259 research outputs found

    State Power to Define Jurisdiction

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    States should have much broader authority to decline jurisdiction over federal claims. The normative considerations supporting this doctrine of “reverse abstention” have been developed in previous work. But what of the Constitution? The traditional reading, reflected in existing precedent, asserts that the Supremacy Clause, Article III, and perhaps Article I operate together to create an inflexible obligation for state courts to hear federal claims. This reading is misguided. The Supremacy Clause contains no jurisdictional obligation of its own force, but only gives supreme effect to other validly enacted federal laws. And no other clause provides the authority to impose such an obligation on the states. Suggestions to the contrary are based on an overly cramped version of originalism that fails to account for the exigencies of constitutional compromise and ratification

    Exploration of 1,2-phenylenediboronic esters as potential bidentate catalysts for organic synthesis

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    Recently, we described the first inverse electron demand Diels-Alder reaction of 1,2-diazene catalyzed by a bidentate Lewis acid. Herein we investigate 1,2-phenylenediboronic esters as potential catalysts for this transformation offering higher stability and easier handling than the currently used boranthracene derivatives. Different 1,2-phenylenediboronic esters were prepared and their ability to form bidentate coordination complexes with phthalazine was analyzed. Although a 1:1 complex was observed, X-ray analysis revealed binding only in a monodentate fashion. Graphical abstrac

    Electronic reconstruction at SrMnO3-LaMnO3 superlattice interfaces

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    We use resonant soft x-ray scattering to study electronic reconstruction at the interface between the Mott insulator LaMnO3 and the "band" insulator SrMnO3. Superlattices of these two insulators were shown previously to have both ferromagnetism and metallic tendencies [Koida et al., Phys. Rev. B 66, 144418 (2002)]. By studying a judiciously chosen superlattice reflection we show that the interface density of states exhibits a pronounced peak at the Fermi level, similar to that predicted by Okamoto et al. [Phys. Rev. B 70, 241104(R) (2004)]. The intensity of this peak correlates with the conductivity and magnetization, suggesting it is the driver of metallic behavior. Our study demonstrates a general strategy for using RSXS to probe the electronic properties of heterostructure interfaces.Comment: 4.2 pages, 4 figure

    In silico assessment of histotripsy-induced changes in catheter-directed thrombolytic delivery

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    Introduction: For venous thrombosis patients, catheter-directed thrombolytic therapy is the standard-of-care to recanalize the occluded vessel. Limitations with thrombolytic drugs make the development of adjuvant treatments an active area of research. One potential adjuvant is histotripsy, a focused ultrasound therapy that lyses red blood cells within thrombus via the spontaneous generation of bubbles. Histotripsy has also been shown to improve the efficacy of thrombolytic drugs, though the precise mechanism of enhancement has not been elucidated. In this study, in silico calculations were performed to determine the contribution of histotripsy-induced changes in thrombus diffusivity to alter catheter-directed therapy.Methods: An established and validated Monte Carlo calculation was used to predict the extent of histotripsy bubble activity. The distribution of thrombolytic drug was computed with a finite-difference time domain (FDTD) solution of the perfusion-diffusion equation. The FDTD calculation included changes in thrombus diffusivity based on outcomes of the Monte Carlo calculation. Fibrin degradation was determined using the known reaction rate of thrombolytic drug.Results: In the absence of histotripsy, thrombolytic delivery was restricted in close proximity to the catheter. Thrombolytic perfused throughout the focal region for calculations that included the effects of histotripsy, resulting in an increased degree of fibrinolysis.Discussion: These results were consistent with the outcomes of in vitro studies, suggesting histotripsy-induced changes in the thrombus diffusivity are a primary mechanism for enhancement of thrombolytic drugs

    Recognition of Antimicrobial Peptides by a Bacterial Sensor Kinase

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    SummaryPhoQ is a membrane bound sensor kinase important for the pathogenesis of a number of Gram-negative bacterial species. PhoQ and its cognate response regulator PhoP constitute a signal-transduction cascade that controls inducible resistance to host antimicrobial peptides. We show that enzymatic activity of Salmonella typhimurium PhoQ is directly activated by antimicrobial peptides. A highly acidic surface of the PhoQ sensor domain participates in both divalent-cation and antimicrobial-peptide binding as a first step in signal transduction across the bacterial membrane. Identification of PhoQ signaling mutants, binding studies with the PhoQ sensor domain, and structural analysis of this domain can be incorporated into a model in which antimicrobial peptides displace divalent cations from PhoQ metal binding sites to initiate signal transduction. Our findings reveal a molecular mechanism by which bacteria sense small innate immune molecules to initiate a transcriptional program that promotes bacterial virulence
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