1,720,986 research outputs found
The significance of glucose transporters in the pathogenesis of abdominal aortic aneurysms
No full textAbdominal aortic aneurysm (AAA) is associated with significant mortality worldwide. At present, the only treatment involves an operation. Understanding the pathogenesis is important to help develop new drug therapies aimed at slowing aneurysm growth. Diabetes mellitus (DM) has been shown to be negatively associated with AAA however the mechanisms underlying this relationship are poorly understood.
This thesis first confirmed the robustness of this epidemiological relationship through a meta-analysis of >70 studies and then, using whole aortic tissue samples (WATS) and aortic smooth muscle cells (AoSMCs) from patients with and without AAA, examined the importance of glucose transporters (GLUTs), a group of proteins responsible for sugar transport across cell membranes, in the pathogenesis of AAA and in explaining the negative relationship between DM and AAA.
Comparing WATS from patients with and without AAA, gene expression of GLUT3 (p=0.004) and GLUT6 (p=0.04) and protein expression of GLUT1 (p=0.002), GLUT3 (p=0.002) and GLUT6 (p=0.004) were significantly higher in WATS from AAA patients. Comparing AoSMCs from patients with and without AAA, gene expression of GLUTs was similar between groups however GLUT activity was significantly higher in AoSMCs from patients with AAA (p=0.02).
To study the effect of DM on GLUTs, AoSMCs from patients with and without AAA were exposed to increasing levels of hyperglycaemia (4.6mmol/L - 50mmol/L). Hyperglycaemia was not associated with a significant change in the gene expression of GLUTs, cathepsins or TIMPs, however hyperglycaemia within the physiological range (up to 25mmol/L) was associated with a significant decrease in GLUT activity (p=0.01) selectively in the AoSMCs from AAA patients, independent of any hyperosmolar effect.
In conclusion, these results suggest that glucose transporters are important in the pathogenesis of AAA and may be involved in regulating the protective effect of DM on AAA. Targeting glucose transporters to slow aneurysm growth merits further investigation
The significance of glucose transporters in the pathogenesis of abdominal aortic aneurysms
No full textAbdominal aortic aneurysm (AAA) is associated with significant mortality worldwide. At present, the only treatment involves an operation. Understanding the pathogenesis is important to help develop new drug therapies aimed at slowing aneurysm growth. Diabetes mellitus (DM) has been shown to be negatively associated with AAA however the mechanisms underlying this relationship are poorly understood.
This thesis first confirmed the robustness of this epidemiological relationship through a meta-analysis of >70 studies and then, using whole aortic tissue samples (WATS) and aortic smooth muscle cells (AoSMCs) from patients with and without AAA, examined the importance of glucose transporters (GLUTs), a group of proteins responsible for sugar transport across cell membranes, in the pathogenesis of AAA and in explaining the negative relationship between DM and AAA.
Comparing WATS from patients with and without AAA, gene expression of GLUT3 (p=0.004) and GLUT6 (p=0.04) and protein expression of GLUT1 (p=0.002), GLUT3 (p=0.002) and GLUT6 (p=0.004) were significantly higher in WATS from AAA patients. Comparing AoSMCs from patients with and without AAA, gene expression of GLUTs was similar between groups however GLUT activity was significantly higher in AoSMCs from patients with AAA (p=0.02).
To study the effect of DM on GLUTs, AoSMCs from patients with and without AAA were exposed to increasing levels of hyperglycaemia (4.6mmol/L - 50mmol/L). Hyperglycaemia was not associated with a significant change in the gene expression of GLUTs, cathepsins or TIMPs, however hyperglycaemia within the physiological range (up to 25mmol/L) was associated with a significant decrease in GLUT activity (p=0.01) selectively in the AoSMCs from AAA patients, independent of any hyperosmolar effect.
In conclusion, these results suggest that glucose transporters are important in the pathogenesis of AAA and may be involved in regulating the protective effect of DM on AAA. Targeting glucose transporters to slow aneurysm growth merits further investigation
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
ACCURATE, ANALYTIC, EMPIRICAL POTENTIALS AND BORN-OPPENHEIMER BREAKDOWN FUNCTIONS FOR THE X(11Σ)-STATES OF BeH, BeD, and BeT
No full textHALO NUCLEIC MOLECULES: MOLECULES FORMED FROM AT LEAST ONE ATOM WITH A HALO NUCLEUS. EMPHASIS ON 11,11Li2 ALONG WITH OTHER EXOTIC ISOTOPOLOGUES.
No full textVariations 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
Computer spectrometers
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Previous issue date: 6"Ideally, the cataloguing of spectroscopic linelists would not demand laborious and expensive experiments. Whatever an experiment might achieve, the same information would be attainable by running a calculation on a computer. Kolos and Wolniewicz were the first to demonstrate that calculations on a computer can outperform even the most sophisticated molecular spectroscopic experiments of the time, when their 1964 calculations of the dissociation energies of H and D were found to be more than 1 cm larger than the best experiments by Gerhard Herzberg, suggesting the experiment violated a strict variational principle. As explained in his Nobel Lecture, it took 5 more years for Herzberg to perform an experiment which caught up to the accuracy of the 1964 calculations._x000d_
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Today, numerical solutions to the Schr\""odinger equation, supplemented with relativistic and higher-order quantum electrodynamics (QED) corrections can provide ro-vibrational spectra for molecules that we strongly believe to be correct, even in the absence of experimental data. Why do we believe these calculated spectra are correct if we do not have experiments against which to test them? All evidence seen so far suggests that corrections due to gravity or other forces are not needed for a computer simulated QED spectrum of ro-vibrational energy transitions to be correct at the precision of typical spectrometers. Therefore a computer-generated spectrum can be considered to be as good as one coming from a more conventional spectrometer, and this has been shown to be true not just for the \chem{H_2} energies back in 1964, but now also for several other molecules._x000d_
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So are we at the stage where we can launch an array of calculations, each with just the atomic number changed in the input file, to reproduce the NIST energy level databases? Not quite. But I will show that for the 6e molecule \chem{Li_2}, we have reproduced the vibrational spacings to within 0.001 cm of the experimental spectrum, and I will discuss present-day prospects for replacing laborious experiments for spectra of certain systems within the reach of today's ``computer spectrometers''._x000d_
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