314 research outputs found

    Krüppel-like factor 8 promotes aerobic glycolysis in prostate cancer cells by regulating AKT/mTOR signaling pathway

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    Purpose: To investigate the effects of Krüppel-like factor 8 (KLF8) in prostate cancer (PCa) cell viability and glycolysis, and explore its role as a regulatory factor.Methods: Immunoblot assays were conducted to assess the expression of KLF8 and proteins in AKT/mTOR pathway in PCa cell lines PC-3 and DU145. Cell Counting Kit-8 assays were performed to assess the effect of KLF8 on PCa cell viability. The glycolysis capacity of PCa cells was determined by measuring the levels of glucose intake, lactic acid production, and cellular ATP levels.Results: Depletion of KLF8 decreased the survival of PCa cells in vitro (p < 0.05). KLF8 depletion also inhibited aerobic glucose metabolism in PCa cells (p < 0.05). Further studies confirmed that KLF8 contributed to the growth and glycolysis of PCa cells via the regulation of AKT/mTOR pathway.Conclusion: KLF8 regulates glycolysis in PCa cells by regulating AKT/mTOR signaling pathway and is thus a promising therapeutic target for PCa treatment. Keywords: Krüppel-like factor 8 (KLF8), Prostate cancer (PCa), Aerobic glucose, AKT/mTOR signaling pathway, Therapeutic targe

    Comparative exergy analysis of direct alcohol fuel cells using fuel mixtures

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    Within the last years there has been increasing interest in direct liquid fuel cells as power sources for portable devices and, in the future, power plants for electric vehicles and other transport media as ships will join those applications. Methanol is considerably more convenient and easy to use than gaseous hydrogen and a considerable work is devoted to the development of direct methanol fuel cells. But ethanol has much lower toxicity and from an ecological viewpoint ethanol is exceptional among all other types of fuel as is the only chemical fuel in renewable supply. The aim of this study is to investigate the possibility of using direct alcohol fuel cells fed with alcohol mixtures. For this purpose, a comparative exergy analysis of a direct alcohol fuel cell fed with alcohol mixtures against the same fuel cell fed with single alcohols is performed. The exergetic efficiency and the exergy loss and destruction are calculated and compared in each case. When alcohol mixtures are fed to the fuel cell, the contribution of each fuel to the fuel cell performance is weighted attending to their relative proportion in the aqueous solution. The optimum alcohol composition for methanol/ethanol mixtures has been determined

    Near-field coupling and resonant cavity modes in plasmonic nanorod metamaterials

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    Plasmonic resonant cavities are capable of confining light at the nanoscale, resulting in both enhanced local electromagnetic fields and lower mode volumes. However, conventional plasmonic resonant cavities possess large Ohmic losses at metal-dielectric interfaces. Plasmonic near-field coupling plays a key role in a design of photonic components based on the resonant cavities because of the possibility to reduce losses. Here, we study the plasmonic near-field coupling in the silver nanorod metamaterials treated as resonant nanostructured optical cavities. Reflectance measurements reveal the existence of multiple resonance modes of the nanorod metamaterials, which is consistent with our theoretical analysis. Furthermore, our numerical simulations show that the electric field at the longitudinal resonances forms standing waves in the nanocavities due to the near-field coupling between the adjacent nanorods, and a new hybrid mode emerges due to a coupling between nanorods and a gold-film substrate. We demonstrate that this coupling can be controlled by changing the gap between the silver nanorod array and gold substrate

    Effect of the Molecular Size of Analytes on Polydiacetylene Chromism

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    The pH chromism of polydiacetylenes (PDAs) is examined with respect to the molecular size and acidity of acid analytes, along with the alkyl spacer length of primary-amine-functionalized diacetylene (DA) lipids. pH turns out to be an important parameter to charge amine headgroups of PDA but a change in pH does not necessarily result in a PDA color change. The molecular size of acid analytes is identified as another factor that can produce a configurational change in PDA amine headgroups, followed by perturbation of the ene–yne conjugated backbone. In addition, the length of a flexible alkyl spacer between the amine headgroup and the amide group of the diacetylene lipids is found to strongly affect the degree of PDA chromatic transition. The longer alkyl spacer shows a smaller chromatic transition from blue to red phase. The alkyl spacer seems to provide a certain degree of freedom to the amine headgroup, thus decreasing the transfer of headgroup steric effects to the PDA backbone. These correlations found for PDA chromism are applied to the development of a system that colorimetrically detects diethyl phosphate (DEP), a degraded nerve agent simulant. PDA liposomes show a selective chromatic transition upon binding with DEP compared to other acid analytes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71360/1/adfm_201000262_sm_supplfigs.pd

    Experimental and Modeling Studies of Secondary Organic Aerosol Formation and Some Applications to the Marine Boundary Layer

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    A series of controlled experiments were carried out in the Calspan Corporation\u27s 600 m3environmental chamber to study some secondary organic aerosol formation processes. Three precursor-ozone systems were studied: cyclopentene-ozone, cyclohexene-ozone, and α-pineneozone. Additionally, SO2 was added to the initial gas mixture in several instances and was likely present at trace levels in the ostensibly organic-only experiments. It was found that all three systems readily formed new submicron aerosols at very low reactant levels. The chemical composition of formed aerosols was consistent with some previous studies, but the yields of organic products were found to be lower in the Calspan experiments. A three-step procedure is proposed to explain the observed particle nucleation behavior: HO · production → H2SO4 formation → H2SO4-H2O (perhaps together with NH3) homogeneous nucleation. It is also proposed that some soluble organic products would partition into the newly formed H2SO4-H2O nuclei, enhance water condensation, and quickly grow these nuclei into a larger size range. While the observations in the two cycloolefin-ozone systems could be well explained by these proposed mechanisms, the exact nature of the nucleation process in the α-pinene-ozone system remains rather opaque and could be the result of nucleation involving certain organics. The results from three simple modeling studies further support these proposals. Their applicability to the marine boundary layer (MBL) is also discussed in some detail. Particularly, such a particle nucleation and growth process could play an important role in secondary aerosol formation and, quite likely, CCN formation as well in certain MBL regions

    Hydrogen atom versus hydride transfer in cytochrome P450 oxidations: A combined mass spectrometry and computational study

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    Biomimetic models of short-lived enzymatic reaction intermediates can give useful insight into the properties and coordination chemistry of transition metal complexes. In this work we investigate a high-valent iron(IV)-oxo porphyrin cation radical complex, namely [FeIV(O)(TPFPP+•)]+ where TPFPP is the dianion of 5,10,15,20-tetrakis(pentafluorophenyl) porphyrin. The [FeIV(O)(TPFPP+•)]+ ion was studied by ion-molecule reactions in a Fourier transform-ion cyclotron resonance mass spectrometer through reactivities with 1,3,5-cycloheptatriene, 1,3-cyclohexadiene and toluene. The different substrates give dramatic changes in reaction mechanism and efficiencies, whereby cycloheptatriene leads to hydride transfer, while cyclohexadiene and toluene react via hydrogen atom abstraction. Detailed computational studies point to major differences in ionization energy as well as C–H bond energies of the substrates that influence the hydrogen atom abstraction versus electron transfer pathways. The various variables that determine the pathways for hydride transfer versus hydrogen atom transfer are elucidated and discussed

    Microstructural and Electrical Features of Yttrium Stabilised Zirconia with ZnO as Sintering Additive

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    Adding ZnO reduces sintering temperature of yttria stabilized zirconia. Adding up to 0.5 wt% of ZnO is possible to densify to 8 mol% yttria stabilized zirconia (TZ8Y) to 95% of relative density at 1300 °C, besides, the electrical conductivity increases about 30% at 800 °C when compared to pure TZ8Y with the same relative density and average grain size. These results show that TZ8Y co-doped with ZnO can be a potential electrolyte to solid oxide fuel cells and electrolyzer cells

    Experimental and Molecular Modeling Study of the Three-Phase Behavior of ( n

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