1,720,981 research outputs found
Etude de la charge nanoparticulaire de divers prélèvements biologiques
No full textThe quantitative and qualitative analysis of nanoparticles in human biological samples is a daunting scientific endeavour as there are no technical procedures capable to cope with the complexity of biological matrices. The central hypothesis of this work is that the increased presence of metal and metal oxide nanoparticles in pulmonary lavage and reproductive fluids may be associated with idiopathic interstitial lung disease and declining female and male fertility, respectively. The developed extraction procedures in the context of this thesis allowed the measuring of the the hydrodynamic size distribution of gold nanoparticles by DLS and their quantitation my means of ICP-OES. Due to the achieved extraction yields and the successful segregation of biological noise, extracted gold nanoparticles could be representatively observed at the nanoscale. Specifically, BSE could detect the dense gold particle cores at low magnification, and TEM and FESEM could be used to resolve the particles’ Feret diameter and morphology, respectively. Finally, the hard biomolecular corona of extracted gold nanoparticle from pulmonary lavages could be probed with AFM, AES, and XPS to acquire information on its morphology, elemental composition, and chemistry, respectively. The application of developed methodologies on patients did not return analytical data that could positively and significantly associate an elevated particle content with increased odds of idiopathic diseases or with low sperm count.L'analyse des nanoparticules dans les échantillons cliniques est une entreprise scientifique redoutable puisqu'il n'existe pas de procédures capables de faire face à la complexité des matrices biologiques. L'hypothèse centrale de ce travail est que la présence accrue de nanoparticules d'oxyde de métal et de métal dans le lavage pulmonaire et les fluides reproducteurs peut être associée à une maladie pulmonaire interstitielle idiopathique et à une baisse de la fertilité féminine et masculine, respectivement. Les procédures d'extraction développées dans le cadre de cette thèse ont permis de mesurer la distribution de la taille hydrodynamique des nanoparticules d'or par DLS et leur quantification par ICP-OES. En raison des rendements d'extraction obtenus et de la ségrégation réussie du bruit biologique, les nanoparticules d'or extraites pourraient être observées de manière représentative à l'échelle nanométrique. Plus précisément, l'ESB pourrait détecter les noyaux denses de particules d'or à faible grossissement, et MET et MEB pourraient être utilisés pour résoudre le diamètre et la morphologie des feret des particules, respectivement. Enfin, la corona biomoleculaire dure de la nanoparticule d'or extraite à partir de lavages pulmonaires pourrait être sondée avec AFM, AES et XPS pour acquérir des informations sur sa morphologie, composition élémentaire et chimie, respectivement. L'application de méthodologies développées sur les patients n'a pas renvoyé de données analytiques qui pourraient associer de manière positive et significative une teneur élevée en particules avec une probabilité accrue de maladies pulmonaire interstitielle idiopathiques ou avec oligospermie
Study of the nanoparticulate load of various human biological samples
No full textL'analyse des nanoparticules dans les échantillons cliniques est une entreprise scientifique redoutable puisqu'il n'existe pas de procédures capables de faire face à la complexité des matrices biologiques. L'hypothèse centrale de ce travail est que la présence accrue de nanoparticules d'oxyde de métal et de métal dans le lavage pulmonaire et les fluides reproducteurs peut être associée à une maladie pulmonaire interstitielle idiopathique et à une baisse de la fertilité féminine et masculine, respectivement. Les procédures d'extraction développées dans le cadre de cette thèse ont permis de mesurer la distribution de la taille hydrodynamique des nanoparticules d'or par DLS et leur quantification par ICP-OES. En raison des rendements d'extraction obtenus et de la ségrégation réussie du bruit biologique, les nanoparticules d'or extraites pourraient être observées de manière représentative à l'échelle nanométrique. Plus précisément, l'ESB pourrait détecter les noyaux denses de particules d'or à faible grossissement, et MET et MEB pourraient être utilisés pour résoudre le diamètre et la morphologie des feret des particules, respectivement. Enfin, la corona biomoleculaire dure de la nanoparticule d'or extraite à partir de lavages pulmonaires pourrait être sondée avec AFM, AES et XPS pour acquérir des informations sur sa morphologie, composition élémentaire et chimie, respectivement. L'application de méthodologies développées sur les patients n'a pas renvoyé de données analytiques qui pourraient associer de manière positive et significative une teneur élevée en particules avec une probabilité accrue de maladies pulmonaire interstitielle idiopathiques ou avec oligospermie.The quantitative and qualitative analysis of nanoparticles in human biological samples is a daunting scientific endeavour as there are no technical procedures capable to cope with the complexity of biological matrices. The central hypothesis of this work is that the increased presence of metal and metal oxide nanoparticles in pulmonary lavage and reproductive fluids may be associated with idiopathic interstitial lung disease and declining female and male fertility, respectively. The developed extraction procedures in the context of this thesis allowed the measuring of the the hydrodynamic size distribution of gold nanoparticles by DLS and their quantitation my means of ICP-OES. Due to the achieved extraction yields and the successful segregation of biological noise, extracted gold nanoparticles could be representatively observed at the nanoscale. Specifically, BSE could detect the dense gold particle cores at low magnification, and TEM and FESEM could be used to resolve the particles’ Feret diameter and morphology, respectively. Finally, the hard biomolecular corona of extracted gold nanoparticle from pulmonary lavages could be probed with AFM, AES, and XPS to acquire information on its morphology, elemental composition, and chemistry, respectively. The application of developed methodologies on patients did not return analytical data that could positively and significantly associate an elevated particle content with increased odds of idiopathic diseases or with low sperm count
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
