Search results for "Static"
showing 10 items of 1528 documents
A differential equation approach to implicit sweeping processes
2019
International audience; In this paper, we study an implicit version of the sweeping process. Based on methods of convex analysis, we prove the equivalence of the implicit sweeping process with a differential equation, which enables us to show the existence and uniqueness of the solution to the implicit sweeping process in a very general framework. Moreover, this equivalence allows us to give a characterization of nonsmooth Lyapunov pairs and invariance for implicit sweeping processes. The results of the paper are illustrated with two applications to quasistatic evolution variational inequalities and electrical circuits.
Acidosis induces multi-drug resistance in rat prostate cancer cells (AT1) in vitro and in vivo by increasing the activity of the p-glycoprotein via a…
2008
Because solid growing tumors often show hypoxia and pronounced extracellular acidosis, the aim of this study was to analyze the impact of an acidotic environment on the activity of the p-glycoprotein (pGP) and on the cellular content and cytotoxicity of the chemotherapeutic drug daunorubicin in the AT1 R-3327 Dunning prostate carcinoma cell line cultured in vitro and in vivo. In vitro, extracellular acidosis (pH 6.6) activated p38 and ERK1/2 and thereby induced daunorubicin resistance via a pronounced activation of pGP. De-novo protein synthesis was not necessary and analysis of transport kinetics indicated a fast and persistent pGP activation at pH 6.6 (when compared with 7.4). Intracellul…
Influences of TP53 and the anti-aging DDR1 receptor in controlling Raf/MEK/ERK and PI3K/Akt expression and chemotherapeutic drug sensitivity in prost…
2020
Background TP53 plays critical roles in sensitivity to chemotherapy, and aging. Collagen is very important in aging. The molecular structure and biochemical properties of collagen changes during aging. The discoidin domain receptor (DDR1) is regulated in part by collagen. Elucidating the links between TP53 and DDR1 in chemosensitivity and aging could improve therapies against cancer and aging. Results Restoration of WT-TP53 activity resulted in increased sensitivity to chemotherapeutic drugs and elevated expression of key components of the Raf/MEK/ERK, PI3K/Akt and DDR1 pathways. DDR1 could modulate the levels of Raf/MEK/ERK and PI3K/Akt pathways as well as sensitize the cells to chemothera…
Starfish and Xenopus oocyte maturation
2007
Treatment with heavy metals, such as nickel, lead or cadmium, elicits different cellular stress responses according to the metal used and the length of treatment. In Paracentrotus lividus embryos the inducible forms of HSP70 (HSP70/72) are different in molecular mass from the constitutively expressed HSP75, and they can be used as markers of cellular stress. Even a short treatment with each metal induces the synthesis of HSP70/72 which remain stable for at least 20h and differ little in their isoelectric points. Continuous treatment from fertilization with nickel or lead produces late irregular pluteus embryos, with peak HSP70/72 synthesis at blastula followed by the arrest of synthesis by …
Static Properties of a Simulated Supercooled Polymer Melt: Structure Factors, Monomer Distributions Relative to the Center of Mass, and Triple Correl…
2004
We analyze structural and conformational properties in a simulated bead-spring model of a non-entangled, supercooled polymer melt. We explore the statics of the model via various structure factors, involving not only the monomers, but also the center of mass (CM). We find that the conformation of the chains and the CM-CM structure factor, which is well described by a recently proposed approximation [Krakoviack et al., Europhys. Lett. 58, 53 (2002)], remain essentially unchanged on cooling toward the critical glass transition temperature of mode-coupling theory. Spatial correlations between monomers on different chains, however, depend on temperature, albeit smoothly. This implies that the g…
VALUTAZIONE DELLA SENSIBILITà E SPECIFICITà DELLA RISONANZA MAGNETICA ENDORETTALE E DELLA ECOGRAFIA TRANSRETTALE NELLA STADIAZIONE DELL'ADENOCARCINOM…
2007
OBJECTIVES. Nowadays endorectal probes for Magnetic Resonance Imaging (MRI) have better resolutions, which allows to acquire high-level images of prostate and to improve the MRI sensitivity and specificity to determine the cancer volume and the extraprostatic extension. The objective of the present study is to evaluate the sensitivity and diagnostic accuracy of endorectal MRI for identifying the local extension of prostate carcinoma compared to transrectal sonography (TRUS) of prostate. MATERIALS AND METHODS. The study included 81 patients with clinical suspect of cancer and/or elevated values of serum prostate specific antigen (PSA), who underwent endorectal MRI with 1.5 T endorectal probe…
Self-assembly and alterable relaxivity of an organic cation-encapsulated gadolinium-containing polyoxometalate
2012
A new amphiphilic molecule bearing poly(ethylene oxide) (PEO) and quaternary ammonium group, was designed and synthesized to encapsulate paramagnetic Gd(III)-containing polyoxometalate (Gd-POM) through electrostatic interaction for obtaining a water-soluble organic-inorganic hybrid building block based on POM. The yielding organic cation-encapsulated Gd-POM (OCEP-Gd) complex exhibited water-solubility and amphiphility, leading to the spontaneous self-assembly into a regular vesicular structure with PEO chains towards water phase and POM units locating at the middle. The vesicular aggregate which has a regular monolayer structure, was further studied by means of dynamic light scattering, tra…
<title>Influence of strong static magnetic field on human cancer HT 1080 cells</title>
2001
The aim of this study was to investigate strong uniform magnetic field influence on the human cancer cells HT 1080. The cells were treated with magnetic field of intensity 1,16 Tesla and with anticancer agent - cis-platinum 0.025 mg/ml or vincristinum 2-3 ng/ml. The intact and the treated cell samples were incubated in a medium with acridine orange (AO). The magnetic field after 15 minutes of influence significantly increased cytoplasmic red fluorescence. Increased AO accumulation in lysosomes suggested to cancer cell metabolic activity stimulation.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Magnetoresistance studies of the ferromagnetic molecular metal (BEDT-TTF)3[MnCr(C2O4)3] under pressure
2003
(BEDT-TTF)3[MnCr(C2O4)3] is the first ferromagnetic molecular metal, in which organic layers of BEDT-TTF alternate with infinite layers of the bimetallic oxalate complex [MnCr(C2O4)3]-. While the bimetallic layer undergoes a magnetic phase transition into a canted ferromagnetic state at 5.5 K, the metallic character of the conductivity is not affected by the magnetic transition [Nature 408 (2000) 447]. We performed magnetoresistance measurements (B≤17 T) at low temperatures (T≥900 mK) and under hydrostatic pressures of up to 2.0 GPa. Oscillations in the magnetoresistance develop under pressure that can be interpreted as Shubnikov-de Haas oscillations, if an internal magnetic field is taken …
Systemic hemostatic agents initiated in trauma patients in the pre-hospital setting: a systematic review
2022
Abstract Purpose The effect of systemic hemostatic agents initiated during pre-hospital care of severely injured patients with ongoing bleeding or traumatic brain injury (TBI) remains controversial. A systematic review and meta-analysis was therefore conducted to assess the effectiveness and safety of systemic hemostatic agents as an adjunctive therapy in people with major trauma and hemorrhage or TBI in the context of developing the Italian National Institute of Health guidelines on major trauma integrated management. Methods PubMed, Embase, and Cochrane Library databases were searched up to October 2021 for studies that investigated pre-hospital initiated treatment with systemic hemostati…