475 research outputs found

    Computed tomography angiography for the interventional cardiologist

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    WOS:000339902400002In recent years, coronary CT angiography (CCTA) has become a widely adopted technique, not only due to its high diagnostic accuracy, but also to the fact that CCTA provides a comprehensive evaluation of the total (obstructive and non-obstructive) coronary atherosclerotic burden. More recently, this technique has become mature, with a large body of evidence addressing its prognostic validation. In addition, CT angiography has moved from the field of `imagers' and clinicians and entered the interventional cardiology arena, aiding in the planning of both coronary and structural heart interventions, being transcatheter aortic valve implantation one of its most successful examples. It is therefore of utmost importance that interventional cardiologists become familiar with image interpretation and up-to-date regarding several CTA features, taking advantage of this information in planning the procedure, ultimately leading to improvement in patient outcomes. On the other hand, the increasing use of CCTA as a gatekeeper for invasive coronary angiography is expected to lead to an increase in the ratio of interventional to diagnostic procedures and significant changes in the daily cath-lab routine. In a foreseeable future, cath-labs will probably offer an invasive procedure only to patients expected to undergo an intervention, perhaps becoming in this change true interventional-labs.publishersversionpublishe

    Functional evaluation of coronary disease by CT angiography

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    Publisher Copyright: © 2015 American College of Cardiology Foundation.In recent years, several technical developments in the field of cardiac computed tomography (CT) have made possible the extraction of functional information from an anatomy-based examination. Several different lines have been explored and will be reviewed in the present paper, namely: 1) myocardial perfusion imaging; 2) transluminal attenuation gradients and corrected coronary opacification indexes; 3) fractional flow reserve computed from CT; and 4) extrapolation from atherosclerotic plaque characteristics. In view of these developments, cardiac CT has the potential to become in the near future a truly 2-in-1 noninvasive evaluation for coronary artery disease.publishersversionpublishe

    Macroecological patterns of species distribution, composition and richness of the Azorean terrestrial biota

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    We investigate the macroecological patterns of the terrestrial biota of the Azorean archipelago, namely the species-range size distributions, the distance decay of similarity, and the island species–area relationship (ISAR). We use the most recent up-to-date checklists to describe the diversity at the island level for nine groups (Lichens, Fungi, Diatoms, Bryophytes, Vascular Plants, Nematodes, Molluscs, Arthropods, Vertebrates). The particularities of the Azorean biota result in some differences to the patterns commonly found in other oceanic archipelagos. Strikingly, bryophytes, molluscs and vertebrates show a bimodal species-range size distribution, and vascular plants a right unimodal distribution due the high numbers of widespread species. Such high compositional homogeneity between islands also results in non-significant or even negative decays of similarity with distance among islands for most groups. Dispersal ability, together with other particular characteristics of each taxon, also shapes these distributions, as well as the relationships between island species richness, and area and time. Strikingly, the degree of departure of the richness of the whole archipelago from the SAR of its constituent islands largely depends on the dispersal ability of each group. Comparative studies with other oceanic archipelagos of the globe are however needed to understand the biogeographical and evolutionary processes shaping the remarkably low diversity of the Azorean biota

    Flexural strength of high-performance soil-cement: a new, alternative, sustainable construction material

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    Soil-cement is a building material that is considered low-cost and has a low environmental impact. Despite its benefits, performance optimisation studies are scarce compared to other materials such as concrete. The possibility of obtaining soil-cement with improved characteristics, such as flexural strength, would enable the increased use of this product in new applications in construction. The aim of this study is to produce high-performance soil-cement (HPSC) specimens and to evaluate and compare this new material with high-performance concrete (HPC) in terms of flexural strength. A total of 12 specimens were produced with a mixture of 23.5% (by mass) of cement with the application of 10 MPa of pressure for its compaction. The results show that, at 28 days, the specimens reached an average strength of 6.73 MPa and, at 240 days, 12.34 MPa. This means that the HPSC reached a flexural strength resistance equivalent to HPC without the need for mined materials, such as sand and gravel, or the additives adopted in some doses of HPC, such as superplasticisers. Therefore, when using local soil, HPSC can be considered an environmentally preferable alternative to HPC for many construction applications where flexural strength is a requirement.Peer ReviewedPostprint (published version

    Prevalence and predictors of coronary artery disease in patients with a calcium score of zero

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    The absence of coronary calcification is associated with an excellent prognosis. However, a calcium score of zero does not exclude the presence of coronary artery disease (CAD) or the possibility of future cardiovascular events. Our aim was to study the prevalence and predictors of coronary artery disease in patients with a calcium score of zero. Prospective registry consisted of 3,012 consecutive patients that underwent cardiac CT (dual source CT). Stable patients referred for evaluation of possible CAD that had a calcium score of zero (n = 864) were selected for this analysis. The variables that were statistically significant were included in a multivariable logistic regression model. From 864 patients with a calcium score of zero, 107 (12.4 %) had coronary plaques on the contrast CT (10.8 %, n = 93 with nonobstructive CAD and 1.6 %, n = 14 with obstructive CAD). By logistic regression analysis, the independent predictors of CAD in this population were age >55 years [odds ratio (OR) 1.63 (1.05-2.52)], hypertension [OR 1.64 (1.05-2.56)] and dyslipidemia [OR 1.54 (1.00-2.36)]. In the presence of these 3 variables, the probability of having coronary plaques was 21 %. The absence of coronary artery calcification does not exclude the presence of coron

    Neuromodulation and neuroprotective effects of chlorogenic acids in excitatory synapses of mouse hippocampal slices

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    The increased healthspan afforded by coffee intake provides novel opportunities to identify new therapeutic strategies. Caffeine has been proposed to afford benefits through adenosine A2A receptors, which can control synaptic dysfunction underlying some brain disease. However, decaffeinated coffee and other main components of coffee such as chlorogenic acids, also attenuate brain dysfunction, although it is unknown if they control synaptic function. We now used electrophysiological recordings in mouse hippocampal slices to test if realistic concentrations of chlorogenic acids directly affect synaptic transmission and plasticity. 3-(3,4-dihydroxycinnamoyl)quinic acid (CA, 1–10 μM) and 5-O-(trans-3,4-dihydroxycinnamoyl)-D-quinic acid (NCA, 1–10 μM) were devoid of effect on synaptic transmission, paired-pulse facilitation or long-term potentiation (LTP) and long-term depression (LTD) in Schaffer collaterals-CA1 pyramidal synapses. However, CA and NCA increased the recovery of synaptic transmission upon re-oxygenation following 7 min of oxygen/glucose deprivation, an in vitro ischemia model. Also, CA and NCA attenuated the shift of LTD into LTP observed in hippocampal slices from animals with hippocampal-dependent memory deterioration after exposure to β-amyloid 1–42 (2 nmol, icv), in the context of Alzheimer’s disease. These findings show that chlorogenic acids do not directly affect synaptic transmission and plasticity but can indirectly affect other cellular targets to correct synaptic dysfunction. Unraveling the molecular mechanisms of action of chlorogenic acids will allow the design of hitherto unrecognized novel neuroprotective strategies

    Descrição da biodiversidade terrestre e marinha dos Açores

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    1. Os Açores são um arquipélago isolado de nove ilhas oceânicas, pertence à região biogeográfica da Macaronésia e está entre as regiões mais ricas em fungos, plantas e animais da Europa. Este capítulo destaca o que sabemos sobre os fungos, a fauna e a flora dos habitats terrestres, dulçaquícolas e marinhos dos Açores. 2. Neste capítulo, são apresentadas as estimativas do número total de espécies e subespécies conhecidas actualmente nos Açores. Todos os grupos taxonómicos terrestres mais importantes foram analisados: fungos, líquenes, diatomáceas dulçaquícolas, briófitos (musgos, hepáticas e antocerotas), plantas vasculares (licófitas, fetos, gimnospérmicas e angiospérmicas), platelmintes (vermes), nemátodos, anelídeos (minhocas), moluscos terrestres (lesmas e caracóis), artrópodes (insectos, aracnídeos, milípedes, etc.) e vertebrados (peixes de água doce, anfíbios, répteis, aves e mamíferos). A presente obra inclui também espécies do ambiente marinho, como as algas (macroalgas), a maioria dos filos de invertebrados do litoral e os vertebrados marinhos (répteis, peixes e mamíferos). As listas de espécies e subespécies (Capítulos 2-15) são baseadas nos taxa identificados numa grande variedade de publicações, tendo essa informação sido compilada por um vasto grupo de especialistas. 3. Actualmente, o número total de taxa (espécies e subespécies) terrestres nos Açores está estimado em cerca de 6164 (cerca de 6112 espécies). A inclusão de uma listagem exaustiva das espécies de aves não-nidificantes e de uma listagem preliminar de espécies de aves potencialmente nidificantes acrescenta 325 espécies e subespécies ao total das espécies açorianas. 4. O número total de espécies e subespécies endémicas terrestres dos Açores é de cerca de 452 (411 espécies). Os animais são os mais diversos em endemismos, com 331 taxa (Arthropoda = 266; Mollusca = 49; Vertebrata = 14; Nematoda = 2), compreendendo cerca de 73% dos endemismos terrestres dos Açores. A percentagem de endemismo nos Mollusca (44%) é notável. As plantas vasculares contam com 73 endemismos, os Fungi (incluindo os líquenes) têm 34 e, tanto as diatomáceas dulçaquícolas como os briófitos, incluem sete espécies endémicas. 5. Quando comparada com os arquipélagos vizinhos da Macaronésia (Madeira e Canárias), a fauna e flora terrestres dos Açores é caracterizada por uma menor taxa de endemismo, de apenas 7%, contrastando com os cerca de 20% para a Madeira e de 30% para as Canárias. 6. No que diz respeito aos organismos marinhos, são listados 1883 taxa pertencentes a 16 filos. O número total de espécies e subespécies marinhas endémicas dos Açores é de cerca de 39, a maior parte delas moluscos (29 espécies). 7. O número total de taxa terrestres e marinhos (espécies e subespécies) nos Açores, está estimado em cerca de 8047. Os organismos marinhos agora listados, perfazem cerca de 23% da biodiversidade dos Açores. 8. O número total de taxa terrestres e marinhos (espécies e subespécies) endémicos dos Açores está estimado em cerca de 491.ABSTRACT: 1. The Azores is a remote oceanic archipelago of nine islands which belongs to the Macaronesia biogeographical region and is among the richest regions concerning fungi, plant and animal diversity in Europe. This chapter highlights what we know about the Azorean terrestrial, freshwater and marine Fungi, Flora and Fauna. 2. In this chapter we summarize the current estimates of the total number of species and subspecies presently known to occur in the Azores. The most important terrestrial taxonomic groups were studied: Fungi, Lichens, Bacillariophyta (freshwater diatoms), Bryophyta sensu lato (mosses, liverworts and hornworts), vascular plants – Tracheobionta, including Lycopodiophyta (quillworts), Pteridophyta (ferns), Pinophyta (gymnosperms) and Magnoliophyta (angiosperms), Platyhelminthes (flatworms), Nematoda (roundworms), Annelida (earthworms), Terrestrial Mollusca (slugs and snails), Arthropoda (millipedes, centipedes, mites, spiders, insects, etc.) and Vertebrata (freshwater fishes, amphibians, reptiles, birds and mammals). In addition, we expand this list to the marine realm, including Algae (macroalgae), coastal invertebrates (most Phyla) and marine vertebrates (fishes, reptiles and mammals). The list of species and subspecies (Chapters 2 to 15) is based on the taxa recognized in primary published literature sources, compiled by a vast group of experts. 3. Currently the total number of terrestrial taxa (species and subspecies) in the Azores is estimated of about 6164 (about 6112 species). The inclusion of an exhaustive listing of non breeding species and a preliminary list of potentially breeding species adds 325 species and subspecies of birds to the Azorean list of species. 4. The total number of terrestrial endemic species and/or subspecies from the Azores is about 452 (411 species). Animals are the most represented in this respect, with 331 taxa (Arthropoda = 266; Mollusca = 49; Vertebrata = 14; Nematoda = 2), that is, about 73% of the Azorean terrestrial endemics. The percentage of endemism within Mollusca (44%) is remarkable. Vascular plants have 73 endemic taxa, while Fungi (including Lichens) have 34, freshwater diatoms and bryophytes have seven endemic species each. 5. Compared to the other nearest Macaronesian archipelagos (Madeira and Canaries), the Azorean terrestrial fauna and flora is characterized by a lower percentage of endemism (only 7%, which contrasts with nearly 20% for Madeira and 30% for the Canary islands). 6. Concerning the marine organisms, we listed about 1883 taxa belonging to 16 Phyla. The total number of marine endemic species and/or subspecies from the Azores is about 39, most of them being molluscs (29 species). 7. Currently, the total number of terrestrial and marine taxa (species and subspecies) in the Azores is estimated in about 8047. The marine organisms currently listed make up about 23% of the Azorean biodiversity. 8. Currently, the total number of terrestrial and marine endemic taxa (species and subspecies) in the Azores is estimated of about 491

    Heme-Induced ROS in Trypanosoma Cruzi Activates CaMKII-Like That Triggers Epimastigote Proliferation. One Helpful Effect of ROS

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    Heme is a ubiquitous molecule that has a number of physiological roles. The toxic effects of this molecule have been demonstrated in various models, based on both its pro-oxidant nature and through a detergent mechanism. It is estimated that about 10 mM of heme is released during blood digestion in the blood-sucking bug's midgut. The parasite Trypanosoma cruzi, the agent of Chagas' disease, proliferates in the midgut of the insect vector; however, heme metabolism in trypanosomatids remains to be elucidated. Here we provide a mechanistic explanation for the proliferative effects of heme on trypanosomatids. Heme, but not other porphyrins, induced T. cruzi proliferation, and this phenomenon was accompanied by a marked increase in reactive oxygen species (ROS) formation in epimastigotes when monitored by ROS-sensitive fluorescent probes. Heme-induced ROS production was time-and concentration-dependent. In addition, lipid peroxidation and the formation of 4-hydroxy-2-nonenal (4-HNE) adducts with parasite proteins were increased in epimastigotes in the presence of heme. Conversely, the antioxidants urate and GSH reversed the heme-induced ROS. Urate also decreased parasite proliferation. Among several protein kinase inhibitors tested only specific inhibitors of CaMKII, KN93 and Myr-AIP, were able to abolish heme-induced ROS formation in epimastigotes leading to parasite growth impairment. Taken together, these data provide new insight into T. cruzi- insect vector interactions: heme, a molecule from the blood digestion, triggers epimastigote proliferation through a redox-sensitive signalling mechanism

    Clinical risk factors and atherosclerotic plaque extent to define risk for major events in patients without obstructive coronary artery disease: the long-term coronary computed tomography angiography CONFIRM registry.

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    AimsIn patients without obstructive coronary artery disease (CAD), we examined the prognostic value of risk factors and atherosclerotic extent.Methods and resultsPatients from the long-term CONFIRM registry without prior CAD and without obstructive (≥50%) stenosis were included. Within the groups of normal coronary computed tomography angiography (CCTA) (N = 1849) and non-obstructive CAD (N = 1698), the prognostic value of traditional clinical risk factors and atherosclerotic extent (segment involvement score, SIS) was assessed with Cox models. Major adverse cardiac events (MACE) were defined as all-cause mortality, non-fatal myocardial infarction, or late revascularization. In total, 3547 patients were included (age 57.9 ± 12.1 years, 57.8% male), experiencing 460 MACE during 5.4 years of follow-up. Age, body mass index, hypertension, and diabetes were the clinical variables associated with increased MACE risk, but the magnitude of risk was higher for CCTA defined atherosclerotic extent; adjusted hazard ratio (HR) for SIS >5 was 3.4 (95% confidence interval [CI] 2.3-4.9) while HR for diabetes and hypertension were 1.7 (95% CI 1.3-2.2) and 1.4 (95% CI 1.1-1.7), respectively. Exclusion of revascularization as endpoint did not modify the results. In normal CCTA, presence of ≥1 traditional risk factors did not worsen prognosis (log-rank P = 0.248), while it did in non-obstructive CAD (log-rank P = 0.025). Adjusted for SIS, hypertension and diabetes predicted MACE risk in non-obstructive CAD, while diabetes did not increase risk in absence of CAD (P-interaction = 0.004).ConclusionAmong patients without obstructive CAD, the extent of CAD provides more prognostic information for MACE than traditional cardiovascular risk factors. An interaction was observed between risk factors and CAD burden, suggesting synergistic effects of both
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