812 research outputs found

    Leukoaraiosis is associated with pneumonia after acute ischemic stroke

    Get PDF
    Diagnostic criteria for stroke associated pneumonia based on the CDC criteria. (DOCX 25 kb

    Investigation on the calibration for the membrane type heat flux sensor using micro heater

    Get PDF
    This paper presents the calibration accuracy of the membrane type heat flux sensor using micro heater. The directional heat flow rate into the thermal sensor is simulated with FEM to estimate the heat flux from micro heater for calibration. Thin film thermopile which is fabricated on the dielectric membrane directly converts the temperature difference between hot and cold junctions of thermopile into heat flux signal created by the thermoelectric effect. However, symmetric design of thermopile is restricted to only measure x-directional heat flow rate, when heat also propagates through y direction via heat conduction and z direction with convection. Therefore, it is highly needed to investigate how amount of heat from the micro heater contributes to the calibration of heat flux sensor. In the case of the calibration using micro heater, heat conduction through the membrane dominates heat flow. Thus, 97% of heat flow from micro heater propagates through the thermopile and generates 1.038 V/W of sensitivity that was estimated by the simulated model as 1.066 V/W. On the other hand, in case of water filled micro channel, 87% of heat flow reaches to thermopile and estimated 0.392 V/W of sensitivity. This heat loss leads to the inaccurate calibration as well as the lowered sensitivity.Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016

    Coordination tuning of cobalt phosphates towards efficient water oxidation catalyst

    Get PDF
    The development of efficient and stable water oxidation catalysts is necessary for the realization of practically viable water-splitting systems. Although extensive studies have focused on the metal-oxide catalysts, the effect of metal coordination on the catalytic ability remains still elusive. Here we select four cobalt-based phosphate catalysts with various cobalt-and phosphate-group coordination as a platform to better understand the catalytic activity of cobalt-based materials. Although they exhibit various catalytic activities and stabilities during water oxidation, Na2CoP2O7 with distorted cobalt tetrahedral geometry shows high activity comparable to that of amorphous cobalt phosphate under neutral conditions, along with high structural stability. First-principles calculations suggest that the surface reorganization by the pyrophosphate ligand induces a highly distorted tetrahedral geometry, where water molecules can favourably bind, resulting in a low overpotential (similar to 0.42 eV). Our findings emphasize the importance of local cobalt coordination in the catalysis and suggest the possible effect of polyanions on the water oxidation chemistry.

    Cocoa polyphenols suppress TNF-α-induced vascular endothelial growth factor expression by inhibiting phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase kinase-1 (MEK1) activities in mouse epidermal cells

    Get PDF
    Cocoa polyphenols have antioxidant and anti-inflammatory effects. TNF-α is a pro-inflammatory cytokine that has a vital role in the pathogenesis of inflammatory diseases such as cancer and psoriasis. Vascular endothelial growth factor (VEGF) expression is associated with tumorigenesis, CVD, rheumatoid arthritis and psoriasis. We tested whether cocoa polyphenol extract (CPE) inhibited TNF-α-induced VEGF expression in promotion-sensitive JB6 mouse epidermal cells. CPE significantly inhibited TNF-α-induced up-regulation of VEGF via reducing TNF-α-induced activation of the nuclear transcription factors activator protein-1 (AP-1) and NF-κB, which are key regulators of VEGF expression. CPE also inhibited TNF-α-induced phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase. CPE blocked activation of their downstream kinases, p70 kDa ribosomal protein S6 kinase and p90 kDa ribosomal protein S6 kinase. CPE suppressed phosphoinositide 3-kinase (PI3K) activity via binding PI3K directly. CPE did not affect TNF-α-induced phosphorylation of mitogen-activated protein kinase kinase-1 (MEK1) but suppressed TNF-α-induced MEK1 activity. Collectively, these results indicate that CPE reduced TNF-α-induced up-regulation of VEGF by directly inhibiting PI3K and MEK1 activities, which may contribute to its chemopreventive potentia

    Quantitative Understanding of Probabilistic Behavior of Living Cells Operated by Vibrant Intracellular Networks

    Get PDF
    For quantitative understanding of probabilistic behaviors of living cells, it is essential to construct a correct mathematical description of intracellular networks interacting with complex cell environments, which has been a formidable task. Here, we present a novel model and stochastic kinetics for an intracellular network interacting with hidden cell environments, employing a complete description of cell state dynamics and its coupling to the system network. Our analysis reveals that various environmental effects on the product number fluctuation of intracellular reaction networks can be collectively characterized by Laplace transform of the time-correlation function of the product creation rate fluctuation with the Laplace variable being the product decay rate. On the basis of the latter result, we propose an efficient method for quantitative analysis of the chemical fluctuation produced by intracellular networks coupled to hidden cell environments. By applying the present approach to the gene expression network, we obtain simple analytic results for the gene expression variability and the environment-induced correlations between the expression levels of mutually noninteracting genes. The theoretical results compose a unified framework for quantitative understanding of various gene expression statistics observed across a number of different systems with a small number of adjustable parameters with clear physical meanings.National Research Foundation of Korea (Grant 2011-0016412)National Research Foundation of Korea (Priority Research Center Program 2009-0093817

    Understanding of hydrogen silsesquioxane electron resist for sub-5-nm-half-pitch lithography

    Get PDF
    The authors, demonstrated that 4.5-nm-half-pitch structures could be achieved using electron-beam lithography, followed by salty development. They also hypothesized a development mechanism for hydrogen silsesquioxane, wherein screening of the resist surface charge is crucial in achieving a high initial development rate, which might be a more accurate assessment of developer performance than developer contrast. Finally, they showed that with a high-development-rate process, a short duration development of 15 s was sufficient to resolve high-resolution structures in 15-nm-thick resist, while a longer development degraded the quality of the structures with no improvement in the resolution

    Surgical Treatment of Inferior Vena Cava Invasion in Patients with Renal Pelvis Transitional Cell Carcinoma by Use of Human Cadaveric Aorta

    Get PDF
    We herein report a case of radical nephroureterectomy and replacement of the inferior vena cava (IVC) with ahuman cadaveric aortic graft for a patient with renal pelvis transitional cell carcinoma associated with IVC infiltration. In advanced disease, radical surgery is essential to achieve long-term survival. This case entails the use of another treatment option among the numerous options currently available for the management of patients with advanced renal cancer associated with IVC invasion

    [Bis(2-pyridylmeth­yl)amine]dichloridomercury(II)

    Get PDF
    The Hg atom in the title complex, [HgCl2(C12H13N3)], adopts a square-pyramidal geometry, being ligated by three N atoms of the tridentate bis­(2-pyridylmeth­yl)amine ligand and two Cl atoms, with one of the latter occupying the apical position. Disorder is noted in the amine portion of the ligand and this was modelled over two sites, with the major component having a site-occupancy factor of 0.794 (14)
    corecore