Development and Application of Computational Tools for the Study and Optimization of Variable Resolution X-ray (VRX) Computed Tomography Scanners

The overall goal of this project was to develop and apply important computerized aids for the design and implementation of Variable Resolution X-ray (VRX) CT scanners developed at the University of Tennessee, Memphis. VRX scanners take advantage of the “projective compression” principle that allows the same device to image objects of very different sizes with the same level of detail by adjusting the field of view and the reconstruction resolution. The first part of this project aimed to develop a set of computational tools specifically tailored for the design, implementation and study of VRX scanners. This included creating a reconstruction algorithm that takes into account the unique geometries of the different VRX systems that have been designed, along with improving the calibration algorithm needed to ensure a proper reconstruction. It also included the development of a computer model of VRX scanners that is an invaluable tool for the development and study of these devices. The second part of the project was composed of a small series of experiments in which the computational tools developed proved to be fundamental in the analysis and evaluation of some aspects of VRX imaging. This included a comparison of the performance of different targeting VRX geometries in terms of spatial and contrast resolution, and a study of the effect of the VRX angle on the severity of common artifacts in single-arm images

Arterial lactate levels and their prognostic value in patients undergoing pulmonary thromboendarterectomy

Objective.  Evaluate the change of lactate levels and its prognostic role in the postoperative period of patients undergoing pulmonary thromboendarterectomy. Methods. Retrospective study between 2001 and 2019. Patients older than 18 years and who underwent pulmonary thromboendarterectomy were included. The U Mann Whitney test was performed to evaluate the change between lactate levels, and Cox regression analysis to evaluate the relationship with mortality. Areas under the curve were constructed for lactate levels. Results. Seventy-three patients were operated on during the study period. Median age was 51 years, 55% female. The median lactate on days 1 was 4.65 mml/L and on day 2 it was 1.62 mml/L with a change of 2.87 mml/L. No differences were found between the levels measured on day 1 and 2 between the people who died and those who did not on day 30. In the multivariate regression of COX, no relationship with mortality was found. The area under the curve shows regular performance on both day 1 and day 2 in predicting mortality outcomes. Conclusions. The behavior of the lactate in patients undergoing pulmonary thromboendarterectomy shows a rapid change during the first hours after the procedure. No role was found as a predictor of mortality neither in-hospital nor in follow-up.Objetivo. Evaluar el cambio de los niveles de lactato y su rol pronóstico en el posoperatorio de pacientes sometidos a tromboendarterectomía pulmonar. Métodos. Estudio retrospectivo entre 2001 y 2019. Se incluyeron pacientes mayores de 18 años que fueron sometidos a tromboendarterectomía pulmonar. Para evaluar el cambio entre los niveles de lactato se realizó la prueba de U Mann Whitney. Para evaluar la relación con la mortalidad se realizó un análisis multivariado de Cox. Se construyeron áreas bajo la curva para los niveles de lactato. Resultados. Setenta y tres pacientes fueron operados durante el período de estudio. La mediana de edad fue de 51 años, 55% mujeres. La mediana de lactato en el día 1 fue de 4,65 mmL/L y en el día 2 fue de 1,62 mmL/L con un cambio de 2,87 mmL/L. No se encontraron diferencias entre los niveles medidos el día 1 y 2 entre las personas que murieron y las que no al día 30 hospitalario. En la regresión multivariada de COX no se encontró relación con la mortalidad. El área bajo la curva muestra un desempeño regular tanto en el día 1 como en el día 2 para predecir el resultado de la mortalidad en especial intrahospitalaria. Conclusiones. El comportamiento del lactato en pacientes sometidos a tromboendarterectomía pulmonar muestra un cambio rápido durante las primeras horas posteriores al procedimiento. No se encontró ningún papel como predictor de mortalidad ni hospitalaria ni durante el seguimiento. &nbsp

GA4GH: International policies and standards for data sharing across genomic research and healthcare.

The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits

Com o diabo no corpo: os terríveis papagaios do Brasil colônia

Desde a Antiguidade, papagaios, periquitos e afins (Psittacidae) fascinaram os europeus por seu vivo colorido e uma notável capacidade de interação com seres humanos. A descoberta do Novo Mundo nada faria além de acrescentar novos elementos ao tráfico de animais exóticos há muito estabelecido pelos europeus com a África e o Oriente. Sem possuir grandes mamíferos, a América tropical participaria desse comércio com o que tinha de mais atrativo, essencialmente felinos, primatas e aves - em particular os papagaios, os quais eram embarcados em bom número. Contudo, a julgar pelos documentos do Brasil colônia, esses voláteis podiam inspirar muito pouca simpatia, pois nenhum outro animal - exceto as formigas - foi tantas vezes mencionado como praga para a agricultura. Além disso, alguns psitácidas mostravam-se tão loquazes que inspiravam a séria desconfiança de serem animais demoníacos ou possessos, pois só três classes de entidades - anjos, homens e demônios - possuíam o dom da palavra. Nos dias de hoje, vários representantes dos Psittacidae ainda constituem uma ameaça para a agricultura, enquanto os indivíduos muito faladores continuam despertando a suspeita de estarem possuídos pelo demônio. Transcendendo a mera curiosidade, essa crença exemplifica o quão intrincadas podem ser as relações do homem com o chamado “mundo natural”, revelando um universo mais amplo e multifacetado do que se poderia supor a princípio. Nesse sentido, a existência de aves capazes de falar torna essa relação ainda mais complexa e evidencia que as dificuldades de estabelecer o limite entre o animal e o humano se estendem além dos primatas e envolvem as mais inusitadas espécies zoológicas.Since ancient times, parrots and their allies (Psittacidae) have fascinated Europeans by their striking colors and notable ability to interact with human beings. The discovery of the New World added new species to the international exotic animal trade, which for many centuries had brought beasts to Europe from Africa and the Orient. Lacking large mammals, tropical America participated in this trade with its most appealing species, essentially felines, primates and birds - especially parrots - which were shipped in large numbers. It should be noted, however, that at times these birds were not well liked. In fact, according to documents from colonial Brazil, only the ants rank higher than parrots as the animals most often mentioned as agricultural pests. On the other hand, some of these birds were so chatty that people suspected them to be demonic or possessed animals, since only three classes of beings - angels, men and demons - have the ability to speak. Nowadays, several Psittacidae still constitute a threat to agriculture, and the suspicion that extremely talkative birds were demon possessed has also survived. More than a joke or a mere curiosity, this belief exemplifies how intricate man’s relationships with the “natural world” may be. In this sense, the existence of birds that are able to speak adds a further twist to these relationships, demonstrating that the problem of establishing a boundary between the animal and the human does not only involve primates, but also includes some unusual zoological species

Extending resolution within a single imaging frame

The resolution of fluorescence microscopy images is limited by the physical properties of light. In the last decade, numerous super-resolution microscopy (SRM) approaches have been proposed to deal with such hindrance. Here we present Mean-Shift Super Resolution (MSSR), a new SRM algorithm based on the Mean Shift theory, which extends spatial resolution of single fluorescence images beyond the diffraction limit of light. MSSR works on low and high fluorophore densities, is not limited by the architecture of the optical setup and is applicable to single images as well as temporal series. The theoretical limit of spatial resolution, based on optimized real-world imaging conditions and analysis of temporal image stacks, has been measured to be 40 nm. Furthermore, MSSR has denoising capabilities that outperform other SRM approaches. Along with its wide accessibility, MSSR is a powerful, flexible, and generic tool for multidimensional and live cell imaging applications

GA4GH: International policies and standards for data sharing across genomic research and healthcare

The Global Alliance for Genomics and Health (GA4GH) aims to accelerate biomedical advances by enabling the responsible sharing of clinical and genomic data through both harmonized data aggregation and federated approaches. The decreasing cost of genomic sequencing (along with other genome-wide molecular assays) and increasing evidence of its clinical utility will soon drive the generation of sequence data from tens of millions of humans, with increasing levels of diversity. In this perspective, we present the GA4GH strategies for addressing the major challenges of this data revolution. We describe the GA4GH organization, which is fueled by the development efforts of eight Work Streams and informed by the needs of 24 Driver Projects and other key stakeholders. We present the GA4GH suite of secure, interoperable technical standards and policy frameworks and review the current status of standards, their relevance to key domains of research and clinical care, and future plans of GA4GH. Broad international participation in building, adopting, and deploying GA4GH standards and frameworks will catalyze an unprecedented effort in data sharing that will be critical to advancing genomic medicine and ensuring that all populations can access its benefits

Outcomes in Newly Diagnosed Atrial Fibrillation and History of Acute Coronary Syndromes: Insights from GARFIELD-AF

BACKGROUND: Many patients with atrial fibrillation have concomitant coronary artery disease with or without acute coronary syndromes and are in need of additional antithrombotic therapy. There are few data on the long-term clinical outcome of atrial fibrillation patients with a history of acute coronary syndrome. This is a 2-year study of atrial fibrillation patients with or without a history of acute coronary syndromes