43 research outputs found

    Enhancement of Memory-Related Long-Term Facilitation by ApAF, a Novel Transcription Factor that Acts Downstream from Both CREB1 and CREB2

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    AbstractThe memory for sensitization of the gill withdrawal reflex in Aplysia is reflected in facilitation of the monosynaptic connection between the sensory and motor neurons of the reflex. The switch from short- to long-term facilitation requires activation of CREB1, derepression of ApCREB2, and induction of ApC/EBP. In search for genes that act downstream from CREB1, we have identified a transcription activator, ApAF, which is stimulated by protein kinase A and can dimerize with both ApC/EBP and ApCREB2. ApAF is necessary for long-term facilitation induced by five pulses of serotonin, by activation of CREB1, or by derepression of ApCREB2. Overexpression of ApAF enhances the long-term facilitation further. Thus, ApAF is a candidate memory enhancer gene downstream from both CREB1 and ApCREB2

    A Transient, Neuron-Wide Form of CREB-Mediated Long-Term Facilitation Can Be Stabilized at Specific Synapses by Local Protein Synthesis

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    AbstractIn a culture system where a bifurcated Aplysia sensory neuron makes synapses with two motor neurons, repeated application of serotonin (5-HT) to one synapse produces a CREB-mediated, synapse-specific, long-term facilitation, which can be captured at the opposite synapse by a single pulse of 5-HT. Repeated pulses of 5-HT applied to the cell body of the sensory neuron produce a CREB-dependent, cell-wide facilitation, which, unlike synapse-specific facilitation, is not associated with growth and does not persist beyond 48 hr. Persistent facilitation and synapse-specific growth can be induced by a single pulse of 5-HT applied to a peripheral synapse. Thus, the short-term process initiated by a single pulse of 5-HT serves not only to produce transient facilitation, but also to mark and stabilize any synapse of the neuron for long-term facilitation by means of a covalent mark and rapamycin-sensitive local protein synthesis

    Design and Implementation of Platform for Embedded Ethernet Control System

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    Full text : http://www.medwelljournals.com/fulltext/ijsscea/2008/180-187.pdfInternational audienceA platform named EMECS based on embedded Ethernet control system is implemented. A PC running Fedora 6 (Linux 2.6) works as a central controller. A kit running Linux 2.4 based on Samsung 2410A (ARM920 t core) works as a remote controller and a DC motor (ESCAP 28HSL18-219/204) made by Portescap Company works as a plant. Firstly, system modeling is presented by analyzing the characteristics of Ethernet and the plant, based on a method of delay measurement proposed. Secondly, implementation of the system including program and hardware is described in detail, respectively. And then delay is measured and control results of the system are tested in three cases with different network load as well. The platform is proved to have flexibility to run different control algorithms and extensibility to add nodes. The results of experiment demonstrate the validity of the system

    An integrated strategy for packet dropout in internet-based control system

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    ISBN: 978-1-4244-3908-9International audiencePacket dropout is one of the key issues which degrade performances of Internet-based Control System(ICS). An integrated strategy composed of active part and passive part to solve this problem is proposed in this paper. In the active part, the priority of control packets in ICS can be improved through differentiated services which decrease probability of control packet dropout. While in the passive part, a data packet dropout compensator is established to reduce the negative influence of packet dropout. The sufficient conditions for stabilizing the new result model are derived in the form of linear matrix inequalities (LMI). At last, the solvability and effectiveness of the results is evaluated using NS2

    Comparison of Serum MicroRNA21 and Tumor Markers in Diagnosis of Early Non-Small Cell Lung Cancer

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    Objective. To compare the clinical value of serum microRNA21 (miR21) and other tumor markers in early diagnosis of non-small cell lung cancer (NSCLC). Methods. Serums carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA21-1), neuron-specific enolase (NSE), and miR21 were detected in 50 NSCLC cases and 60 healthy control individuals. Results. Average serums miR21, CEA, NSE, and CYFRA21-1 levels were significantly higher in the case group than in control group (P<0.01). Analysis of areas under the receiver operating characteristic (ROC) curve (AUC) revealed that CEA had the highest diagnostic efficiency for NSCLC. Serums miR21 and CYFRA21-1 levels were significantly lower at TNM stages I-II than stages III-IV (P<0.05). Further, logistic multivariate regression analysis showed that the incidence of early NSCLC (TNM stages I-II) was correlated with serums CYFRA21-1 (OR = 1.076) and miR21 (OR = 2.473) levels (P<0.05). By AUC analysis, miR21 had the highest diagnostic efficiency for early NSCLC, and single or combined detection of serums CYFRA21-1 and miR21 levels showed improved diagnostic efficiency for joint detection of both markers. Conclusions. Serum miR21 could serve as an important marker for auxiliary diagnosis of early NSCLC, while joint detection of serums miR21 and CYFRA21-1 levels could improve diagnostic efficiency

    Fluorofenidone alleviates liver fibrosis by inhibiting hepatic stellate cell autophagy via the TGF-β1/Smad pathway: implications for liver cancer

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    Objectives Liver fibrosis is a key stage in the progression of various chronic liver diseases to cirrhosis and liver cancer, but at present, there is no effective treatment. This study investigated the therapeutic effect of the new antifibrotic drug fluorofenidone (AKF-PD) on liver fibrosis and its related mechanism, providing implications for liver cancer. Materials and Methods The effects of AKF-PD on hepatic stellate cell (HSC) autophagy and extracellular matrix (ECM) expression were assessed in a carbon tetrachloride (CCl4)-induced rat liver fibrosis model. In vitro, HSC-T6 cells were transfected with Smad2 and Smad3 overexpression plasmids and treated with AKF-PD. The viability and number of autophagosomes in HSC-T6 cells were examined. The protein expression levels of Beclin-1, LC3 and P62 were examined by Western blotting. The Cancer Genome Atlas (TCGA) database was used for comprehensively analyzing the prognostic values of SMAD2 and SMAD3 in liver cancer. The correlation between SMAD2, SMAD3, and autophagy-related scores in liver cancer was explored. The drug prediction of autophagy-related scores in liver cancer was explored. Results AKF-PD attenuated liver injury and ECM deposition in the CCl4-induced liver fibrosis model. In vitro, the viability and number of autophagosomes in HSCs were reduced significantly by AKF-PD treatment. Meanwhile, the protein expression of FN, α-SMA, collagen III, Beclin-1 and LC3 was increased, and P62 was reduced by the overexpression of Smad2 and Smad3; however, AKF-PD reversed these effects. SMAD2 and SMAD3 were hazardous factors in liver cancer. SMAD2 and SMAD3 correlated with autophagy-related scores in liver cancer. Autophagy-related scores could predict drug response in liver cancer. Conclusions AKF-PD alleviates liver fibrosis by inhibiting HSC autophagy via the transforming growth factor (TGF)-β1/Smadpathway. Our study provided some implications about how liver fibrosis was connected with liver cancer by SMAD2/SMAD3 and autophagy

    Binder-free graphene foams for O2 electrodes of Li-O2 batteries

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    We report a novel method to prepare bind-free graphene foams as O2 electrodes for Li–O2 batteries. The graphene foams are synthesized by electrochemical leavening of the graphite papers, followed by annealing in inert gas to control the amount of structural defects in the graphene foams. It was found that the structural defects were detrimental to the processes of the ORR and OER in Li–O2 batteries. The round-trip efficiencies and the cycling stabilities of the graphene foams were undermined by the structural defects. For example, the as-prepared graphene foam with a high defect level (ID/IG = 0.71) depicted a round-trip efficiency of only 0.51 and a 20th-cycle discharge capacity of only 340 mA h g−1 at a current density of 100 mA g−1. By contrast, the graphene foam electrode annealed at 800 °C with ID/IG = 0.07 delivered a round-trip efficiency of up to 80% with a stable discharge voltage at 2.8 V and a stable charge voltage below 3.8 V for 20 cycles. According to the analysis on the electrodes after 20 cycles, the structural defects led to the quickened decay of the graphene foams and boosted the formation of side products

    Self-Healable Electro-Conductive Hydrogels Based on Core-Shell Structured Nanocellulose/Carbon Nanotubes Hybrids for Use as Flexible Supercapacitors

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    Recently, with the development of personal wearable electronic devices, the demand for portable power is miniaturization and flexibility. Electro-conductive hydrogels (ECHs) are considered to have great application prospects in portable energy-storage devices. However, the synergistic properties of self-healability, viscoelasticity, and ideal electrochemistry are key problems. Herein, a novel ECH was synthesized by combining polyvinyl alcohol-borax (PVA) hydrogel matrix and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-cellulose nanofibers (TOCNFs), carbon nanotubes (CNTs), and polyaniline (PANI). Among them, CNTs provided excellent electrical conductivity; TOCNFs acted as a dispersant to help CNTs form a stable suspension; PANI enhanced electrochemical performance by forming a core-shell structural composite. The freeze-standing composite hydrogel with a hierarchical 3D-network structure possessed the compression stress (~152 kPa) and storage modulus (~18.2 kPa). The composite hydrogel also possessed low density (~1.2 g cm), high water-content (~95%), excellent flexibility, self-healing capability, electrical conductivity (15.3 S m), and specific capacitance of 226.8 F g at 0.4 A g. The fabricated solid-state all-in-one supercapacitor device remained capacitance retention (~90%) after 10 cutting/healing cycles and capacitance retention (~85%) after 1000 bending cycles. The novel ECH had potential applications in advanced personalized wearable electronic devices

    Inhibition of Abl Kinase by Imatinib Can Rescue the Compromised Barrier Function of 22q11.2DS Patient-iPSC-Derived Blood&ndash;Brain Barriers

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    We have previously established that the integrity of the induced blood&ndash;brain barrier (iBBB) formed by brain microvascular endothelial cells derived from the iPSC of 22q11.2 DS (22q11.2 Deletion Syndrome, also called DiGeorge Syndrome) patients is compromised. We tested the possibility that the haploinsufficiency of CRKL, a gene within the 22q11.2 DS deletion region, contributes to the deficit. The CRKL is a major substrate of the Abl tyrosine kinase, and the Abl/CRKL signaling pathway is critical for endothelial barrier functions. Imatinib, an FDA-approved drug, inhibits Abl kinase and has been used to treat various disorders involving vascular leakages. To test if imatinib can restore the compromised iBBB, we treated the patient&rsquo;s iBBB with imatinib. After treatment, both trans-endothelial electrical resistance and solute permeability returned to comparable levels of the control iBBB. Correspondingly, changes in tight junctions and endothelial glycocalyx of the iBBB were also restored. Western blotting showed that imatinib increased the level of active forms of the CRKL protein. A transcriptome study revealed that imatinib up-regulated genes in the signaling pathways responsible for the protein modification process and down-regulated those for cell cycling. The KEGG pathway analysis further suggested that imatinib improved the gene expression of the CRKL signaling pathway and tight junctions, which agrees with our expectations and the observations at protein levels. Our results indicate that the 22q11.2DS iBBB is at least partially caused by the haploinsufficiency of CRKL, which can be rescued by imatinib via its effects on the Abl/CRKL signaling pathway. Our findings uncover a novel disease mechanism associated with 22q11.2DS
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