1,917 research outputs found

    Superconductivity emerging from an electronic phase separation in the charge ordered phase of RbFe2_2As2_2

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    75^{75}As, 87^{87}Rb and 85^{85}Rb nuclear quadrupole resonance (NQR) and 87^{87}Rb nuclear magnetic resonance (NMR) measurements in RbFe2_2As2_2 iron-based superconductor are presented. We observe a marked broadening of 75^{75}As NQR spectrum below T0โ‰ƒ140T_0\simeq 140 K which is associated with the onset of a charge order in the FeAs planes. Below T0T_0 we observe a power-law decrease in 75^{75}As nuclear spin-lattice relaxation rate down to Tโˆ—โ‰ƒ20T^*\simeq 20 K. Below that temperature the nuclei start to probe different dynamics owing to the different local electronic configurations induced by the charge order. A fraction of the nuclei probes spin dynamics associated with electrons approaching a localization while another fraction probes activated dynamics possibly associated with a pseudogap. These different trends are discussed in the light of an orbital selective behaviour expected for the electronic correlations.Comment: 5 pages, 3 figures and 4 pages of supplemental materia

    What Does It Mean to Say That Aggressive Children Are Competent or Incompetent?

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    In contrast to the view that the association between aggression and competence (i.e., the capacity to compete in the company of others) is negative and linear, the present papers indicate that (a) children whose level of aggression is moderately above the mean show the highest level of competence whereas competence is lowest in children who show no signs of aggression or whose aggression is high and undifferentiated; (b) that the association between aggression and competence is moderated by the function the aggression serves; and (c) that moderately aggressive children are given status within the peer system even though other children do not typically like them. The association between aggression and competence needs to be understood according to basic aspects of group process such as dominance, resource control, and regulation of retaliatory gestures between group members. Although children who show moderate levels of aggression may be given status and power within the peer group, it does not mean they are adjusted or that they will receive or benefit from the affection or kindness from their peers

    Critical appraisal of pazopanib as treatment for patients with advanced metastatic renal cell carcinoma

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    The management of renal cell carcinoma (RCC) has undergone significant changes during the past 10 years, with the treatment of metastatic RCC undergoing the most radical changes. These developments reflect an enhanced understanding of this tumorโ€™s underlying biology, which was then translated into the development of a new treatment paradigm. Current therapeutic approaches for the management of patients with metastatic RCC utilize knowledge of histology, molecular abnormalities, clinical prognostic factors, the natural history of this malignancy, and the treatment efficacy and toxicity of available agents. The treatment options available for patients with metastatic RCC have changed dramatically over the past 6 years. Interferon-ฮฑ and interleukin-2 were the previous mainstays of therapy, but since December 2005, six new agents have been approved in the US for the treatment of advanced RCC. Three are multi-targeted tyrosine kinase inhibitors (TKI) including sunitinib, sorafenib, and pazopanib, two target the mammalian target of rapamycin (temsirolimus and everolimus), and one is a humanized monoclonal antibody (bevacizumab in combination with interferon-ฮฑ). The current review focuses on the newest TKI available to treat patients with metastatic RCC, pazopanib. The development of this agent both preclinically and clinically is reviewed. The efficacy and safety data from the pivotal clinical trials are discussed, and the potential role of pazopanib in the treatment of patients with metastatic RCC in comparison to other treatment alternatives is critically appraised. This agent has a favorable overall risk benefit, and the available data demonstrate efficacy in patients with metastatic RCC who are either treatment-naรฏve or cytokine refractory. It therefore represents another alternative for treatment of metastatic RCC patients

    The optimization of sol-gels as sensing arrays and the testing of sol-gel precursors through the use of fluorescence measurements of eosin-y

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    The purpose of the first project, performed in collaboration with Professor Frank Bright of SUNY at Buffalo, was to optimize the conditions and variables for a Cartesian Technologies Pinprinter to print reproducible spots of sol-gels doped with Ruthenium Diphenylphenathrene (Ru(dpp)32+), an oxygen-sensing complex, on microscope slides. We attempted to optimize these variables by l) the alteration of the printing speed of the sol-gel microarrays, 2) variation of the drying temperature of the gels after they had been printed, 3) controlling the reaction rate of the sol-gel, and 4) various methods of slide pre-treatment. We found that a print speed of 10-25ms, drying the sol-gels at room temperature and no spin-coating over the microarrays were the most optimal results, and the resulting microarrays could be employed for analytical chemistry research purposes. The primary purpose of the second project was to create an effective pH sensor through the use of Eosin-Y within a sol-gel monolith matrix. The most effective precursor(s) must meet the criteria of adherence to a linear plot of fluorescence intensity versus concentration of encapsulated Eosin-Y, reversibility of the sensing capabilities as close to 100% as possible, and minimal cracking in the monolith. The precursors tested were TMOS, TEOS, n-propyl TMOS/ TMOS, methyl-TMOS/ TMOS and phenyl TEOS/ TEOS. It was found that the ormosils n-propyl TMOS/TMOS and methyl TMOS/ TMOS yielded the most effective sensors, overall. The use of Eosin-Y as an indicator for reaction rate of the sol-gel was also explored, as its emission spectra shifts when the ratio of water to ethanol in the solvent is varied

    Third Generation Tyrosine Kinase Inhibitors and Their Development in Advanced Renal Cell Carcinoma

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    Angiogenesis in general and the vascular endothelial growth factor (VEGF) signaling axis in particular is a validated target in renal cell carcinoma (RCC). Clear-cell carcinoma of the kidney is now recognized as a malignancy that is sensitive to inhibitors of the VEGF pathway. Treatment options for patients with metastatic renal cell carcinoma have evolved in dramatic fashion over the past 6โ€‰years, and a new paradigm has developed. The cytokines interferon-ฮฑ and interleukin-2 were previously utilized for therapy, but since December 2005, six new agents have been approved in the United States for the treatment of advanced RCC. Two are tyrosine kinase inhibitors (TKIโ€™s) including sunitinib and recently pazopanib, and the multikinase inhibitor sorafenib. The current review examines the evolving data with the next generation of TKIโ€™s, axitinib and tivozanib being developed for the treatment of advanced RCC. These agents were synthesized to provide increased target specificity and enhanced target inhibition. The preclinical and clinical data are examined, an overview of the development of these TKIโ€™s is provided, and discussion plus speculation concerning their potential roles as RCC therapy is provided

    Metastatic clear cell carcinoma of the kidney: therapeutic role of bevacizumab

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    The biology and pathogenesis of clear cell carcinoma of the kidney has been extensively investgated, and the role of von Hipple-Landau gene inactivation and tumor associated angiogenesis is now recognized. Development of vascular endothelial growth factor inhibitors and phase 3 clinical trials utilizing this class of agents has produced a new treatment paradigm for patients with metastatic renal cell carcinoma (RCC). One of the active regimens identified is the combination of bevacizumab and interferon-ฮฑ. Recently published reports provided evidence of the clinical and biologic activity of this therapy. The current manuscript reviews the background and rationale for the activity of bevacizumab in RCC, and results from recent clinical trials with this agent alone or in combination with targeted agents or cytokines. The role of this therapy in contrast to other targeted agents is reviewed, and the potential utility as well as questions raised by recent studies are discussed

    The optimization of sol-gels as sensing arrays and the testing of sol-gel precursors through the use of fluorescence measurements of eosin-y

    Get PDF
    The purpose of the first project, performed in collaboration with Professor Frank Bright of SUNY at Buffalo, was to optimize the conditions and variables for a Cartesian Technologies Pinprinter to print reproducible spots of sol-gels doped with Ruthenium Diphenylphenathrene (Ru(dpp)32+), an oxygen-sensing complex, on microscope slides. We attempted to optimize these variables by l) the alteration of the printing speed of the sol-gel microarrays, 2) variation of the drying temperature of the gels after they had been printed, 3) controlling the reaction rate of the sol-gel, and 4) various methods of slide pre-treatment. We found that a print speed of 10-25ms, drying the sol-gels at room temperature and no spin-coating over the microarrays were the most optimal results, and the resulting microarrays could be employed for analytical chemistry research purposes. The primary purpose of the second project was to create an effective pH sensor through the use of Eosin-Y within a sol-gel monolith matrix. The most effective precursor(s) must meet the criteria of adherence to a linear plot of fluorescence intensity versus concentration of encapsulated Eosin-Y, reversibility of the sensing capabilities as close to 100% as possible, and minimal cracking in the monolith. The precursors tested were TMOS, TEOS, n-propyl TMOS/ TMOS, methyl-TMOS/ TMOS and phenyl TEOS/ TEOS. It was found that the ormosils n-propyl TMOS/TMOS and methyl TMOS/ TMOS yielded the most effective sensors, overall. The use of Eosin-Y as an indicator for reaction rate of the sol-gel was also explored, as its emission spectra shifts when the ratio of water to ethanol in the solvent is varied

    The optimization of sol-gels as sensing arrays and the testing of sol-gel precursors through the use of fluorescence measurements of eosin-y

    Get PDF
    The purpose of the first project, performed in collaboration with Professor Frank Bright of SUNY at Buffalo, was to optimize the conditions and variables for a Cartesian Technologies Pinprinter to print reproducible spots of sol-gels doped with Ruthenium Diphenylphenathrene (Ru(dpp)32+), an oxygen-sensing complex, on microscope slides. We attempted to optimize these variables by l) the alteration of the printing speed of the sol-gel microarrays, 2) variation of the drying temperature of the gels after they had been printed, 3) controlling the reaction rate of the sol-gel, and 4) various methods of slide pre-treatment. We found that a print speed of 10-25ms, drying the sol-gels at room temperature and no spin-coating over the microarrays were the most optimal results, and the resulting microarrays could be employed for analytical chemistry research purposes. The primary purpose of the second project was to create an effective pH sensor through the use of Eosin-Y within a sol-gel monolith matrix. The most effective precursor(s) must meet the criteria of adherence to a linear plot of fluorescence intensity versus concentration of encapsulated Eosin-Y, reversibility of the sensing capabilities as close to 100% as possible, and minimal cracking in the monolith. The precursors tested were TMOS, TEOS, n-propyl TMOS/ TMOS, methyl-TMOS/ TMOS and phenyl TEOS/ TEOS. It was found that the ormosils n-propyl TMOS/TMOS and methyl TMOS/ TMOS yielded the most effective sensors, overall. The use of Eosin-Y as an indicator for reaction rate of the sol-gel was also explored, as its emission spectra shifts when the ratio of water to ethanol in the solvent is varied
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