323 research outputs found

    Synthesis and evaluation of new designed multiple ligands directed towards both peroxisome proliferator-activated receptor-γ and angiotensin II type 1 receptor

    Get PDF
    Because of the complex biological networks, many pathologic disorders fail to be treated with a molecule directed towards a single target. Thus, combination therapies are often necessary, but they have many drawbacks. An alternative consists in building molecules intended to interact with multiple targets, called designed multiple ligands. We followed such a strategy in order to treat metabolic syndrome, by setting up molecules directed towards both type 1 angiotensin II (AT1) receptor and peroxisome proliferator-activated receptor-γ (PPAR-γ). For this purpose, many molecules were prepared by merging both pharmacophores following three different strategies. Their ability to activate PPAR-γ and to block AT1 receptors were evaluated in vitro. This strategy led to the preparation of many new PPAR-γ activating and AT1 blocking molecules. Among them, some exhibited both activities, highlighting the convenience of this approach

    The failed liberalisation of Algeria and the international context: a legacy of stable authoritarianism

    Get PDF
    The paper attempts to challenge the somewhat marginal role of international factors in the study of transitions to democracy. Theoretical and practical difficulties in proving causal mechanisms between international variables and domestic outcomes can be overcome by defining the international dimension in terms of Western dominance of world politics and by identifying Western actions towards democratising countries. The paper focuses on the case of Algeria, where international factors are key in explaining the initial process of democratisation and its following demise. In particular, the paper argues that direct Western policies, the pressures of the international system and external shocks influence the internal distribution of power and resources, which underpins the different strategies of all domestic actors. The paper concludes that analysis based purely on domestic factors cannot explain the process of democratisation and that international variables must be taken into more serious account and much more detailed

    Understanding Battery Interfaces by Combined Characterization and Simulation Approaches: Challenges and Perspectives

    Get PDF
    Driven by the continuous search for improving performances, understanding the phenomena at the electrode/electrolyte interfaces has become an overriding factor for the success of sustainable and efficient battery technologies for mobile and stationary applications. Toward this goal, rapid advances have been made regarding simulations/modeling techniques and characterization approaches, including high-throughput electrochemical measurements coupled with spectroscopies. Focusing on Li-ion batteries, current developments are analyzed in the field as well as future challenges in order to gain a full description of interfacial processes across multiple length/timescales; from charge transfer to migration/diffusion properties and interphases formation, up to and including their stability over the entire battery lifetime. For such complex and interrelated phenomena, developing a unified workflow intimately combining the ensemble of these techniques will be critical to unlocking their full investigative potential. For this paradigm shift in battery design to become reality, it necessitates the implementation of research standards and protocols, underlining the importance of a concerted approach across the community. With this in mind, major collaborative initiatives gathering complementary strengths and skills will be fundamental if societal and environmental imperatives in this domain are to be met

    Cation insertion to break the activity/stability relationship for highly active oxygen evolution reaction catalyst

    Get PDF
    The production of hydrogen at a large scale by the environmentally-friendly electrolysis process is currently hampered by the slow kinetics of the oxygen evolution reaction (OER). We report a solid electrocatalyst α-Li2IrO3 which upon oxidation/delithiation chemically reacts with water to form a hydrated birnessite phase, the OER activity of which is five times greater than its non-reacted counterpart. This reaction enlists a bulk redox process during which hydrated potassium ions from the alkaline electrolyte are inserted into the structure while water is oxidized and oxygen evolved. This singular charge balance process for which the electrocatalyst is solid but the reaction is homogeneous in nature allows stabilizing the surface of the catalyst while ensuring stable OER performances, thus breaking the activity/stability tradeoff normally encountered for OER catalysts

    Rechargeable Batteries of the Future—The State of the Art from a BATTERY 2030+ Perspective

    Get PDF
    The development of new batteries has historically been achieved through discovery and development cycles based on the intuition of the researcher, followed by experimental trial and error—often helped along by serendipitous breakthroughs. Meanwhile, it is evident that new strategies are needed to master the ever-growing complexity in the development of battery systems, and to fast-track the transfer of findings from the laboratory into commercially viable products. This review gives an overview over the future needs and the current state-of-the art of five research pillars of the European Large-Scale Research Initiative BATTERY 2030+, namely 1) Battery Interface Genome in combination with a Materials Acceleration Platform (BIG-MAP), progress toward the development of 2) self-healing battery materials, and methods for operando, 3) sensing to monitor battery health. These subjects are complemented by an overview over current and up-coming strategies to optimize 4) manufacturability of batteries and efforts toward development of a circular battery economy through implementation of 5) recyclability aspects in the design of the battery

    Second malignant neoplasms after a first cancer in childhood: temporal pattern of risk according to type of treatment

    Get PDF
    The variation in the risk of solid second malignant neoplasms (SMN) with time since first cancer during childhood has been previously reported. However, no study has been performed that controls for the distribution of radiation dose and the aggressiveness of past chemotherapy, which could be responsible for the observed temporal variation of the risk. The purpose of this study was to investigate the influence of the treatment on the long-term pattern of the incidence of solid SMN after a first cancer in childhood. We studied a cohort of 4400 patients from eight centres in France and the UK. Patients had to be alive 3 years or more after a first cancer treated before the age of 17 years and before the end of 1985. For each patient in the cohort, the complete clinical, chemotherapy and radiotherapy history was recorded. For each patient who had received external radiotherapy, the dose of radiation received by 151 sites of the body were estimated. After a mean follow-up of 15 years, 113 children developed a solid SMN, compared to 12.3 expected from general population rates. A similar distribution pattern was observed among the 1045 patients treated with radiotherapy alone and the 2064 patients treated with radiotherapy plus chemotherapy; the relative risk, but not the excess absolute risk, of solid SMN decreased with time after first treatment; the excess absolute risk increased during a period of at least 30 years after the first cancer. This pattern remained after controlling for chemotherapy and for the average dose of radiation to the major sites of SMN. It also remained when excluding patients with a first cancer type or an associated syndrome known to predispose to SMN. When compared with radiotherapy alone, the addition of chemotherapy increases the risk of solid SMN after a first cancer in childhood, but does not significantly modify the variation of this risk during the time after the first cancer. © 1999 Cancer Research Campaig

    The therapeutic effect of the neuropeptide hormone somatostatin on Schistosoma mansoni caused liver fibrosis

    Get PDF
    BACKGROUND: The neuropeptide somatostatin is one of the major regulatory peptides in the central nervous system and the digestive tract. Our recent work has delineated an association between fibrosis and low levels of endogenous somatostatin plasma levels in Schistosoma mansoni infected subjects. Based on these results this paper explores the therapeutic potential of somatostatin in a mouse model of hepatic fibrosis associated with S. mansoni infections. METHODS: Groups of outbred Swiss mice were infected with 100 S. mansoni cercariae, infection maintained till weeks 10 or 14, and then somatostatin therapy delivered in two regimens – Either a one or a two-day treatment. All animals were sacrificed one week after therapy and controlled for liver, spleen and total body weight. Circulating somatostatin levels in mice plasma were measured at the time of sacrifice by means of a radio-immuno assay. GraphPad Prism(® )was used for statistical calculations. RESULTS: Somatostatin administration showed little toxicity, probably due to its short half-life. Total liver and spleen weights of S. mansoni infected animals increased over time, with no changes observed due to somatostatin therapy. Total body weights were decreased after infection but were not affected by somatostatin therapy. Snap frozen liver sections were stained with haematoxylin-eosin or Masson's trichrome to study parasite count, hepatocyte status, granuloma size and cellularity. After somatostatin treatment mean egg counts per liver section (43.76 ± 3.56) were significantly reduced as compared to the egg counts in untreated mice after 10 weeks of infection (56.01 ± 3.34) (P = 0.03). Similar significant reduction in parasite egg counts were also observed after somatostatin treatment at 14 weeks of infection (56.62 ± 3.02) as compared to untreated animals (69.82 ± 2.77)(P = 0.006). Fibrosis was assessed from the spectrophotometric determination of tissue hydroxyproline. Infection with S. mansoni caused increased hydroxyproline levels (9.37 ± 0.63 μmol at wk10; 9.65 ± 0.96 μmol at wk14) as compared to uninfected animals (1.06 ± 0.10 μmol). This significant increase in collagen content (P = 0.01; 0.007 respectively) marks the fibrosis observed at these time points. Treatment with somatostatin resulted in a significant decrease in hydroxyproline levels both at wk10 (4.76 ± 0.58 μmol) and at wk14 (5.8 ± 1.13 μmol) (P = 0.01; 0.03 respectively). Endogenous somatostatin levels were increased at wk10 (297 ± 37.24 pg/ml) and wk14 (206 ± 13.30 pg/ml) of infection as compared to uninfected mice (119 ± 11.99 pg/ml) (P = 0.01; 0.008 respectively). Circulating somatostatin levels in infected animals were not significantly affected by somatostatin treatment. Hepatocyte status remained unaltered and granulomas were not remarkably changed in size or cellularity. CONCLUSION: Our experiments reveal an antifibrotic effect of somatostatin in schistosomiasis. We have previously shown that the somatostatin receptors SSTR2 and SSTR3 are present on the parasite egg and worms. We therefore hypothesize that somatostatin reduces either the number of parasite eggs or the secretion of fibrosis inducing-mediators. Our data suggest somatostatin may have therapeutic potential in S. mansoni mediated liver pathology
    corecore