Prognosis following acute coronary syndromes according to prior coronary artery bypass grafting: Meta-analysis

PURPOSE: Conduct a meta-analysis to study the prognostic influence of a previous coronary artery bypass grafting (CABG) in patients admitted for an acute coronary syndrome (ACS). METHODS: A systematic review of the literature was performed using electronic reference databases through January 2013 (MEDLINE, Cochrane Library, Web of Knowledge, Google Scholar and references cited in other studies). Studies in which ACS outcomes with a previous history of CABG were compared with ACS outcomes with no history of previous CABG were considered for inclusion. The main endpoints of interest were mortality and non-fatal acute myocardial infarction. Data was aggregated at three follow-up times using random-effects meta-analysis models. RESULTS: Twenty-four studies were included which provided 387,181 patients for analysis. Previous CABG ACS patients were older, more diabetic and had a more frequent history of a previous myocardial infarction. Pooled in-hospital mortality was higher for the previous CABG ACS patients (OR 1.22 [1.04-1.44], p<0.01, I(2) 88%). The pooled adjusted OR showed no significant differences for the two groups (adjusted OR 1.13 [0.93-1.37], p=0.22, I(2) 92%). Previous CABG ACS patient had a higher pooled 30-day mortality (OR 1.28 [1.05-1.55], p=0.02, I(2) 74%); a higher non-adjusted (OR 1.61 [1.38-1.88], p<0.01, I(2) 70%) and adjusted (adjusted OR 1.37 [1.15-1.65], p<0.01, I(2) 0%) long-term mortality. Both the in-hospital and the long-term re-infarction rates were higher for the previous CABG ACS patients. CONCLUSIONS: According to our data, ACS patients with previous CABG history had a higher risk for short- and long-term adverse events

Compact automotive thermoelectric generator with embedded heat pipes for thermal control

Currently, the automotive industry faces challenges to implement solutions that provide reductions in energy consumption, pollutants and greenhouse-gas (GHG) emissions. Exhaust heat recovery employing Thermoelectric generators (TEGs) enables the direct conversion of heat into electric energy without moving parts and little to no maintenance. On-board electrical production is especially useful given the growing electrification trend of road vehicles. The present work assesses the performance of a novel temperature-controlled thermoelectric generator (TCTG) concept in a light duty vehicle and its impact on fuel economy and GHG emissions under realistic driving conditions. The novel exhaust heat exchanger (HE) concept consists of corrugated pipes embedded in a cast aluminium matrix along with variable conductance heat pipes (VCHPs) acting as spreaders of excess heat along the longitudinal direction. This concept seems to have a quite good potential for highly variable thermal load applications, as it is able to avoid overheating by spreading heat instead of wasting it through by-pass systems. Furthermore, when compared to previous concepts by the group, it does not need gravity assistance and has a form factor similar to conventional generators. It also appears to be capable of delivering a breakthrough electric output for TEG systems in such light vehicles, with as much as 572 W and 1538 W of average and maximum electric powers during a driving cycle, respectively, and showing a quite promising reduction of 5.4% in fuel consumption and CO2 emissions.- This work has been supported by FCT e Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDP/04077/2020 within MEtRICs - Mechanical Engineering and Resource Sustainability Centre, Project Exhaust2Energy (PTDC/EMS-ENE/3009/2014) and M-ERA.net Project THERMOSS (M-ERA.net2_0011_2016), financed by European Regional Development Fund (ERDF) funds through P.O.F.C. e COMPETE and National funds through PIDDAC and FCT. The authors also wish to thank Dr. Helder Puga from the Casting Lab of the Mechanical Engineering Department of University of Minho, Paulo Moutinho and BorgWarner Emissions Systems (Spain Technical Center -Vigo, Spain)

Finite elements versus experimental for a CFRP structure

The work presented herein is part of a project focused on the optimization of a carbon fibre reinforced epoxy matrix (CFRP) structure. The implemented process resorts to finite elements modelling in order to evaluate the performance of the analysed structure. To validate the finite elements model at the basis of the optimization process a scale model prototype of the composite structure was built and tested under similar loading conditions. The experimental results determined were then compared with those obtained from simulations of a built numerical model depicting the experimental set up and taken into account the mechanical and geometrical properties of the composite part, the used accessories, the interface between parts and production constraints.Portuguese Foundation for Science and Technology under project UID/CTM/50025/2013 and scholarship SFRH / BD / 51106 / 201

Phase diagram of a random-anisotropy mixed-spin Ising model

We investigate the phase diagram of a mixed spin-1/2--spin-1 Ising system in the presence of quenched disordered anisotropy. We carry out a mean-field and a standard self-consistent Bethe--Peierls calculation. Depending on the amount of disorder, there appear novel transition lines and multicritical points. Also, we report some connections with a percolation problem and an exact result in one dimension.Comment: 8 pages, 4 figures, accepted for publication in Physical Review

Local seismic cultures: the use of timber frame structures in the south of Portugal

Given the fact that using timber frame structures has proven to improve the seismic behavior of vernacular architecture, as has been reported in past earthquakes in many countries, its preservation as a traditional earthquake resistant practice is important. This paper firstly intends to evaluate whether the use of timber frames as a traditional seismic resistant technique for vernacular architecture in the South of Portugal, traditionally a seismic region, is still active. Secondly, the city of Vila Real de Santo António was selected as a case study because it also followed a Pombaline development contemporary to the reconstruction of Lisbon. The plan included the provision of timber frame partition walls for some of the buildings and, thus, an overview of the type of constructions originally conceived is provided. Finally, the alterations done in the original constructions and the current state of the city center are described and the effect of these changes on the seismic vulnerability of the city is discussed.The authors wish to express their gratitude to the Portuguese Science and Technology Foundation (FCT) for the scholarship granted in the scope of the research project 'SEISMIC-V-Vernacular Seismic Culture in Portugal' (PTDC/ATP-AQI/3934/2012)

Concentration of photosynthetic pigments and chlorophyll fluorescence of mahogany and tonka bean under two light environments

This study was carried out in a plantation of a degraded area in Central Amazon, Brazil, in order to assess environmental light effects on leaf pigment concentrations and chlorophyll a fluorescence in mahogany (Swietenia macrophylla King) and tonka bean (Dipteryx odorata Aubl. Willd). Three-year old saplings were grown in an open site (sun) with maximum radiation of approximately 2000 μmol m-2 s-1 and under the shade of a Ochroma pyramidale (Cav. ex Lam. Urb) canopy. A leaf area index of 2.46 was optically determined for the Ochroma foliage with 13% of full sunlight (maximum radiation about 260 μmol m-2 s-1). Carotenoid and chlorophyll concentrations were spectrophotometrically determined. Initial (Fo), maximum (Fm) and variable fluorescence (Fv) were determined with a portable fluorometer. Chlorophyll concentrations (Chl a, Chl b and Chl tot) on a fresh mass basis were greater in shade leaves than in sun acclimated leaves in both species. On the other hand, when comparisons were made on a per area basis, Chl a concentrations were greater in the sun than in shade leaves of tonka bean. In contrast, Chl b concentrations were higher in the shade environment for this species. No differences were observed in Chl concentrations per unit area in mahogany leaves. Carotenoid concentrations were higher for sun-acclimated leaves of mahogany, both on a per unit area and on a fresh mass basis. In tonka bean, higher carotenoid concentrations in shade leaves were only observed on a fresh weight basis. No differences were found between environments when carotenoid concentrations were expressed as a function of leaf area. Fluorescence variables (Fo, Fm, and Fv) were greater in sun leaves than in shade leaves of mahogany. In contrast, Fv and Fm, but not Fo, values were higher in shade acclimated leaves than in full sunlight-adapted leaves of tonka bean. However, there was a higher Fv/Fm ratio value for tonka bean in sunlight environments. We conclude that these species, classified as mid and late successional species, differ markedly regarding the utilization of photosynthetic pigments, increasing either light harvesting efficiency at low irradiance or protection against photosynthetic machinery damage in higher solar radiation environments

Atmospheric trends of CO and CH4 from extreme wildfires in Portugal using sentinel-5P TROPOMI level-2 data

PCIF/GFC/0078/2018 UIDB/00100/2020 UIDB/04085/2020 DL 57/2016Large forest fires have repeatedly affected Europe, in particular the Mediterranean countries. It is now crucial to continue the effort to feed the several layers of prediction models and understand how wildfire spreads in order to develop modern preventative and mitigation methods. The present study evaluates the performance of Sentinel 5-P TROPOMI for the monitoring of carbon monoxide (CO) and methane (CH4) during extreme fire events in Portugal, focusing on the Monchique (2018) and Vila de Rei/Mação (2019) wildfires, which devastated 27,154 ha and 9249 ha, respectively. The spatial distribution and trend of CO and CH4 prior to, during, and following the fire event were accessed and linked with in situ data in a qualitative and quantitative exploration. Large CO plumes were observed with CO columns exceeding 4.5 × 1018 and 6 × 1018 molecules/cm2 on 21 July 2019, and 7 August 2018, respectively. CO distribution profiles after consecutive digital processing steps showed the ability to follow CO fluctuations according to the fire spread. Furthermore, statistically significant differences were found between CO emissions inside and outside the burning area in both fire events. Finally, the CO2 estimated through CO column data presented an emission of 7.6 × 1019 molecules/cm2 for the uppermost emission day on 7 August 2018. Although CH4 monitoring is still unwavering to draw exact conclusions, the CO patterns during extreme fire events show promising and consistent data when compared with in situ data.publishersversionpublishe