186,190 research outputs found
Calorimetric Investigation of the Solvation Process of Organic Compounds in Solvents belonging to the "Critical Quartet"
No full textAggregation of Cesium Perfluorooctanoate on Poly(ethylene glycol) Oligomers in Water
No full textThe interaction of cesium perfluorooctanoate (CsPFO) with poly(ethylene glycol) (PEG) of different molecular
weight (300 e MW e 20000 Da) has been investigated at 298.15 K by isothermal titration calorimetry
(ITC), density, viscosity, and conductivity measurements. Calorimetric titrations exhibited peculiar trends
analogous to those already observed for sodium dodecyl sulfate (SDS). Micelles of the perfluorosurfactant,
as compared to those of SDS, yield complexes with the polymer of similar thermodynamic stability but are
able to interact with shorter PEG oligomers. The average number of surfactant molecules bonded per polymer
chain at the saturation is about twice that observed for SDS. ITC data at 308.15 K indicate a larger
thermodynamic stability of the aggregates but an almost constant stoichiometry. The peculiar thermal effects
and the viscosity trend observed during the titration of an aqueous PEG solution with the surfactant appear
consistent with a conformational change of the polymer. The PEG chain would evolve from a strained to an
expanded conformation, induced by the growing of the surfactant micellar clusters bonded to the polymer, as
suggested in a previous study of the PEG/SDS/H2O system
Group contributions to enthalpies of solvation in octan-1-ol and di-n-butyl ether
No full textThe standard enthalpies of solvation of selected n-alkanes (hexane, heptane, nonane, decane, dodecane, hexadecane) and aromatic hydrocarbons
(benzene, toluene, ethylbenzene) in 1-octanol and di-n-butyl ether (DBE) have been determined at 298.15K from experimental
heats of solution. The values obtained, together with the data collected from literature, form a dataset of 89 and 59 enthalpies of solvation
in 1-octanol and di-n-butyl ether, respectively. The data have been employed for setting up a group contributions scheme to the enthalpies
of solvation of organic compounds in the two solvents. Two different methods, the first based on a multiple regression analysis, the second
consisting by a step procedure which takes the n-alkanes as reference compounds, have been used to calculate the values of the contributions.
The different results obtained with these approaches have been compared and discussed
The role of macrophages in regulating inflammation by oxidative burst
No full textThe production of reactive oxygen species (ROS) through a process called oxidative burst is an essential defence mechanism against pathogens. In phagocytes, such as neutrophils and macrophages, the NADPH oxidase 2 (NOX2) complex is the main source of ROS. Genetic alterations in any of the components of the NOX2 complex that impair the ROS production are at the origin of a condition called chronic granulomatous disease (CGD), characterized by recurrent life threatening bacterial and fungal infections. Recently, natural occurring mutations in Ncf1, a regulatory component of the NOX2 complex, were described to compromise the protein function and to increase arthritis severity in rats and mice. Macrophages are phagocytes that express NCF1 and are able to kill pathogens. At the same time, they are antigen- presenting cells known to play an important role in arthritis. We therefore hypothesized that expression of NCF1 in macrophages would have an impact on the immune response during arthritis and bacterial infections. The aim of the studies presented in this thesis is to evaluate the influence of NCF1 expressed by macrophages on development of arthritis and resolution of bacterial infections.Using transgenic mouse models we could describe a role for macrophages in both priming and activation of arthritogenic T cells. In a first transgenic mouse, expression of functional NCF1 restricted to macrophages reduced arthritis severity, priming of Th1 T cells and T cell proliferation, therefore limiting the T cell-dependent autoimmune outbreak. In a second transgenic mouse strain, where macrophages were the only cells expressing the arthritis-prone MHC class II Aq molecule, macrophages could prime arthritogenic T cells and mediate arthritis development, but only in NCF1 deficient setting. We could conclude that ROS production by macrophages is important in determining the activation state of T cells and in regulating the severity of arthritis.As in the human CGD situation, mice carrying the Ncf1 mutation were more susceptible to spontaneous and induced bacterial infections. Using the transgenic mouse where macrophages expressed the functional NCF1, we observed that macrophage-derived ROS effectively protected mice from bacterial infections, a function believed to be executed mainly by neutrophils.Finally, we tested a new model of arthritis where the disease was induced with a peptide of a glycolytic enzyme. We found that the symptoms and pathogenesis of the disease resembled the one of the most common arthritis model, collagen-induced arthritis, which is induced with the full collagen protein. Both diseases are dependent on an intact adaptive immune system and their severity is influenced by Ncf1. We were also able to identify one of the important residues causing the peptide’s arthritogenicity.In summary, our data highlight the crucial role of NCF1, and consequently of NOX2 complex, in regulating both innate and adaptive immune responses. NCF1-dependent ROS in macrophages was important during both phagocytosis and antigen presentation, resulting in clearance of bacterial infection and suppression of chronic inflammation. These findings will facilitate further investigations of the molecular pathways through which ROS influence arthritis pathogenesis and hopefully lead to identification of new therapeutic targets.List of scientific papersI. Macrophages suppress T cell responses and arthritis development in mice by producing reactive oxygen species. Kyra A. Gelderman, Malin Hultqvist, Angela Pizzolla, Ming Zhao, Kutty Selva Nandakumar, Ragnar Mattsson, Rikard Holmdahl. Journal of Clinical Investigation. 2007; 117(10):3020-8. https://doi.org/10.1172/JCI31935 II. CD68-expressing cells can prime T cells and initiate autoimmune arthritis in the absence of reactive oxygen species. Angela Pizzolla, Kyra A. Gelderman, Malin Hultqvist, Mikael Vestberg, Kenth Gustafsson, Ragnar Mattsson, Rikard Holmdahl. European Journal of Immunology. 2011; 41(2):403-12. https://doi.org/10.1002/eji.201040598 III. Reactive Oxygen Species produced by the NOX2 Complex in Monocytes Protect from Bacterial Infections in Mice. Angela Pizzolla, Malin Hultqvist, Bo Nilson, Melissa J. Grimm, Tove Eneljung, Ing-Marie Jonsson, Margareta Verdrengh, Tiina Kelkka, Inger Gjertsson, Brahm H. Segal, Rikard Holmdahl. [Submitted]IV. A new model of arthritis induced by a glucose-6-phosphate isomerase peptide: immunological requirements and peptide characterization. Angela Pizzolla, Frida Laulund and Rikard Holmdahl. [Manuscript]</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Integrating Artificial Intelligence into Medical Education: Lessons Learned From a Belgian Initiative
No full textpeer reviewedIn the last decades, the medical practice has been facing noteworthy transformations driven by the advancement of innovative technologies like Artificial Intelligence (AI). This rapid and widespread transition generated the increasing need for an adequate education curriculum, capable of properly teaching medical students about the prospects and potentials of AI in healthcare. In this paper, we aim to present and describe the elaboration and implementation of a new academic program at the University of Mons (UMONS) designed to educate medical students about AI in healthcare. The course Pizzolla, Aro, Duez, De Lièvre, and Briganti was implemented in the 2022-2023 academic year aiming to train the next generation of healthcare professionals to effectively leverage AI in their work, ultimately leading to improved patient outcomes and advances in medical research
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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