746 research outputs found

    Initial/boundary-value problems of tumor growth within a host tissue

    Full text link
    This paper concerns multiphase models of tumor growth in interaction with a surrounding tissue, taking into account also the interplay with diffusible nutrients feeding the cells. Models specialize in nonlinear systems of possibly degenerate parabolic equations, which include phenomenological terms related to specific cell functions. The paper discusses general modeling guidelines for such terms, as well as for initial and boundary conditions, aiming at both biological consistency and mathematical robustness of the resulting problems. Particularly, it addresses some qualitative properties such as a priori nonnegativity, boundedness, and uniqueness of the solutions. Existence of the solutions is studied in the one-dimensional time-independent case.Comment: 30 pages, 5 figure

    The Relevance of Academic Libraries in the Twenty-First Century

    Get PDF
    The biggest challenge facing the library profession in the twenty-first century is staying relevant to its users. It is often stated that the Internet and Google have changed librarianship. This challenge, while significant, does not mean that libraries will go away. It is causing us to re-evaluate what we do, how we do it, and what role libraries have in the academy and in our culture at large. This column addresses some of the ways in which academic libraries can stay relevant throughout the twenty-first century

    Electrochemical C(sp3)-H functionalization of ethers via hydrogen-atom transfer by means of cathodic reduction

    Get PDF
    : The chemo- and stereoselective electrochemical allylation/alkylation of ethers is presented via a C(sp3)-H activation event. The electrosynthetic protocol enables the realization of a large library of functionalized ethers (35 examples) in high yields (up to 84%) via cathodic activation of a new type of redox-active carbonate (RAC), capable of triggering HAT (Hydrogen-Atom-Transfer) events through the generation of electrophilic oxy radicals. The process displayed high functional group tolerance and mild reaction conditions. A mechanistic elucidation via voltammetric analysis completes the study

    Vitamin E as Adjuvant in Emulsified Vaccine for Chicks

    Get PDF
    Abstract Mineral oil was partially replaced with D, L-α-tocopheryl acetate (vitamin E) in bacterial and viral inactivated emulsified vaccines. Vitamin E increased the immune response to the viral antigen (Newcastle disease virus) used but not to the bacterial antigen (Escherichia coli) when its presence in the oil phase did not exceed 30%. Inoculated vitamin E may have enhanced the immune response by interacting with the immune-competent cells involved in the inflammatory reaction that followed inoculation of emulsified vaccines

    Merging C-C σ-bond activation of cyclobutanones with CO2 fixation via Ni-catalysis

    Get PDF
    A carboxylative Ni-catalyzed tandem C-C σ-bond activation of cyclobutanones followed by CO2-electrophilic trapping is documented as a direct route to synthetically valuable 3-indanone-1-acetic acids. The protocol shows an adequate functional group tolerance and useful chemical outcomes (yield up to 76%) when AlCl3 is adopted as an additive. Manipulations of the targeted cyclic scaffolds and a mechanistic proposal based on experimental evidence complete the investigation

    Genome Sequence of Staphylococcus saprophyticus DPC5671, a Strain Isolated from Cheddar Cheese

    Get PDF
    peer-reviewedThe draft genome sequence of Staphylococcus saprophyticus DPC5671, isolated from cheddar cheese, was determined. S. saprophyticus is a common Gram-positive bacterium detected on the surface of smear-ripened cheese and other fermented foods

    EFFECTS OF EXTERNAL LOADING ON POWER OUTPUT DURING VERTICAL JUMP: A PILOT STUDY WITH WATER POLO GOAL KEEPERS.

    Get PDF
    The purpose of this study was to describe preliminary results of the effects of external loading on power output during vertical jumps performed on a force platform by three elite water polo goal keepers (1 female and 2 male). Peak power output was calculated from time-force curves during vertical jumps with and without external additional loads corresponding to 0%, 5%, 10% and 15 % of their body weight. The jumps were performed from a squat position, without lower limb counter-movement or arm swings. The peak instantaneous power was reached at 0% additional load (body weight) by two of the athletes, and for the third, the peak instantaneous power was reached at 5% additional load. This study suggests that for water polo goal keepers, the load that generates maximum power output in dry land exercises is body weight, without any additional load

    Lessons from in vitro perifusion of pancreatic islets isolated from 80 human pancreases.

    Get PDF
    We report the average insulin response to acute glucose measured by in vitro perifusion of pancreatic islets isolated from 80 consecutive human organs. Different perifusion parameters were considered [basal release, stimulation index (SI), time to peak, incremental area under the curve Δ-AUCa)], and the correlation among them was determined. SI positively correlated with Δ-AUCa (p < 0.001, r = 0.80) while negatively with time to peak (p < 0.05, r = −0.23). We also evaluated several variables of the isolation procedure that might affect responsiveness to glucose by human islets. Sex and age of pancreas donors, cold ischemia time, duration of the digestion, collagenase concentration, and lot characteristics (collagenase, trypsin, clostripain, and proteases activity), and final islet yield were considered. Multivariate regression analysis showed only an independent association between SI and the concentration of collagenase (p = 0.01)

    Visible-Light Assisted Covalent Surface Functionalization of Reduced Graphene Oxide Nanosheets with Arylazo Sulfones

    Get PDF
    We present an environmentally benign methodology for the covalent functionalization (arylation) of reduced graphene oxide (rGO) nanosheets with arylazo sulfones. A variety of tagged aryl units were conveniently accommodated at the rGO surface via visible-light irradiation of suspensions of carbon nanostructured materials in aqueous media. Mild reaction conditions, absence of photosensitizers, functional group tolerance and high atomic fractions (XPS analysis) represent some of the salient features characterizing the present methodology. Control experiments for the mechanistic elucidation (Raman analysis) and chemical nanomanipulation of the tagged rGO surfaces are also reported

    Does coffee protect against hepatocellular carcinoma?

    Get PDF
    We analysed the relation between coffee consumption and hepatocellular carcinoma in two case-control studies conducted between 1984 and 1998 in Italy and Greece, including 834 cases and 1912 controls. Compared to non coffee drinkers, the multivariate odds ratio was 0.7 for drinkers of three or more cups per day
    corecore