51 research outputs found

    Experimental study of pipe-pile-based micro-scale compressed air energy storage (PPMS-CAES) for a building

    Get PDF
    Compressed air energy storage (CAES) technology has been re-emerging as one of the promising options to address the challenge coming from the intermittency of renewable energy resources. Unlike the large-scale CAES, which is limited by the geologic location, small- and micro-scale CAES that uses a human-made pressure vessel is adaptable for both grid-connected and standalone distributed units equipped with the energy generation capacity. The research team recently suggested a new concept of pipe- pile-based micro-scale CAES (PPMS-CAES) that uses pipe-pile foundations of a building as compressed air storage vessels. To ascertain the mechanical feasibility of the new concept, we conducted lab-scale pile loading tests with a model test pile in both a loose and dense soil chamber that emulates an actual closed- ended pipe pile. The test pile was subjected to a repeated cycle of compressed air charge (to Pmax=10 MPa) and discharge (to Pmin=0.1 MPa) during the experimental study. The displacement at the top of the test pile, with and without a structural loading, in loose and dense sand, was closely monitored during the repetitive air pressurization-and-depressurization. It was observed that the vertical displacement at the pile head under different conditions was accumulated during the extended cycle of air charge and discharge, but the rate of displacement gradually attenuates during the cycle. And, the presence of structural load and density of soil affected the magnitude of the accumulated vertical displacement. From the analysis, it can be concluded that the concept of PPMS-CAES is not likely to compromise the mechanical integrity of pipe piles while showing a promising capacity for energy storage

    Involvement of the accumbal osteopontin-interacting transmembrane protein 168 in methamphetamine-induced place preference and hyperlocomotion in mice

    Get PDF
    Chronic exposure to methamphetamine causes adaptive changes in brain, which underlie dependence symptoms. We have found that the transmembrane protein 168 (TMEM168) is overexpressed in the nucleus accumbens of mice upon repeated methamphetamine administration. Here, we firstly demonstrate the inhibitory effect of TMEM168 on methamphetamine-induced behavioral changes in mice, and attempt to elucidate the mechanism of this inhibition. We overexpressed TMEM168 in the nucleus accumbens of mice by using an adeno-associated virus vector (NAc-TMEM mice). Methamphetamine-induced hyperlocomotion and conditioned place preference were attenuated in NAc-TMEM mice. Additionally, methamphetamine-induced extracellular dopamine elevation was suppressed in the nucleus accumbens of NAc-TMEM mice. Next, we identified extracellular matrix protein osteopontin as an interacting partner of TMEM168, by conducting immunoprecipitation in cultured COS-7 cells. TMEM168 overexpression in COS-7 cells induced the enhancement of extracellular and intracellular osteopontin. Similarly, osteopontin enhancement was also observed in the nucleus accumbens of NAc-TMEM mice, in in vivo studies. Furthermore, the infusion of osteopontin proteins into the nucleus accumbens of mice was found to inhibit methamphetamine-induced hyperlocomotion and conditioned place preference. Our studies suggest that the TMEM168-regulated osteopontin system is a novel target pathway for the therapy of methamphetamine dependence, via regulating the dopaminergic function in the nucleus accumbens

    Histone deacetylase controls adult stem cell aging by balancing the expression of polycomb genes and jumonji domain containing 3

    Get PDF
    Aging is linked to loss of the self-renewal capacity of adult stem cells. Here, we observed that human multipotent stem cells (MSCs) underwent cellular senescence in vitro. Decreased expression of histone deacetylases (HDACs), followed by downregulation of polycomb group genes (PcGs), such as BMI1, EZH2 and SUZ12, and by upregulation of jumonji domain containing 3 (JMJD3), was observed in senescent MSCs. Similarly, HDAC inhibitors induced cellular senescence through downregulation of PcGs and upregulation of JMJD3. Regulation of PcGs was associated with HDAC inhibitor-induced hypophosphorylation of RB, which causes RB to bind to and decrease the transcriptional activity of E2F. JMJD3 expression regulation was dependant on histone acetylation status at its promoter regions. A histone acetyltransferase (HAT) inhibitor prevented replicative senescence of MSCs. These results suggest that HDAC activity might be important for MSC self-renewal by balancing PcGs and JMJD3 expression, which govern cellular senescence by p16INK4A regulation

    Comparison of Clinico-Physiologic and CT Imaging Risk Factors for COPD Exacerbation

    Get PDF
    To date, clinico-physiologic indices have not been compared with quantitative CT imaging indices in determining the risk of chronic obstructive pulmonary disease (COPD) exacerbation. We therefore compared clinico-physiologic and CT imaging indices as risk factors for COPD exacerbation in patients with COPD. We retrospectively analyzed 260 COPD patients from pulmonary clinics at 11 hospitals in Korea from June 2005 to November 2009 and followed-up for at least one year. At the time of enrollment, none of these patients had COPD exacerbations for at least 2 months. All underwent clinico-physiologic and radiological evaluation for risk factors of COPD exacerbation. After 1 yr, 106 of the 260 patients had at least one exacerbation of COPD. Multiple logistic regression analysis showed that old age, high Charlson Index, and low FEV1 were significant in a clinico-physiologic model, with C-statistics of 0.69, and that increased age and emphysema index were significant in a radiologic model, with C-statistics of 0.64. The difference between the two models was statistically significant (P = 0.04 by bootstrap analysis). Combinations of clinico-physiologic risk factors may be better than those of imaging risk factors in predicting COPD exacerbation

    Histone deacetylase regulates high mobility group A2-targeting microRNAs in human cord blood-derived multipotent stem cell aging

    Get PDF
    Cellular senescence involves a reduction in adult stem cell self-renewal, and epigenetic regulation of gene expression is one of the main underlying mechanisms. Here, we observed that the cellular senescence of human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs) caused by inhibition of histone deacetylase (HDAC) activity leads to down-regulation of high mobility group A2 (HMGA2) and, on the contrary, to up-regulation of p16INK4A, p21CIP1/WAF1 and p27KIP1. We found that let-7a1, let-7d, let-7f1, miR-23a, miR-26a and miR-30a were increased during replicative and HDAC inhibitor-mediated senescence of hUCB-MSCs by microRNA microarray and real-time quantitative PCR. Furthermore, the configurations of chromatins beading on these miRNAs were prone to transcriptional activation during HDAC inhibitor-mediated senescence. We confirmed that miR-23a, miR-26a and miR-30a inhibit HMGA2 to accelerate the progress of senescence. These findings suggest that HDACs may play important roles in cellular senescence by regulating the expression of miRNAs that target HMGA2 through histone modification

    Poxvirus-based vaccine therapy for patients with advanced pancreatic cancer

    Get PDF
    <p>Abstract</p> <p>Purpose</p> <p>An open-label Phase 1 study of recombinant prime-boost poxviruses targeting CEA and MUC-1 in patients with advanced pancreatic cancer was conducted to determine safety, tolerability and obtain preliminary data on immune response and survival.</p> <p>Patients and methods</p> <p>Ten patients with advanced pancreatic cancer were treated on a Phase I clinical trial. The vaccination regimen consisted of vaccinia virus expressing tumor antigens carcinoembryonic antigen (CEA) and mucin-1 (MUC-1) with three costimulatory molecules B7.1, ICAM-1 and LFA-3 (TRICOM) (PANVAC-V) and fowlpox virus expressing the same antigens and costimulatory molecules (PANVAC-F). Patients were primed with PANVAC-V followed by three booster vaccinations using PANVAC-F. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was used as a local adjuvant after each vaccination and for 3 consecutive days thereafter. Monthly booster vaccinations for up to 12 months were provided for patients without progressive disease. Peripheral blood was collected before, during and after vaccinations for immune analysis.</p> <p>Results</p> <p>The most common treatment-related adverse events were mild injection-site reactions. Antibody responses against vaccinia virus was observed in all 10 patients and antigen-specific T cell responses were observed in 5 out of 8 evaluable patients (62.5%). Median overall survival was 6.3 months and a significant increase in overall survival was noted in patients who generated anti CEA- and/or MUC-1-specific immune responses compared with those who did not (15.1 vs 3.9 months, respectively; <it>P </it>= .002).</p> <p>Conclusion</p> <p>Poxvirus vaccination is safe, well tolerated, and capable of generating antigen-specific immune responses in patients with advanced pancreatic cancer.</p

    DNA Methyltransferase Controls Stem Cell Aging by Regulating BMI1 and EZH2 through MicroRNAs

    Get PDF
    Epigenetic regulation of gene expression is well known mechanism that regulates cellular senescence of cancer cells. Here we show that inhibition of DNA methyltransferases (DNMTs) with 5-azacytidine (5-AzaC) or with specific small interfering RNA (siRNA) against DNMT1 and 3b induced the cellular senescence of human umbilical cord blood-derived multipotent stem cells (hUCB-MSCs) and increased p16INK4A and p21CIP1/WAF1 expression. DNMT inhibition changed histone marks into the active forms and decreased the methylation of CpG islands in the p16INK4A and p21CIP1/WAF1 promoter regions. Enrichment of EZH2, the key factor that methylates histone H3 lysine 9 and 27 residues, was decreased on the p16INK4A and p21CIP1/WAF1 promoter regions. We found that DNMT inhibition decreased expression levels of Polycomb-group (PcG) proteins and increased expression of microRNAs (miRNAs), which target PcG proteins. Decreased CpG island methylation and increased levels of active histone marks at genomic regions encoding miRNAs were observed after 5-AzaC treatment. Taken together, DNMTs have a critical role in regulating the cellular senescence of hUCB-MSCs through controlling not only the DNA methylation status but also active/inactive histone marks at genomic regions of PcG-targeting miRNAs and p16INK4A and p21CIP1/WAF1 promoter regions

    Experimental study of pipe-pile-based micro-scale compressed air energy storage (PPMS-CAES) for a building

    Get PDF
    Compressed air energy storage (CAES) technology has been re-emerging as one of the promising options to address the challenge coming from the intermittency of renewable energy resources. Unlike the large-scale CAES, which is limited by the geologic location, small- and micro-scale CAES that uses a human-made pressure vessel is adaptable for both grid-connected and standalone distributed units equipped with the energy generation capacity. The research team recently suggested a new concept of pipe- pile-based micro-scale CAES (PPMS-CAES) that uses pipe-pile foundations of a building as compressed air storage vessels. To ascertain the mechanical feasibility of the new concept, we conducted lab-scale pile loading tests with a model test pile in both a loose and dense soil chamber that emulates an actual closed- ended pipe pile. The test pile was subjected to a repeated cycle of compressed air charge (to Pmax=10 MPa) and discharge (to Pmin=0.1 MPa) during the experimental study. The displacement at the top of the test pile, with and without a structural loading, in loose and dense sand, was closely monitored during the repetitive air pressurization-and-depressurization. It was observed that the vertical displacement at the pile head under different conditions was accumulated during the extended cycle of air charge and discharge, but the rate of displacement gradually attenuates during the cycle. And, the presence of structural load and density of soil affected the magnitude of the accumulated vertical displacement. From the analysis, it can be concluded that the concept of PPMS-CAES is not likely to compromise the mechanical integrity of pipe piles while showing a promising capacity for energy storage

    Experimental study of pipe-pile-based micro-scale compressed air energy storage (PPMS-CAES) for a building

    No full text
    Compressed air energy storage (CAES) technology has been re-emerging as one of the promising options to address the challenge coming from the intermittency of renewable energy resources. Unlike the large-scale CAES, which is limited by the geologic location, small-and micro-scale CAES that uses a human-made pressure vessel is adaptable for both grid-connected and standalone distributed units equipped with the energy generation capacity. The research team recently suggested a new concept of pipe-pile-based micro-scale CAES (PPMS-CAES) that uses pipe-pile foundations of a building as compressed air storage vessels. To ascertain the mechanical feasibility of the new concept, we conducted lab-scale pile loading tests with a model test pile in both a loose and dense soil chamber that emulates an actual closed-ended pipe pile. The test pile was subjected to a repeated cycle of compressed air charge (to Pmax=10 MPa) and discharge (to Pmin=0.1 MPa) during the experimental study. The displacement at the top of the test pile, with and without a structural loading, in loose and dense sand, was closely monitored during the repetitive air pressurization-and-depressurization. It was observed that the vertical displacement at the pile head under different conditions was accumulated during the extended cycle of air charge and discharge, but the rate of displacement gradually attenuates during the cycle. And, the presence of structural load and density of soil affected the magnitude of the accumulated vertical displacement. From the analysis, it can be concluded that the concept of PPMS-CAES is not likely to compromise the mechanical integrity of pipe piles while showing a promising capacity for energy storage

    Supercritical CO<sub>2</sub>-Induced Evolution of Alkali-Activated Slag Cements

    No full text
    The phase changes in alkali-activated slag samples when exposed to supercritical carbonation were evaluated. Ground granulated blast furnace slag was activated with five different activators. The NaOH, Na2SiO3, CaO, Na2SO4, and MgO were used as activators. C-S-H is identified as the main reaction product in all samples along with other minor reaction products. The X-ray diffractograms showed the complete decalcification of C-S-H and the formation of CaCO3 polymorphs such as calcite, aragonite, and vaterite. The thermal decomposition of carbonated samples indicates a broader range of CO2 decomposition. Formation of highly cross-linked aluminosilicate gel and a reduction in unreacted slag content upon carbonation is observed through 29Si and 27Al NMR spectroscopy. The observations indicate complete decalcification of C-S-H with formation of highly cross-linked aluminosilicates upon sCO2 carbonation. A 20–30% CO2 consumption per reacted slag under supercritical conditions is observed
    • …
    corecore