54 research outputs found

    Myocardial tagging by Cardiovascular Magnetic Resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications

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    Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging

    Small mammal community response to early meadow–forest succession

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    Abstract Background With farmland afforestation becoming common policy in many European Union countries, we studied how early forest succession (from meadow to young stand) influences small mammal species composition, diversity, abundance and biomass. Despite numerous investigations into forest succession, almost no attention has been given to the small mammal community change in the early-successional forest ecosystems, starting with the pre-forest habitat and ending with stand formation and the establishment of tree dominance. We compared small mammal communities in meadows at the initial stage of regrowth (with saplings less than 10 cm in height), in young forest (5–10 years old) and more advanced forest (15–20 years) in both cases of human-induced forest succession, where the trees had been planted, and natural forest succession, where natural regrowth of meadows had occurred. Results The greatest diversity of small mammal species was recorded in the meadow (H  =  2.95), with a lower diversity found in the young forest (H  =  2.61) and even lower in the advanced forest (H  =  2.04), the last habitat being the most monodominantic. The order of species dominance from Microtus sp. (M. arvalis, M. agrestis), Myodes glareolus, Apodemus flavicollis, Sorex araneus, A. agrarius in the meadow changed to M. glareolus, S. araneus, M. arvalis, M. agrestis in the young forest and to M. glareolus, A. flavicollis, S. araneus in the advanced forest. The lowest relative abundance of small mammals was recorded in the meadow (18.19  ±  2.27 ind. Per 100 trap-days), with Microtus voles being the most abundant. Relative abundance was higher in the young forest (22.72  ±  2.25 ind. Per 100 trap-days), with Myodes glareolus being the most abundant (7.59  ±  0.96 ind. Per 100 trap-days) and at its highest in the advanced forest (23.91  ±  2.77 ind. Per 100 trap-days), again with M. glareolus being the most abundant (15.54  ±  2.35 ind. Per 100 trap-days). Conclusions Thus, our analysis suggests that that during early meadow-forest succession, the diversity of the small mammal community declines – the number of species decreases as typical meadow species are lost due to the transformation of the habitat and one or a few species became dominants. However, the relative abundance of the small mammals increases. Biological indices of small mammal communities differed between natural and human-induced meadow-forest succession

    Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

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    Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

    Omics-based molecular techniques in oral pathology centred cancer: Prospect and challenges in Africa

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    : The completion of the human genome project and the accomplished milestones in the human proteome project; as well as the progress made so far in computational bioinformatics and “big data” processing have contributed immensely to individualized/personalized medicine in the developed world.At the dawn of precision medicine, various omics-based therapies and bioengineering can now be applied accurately for the diagnosis, prognosis, treatment, and risk stratifcation of cancer in a manner that was hitherto not thought possible. The widespread introduction of genomics and other omics-based approaches into the postgraduate training curriculum of diverse medical and dental specialties, including pathology has improved the profciency of practitioners in the use of novel molecular signatures in patient management. In addition, intricate details about disease disparity among diferent human populations are beginning to emerge. This would facilitate the use of tailor-made novel theranostic methods based on emerging molecular evidences
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