1,725,639 research outputs found
Transport and deposition of nanoparticles in microvascular networks
No full textTargeted delivery of therapeutic drugs to specific sites in the body is becoming a norm for treating many diseases, such as cancer. Engineered nanoparticles have emerged as the most suitable carriers for this purpose. Often times, these particles are directly injected into the bloodstream and carried by the circulation to the targeted sites. The efficiency of the nanoparticle delivery depends on how many of them eventually reach the target sites before being removed by kidney filtration or by phagocytosis. Two hydrodynamic processes that are critical in the efficient delivery are margination of these particles from the core of a blood vessel towards the vessel wall, and adhesion of the particles on to the endothelial cell surface lining the vessel wall. Previous studies have considered margination and adhesion of nanoparticles in simple geometry, such as parallel plate flow chambers, and bifurcating channels. These studies have shown that the particle size and shape significantly affect their margination. However, blood vessels in the microcirculation form complex networks known as microvascular networks that are characterized by highly tortuous vessels, and frequent and hierarchical bifurcations and mergers. A detailed quantitative analysis of particle margination and adhesion under such complex geometry is missing. Towards that end, in this thesis we utilize a high-fidelity computational model of cellular-scale blood flow in physiologically-realistic microvascular networks to study the margination and adhesion of nano- and micro-particles. The objective is to understand the simultaneous effects of the flowing red blood cells and the complex geometry of the vasculatures on the margination and adhesion of particles. In the first part of the work, we model nanoparticles as volume-less point particles that are simply advected by the streamlines. We find that margination and adhesion are highly non-uniform across the networks. Specifically, we find that adhesion is significantly high in the bifurcation regions, while margination is high in the venular segments. In the second part of this work, we modeled particles as rigid finite-size spheres. Similar heterogeneity is observed herein, and the margination area density is also correlated to the CFL thickness. Arterioles and venules have high levels of margination and adhesion likelihood, while capillaries have the lowest. Our simulations show that irrespective of hematocrit levels and network topology, the accumulation of the marginated particles and the likelihood of adhesion increase with increasing particle size. In the last part of this work, we study shape effect of particles by considering oblate and prolate shapes. Similar heterogeneity is observed, and the margination area density is also correlated to the CFL thickness. Irrespective of hematocrit levels and network topology, margination of ellipsoidal particles was observed to be higher, with the oblate particles showing the maximum margination compared to other shapes. Our work underscores the importance of network topology on the distribution of the therapeutic drug within the targeted tissue.Ph.D.Includes bibliographical referencesby Hassan M. Al-Sira
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
- …
