Paul Sabatier University

About: Paul Sabatier University is a education organization based out in Toulouse, France. It is known for research contribution in the topics: Population & Catalysis. The organization has 15431 authors who have published 23386 publications receiving 858364 citations.

Change in abstract argumentation frameworks: adding an argument

Abstract: In this paper, we address the problem of change in an abstract argumentation system. We focus on a particular change: the addition of a new argument which interacts with previous arguments. We study the impact of such an addition on the outcome of the argumentation system, more particularly on the set of its extensions. Several properties for this change operation are defined by comparing the new set of extensions to the initial one, these properties are called "structural" when the comparisons are based on set-cardinality or set-inclusion relations. Several other properties are proposed where comparisons are based on the status of some particular arguments: the accepted arguments; these properties refer to the "evolution of this status" during the change, e.g., Monotony and Priority to Recency. All these properties may be more or less desirable according to specific applications. They are studied under two particular semantics: the grounded and preferred semantics.

Methotrexate in psoriasis: a systematic review of treatment modalities, incidence, risk factors and monitoring of liver toxicity.

Abstract: Background/Aim To define practical use and to specify the ideal method for monitoring the liver toxicity of MTX in the management of psoriasis. Objective To systematically review the literature regarding treatment modalities with methotrexate (MTX) in psoriasis, risk of MTX-mediated liver fibrosis and monitoring of hepatic toxicity. Methods A systematic literature search was carried out in Medline, Embase and Cochrane Library databases from 1980 to 2010 searching for randomized controlled trials and observational studies on methods of administering MTX in psoriasis and risk factors and assessment of liver toxicity. We limited the literature search to articles on human subjects over 19 years of age, articles in English or French on psoriasis and articles including psoriatic arthritis and original data. Results Among 949 references identified, 23 published studies were included. There were no studies focusing directly on the question of MTX treatment modalities. Treatment outcome appears to be dose dependent. A single study in rheumatoid arthritis showed the slightly superior efficacy of subcutaneous administration vs. oral dosing with a similar safety profile. Combination with folic acid may decrease the efficacy of MTX while improving tolerability. The extreme variability of the incidence of hepatic fibrosis in the literature does not allow the risk of hepatic fibrosis to be quantified. Type 2 diabetes and obesity, were associated with a significant increased risk of liver fibrosis. Hepatitis B and C and alcohol consumption were associated with a modest and non-significant increased risk of liver fibrosis. Procollagen III for detection of hepatic fibrosis dosing was the most extensively validated method to monitor liver fibrosis showing a sensitivity of 77.3% and a specificity of 91.5%. The Positive Predictive Value and Negative Predictive Value fluctuated depending on the prevalence of hepatic fibrosis. The sensitivities of the FibroTest and the fibroscan were of 83 and 50%, respectively, with specific features amounting to 61 and 88% respectively. Conclusions Based on expert experience, the starting dose of MTX is between 5 and 10 mg/week for the first week. Fast dose escalation is recommended in order to obtain a therapeutic target dose of 15–25 mg/week. The maximum recommended dose is 25 mg/week. A folic acid supplement is necessary. The initiation of treatment by oral administration is preferred. In cases where inadequate response is obtained or in the event of poor gastrointestinal tolerance, subcutaneous dosing can be proposed at the same dose. Published data do not confirm the incidence of hepatic fibrosis. Type 2 diabetes and obesity appear to be significant risk factors in fibrosis. A combination of FibroTests and fibroscans together with measurement of the type III serum procollagen aminopeptide seem to be ideal method for monitoring liver toxicity.

Exciton transfer dynamics and quantumness of energy transfer in the Fenna-Matthews-Olson complex.

Abstract: We present numerically exact results for the quantum coherent energy transfer in the Fenna-Matthews-Olson molecular aggregate under realistic physiological conditions, including vibrational fluctuations of the protein and the pigments for an experimentally determined fluctuation spectrum. We find coherence times shorter than observed experimentally. Furthermore, we determine the energy transfer current and quantify its ``quantumness'' as the distance of the density matrix to the classical pointer states for the energy current operator. Most importantly, we find that the energy transfer happens through a ``Schr\"odinger-cat-like'' superposition of energy current pointer states.

Thermoplasmonics modeling: A Green’s function approach

Abstract: We extend the discrete dipole approximation (DDA) and the Green's dyadic tensor (GDT) methods---previously dedicated to all-optical simulations---to investigate the thermodynamics of illuminated plasmonic nanostructures. This extension is based on the use of the thermal Green's function and a original algorithm that we named Laplace matrix inversion. It allows for the computation of the steady-state temperature distribution throughout plasmonic systems. This hybrid photothermal numerical method is suited to investigate arbitrarily complex structures. It can take into account the presence of a dielectric planar substrate and is simple to implement in any DDA or GDT code. Using this numerical framework, different applications are discussed such as thermal collective effects in nanoparticles assembly, the influence of a substrate on the temperature distribution and the heat generation in a plasmonic nanoantenna. This numerical approach appears particularly suited for new applications in physics, chemistry, and biology such as plasmon-induced nanochemistry and catalysis, nanofluidics, photothermal cancer therapy, or phase-transition control at the nanoscale.

Chronic Estradiol Administration In Vivo Promotes the Proinflammatory Response of Macrophages to TLR4 Activation: Involvement of the Phosphatidylinositol 3-Kinase Pathway

Abstract: Short-term exposure to 17beta-estradiol (E2) in vitro has been reported to decrease the production of proinflammatory cytokines by LPS-activated macrophages through estrogen receptor alpha (ERalpha)-dependent activation of the PI3K pathway. In the present study, we confirm that in vitro exposure of mouse peritoneal macrophages to E2 enhanced Akt phosphorylation and slightly decreased LPS-induced cytokine production. In striking contrast, we show that chronic administration of E2 to ovariectomized mice markedly increases the expression of IL-1beta, IL-6, IL-12p40, and inducible NO synthase by resident peritoneal macrophages in response to LPS ex vivo. These results clearly indicate that short-term E2 treatment in vitro does not predict the long-term effect of estrogens in vivo on peritoneal macrophage functions. We show that this in vivo proinflammatory effect of E2 was mediated through ERalpha. Although the expression of components of the LPS-recognition complex remained unchanged, we provided evidences for alterations of the TLR4 signaling pathway in macrophages from E2-treated mice. Indeed, E2 treatment resulted in the inhibition of PI3K activity and Akt phosphorylation in LPS-activated macrophages, whereas NF-kappaB p65 transcriptional activity was concomitantly increased. Incubation of macrophages with the PI3K inhibitor wortmanin enhanced proinflammatory cytokine gene expression in response to TLR4 activation, and abolishes the difference between cells from placebo- or E2-treated mice, demonstrating the pivotal role of the PI3K/Akt pathway. We conclude that the macrophage activation status is enhanced in vivo by E2 through ERalpha and, at least in part, by the down-modulation of the PI3K/Akt pathway, thereby alleviating this negative regulator of TLR4-signaling.