A Clustering Sleep Scheduling Mechanism Based on Sentinel Nodes Monitor for WSN

Zhan-Yang Xu,Song-Gang Zhao,Zheng-Jun Jing 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.1

This paper proposes a clustering sleep scheduling mechanism based on sentinel nodes monitoring for WSN. The mechanism combines the network clustering strategy with the node dormancy strategy, and improves the method of selecting the candidate cluster heads randomly in Energy-Efficient Unequal Clustering (EEUC) algorithm. The conception of sentinel node is introduced based on EEUC, and the neighbor node set of sentinel node will be dormant when the sentinel node’s data change rate is lower than the setting threshold. Simulation results show that this mechanism can effectively balance the energy consumption of the entire network, and significantly extend the network lifetime.

Effects of L-malic acid on alpha-glucosidase: inhibition kinetics and computational molecular dynamics simulations.

Gou, Lin,Zhan, Yi,Lee, Jinhyuk,Li, Xuan,Lü,, Zhi-Rong,Zhou, Hai-Meng,Lu, Hang,Wang, Xi-Yao,Park, Yong-Doo,Yang, Jun-Mo Humana Press 2015 Applied biochemistry and biotechnology Vol.175 No.4

<P>The inhibitory effect of L-malic acid (MA) on alpha-glucosidase (EC 3.2.1.20) was investigated by combination study between inhibition kinetics and computational simulations. The results from the serial kinetics demonstrated that MA could directly inactivate the enzyme activity in a dose-dependent manner and a typical non-competitive type, as well as in a fast inactivate process without detectable time course. The tertiary conformation study with an application of spectrofluorimetry showed that MA modulated the tertiary structural conformation of alpha-glucosidase both on the overall and on regional active site pocket, which monitored by red-shift intrinsic fluorescence peak with decreases intensities, and the significant intensity increasing of 1-anilinonaphthalene-8-sulfonate (ANS)-binding fluorescence, respectively. To have more insight, we also adapted the computational molecular dynamics (MD) simulations. The results showed that MA was located in the entrance of active pocket for the catalytic reaction and blocked the passage of substrate. It confirmed that MA inhibits as a non-competitive type, not direct docking to the glucose binding site. Our study provides important molecular mechanisms to figure out alpha-glucosidase inhibition that might associate to development of type 2 diabetes mellitus drug.</P>

Antioxidant Flavone Glycosides from the Root of Pteroxygonum giraldii

Li, Bao-Lin,Yang, Zhan-Jun,Jiang, Lin-Ling,Zhang, Xi-Quan,Gu, Hong-Mei,Wang, Hui-Chun,Tian, Xian-Hua Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.7

Two new flavone glycosides, giraldiin A and B, together with three known compounds, annulatin, myricetin 3-O-$\alpha$- L-rhamnopyranoside and gallic acid, were isolated from the ethanol extract of the root of Pteroxygonum giraldii Damm. et Diels. The structures of giraldiin A and B are designated as 3'-($\alpha$-L-arabinopyranosyloxy)-4',5,5',7- tetrahydroxy-3-methoxyflavone and 4'-($\beta$-D-glucopyranosyloxy)-5,5',7-trihydroxy-2',3-dimethoxyflavone, respectively, on the basis of detailed spectroscopic analyses. The free radical scavenging activity of giraldiin A was evaluated by decolouring spectrophotometry of pentamethine cyanine dye (Cy5) with $Fe^{2+}-H_2O_2$ Fenton radical generating system. The results indicated the hydroxyl free radical scavenging activity of giraldiin A (E$D_{50}$ = 23.7 nmol/mL) is higher than that of some known antioxidants such as rutin, puerarin, daidzein and 2,6-di-tertbutyl-4-methylphenol.

Radiosensitivity Enhancement by Arsenic Trioxide in Conjunction with Hyperthermia in the EC-1 Esophageal Carcinoma Cell Line

Cui, Yan-Hui,Liang, Hai-Jun,Zhang, Qing-Qin,Li, Si-Qing,Li, Xiao-Rui,Huo, Xiao-Qing,Yang, Qing-Hui,Li, Wei-Wei,Gu, Jian-Fa,Hua, Qin-Liang,Lu, Ping,Miao, Zhan-Hui Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Objective: To explore the effect on radiosensitivity of arsenic trioxide ($As_20_3$) in conjunction with hyperthermia on the esophageal carcinoma EC-1 cell line. Method: Inhibition of EC-1 cell proliferation at different concentrations of $As_20_3$ was assessed using the methyl thiazolyl blue colorimetric method (MTT method), with calculation of $IC_{50}$ value and choice of 20% of the $IC_{50}$ as the experimental drug concentration. Blank control, $As_20_3$, hyperthermia, radiotherapy group, $As_20_3$ + hyperthermia, $As_20_3$ + radiotherapy, hyperthermia + radiotherapy and $As_20_3$ + hyperthermia + radiotherapy groups were established, and the cell survival fraction (SF) was calculated from flat panel colony forming analysis, and fitted by the 'multitarget click mathematical model'. Flow cytometry (FCM) was used to detect changes in cell apoptosis and the cell cycle. Results: $As_20_3$ exerted inhibitory effects on proliferation of esophageal carcinoma EC-1 cells, with an $IC_{50}$ of 18.7 ${\mu}mol/L$. After joint therapy of $As_20_3$ + hyperthermia + radiotherapy, the results of FCM showed that cells could be arrested in the $G_2$/M phase, and as the ratio of cells in $G_0/G_1$ and S phases decreased, cell death became more pronounced. Conclusion: $As_20_3$ and hyperthermia exert radiosensitivity effects on esophageal carcinoma EC-1 cells, with synergy in combination. Mechanistically, $As_20_3$ and hyperthermia mainly influence the cell cycle distribution of EC-1 esophageal carcinoma cells, decreasing the repair of sublethal damage and inducing apoptosis, thereby enhancing the killing effects of radioactive rays.

Network Analyses of Gene Expression following Fascin Knockdown in Esophageal Squamous Cell Carcinoma Cells

Du, Ze-Peng,Wu, Bing-Li,Xie, Jian-Jun,Lin, Xuan-Hao,Qiu, Xiao-Yang,Zhan, Xiao-Fen,Wang, Shao-Hong,Shen, Jin-Hui,Li, En-Min,Xu, Li-Yan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.13

Fascin-1 (FSCN1) is an actin-bundling protein that induces cell membrane protrusions, increases cell motility, and is overexpressed in various human epithelial cancers, including esophageal squamous cell carcinoma (ESCC). We analyzed various protein-protein interactions (PPI) of differentially-expressed genes (DEGs), in fascin knockdown ESCC cells, to explore the role of fascin overexpression. The node-degree distributions indicated these PPI sub-networks to be characterized as scale-free. Subcellular localization analysis revealed DEGs to interact with other proteins directly or indirectly, distributed in multiple layers of extracellular membrane-cytoskeleton/ cytoplasm-nucleus. The functional annotation map revealed hundreds of significant gene ontology (GO) terms, especially those associated with cytoskeleton organization of FSCN1. The Random Walk with Restart algorithm was applied to identify the prioritizations of these DEGs when considering their relationship with FSCN1. These analyses based on PPI network have greatly expanded our comprehension of the mRNA expression profile following fascin knockdown to future examine the roles and mechanisms of fascin action.

Antioxidant Flavone Glycosides from the Root of Pteroxygonum giraldii

Bao-Lin Li,Lin-Ling Jiang,Hui-Chun Wang,Zhan-Jun Yang,Xi-Quan Zhang,Hong-Mei Gu,Xian-Hua Tian 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.7

Two new flavone glycosides, giraldiin A and B, together with three known compounds, annulatin, myricetin 3-O-α-L-rhamnopyranoside and gallic acid, were isolated from the ethanol extract of the root of Pteroxygonum giraldii Damm. et Diels. The structures of giraldiin A and B are designated as 3'-(α-L-arabinopyranosyloxy)-4',5,5',7-tetrahydroxy-3-methoxyflavone and 4'-(β-D-glucopyranosyloxy)-5,5',7-trihydroxy-2',3-dimethoxyflavone, respectively,on the basis of detailed spectroscopic analyses. The free radical scavenging activity of giraldiin A was evaluated by decolouring spectrophotometry of pentamethine cyanine dye (Cy5) with Fe2+-H2O2 Fenton radical generating system. The results indicated the hydroxyl free radical scavenging activity of giraldiin A (ED50 = 23.7 nmol/mL) is higher than that of some known antioxidants such as rutin, puerarin, daidzein and 2,6-di-tertbutyl-4-methylphenol.

Alu Tandem Sequences Inhibit GFP Gene Expression by Triggering Chromatin Wrapping

Xiu Fang Wang,Xiao Yan Wang,Jing Liu,Jing Jing Feng,Wen Li Mu,Xiao Juan Shi,Qin Qing Yang,Xiao Cui Duan,Ying Xie,Zhan Jun Lu 한국유전학회 2009 Genes & Genomics Vol.31 No.3

Alu elements belonging to the short interspersed nuclear elements (SINE) of repetitive elements are present in more than one million copies which altogether represent 10% of the whole human genome. In this study, the roles of Alu tandem sequences in the process of GFP gene (GFP) expression and packing into chromatin of its DNA were studied. To detect the effect of Alu repeats on gene expression, different copies of Alus were inserted GFP downstream respectively in pEGFP-C1 vector. We found that Alu sequences decreased the amount of GFP transcription, the percentage of GFP positive cells and the accessibility to DNase I in length-dependent manner. Inserting Alu caused the production of higher-molecular-mass RNA, indicating Alu sequence did not induce premature transcriptional termination. Tight packing chromatins keep silent and resist to DNase I digestion, which is a general phenomenon. We suggested that head and tail tandem Alu sequences suppressed GFP expression in length dependent manner by triggering chromatin packing.