1,721,008 research outputs found
EXTENDED PRESERVATION OF KIDNEYS FOR TRANSPLANT AT SUBZERO TEMPERATURES USING BIOINSPIRED CRYOPROTECTANTS
No full textOn-demand replacement of organs and tissues could be a transformative solution to one of the most pressing challenges facing biomedical science today: the severe and global shortage of organs for transplantation. Yet one challenge remains: our inability to preserve organs during recovery, storage, and transport for extended durations. Organ-specific ischemia windows of 4-24 hours, and the reliance on the nearly 70-year-old practice of storing organs on wet ice at 4°C, severely limit the life-saving potential of organ transplantation, as organs continuously deteriorate with every additional hour of cold ischemia. Extending the preservation time of
organs from hours to multiple days could increase the availability of organs. Lowering the storage temperature to below freezing slows metabolism and theoretically could halt biological time. Previous attempts to store human-sized organs at subzero temperatures have failed to address the challenge of ice formation. Thus, the challenge emerges: How can we store whole organs at temperatures below their freezing points while avoiding damage from ice formation? This dissertation presents an alternative approach to extended preservation that is inspired by naturally occurring antifreeze proteins (AFPs), which enable certain species to survive at subzero temperatures. We introduce a new class of cryoprotective agent (CPA)—called peptoid CPA—and show that it can maintain organs in a non-frozen state at subzero temperatures for multiple days. We find that peptoid CPA at subzero temperatures, around -5°C, significantly extends the viable preservation time of donor organs to up to 5 days. We probe the pathophysiological mechanisms that enable subzero preservation to maintain tissue viability and function and provide biological evaluation of subzero preservation in an ex vivo machine perfusion and a large animal preclinical autotransplantation model. We demonstrate, for the first time, that subzero-preserved organs can restore renal function and support the life of nephrectomized animals for over 200 days. Finally, we demonstrate the real-world potential of this technology by successfully transporting a pig kidney preserved at subzero temperatures on a commercial flight across the Atlantic Ocean. The peptoid preservation solution provides a clinically translatable system that significantly extends organ preservation without modifying peri-transplant workflow
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
EXPLORING THE ROLE AND PARTICIPATION OF IMMUNE CELLS IN RENAL COMPENSATORY HYPERTROPHY AFTER UNILATERAL NEPHRECTOMY
No full textThe surgical removal of one kidney, also known as nephrectomy, will cause the size increase and functional compensation of the remaining kidney. Compensatory hypertrophy is considered a phenomenon with clinical importance for maintaining healthy renal function in the living kidney transplant donors after unilateral nephrectomy. However, the mechanisms behind the compensatory hypertrophy (CRH) are still largely unclear. Although previous studies about possible hemodynamic and epithelial cell mechanisms involved in hypertrophic growth in kidney have been conducted, the roles for kidney immune cells have been overlooked. This thesis provides an elaborate description on the changes in kidney immune cells after unilateral nephrectomy. Flow cytometry was used to reveal the changes of kidney immune cells while single-cell RNA sequencing was applied to elucidate the gene expression changes in different immune cells. The role of immune cell’s participation in CRH was further tested in an immune deficient mouse —the RAG1 knockout. Chapter 1 provides a comprehensive literature review of the clinical relevance of CRH and current studies exploring CRH mechanisms. Chapter 2 describes experimental designs and methods of this thesis study. Chapter 3 demonstrates the results of this study from multiple perspectives and the discussions in regarding the findings were shown
EXPLORING THE ROLE AND PARTICIPATION OF IMMUNE CELLS IN RENAL COMPENSATORY HYPERTROPHY AFTER UNILATERAL NEPHRECTOMY
No full textThe surgical removal of one kidney, also known as nephrectomy, will cause the size increase and functional compensation of the remaining kidney. Compensatory hypertrophy is considered a phenomenon with clinical importance for maintaining healthy renal function in the living kidney transplant donors after unilateral nephrectomy. However, the mechanisms behind the compensatory hypertrophy (CRH) are still largely unclear. Although previous studies about possible hemodynamic and epithelial cell mechanisms involved in hypertrophic growth in kidney have been conducted, the roles for kidney immune cells have been overlooked. This thesis provides an elaborate description on the changes in kidney immune cells after unilateral nephrectomy. Flow cytometry was used to reveal the changes of kidney immune cells while single-cell RNA sequencing was applied to elucidate the gene expression changes in different immune cells. The role of immune cell’s participation in CRH was further tested in an immune deficient mouse —the RAG1 knockout. Chapter 1 provides a comprehensive literature review of the clinical relevance of CRH and current studies exploring CRH mechanisms. Chapter 2 describes experimental designs and methods of this thesis study. Chapter 3 demonstrates the results of this study from multiple perspectives and the discussions in regarding the findings were shown
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
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