1,782 research outputs found
Is Radiation of Quantized Black Holes Observable?
If primordial black holes (PBH) saturate the present upper limit on the dark
matter density in our Solar system and if their radiation spectrum is discrete,
the sensitivity of modern detectors is close to that necessary for detecting
this radiation. This conclusion is not in conflict with the upper limits on the
PBH evaporation rate.Comment: 6 pages, 1 figure (reproduced properly in pdf file
Molecular Modeling Studies to Probe the Binding Hypothesis of Novel Lead Compounds against Multidrug Resistance Protein ABCB1.
The expression of drug efflux pump ABCB1/P-glycoprotein (P-gp), a transmembrane protein belonging to the ATP-binding cassette superfamily, is a leading cause of multidrug resistance (MDR). We previously curated a dataset of structurally diverse and selective inhibitors of ABCB1 to develop a pharmacophore model that was used to identify four novel compounds, which we showed to be potent and efficacious inhibitors of ABCB1. Here, we dock the inhibitors into a model structure of the human transporter and use molecular dynamics (MD) simulations to report the conformational dynamics of human ABCB1 induced by the binding of the inhibitors. The binding hypotheses are compared to the wider curated dataset and those previously reported in the literature. Protein-ligand interactions and MD simulations are in good agreement and, combined with LipE profiling, statistical and pharmacokinetic analyses, are indicative of potent and selective inhibition of ABCB1
Identification and Empiric Evaluation of New Inhibitors of the Multidrug Transporter P-Glycoprotein (ABCB1)
Elastic waves trapped above a cylindrical cavity
The existence of trapped elastic waves above a circular cylindrical cavity in a half-space is demonstrated. These modes propagate parallel to the cylinder, and their amplitude decays exponentially as the observer moves away from it. Dispersion relations connecting the frequency with the wavenumber along the cylinder are obtained using an analytical technique based on multipole expansions, and are solved numerically. Critical frequencies at which modes cut on and off are determined, and a range of contour plots illustrating the displacement fields is presented
Oblique Rayleigh wave scattering by a cylindrical cavity
The problem of oblique wave scattering of a Rayleigh wave by a cylindrical cavity in an elastic half-space is solved using the multipole expansion method. Whereas in the analogous water wave problem a single scalar field is expressed as an infinite multipole expansion, and in the Rayleigh wave case with normal incidence two scalar fields suffice, here we require three coupled scalar multipole expansions. The focus of our numerical results is on the energy scattered by the cavity and in particular the proportion of the incident wave energy that is reflected and transmitted in the form of Rayleigh waves and the proportion that is transformed into cylindrical bulk waves which propagate into the half-space
Residual Stresses Induced in T Butt Welds from Submerged Arc Welding of High Strength Thick Section Steel Members
The overall residual stress profiles of a weld fabricated structures such as a submarine pressure hull fabricated using high strength welds joining quench and tempered steels is complex as they are the net profiles from the build-up or relaxation of the residual stresses induced into the welds and structural members from each step in the fabrication process. University of Adelaide with its research partners has attempted to increase the knowledge of residual stresses in this type of structure by undertaking a comprehensive residual stress measurement program using test pieces representing each stage of the fabrication of a submarine pressure hull including full scale test pieces. The primary methods of measuring subsurface residual stress profiles was the neutron diffraction method with the Deep Hole Drilling technique (DHD) to validate key results. The X ray diffraction method and Incremental Centre Hole Drilling methods were used for determining surface residual stresses. This paper presents an overview of the results for residual stress profiles resulting from a full penetration double sided T Butt weld joining a T Frame to a thick flat plate by Submerged Arc Welding. The test piece used a specific pass placement strategy that placed the last pass each side on the base plate. The results presented show that the actual profile is considerably different than those for established fracture mechanics residual stress profiles in that these are over conservative. The discussion will include comparison of results to other measurement results undertaken on similar test pieces but undertaken with an alternate pass placement strategy
Inferring Cell-State Transition Dynamics from Lineage Trees and Endpoint Single-Cell Measurements
As they proliferate, living cells undergo transitions between specific molecularly and developmentally distinct states. Despite the functional centrality of these transitions in multicellular organisms, it has remained challenging to determine which transitions occur and at what rates without perturbations and cell engineering. Here, we introduce kin correlation analysis (KCA) and show that quantitative cell-state transition dynamics can be inferred, without direct observation, from the clustering of cell states on pedigrees (lineage trees). Combining KCA with pedigrees obtained from time-lapse imaging and endpoint single-molecule RNA-fluorescence in situ hybridization (RNA-FISH) measurements of gene expression, we determined the cell-state transition network of mouse embryonic stem (ES) cells. This analysis revealed that mouse ES cells exhibit stochastic and reversible transitions along a linear chain of states ranging from 2C-like to epiblast-like. Our approach is broadly applicable and may be applied to systems with irreversible transitions and non-stationary dynamics, such as in cancer and development
EHA/ESMO Clinical Practice Guidelines for the Management of Malignant Lymphoma: Recommendations for the Second Phase of the COVID-19 Pandemic
No abstract availabl
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