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排序方式: 共有341条查询结果,搜索用时 15 毫秒
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Jin-yi Wu Almutamad Sheikho He Ma Tian-ci Li Ya-qi Zhao Ya-lin Zhang Dun Wang 《Cytotechnology》2017,69(6):875-883
Bombyx batryticatus is a traditional Chinese medicine. To understand apoptotic effect of B. batryticatus ethanol extract (BBE), we investigated the role of BBE in inducing apoptosis of human gastric cancer cells SGC-7901. Cells treated with BBE and apoptosis was assessed by methyl thiazolyl tetrazolium (MTT) assay, morphological changes, DNA fragmentation and flow cytometry assays. The expression of Bcl-2, Bax and P21 were evaluated by western blot analysis and real time polymerase chain reaction. MTT assay showed that the cytotoxicity of BBE extract on SGC-7901 cells was correlated with treatment time and concentration. After treatment with 6 mg/mL of BBE the microscopy showed that, the majority of SGC-7901 cells were obviously reduced, distorted and grew slowly. Annexin-V/propidium iodide double-staining assay emerge the early apoptosis and the late apoptosis after treatment with different times by laser confocal fluorescence microscopy and flow cytometer. Cell cycle analysis of SGC 79 cells showed that BBE induced cell cycle arrest in the G1 and G2 phases. DNA fragmentation indicated the trend of BBE inducing apoptosis on SGC-7901 cells. The qRT-PCR and western blot analysis indicated that the mRNA and protein expressions of Bax and P21 were significantly up-regulated whereas that of Bc1-2 was down-regulated after treatment with BBE for 24 h. Our results revealed a correlation between gene regulation and BBE-induced apoptosis, which might indicate the potential of BBE in cancer therapy. 相似文献
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Peripheral Lipopolysaccharide Challenge Induces Long‐Term Changes in Tyrosine Hydroxylase Regulation in the Adrenal Medulla 下载免费PDF全文
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We herein report an electrochemical biosensor for the sequence-specific detection of DNA with high discrimination ability for single-nucleotide polymorphisms (SNPs). This DNA sensor was constructed by a pair of flanking probes that "sandwiched" the target. A 16-electrode electrochemical sensor array was employed, each having one individual DNA capture probe immobilized at gold electrodes via gold-thiol chemistry. By coupling with a biotin-tagged detection probe, we were able to detect multiple DNA targets with a single array. In order to realize SNP detection, a ligase-based approach was employed. In this method, both the capture probe and the detection probe were in tandem upon being hybridized with the target. Importantly, we employed a ligase that specifically could ligate tandem sequences only in the absence of mismatches. As a result, when both probes were complementary to the target, they were ligated in the presence of the ligase, thus being retained at the surface during the subsequent stringent washing steps. In contrast, if there existed 1-base mismatch, which could be efficiently recognized by the ligase, the detection probe was not ligated and subsequently washed away. A conjugate of avidin-horseradish peroxidase was then attached to the biotin label at the end of the detection probe via the biotin-avidin bridge. We then electrochemically interrogated the electrical current for the peroxidase-catalyzed reduction of hydrogen peroxide. We demonstrated that the electrochemical signal for the wild-type DNA was significantly larger than that for the sequence harboring the SNP. 相似文献
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In order to explore the relationship between the pollinator and pollination syndromes, and to evaluate the possibility of predicting likely pollinators based on pollination syndromes, the pollination biology of Paphiopedilum dianthum was examined. This species shares a close phylogenetic relationship, similar habit, and a recognizable syndrome of floral features (including helmet-shaped labellum, big dorsal sepal, and black warts or hairs on petals) with other brood-site deceptive Paphiopedilum species. According to the pollination syndrome concept, P. dianthum would be pollinated by hoverflies and attract pollinators with brood-site deception. Results were consistent with this prediction. Paphiopedilum dianthum was mainly pollinated by female hoverflies (Episyrphus balteatus), and these flies were indeed lured by the false brood-site on the orchid flower. It is suggested that the pollination syndrome may be correlated with pollination selective pressure, but not simply with pollinator species, and that accurate prediction requires consideration of all factors influencing floral characters, including habit and evolutionary history. 相似文献
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Pasquier CM; Promponas VI; Varvayannis NJ; Hamodrakas SJ 《Bioinformatics (Oxford, England)》1998,14(8):749-750
Summary : FT is a tool written in C++, which implements the Fourier
analysis method to locate periodicities in aminoacid or DNA sequences. It
is provided for free public use on a WWW server with a Java interface.
Availability : The server address is http://o2.db. uoa.gr/FT Contact :
shamodr@atlas.uoa.gr
相似文献
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结合膜片钳测量的味觉感受细胞离子通道实验数据,提出了一个哺乳动物味觉感受细胞动作电位的数学模型.首先,建立了味觉感受细胞的电压门控Na+通道和外向延迟整流K+通道的模型,在此基础上建立了味觉感受细胞的单细胞计算模型.其次,仿真研究了味觉感受细胞在电刺激和酸味刺激下产生的动作电位,以及离子通道动力学特性对其的影响.该模型对于研究味觉感受细胞在味觉物质刺激下产生的动作电位及其离子通道的工作机制,以及味觉信息在外周神经的传递和信息编码具有指导意义。 相似文献
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