558 research outputs found

    Platelet Redox Imbalance in Hypercholesterolemia: A Big Problem for a Small Cell

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    The imbalance between reactive oxygen species (ROS) synthesis and their scavenging by anti-oxidant defences is the common soil of many disorders, including hypercholesterolemia. Platelets, the smallest blood cells, are deeply involved in the pathophysiology of occlusive arterial thrombi associated with myocardial infarction and stroke. A great deal of evidence shows that both increased intraplatelet ROS synthesis and impaired ROS neutralization are implicated in the thrombotic process. Hypercholesterolemia is recognized as cause of atherosclerosis, cerebro- and cardiovascular disease, and, closely related to this, is the widespread acceptance that it strongly contributes to platelet hyperreactivity via direct oxidized LDL (oxLDL)-platelet membrane interaction via scavenger receptors such as CD36 and signaling pathways including Src family kinases (SFK), mitogen-activated protein kinases (MAPK), and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. In turn, activated platelets contribute to oxLDL generation, which ends up propagating platelet activation and thrombus formation through a mechanism mediated by oxidative stress. When evaluating the effect of lipid-lowering therapies on thrombogenesis, a large body of evidence shows that the effects of statins and proprotein convertase subtilisin/kexin type 9 inhibitors are not limited to the reduction of LDL-C but also to the down-regulation of platelet reactivity mainly by mechanisms sensitive to intracellular redox balance. In this review, we will focus on the role of oxidative stress-related mechanisms as a cause of platelet hyperreactivity and the pathophysiological link of the pleiotropism of lipid-lowering agents to the beneficial effects on platelet function

    Una visión de la obra y el herbario de Rouy a través del género Carex L.

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    Se analiza la obra de Georges Rouy, célebre botánico francés, mediante el estudio de sus materiales así como del tratamiento del género Carex (Cyperaceae) en la Flore de France. Se valora favorablemente el conocimiento que el autor demuestra sobre este género, puesto de manifi esto al incluir subgéneros en la clasifi cación taxonómica. Asimismo la sinonimia que propone para cada nombre y las descripciones de los taxones son muy completas. Al contrario, se valora negativamente la excesiva fragmentación que estableció, pues incluyó demasiadas secciones y subsecciones. Finalmente, su rechazo a utilizar las normas nomenclaturales establecidas por el Código de Nomenclatura Botánica conduce a la confusión e impide que la mayoría de sus nombres sean válidos.The George Rouy’s work, a famous French botanist, is studied by means of his material and literature of the genus Carex (Cyperaceae). We assess positively the knowledge that he demonstrated of this genus; because of the subgenera differentiated in his treatment, besides the complete synonymy presented for each name and the taxa descriptions. But he splitted excessively the infrageneric classifi cation including too many sections and subsections. Finally, most of the names he proposed are invalid because of his rejection of the International Code of Botanical Nomenclature recommendations and rules

    Ornamental Stones of Piemonte (NW Italy): an updated geo-lithological map

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    The 'Ornamental Stones of Piemonte Region' geo-lithological map at 1:250,000 scale aims at reviewing the ornamental stone heritage of Piemonte at the regional scale. The map derives from a thorough revision of the available literature, integrated with some unpublished original data. The map shows the location of the main quarries of ornamental stones of the region, selected on the basis of their historical, cultural and architectonic relevance. A geo-lithological basemap was produced, deriving it from a basic Geological Map of Piemonte, available at the same scale. The large varieties of lithotypes of Piemonte have been resumed, in the new map, into 21 classes, which all the ornamental stones have been assigned to. The Main Map is enriched by some significant examples of using the ornamental stones in historical buildings, and it is supported by a supplementary data base containing essential information about the quarry sites and the quarried material

    A fossil peat deposit from the Late Triassic (Carnian) of Zimbabwe with preserved cuticle of Pteridospermopsida and Ginkgoales, and its geological setting

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    Well-preserved cuticular material of Pteridospermopsida and Ginkgoales from the Late Triassic of Zimbabwe is described here for the first time. It is preserved within a brown peat-like lens in the Upper Karoo Angwa Sandstone Formation. The locality is on the Manyima River in the lower portion of the mid-Zambezi Valley of Zimbabwe. Using SEM and light microscopy to identify the taxa, the fragmentary cuticles are of Pteridospermopsida type and have been assigned to Lepidopteris sp. (Peltaspermales) and Dicroidium sp. A, B, (Corystospermales). Cuticles of the ginkgoalean leaf genus, Sphenobaiera, are also described. Well-preserved ovules were found in close association with the cuticles, but as the stomata are not visible they cannot be assigned to any genus. Based on their close similarity to the Dicroidium flora of the South African Upper Karoo, the plants are considered to be equivalent to the South African Molteno Formation in age (Carnian). The palynoflora supports this age bracket, as does fauna preserved nearby. The taphonomic process was one of transport, sorting and deposition in a fluvial system.The CNRS-NRF agreement between France and South Afric
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