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991.
对7个产地丹参(Salvia miltiorrhiza Bge.)药材进行了HPLC分析并确定了其指纹图谱的共有模式谱,在此基础上比较了7个产地丹参药材中4种菲醌类成分(二氢丹参酮Ⅰ、丹参酮Ⅰ、隐丹参酮和丹参酮ⅡA)的相对含量。结果表明:来源于不同产地的丹参药材的HPLC图谱均有21个峰,其中有8个共有峰;各共有峰的相对保留时间基本相同,RSD值均小于0.086%;但相对峰面积差异明显。以4号峰(二氢丹参酮Ⅰ)为参照峰,初步构建了丹参药材的HPLC指纹图谱的共有模式谱,7个产地丹参药材的HPLC指纹图谱与共有模式谱的相似性良好,相似度值为0.916~0.973。不同产地丹参药材中4种菲醌类成分的相对含量有明显差异,其中,河南产药材中4种菲醌类成分含量均最高,而河北产药材中均最低;此外,不同产地丹参药材中4种成分的组成比例也有明显差异。根据实验结果,建议将丹参药材的HPLC指纹图谱的共有模式谱作为丹参药材质量控制和真伪辨别的标准之一。  相似文献   
992.
993.
Inflammatory responses are controlled through members of the interleukin-1 receptor (IL-1R)/Toll-like receptor superfamily. Our earlier work demonstrates that the IL-1 receptor type 1 (IL-1RI) co-receptor, Toll-like and IL-1 receptor regulator (TILRR), amplifies IL-1 activation of NF-κB and inflammatory genes. Here we show that TILRR similarly promotes IL-1-induced anti-apoptotic signals and reduces caspase-3 activity. Further, the TILRR-induced effects on cell survival and inflammatory responses are controlled through distinct parts of the IL-1RI regulatory Toll IL-1 receptor (TIR) domain. Alanine-scanning mutagenesis identified a functional TILRR mutant (R425A), which blocked increases in cell survival and upstream activation of Akt but had no effect on amplification of MyD88-dependent inflammatory responses. A second mutant (D448A) blocked TILRR potentiation of MyD88-dependent signals and inflammatory activation but had no impact on cell survival. Secondary structure predictions suggested that the mutations induce distinct alterations in the α-helical structure of the TILRR core protein. The results indicate a role for TILRR in selective amplification of NF-κB responses through IL-1RI and suggest that the specificity is determined by changes in receptor conformation and adapter protein recruitment.  相似文献   
994.
995.
麻疯树(Jatropha curcas L. )为大戟科(Euphorbiaceae)麻疯树属(Jatropha L. )植物,果实含油量高,种仁含油量在60%左右,可用于加工提炼优质生物柴油,以替代日益紧缺的石油能源~([1-2]).近年来,由国家科学技术部和联合国开发计划署共同开展的绿色扶贫项目中,麻疯树已经在中国石漠化最为严重的贵州、四川及云南等省区试种成功.麻疯树全株有毒,其种子、树皮、叶、根和乳汁中含有多种化学成分,可作为医药和生物农药资源;其种子加工后残留的油饼中蛋白质含量较高,可作为优质肥料,经脱毒后也可作为饲料~([3]).  相似文献   
996.
997.
This study consisted of sampling benthic algae at 32 sites in the Gangqu River, an important upstream tributary of the Yangtze River. Our aims were to characterize the benthic algae communities and relationships with environmental variables. Among the 162 taxa observed, Achnanthes linearis and Achnanthes lanceolata var. elliptica were the dominant species (17.10% and 14.30% of the total relative abundance, respectively). Major gradients and principal patterns of variation within the environmental variables were detected by principal component analysis (PCA). Then non-metric multidimensional scaling (NMS) divided all the sites into three groups, which were validated by multi-response permutation procedures (MRPP). Canonical correspondence analysis (CCA) indicated that three environmental variables (TN, TDS, and TP) significantly affected the distribution of benthic algae. Weighted averaging regression and cross-calibration produced strong models for predicting TN and TDS concentration, which enabled selection of algae taxa as potentially sensitive indicators of certain TN and TDS levels: for TN, Achnanthes lanceolata, Achnanthes lanceolata var. elliptica, and Cymbella ventricosa var. semicircularis; for TDS, Cocconeis placentula, Cymbella alpina var. minuta, and Fragilaria virescens. The present study represents an early step in establishing baseline conditions. Further monitoring is suggested to gain a better understanding of this region.  相似文献   
998.
A DNA biochip for on-the-spot multiplexed pathogen identification   总被引:4,自引:0,他引:4  
Miniaturized integrated DNA analysis systems have largely been based on a multi-chamber design with microfluidic control to process the sample sequentially from one module to another. This microchip design in connection with optics involved hinders the deployment of this technology for point-of-care applications. In this work, we demonstrate the implementation of sample preparation, DNA amplification, and electrochemical detection in a single silicon and glass-based microchamber and its application for the multiplexed detection of Escherichia coli and Bacillus subtilis cells. The microdevice has a thin-film heater and temperature sensor patterned on the silicon substrate. An array of indium tin oxide (ITO) electrodes was constructed within the microchamber as the transduction element. Oligonucleotide probes specific to the target amplicons are individually positioned at each ITO surface by electrochemical copolymerization of pyrrole and pyrrole−probe conjugate. These immobilized probes were stable to the thermal cycling process and were highly selective. The DNA-based identification of the two model pathogens involved a number of steps including a thermal lysis step, magnetic particle-based isolation of the target genomes, asymmetric PCR, and electrochemical sequence-specific detection using silver-enhanced gold nanoparticles. The microchamber platform described here offers a cost-effective and sample-to-answer technology for on-site monitoring of multiple pathogens.  相似文献   
999.
Glutamyl aminopeptidase (GluAP, EC 3.4.11.7, ENPEP) is a 130-kDa homodimeric zinc metallopeptidase which specifically cleaves the N-terminal glutamate or aspartate residue of peptidic substrates such as cholecystokinin-8 or angiotensin (Ang) II, in vitro. We used a DNA microarray hybridization (Genechip Rat Expression Array 230A, Affymetrix Inc., Santa Clara, CA, USA) to demonstrate that GluAP was upregulated in osteogenic induced rat bone marrow stromal cells (BMSCs). To compare the expression of GluAP in the osteogenic differentiation and non-osteogenic differentiation of rat BMSCs in vitro, the cells were osteogenic induced in vitro. We also performed an MTT assay, alkaline phosphatase assay, alizarin red staining, and an immunohistochemical analysis to determine the osteogenic differentiation of BMSCs. The expression of GluAP was examined by real-time polymerase chain reaction (PCR). The real-time PCR results showed that GluAP was upregulated in osteogenic differentiated BMSCs in vitro, suggesting that GluAP may be correlated with the osteogenic differentiation of BMSCs.  相似文献   
1000.
SMAD3介导TGF-β1抑制MMP9在COS7细胞中的表达   总被引:3,自引:0,他引:3  
用明胶酶谱的方法检查了野生型和Smad3ex8 ex8纯合突变小鼠血清中基质金属蛋白酶(MMP9)的活性 .发现突变小鼠血清中MMP9的含量较正常小鼠的明显增高 ,提示SMAD3有抑制MMP9表达的功能 .通过细胞转染实验证实 ,TGF β1和野生型的SMAD3可以抑制COS7细胞分泌MMP9,而C端缺失的突变型Smad3基因过表达可以解除这种抑制作用 ,说明SMAD3介导TGF β1信号抑制MMP9在COS7细胞中的表达 .  相似文献   
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