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1.
Comput Methods Biomech Biomed Engin ; 26(2): 235-248, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35587791

ABSTRACT

Computational hemodynamic (CH) characteristics play a central role in the onset and expansion of atherosclerotic plaques in the coronary main arteries. This study has explored the effects of hemodynamic properties especially coronary arterial wall tangential stresses on various healthy and diseased patient-based coronary artery models based on coronary computed tomography angiography (CCTA) imaging. The key components of the work are the CCTA image acquisition, accurate three-dimensional (3 D) model segmentation, reconstruction, appropriate grid generation, CH simulations, and analysis of the results by using open-source techniques. The CH simulation results have produced hemodynamic variables, including velocity magnitude (VM), mean arterial pressure difference, wall shear stress (WSS), time-averaged WSS (TAWSS), oscillatory shear index (OSI), relative residence time (RRT), and finally, computational fractional flow reserve (cFFR), that allow the pathophysiological conditions in patient-based coronary models. The VM, mean pressure difference, and WSS indices have yielded consistent simulation results for predicting the severity conditions of coronary diseases. We have compared our cFFR results with the published results and observed that the WSS indices were a good alternative approach for measuring the severity of coronary lesions. The CH results allow a medical expert to estimate the severity of a lumen area and stenosis physiological blood flow conditions in a non-invasive way.


Subject(s)
Cardiovascular Abnormalities , Coronary Artery Disease , Fractional Flow Reserve, Myocardial , Plaque, Atherosclerotic , Humans , Coronary Artery Disease/diagnostic imaging , Coronary Vessels/diagnostic imaging , Hemodynamics , Computer Simulation , Models, Cardiovascular , Stress, Mechanical
2.
Conserv Biol ; 33(6): 1286-1295, 2019 12.
Article in English | MEDLINE | ID: mdl-30848502

ABSTRACT

Developments in CRISPR-based gene-editing technologies have generated a growing number of proposals to edit genes in wildlife to meet conservation goals. As these proposals have attracted greater attention, controversies have emerged among scientists and stakeholder groups over potential consequences and ethical implications of gene editing. Responsible governance cannot occur without consulting broader publics, yet little effort has been made to systematically assess public understandings and beliefs in relation to this new area of applied genetic engineering. We analyzed data from a survey of U.S. adults (n = 1600), collected by YouGov, and that examined respondents' concerns about gene editing in animal and plant wildlife and how those concerns are shaped by cultural dispositions toward science and beliefs about the appropriateness of intervening in nature at the genetic level. On average, respondents perceived more risk than benefit in using these tools. Over 70% agreed that gene editing in wildlife could be "easily used for the wrong purposes." When evaluating the moral acceptability of gene editing in wildlife, respondents evaluated applications to improve survival in endangered wildlife as more morally acceptable than applications to decrease abundance in a population or eliminate a population. Belief in the authority of scientific knowledge was positively related to favorable views of the benefits, risks, and moral acceptability of editing genes in wildlife. The belief that editing genes in wildlife inappropriately intervenes in nature predicted relatively more concern about risks and moral acceptability and skepticism about benefits. Given high levels of concern and skepticism about gene editing in wildlife for conservation among the U.S. public, a take-it-slow approach to making decisions about when or whether to use these tools is advisable. Early opinions, including those uncovered in this study, are likely to be provisional. Thus, consulting the public should be an ongoing process.


Opinión Pública sobre la Edición de Genes en la Conservación de Fauna Resumen El desarrollo de tecnologías de edición de genes basada en CRISPR ha generado un número creciente de propuestas para editar los genes de especies silvestres y así lograr los objetivos de conservación. Conforme estas propuestas han atraído la atención, han surgido controversias entre los grupos de científicos y accionistas sobre las consecuencias potenciales y las implicaciones éticas de la edición de genes. La gobernanza responsable no puede ocurrir sin consultar a una audiencia más amplia, y aun así se han realizado muy pocos esfuerzos por evaluar sistemáticamente las creencias y el entendimiento público relacionados con esta nueva etapa de ingeniería genética aplicada. Analizamos los resultados de una encuesta en línea realizado por YouGov entre adultos de los Estados Unidos (n = 1,600), la cual examinaba las preocupaciones de los respondientes sobre la edición genética en animales y plantas y cómo estas preocupaciones están moldeadas por la disposición cultural hacia la ciencia y las creencias sobre lo correcto que es intervenir en la naturaleza a nivel genético. En promedio, los respondientes percibieron más un riesgo que un beneficio al usar estas herramientas. Más del 70% estuvo de acuerdo en que la edición genética de especies silvestres podría "usarse fácilmente para los propósitos equivocados". Cuando evaluamos la aceptación moral de la edición genética de la fauna, los respondientes calificaron a las aplicaciones para incrementar la supervivencia de las especies amenazadas como más aceptables moralmente que las aplicaciones para disminuir la abundancia de una población o eliminarla totalmente. La creencia en la autoridad del conocimiento científico estuvo relacionada positivamente con la opinión favorable sobre los beneficios, riesgos y la aceptación moral de la edición genética de especies silvestres. La creencia de que la edición genética de especies silvestres interviene inapropiadamente con la naturaleza predijo relativamente una mayor preocupación por los riesgos y la aceptación moral y mayor escepticismo sobre los beneficios de la edición genética. Debido a los altos niveles de preocupación y escepticismo sobre la edición genética de especies silvestres para la conservación mostrados por el público estadunidense, se recomienda utilizar una estrategia de hazlo-con-calma para decidir cuándo o si usar estas herramientas. Es probable que las primeras opiniones, incluyendo las descubiertas con este estudio, sean provisionales. Por lo tanto, consultar al público debe ser un proceso continuo.


Subject(s)
Animals, Wild , Conservation of Natural Resources , Animals , Attitude , Morals , Surveys and Questionnaires
3.
Ann Biomed Eng ; 40(7): 1443-54, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22234864

ABSTRACT

Asymptomatic vulnerable plaques (VP) in coronary arteries accounts for significant level of morbidity. Their main risk is associated with their rupture which may prompt fatal heart attacks and strokes. The role of microcalcifications (micro-Ca), embedded in the VP fibrous cap, in the plaque rupture mechanics has been recently established. However, their diminutive size offers a major challenge for studying the VP rupture biomechanics on a patient specific basis. In this study, a highly detailed model was reconstructed from a post-mortem coronary specimen of a patient with observed VP, using high resolution micro-CT which captured the microcalcifications embedded in the fibrous cap. Fluid-structure interaction (FSI) simulations were conducted in the reconstructed model to examine the combined effects of micro-Ca, flow phase lag and plaque material properties on plaque burden and vulnerability. This dynamic fibrous cap stress mapping elucidates the contribution of micro-Ca and flow phase lag VP vulnerability independently. Micro-Ca embedded in the fibrous cap produced increased stresses predicted by previously published analytical model, and corroborated our previous studies. The 'micro-CT to FSI' methodology may offer better diagnostic tools for clinicians, while reducing morbidity and mortality rates for patients with vulnerable plaques and ameliorating the ensuing healthcare costs.


Subject(s)
Calcinosis , Coronary Angiography , Coronary Artery Disease , Coronary Vessels/physiopathology , Models, Cardiovascular , Plaque, Atherosclerotic , X-Ray Microtomography , Calcinosis/diagnostic imaging , Calcinosis/physiopathology , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/physiopathology , Female , Humans , Male , Plaque, Atherosclerotic/diagnostic imaging , Plaque, Atherosclerotic/physiopathology , Rupture, Spontaneous/diagnostic imaging , Rupture, Spontaneous/physiopathology
4.
J Endod ; 36(7): 1130-4, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20630284

ABSTRACT

INTRODUCTION: The purpose of this study was to compare decision-making choices among dentists with different levels of training. METHODS: Scanned periapical radiographs and a leaflet with relevant information of 17 endodontically treated teeth were mailed to 40 undergraduate students, 25 general practitioners, 20 postgraduate students, and 40 endodontists. All teeth were symptom-free. The hypothetical scenario referred to patients who sought treatment for first time and had noncontributory medical history. Five treatment options were given for each situation: (1) Extraction, (2) Surgical Retreatment, (3) Nonsurgical Retreatment, (4) Wait and See, and (5) No Therapy. Statistical analysis was performed by using multinomial logistic regression models. RESULTS: The overall response rate was 70.4%, with endodontists exhibiting the lowest response. The undergraduates gave 4 or 5 treatment solutions for all cases, in contrast to endodontists, who gave 2 or 3 treatment solutions in a percentage of 82%. Nonsurgical Retreatment predominated among the participants' choices. Significant differences were detected in (1) Extraction for postgraduate students (P = .008) and endodontists (P = .001), (2) Surgical Retreatment for general practitioners (P = .002), postgraduate students (P = .002), and endodontists (P = .001), and (3) Wait and See for postgraduate students (P = .023). CONCLUSIONS: Differences in specialty training and experience strongly influence endodontic decision making. Endodontists showed the most consistent agreement among the groups.


Subject(s)
Clinical Competence , Decision Making , Root Canal Therapy , Specialties, Dental/education , Education, Dental, Graduate , Endodontics/education , General Practice, Dental , Humans , Patient Care Planning , Radiography, Bitewing , Retreatment , Students, Dental , Tooth Extraction , Tooth, Nonvital/therapy
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