能力,采用与P-gp结合能力最强的Apt5在人结直肠腺癌细胞（Caco-2）、人脑微管内皮细胞（hCMEC/D3）两种细胞系上考察了对P-gp外排功能的抑制效果.筛选得到10条长度为81 bp的P-gp核酸适配体,结合能力大小顺序为:Apt5>Apt8>Apt1>Apt4>Apt6>Apt10>Apt7>Apt2>Apt9>Apt3.Apt5使hCMEC/D3及Caco-2细胞内罗丹明123的蓄积量分别增加了40.77%（P<0.01）,32.39%（P<0.05）,能潜在抑制P-gp的外排功能.本研究首次报道了P-gp的多条核酸适配体,与P-gp有较强的结合能力,并能抑制P-gp的外排功能,有望成为P-gp的潜在新型抑制剂.      

水生生物病原核酸适配体研究进展

核酸适配体(Aptamer)是指利用指数富集配体系统进化(Systematic evolution of ligands by exponential enrichment,SELEX)技术筛选得到的能特异性识别和结合靶标的ssDNA或RNA分子,具有高亲和力和高特异性的特点,在快速检测和靶向治疗方面应用广阔。近年来,水生生物细菌和病毒性病原疾病的频繁暴发,严重制约了水生态的健康以及水产养殖业的迅速发展。核酸适配体作为一种新型的识别分子,在水生生物病原的应用上也已取得了一些进展。本文对水生生物细菌和病毒性病原核酸适配体的筛选,及其在检测和治疗领域的研究现状进行综述,并对该领域核酸适配体技术的应用方向进行展望。     

闭锁连接蛋白-1核酸适配体的筛选与初步应用

基于配体指数富集系统进化技术筛选闭锁连接蛋白-1的核酸适配体,最终筛选到15条ZO-1的核酸适配体(APT_ZO-1).排除线性结构与相似结构后,采用酶联免疫吸附法表征了9条APTZO-1与ZO-1亲和力的大小,排序依次为：APT_ZO-1 8>APT_ZO-1 2>APT_ZO-1 7>APT_ZO-1 13>APT_ZO-1 1>APT_ZO-1 5>APT_ZO-1 15>APT_ZO-1 12>APT_ZO-1 4.采用Cy5荧光基团标记APT_ZO-1 8(Cy5-APTZ_O-1 8),证实了其能对人结直肠腺癌细胞(Caco-2)与人脑微管内皮细胞(hCMEC/D3)的ZO-1进行荧光定位与半定量分析,且与基于ZO-1抗体法的免疫荧光与蛋白印迹实验结果基本相似.本研究首次筛选到了ZO-1的系...     

适配体技术及其在肿瘤标志物检测中的应用

随着一种新型指数富集的配基系统进化技术（systematic evaluati on of ligands by exponential enrichment,SELEX）不断的发展和完善,适配子技术已成功用于药物筛选、临床诊断、疾病治疗和基础医学研究等方面,特别在临床肿瘤标志物方面的应用,已经发挥了巨大的作用。阐述了目前适配体技术及其在肿瘤标志物检测中的应用的研究进展。     

降低酶联核酸适配体分析方法中非特异性吸附的分析研究

以检测蜂蜜中的四环素残留为例,构建间接竞争酶联核酸适体分析法（ic-ELAA）,就ic-ELAA中非特异性吸附的影响因素进行分析,探讨降低非特异性吸附的措施。结果表明：选择2 μg/mL四环素-牛血清蛋白在10 mmol/L Tris-HCl（pH 8.0）中过夜包被,次日用0.5 g/mL酪蛋白封闭1 h,竞争反应后用6 μg/mL链霉亲和素-辣根过氧化物酶催化颜色反应放大竞争效果,最后采用450 nm和630 nm双波长读数,可得到灵敏度为0.035 ng/mL的竞争曲线。同时,根据长期实验经验,提出其他降低非特异性吸附的注意事项。     

核酸适体的筛选及其在生物医学领域的研究进展

核酸适体是由指数富集配体系统进化技术(SELEX)筛选获得的能够与靶标物质特异性、高亲和力结合的单链DNA或RNA.能够被核酸适体识别的靶标物质包括各种小分子物质、大分子蛋白质、细胞等,广泛应用于生物医学研究各领域.为此,对核酸适体的筛选制备技术、对生物医学靶标物质的检测方法以及在疾病的靶向诊断和治疗中的研究进展进行了综述,并对其在生物医学领域中的应用进行了展望.     

The influence of tectonic evolution on the accumulation and enrichment of coalbed methane (CBM)

The current accumulation and enrichment of CBM reservoir is a result of the preservation and destruction of former CBM, after the superposing evolution of reversing-and-uplifting and the subsequent evolution within the coal-bearing basin. The critical moment of the CBM reservoir formation is the time when the burying depth of the overlying net thickness amounts to the least in geological history after the gas generation of coal beds. Except the coal-bearing basins of lower metamorphism, most basins suffered the evolution stage of reversion and uplift. The formation of the CBM reservoir is controlled by the beginning and lasting time, and the intensity of reversing and uplifting. The tectonic evolution after reversing and uplifting also affects the accumulation of CBM in coal-bearing basin. The CBM constantly dissipates in the area of chronically uplifting and de-nudating. The area developed overlying sedimentation is advantageous to the preservation of CBM, but also can lead to the reduction of CBM saturation.     

Study on the specific interaction between angiogenin and aptamer by atomic force microscopy （AFM）

The specific interaction between angiogenin and aptamer has been investigated by using AFM. The specificity of the interaction is revealed by comparing the binding probability of aptamer to other elements in a series of control experiments. The results have shown that there is specific interaction force between angiogenin and aptamer. Moreover, the single molecular pull-off force between angiogenin and aptamer has also been determined using the Poisson statistical method to be 133.7±11.7 pN. These findings obtained are helpful to the better revelation of recognition mechanism between angiogenin and aptamer, which provided basis for further understanding the inhibition of the aptamer to angiogenic activity.     

包结聚合树脂富集分离水中痕量Mn（Ⅱ）

以环氧氯丙烷为交联剂，与β-环糊精反应，生成一种具有三维网状结构且不溶于水的聚合物。该物质与酸性铬蓝K显色剂发生包结反应，形成包结聚合树脂。用此树脂富集水中痕量Mn(Ⅱ)，结果令人满意。     

聚苯撑乙炔与电子受体共聚物的合成及光伏研究

利用钯催化剂(Pd(PPh3)2Cl2)和相转移催化剂(PTC),采用Heck交叉偶联缩聚反应合成了聚(苯撑乙炔撑-苯并噻二唑)系列交替共聚物(PPE-BT),比较了聚合物的紫外吸收光谱和荧光光谱特征。PPE-BT与给体MEH-PPV构成器件时,其能量转换效率为2.54×10-3,说明电子在PPE-BT和PPE-DCNTB中的迁移率较小。     

(CdSe)_n(n=1-10)团簇与含硫配体相互作用的理论研究

采用密度泛函理论方法系统的研究了(CdSe)_n(n=1-10)团簇与有机配体SCH_3相互作用生成稳定产物的结构和性质.研究表明,有机配体SCH_3中的S原子能与CdSe中的Cd原子形成Cd-S配位键.通过比较该系列团簇吸附产物的吸附能、电荷、LUMO轨道、态密度和电子吸收光谱等性质,揭示了含硫配体在(CdSe)_n(n=1-10)团簇上的配体效应.     

Responses of rice growth to copper stress under free-air CO2 enrichment （FACE）

The responses of rice to the second degree contamination of copper were studied by pot experiments under free-air CO2 enrichment （FACE） with 570 μmol ·mol^-1 of CO2. The results showed that the content of copper in rice leaves was reduced with the CO2 concentration reaching 570 μmol· mol^-1 and this happened more significantly under the second degree contamination of copper. Under FACE, activities of superoxide dismutase （SOD） enzyme in rice leaves treated by copper contamination were induced, whereas the contents of glutathione （GSH） and glutathione disulfide （GSSG） had no significant difference from the control. In the presence of ambient CO2, activities of SOD enzyme treated by copper pollution were suppressed during the whole rice growth, however, the contents of GSH and GSSG were induced at tillering and jointing stages, and then restored to the control levels in later growth under the second degree contamination of copper. With the rice growing, the content of malondialdehyde （MDA） rises continuously, but there had been no significant difference between the treatments at the same growth stage. Further studies are needed on the response mechanism of rice to Cu stress under elevated CO2.     

Phylogenetic relationship and morphological evolution in the subfamily Limenitidinae （Lepidoptera： Nymphalidae）

The mitochondrial cytochrome oxidase subunit I （CO1） gene and the nuclear elongation factor 1 α（EF-1α） gene were sequenced from 29 species of Nymphalidae （Nymphalidae, Lepidoptera）. Phylogenetic trees were constructed based on the sequences determined from the 29 species and sequences of other 36 species deposited in GenBank using the neighbor-joining （NJ）, maximum likelihood （ML） and Bayesian methods with Libythea celtis （Libytheinae） as the outgroup. Our phylogenetic trees indicated four major clades. Clade A includes three subfamilies： Apaturinae, Nymphalinae, and Limenitidinae, excluding the tribe Limenitidini; Clade B includes the subfamilies Heliconiinae and the tribe Limenitidini; Clade C includes Satyrinae, Calinaginae, Charaxinae and Morphinae; and Clade D includes subfamily Danainae. Our study suggested that the tribes Pseudergolini, Biblidini, Limenitidini and Cyrestidini should be considered as subfamilies and confirmed the interspecific relationships within the subfamily Pseudergolinae, namely Amnosia ＋（Pseudergolis ＋ （Stibochiona ＋ Dichorragia））. We then mapped three morphological characters （spot of anal angle, eyespots, and process from outer margin of hind wing） onto the phylogenetic tree constructed by ML analysis using the combined sequence data. Based on this the evolutionary patterns of these morphological characters were identified, they indicated that the three characters evolved repeatedly in the family Nymphalidae.     

Environmental evolution of Xingkai （Khanka） Lake since 200 ka by OSL dating of sand hills

Crossing the Sino-Russian boundary, Xingkai Lake is the largest freshwater lake in Northeast Asia. In addition to the lakeshore, there are four sand hills on the north side of the lake that accumulated during a period of sustainable and stable lacustrine trans gression and were preserved after depression. Analysis of well-dated stratigraphic sequences based on 18 OSL datings combined with multiple index analysis of six sites in the sand hills revealed that the north shoreline of Xingkai Lake retreated in a stepwise fashion since the middle Pleistocene, and that at least four transgressions (during 193-183 ka, 136-130 ka, 24-15 ka and since 3 ka) and three depressions occurred during this process. The results of this study confirmed that transgressive stages were concur- rent with epochs of climate cooling, whereas the period of regression corresponded to the climatic optima. Transgressions and regressions were primarily caused by variations in the intensity of alluvial accumulation in the Ussuri River Valley and fluctuations in regional temperature and humidity that were controlled by climatic change. Moreover, one obvious transgressive process that occurred in MIS3 may have been related to enhanced precipitation that was reportedly widespread in the west of China, while shortterm fluctuations in the lake level might well be a direct response to regional precipitation variations on the millennial scale.     

聚N-乙烯基己内酰胺合成及性能测试

以偶氮二异丁腈（AIBN）为引发剂、异丙醇为溶剂、N-乙烯基己内酰胺（NVCL）为单体合成了温敏性聚N-乙烯基己内酰胺（PNVCL），考察了合成条件对产品产率的影响。结果表明，在NVCL质量为6g，异丙醇体积为30mL，AIBN质量为0．04g，反应时间为14h，温度为65℃的条件下，PNVCL产率达到91．8％。用Vis，FT—IR，NMR对产品进行了温敏性测试和结构表征。结果表明，PNVCL的低，临界溶液温度（LCST）在38℃左右，且随浓度增加和无机盐的加入而减小。     

氯甲基杂萘联苯聚醚砜的制备及表征

采用杂萘联苯聚醚砜(PPES)与氯甲醚反应,制备了氯甲基杂萘联苯聚醚砜(CMPPES).用FTIR、1H-NMR等测试手段对聚合物的结构进行了表征,用氧瓶燃烧法对产物中氯含量进行了测定.为了获得不同氯甲基进程的产物,考察了溶剂、反应温度、氯甲醚用量、不同催化剂及其用量对产物中氯含量的影响,得到了特定氯含量的适宜的合成工艺条件.