6,763 research outputs found

    Photoelectrochemical reduction of aqueous protons with a CuO|CuBi2O4 heterojunction under visible light irradiation.

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    A p-type heterojunction photoelectrode consisting of platinized CuBi2O4 layered on a CuO film was prepared. The CuO|CuBi2O4|Pt electrode photo-generates H2 in pH neutral aqueous solution during visible light irradiation and exhibits a substantially enhanced photocurrent compared to CuO|Pt and CuBi2O4|Pt electrodes. Reduced electron-hole recombination by the band offsets in the heterostructure is responsible for the improved photoelectrochemical performance of CuO|CuBi2O4 with a small band-gap of approximately 1.5 eV.The work at Cambridge was supported by the Christian Doppler Research Association (Austrian Federal Ministry of Economy, Family and Youth and National Foundation for Research, Technology and Development), the OMV Group the EPSRC (EP/H00338X/2) and BBSRC (BB/K010220/1).This is the accepted manuscript version. The final published version is available from the RSC at http://pubs.rsc.org/en/Content/ArticleLanding/2014/CP/C4CP03883E#!divAbstract

    Modified reverse tapering method to prevent frequency shift of the radiation in the planar undulator

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    This paper presents a modified reverse tapering method to generate a polarized soft x ray in x-ray free-electron lasers (XFELs) with a higher photon power and a shorter undulator length than the simple linear reverse tapering method. In the proposed method, a few untapered planar undulators are added before the simple linear reverse tapering section of the undulator line. This simple modification prevents the frequency shift of the radiation that occurs when the simple linear reverse tapering method is applied to planar undulators. In the proposed method, the total length of planar undulators decreased in spite of the additional untapered undulators. When the modified reverse tapering method is used with four untapered planar undulators, the total length of the planar undulators is 64.6 m. On the other hand, the required length of the planar undulators is 94.6 m when the simple linear reverse tapering method is used. The proposed method gives us a way to generate a soft x-ray pulse (1.24 keV) with a high degree of polarization (>0.99) and radiation power (>30 GW) at the new undulator line with a 10-GeV electron beam in the Pohang Accelerator Laboratory X-ray Free-Electron Laser. This method can be applied in the existing XFELs in the world without any change in the undulator lines. ? 2017 authors. Published by the American Physical Society.111Ysciescopu

    The absurd and the comic

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    In my thesis, I propose a theory that posits a connection between our absurd existential situation and our comic tendencies. I work within a framework of existentialist assumptions, the most important of which being the assumption that, as Sartre writes, "man is nothing else but that which he makes of himself." Consequently, I focus on the process of how human beings use humor to form themselves by using it to form their conception of reality. What I propose in my thesis is not an explanation of humor as much as it is an existential interpretation of its source and function. I begin with an analysis of the absurd. After considering and rejecting the arguments against the claim that life is not absurd, I argue that the disunity that we encounter in the world creates a need within us for stability and that one of the main ways in which we find this stability is through the comic. I use Berger and Luckmann's analysis of reality construction in my argument that the connections that we form with others through comical experiences construct and maintain a system of knowledge that satisfies what Camus calls our "nostalgia for unity," a desire that remains unfulfilled when we attempt to encounter the absurdity of human experience alone. The conclusion of my research is that it is through our laughing with others that we reify our expectations of reality. Our laughter at the objects that contradict our normative understanding of reality confirms that others share the same cognitive and affective position that we hold in a given situation, thus confirming our expectations of reality to be valid, a confirmation that protects us against the terror of the absurd

    Dynamical mean-field theory of Hubbard-Holstein model at half-filling: Zero temperature metal-insulator and insulator-insulator transitions

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    We study the Hubbard-Holstein model, which includes both the electron-electron and electron-phonon interactions characterized by UU and gg, respectively, employing the dynamical mean-field theory combined with Wilson's numerical renormalization group technique. A zero temperature phase diagram of metal-insulator and insulator-insulator transitions at half-filling is mapped out which exhibits the interplay between UU and gg. As UU (gg) is increased, a metal to Mott-Hubbard insulator (bipolaron insulator) transition occurs, and the two insulating states are distinct and can not be adiabatically connected. The nature of and transitions between the three states are discussed.Comment: 5 pages, 4 figures. Submitted to Physical Review Letter

    Ginseng Purified Dry Extract, BST204, Improved Cancer Chemotherapy-Related Fatigue and Toxicity in Mice

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    Cancer related fatigue (CRF) is one of the most common side effects of cancer and its treatments. A large proportion of cancer patients experience cancer-related physical and central fatigue so new strategies are needed for treatment and improved survival of these patients. BST204 was prepared by incubating crude ginseng extract with ginsenoside-β-glucosidase. The purpose of the present study was to examine the effects of BST204, mixture of ginsenosides on 5-fluorouracil (5-FU)-induced CRF, the glycogen synthesis, and biochemical parameters in mice. The mice were randomly divided into the following groups: the naïve normal (normal), the HT-29 cell inoculated (xenograft), xenograft and 5-FU treated (control), xenograft + 5-FU + BST204-treated (100 and 200 mg/kg) (BST204), and xenograft + 5-FU + modafinil (13 mg/kg) treated group (modafinil). Running wheel activity and forced swimming test were used for evaluation of CRF. Muscle glycogen, serum inflammatory cytokines, aspartic aminotransferase (AST), alanine aminotransferase (ALT), creatinine (CRE), white blood cell (WBC), neutrophil (NEUT), red blood cell (RBC), and hemoglobin (HGB) were measured. Treatment with BST204 significantly increased the running wheel activity and forced swimming time compared to the control group. Consistent with the behavioral data, BST204 markedly increased muscle glycogen activity and concentrations of WBC, NEUT, RBC, and HGB. Also, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), AST, ALT, and CRE levels in the serum were significantly reduced in the BST204-treated group compared to the control group. This result suggests that BST204 may improve chemotherapy-related fatigue and adverse toxic side effects

    Erratum: Dirichlet Forms and Dirichlet Operators for Infinite Particle Systems: Essential Self-adjointness

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    We reprove the essential self-adjointness of the Dirichlet operators of Dirchlet forms for infinite particle systems with superstable and sub-exponentially decreasing interactions.Comment: This is an erratum to the work appeared in J. Math. Phys. 39(12), 6509-6536 (1998

    Antepartum Pituitary Necrosis Occurring In Pregnancy with Uncontrolled Gestational Diabetes Mellitus: A Case Report

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    Antepartum pituitary necrosis is a rare medical condition that has only been reported in pregnant women with type I diabetes attributable to diabetes-related vasculopathy and hypercoagulability. We present for the first time a case of antepartum pituitary necrosis occurring in an uncontrolled gestational diabetes mellitus (GDM) patient. The patient was a 32-yr-old woman at 33 weeks and 2 days of gestation. She suffered from severe headache, blurred vision, dizziness, and vomiting. Her baby was delivered by Cesarean section. The brain magnetic resonance images revealed pituitary necrosis. This suggests that pituitary gland necrosis may also complicate GDM pregnancy when glucose levels are uncontrolled
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