448 research outputs found
Chlamydia trachomatis diversity viewed as a tissue-specific coevolutionary arms race
Analysis of 15 serovars of Chlamydia trachomatis reveals an evolutionary arms race in pathogen-host interactions
Free-form ceramic vault system: taking ceramic additive manufacturing to real scale
The use of Additive Manufacturing (AM) for the production of architectural components has more and more examples attesting the possibilities and the advantages of its application. At the same time we seen a fast grow of the usage of ceramic materials to produce fully customised architectural components using Layer Deposition Modelling (LDM) techniques. However, the use of this material, as paste, leads to a series of constraints relative to its behaviour when in the viscous state, but also in the drying and firing stages. Thus, when ceramic dries, the retraction effects may be a barrier to the regular use of this material to build future architectural systems. In this sense, it is important to study the material behaviour and know how to control and use it as a primary construction material. To do that we present the challenges and outcomes of project
Hexashade, a ceramic vault shading system prototype whose geometry and internal structure is defined according to the solar incidence. This paper explain how we expect to build a real scale self-supporting prototype.This work has the financial support of the Project Lab2PT - Landscapes, Heritage and Territory laboratory - AUR/04509 and FCT through national founds and when applicable of the FEDER cofinancing, in the aim of the new partnership agreement PT2020 and COMPETE2020 - POCI 01 0145FEDER 007528
Insight into the epidemiology of infective endocarditis in Portugal : a contemporary nationwide study from 2010 to 2018
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.Background
Nationwide hospital admissions data series have contributed to a reliable assessment of the changing epidemiology of infective endocarditis, even though conclusions are not uniform. We sought to use a recent populational series to describe the temporal trends on the incidence of infective endocarditis, its clinical characteristics and outcome results, in Portugal.
Methods
A nationwide retrospective temporal trend study on the incidence and clinical characterization of patients hospitalized with infective endocarditis, between 2010 and 2018.
Results
7574 patients were hospitalized with infective endocarditis from 2010 to 2018 in Portuguese public hospitals. The average length of hospitalization was 29.3 ± 28.7 days, predominantly men (56.9%), and 47.1% had between 60 and 79 years old. The most frequent infectious agents involved were Staphylococcus (16.4%) and Streptococcus (13.6%). During hospitalization, 12.4% of patients underwent heart valve surgery and 20% of the total cohort died. After a 1-year post-discharge follow-up, 13.2% of the total initial cohort had had heart valve surgery and 21.2% in total died. The annual incidence of infective endocarditis was 8.31 per 100,000 habitants, being higher in men (9.96 per 100,000 in males versus 6.82 in females, p < 0.001) and increased with age, peaking at patients 80 years old or older (40.62 per 100,000). In-hospital mortality rate significantly increased during the analyzed period, the strongest independent predictors being ischemic or hemorrhagic stroke, sepsis, and acute renal failure. Younger age and cardiac surgery had a protective effect towards a fatal outcome.
Conclusions
In Portugal, between 2010 and 2018, the incidence of infective endocarditis presented a general growth trend with a deceleration in the most recent years. Also, a significant rate of in-hospital complications, a mildly lower than expected stable surgical rate and a still high and growing mortality rate were noted.info:eu-repo/semantics/publishedVersio
Adaptive Evolution of the Chlamydia trachomatis Dominant Antigen Reveals Distinct Evolutionary Scenarios for B- and T-cell Epitopes: Worldwide Survey
Background: Chlamydia trachomatis is one of the most disseminated human pathogens, for which no vaccine is available yet. Understanding the impact of the host pressure on pathogen antigens is crucial, but so far it was only assessed for highly-restricted geographic areas. We aimed to evaluate the evolutionary picture of the chlamydial key antigen (MOMP), which is one of the leading multi-subunit vaccine candidates, in a worldwide basis. Methodology/Principal Findings: Using genetics, molecular evolution methods and mathematical modelling, we analyzed all MOMP sequences reported worldwide, composed by 5026 strains from 33 geographic regions of five continents. Overall, 35.9 % of variants were detected. The evolutionary pattern of MOMP amino acid gains/losses was found to differ from the remaining chromosome, reflecting the demanding constraints of this porin, adhesin and dominant antigen. Amino acid changes were 4.3-fold more frequent in host-interacting domains (P,10 212), specifically within B-cell epitopes (P,10 25), where 25 % of them are at fixation (P,10 25). According to the typical pathogen-host arms race, this rampant B-cell antigenic variation likely represents neutralization escape mutants, as some mutations were previously shown to abrogate neutralization of chlamydial infectivity in vitro. In contrast, T-cell clusters of diverse HLA specificities are under purifying selection, suggesting a strategy that may lead to immune subversion. Moreover, several silent mutations are at fixation, generating preferential codons that may influence expression, and may also reflect recombination-derived ‘hitchhikingeffect
Avaliação do impacto de descargas em sistemas fluviais urbanos : o caso da ribeira de Couros
Os recursos hídricos, apesar de desempenharem um papel fulcral e insubstituível para o equilíbrio ecológico e para a manutenção da vida na Terra, são dos recursos naturais mais afetados pelas atividades antropogénicas. Nas últimas décadas, o uso sustentável da água e a preservação das suas origens tem merecido uma atenção crescente das entidades responsáveis, face à premente necessidade de se adotarem medidas adequadas ao efetivo controlo da qualidade da água dos sistemas aquáticos.
O presente trabalho insere-se num projeto mais abrangente, relativo à Regularização e Requalificação da Ribeira de Couros (na bacia hidrográfica do rio Ave), que atravessa a zona urbana de Guimarães, constituindo uma fase preliminar da vertente associada à gestão da qualidade da água. O principal objetivo desta fase é o de monitorizar a evolução das concentrações de oxigénio dissolvido (OD) ao longo de um trecho inicial da ribeira de Couros, no sentido de calibrar e validar o modelo de qualidade da água da ribeira (em desenvolvimento), de modo a simular o balanço de oxigénio dissolvido ao longo desse trecho e a avaliar o impacto das descargas antrópicas nesse meio hídrico. Face à indisponibilidade de dados de qualidade da água, foi implementado um programa de
monitorização através da realização de campanhas de amostragem semanais de modo a avaliar a evolução dos parâmetros de qualidade da água (OD, CBO, pH, temperatura e potencial oxi-redox) considerados mais relevantes para a avaliação do estado de oxigenação deste ecossistema aquático.
Neste artigo apresenta-se uma síntese dos principais resultados obtidos ao longo dessas campanhas de monitorização, evidenciando aqueles que permitem identificar os trechos mais críticos no sentido de avaliar a sua correlação com a eventual presença de descargas de águas residuais e/ou pluviais não tratadas
Improvement of messages delivery time on vehicular delay-tolerant networks
“Copyright © [2009] IEEE. Reprinted from International Conference on Parallel Processing Workshops ICPPW '09.ISSN:1530-2016. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to pubs [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”Vehicular Delay-Tolerant Networks (VDTNs) are an application of the Delay-Tolerant Network (DTN) concept, where the movement of vehicles and their message relaying service is used to enable network connectivity under unreliable conditions. To address the problem of intermittent connectivity, long-term message storage is combined with routing schemes that replicate messages at transfer opportunities. However, these strategies can be inefficient in terms of network resource usage. Therefore, efficient scheduling and dropping policies are necessary to improve the overall network performance. This work presents a performance analysis, based on simulation, of the impact of different scheduling and dropping policies enforced on Epidemic and Spray and Wait routing schemes. This paper evaluates these policies from the perspective of their efficiency in reducing the message’s end-to-end delay. In our scenario, it is shown that when these policies are based on the message’s lifetime criteria, the message average delay decreases significantly and the overall message delivery probability also increases for both routing protocols. Further simulations show that these results outperform the MaxProp and PRoPHET routing protocols that have their own scheduling and dropping mechanisms.Part of this work has been supported by Instituto de Telecomunicações, Next Generation Networks and Applications Group, Portugal, in the framework of the VDTN@Lab Project, and by the Euro-NF Network of Excellence from the Seventh Framework Programme of EU
3DCP for complex sites: robotic fabrication of custom-fit slabs in irregular pontoons
This paper presents a case study on the use of 3DCP to qualify rocky pontoons with spaces for recreational use—namely sitting areas, circulation trails and fishing activities—and biodiversity protection—providing habitat and refuge for native marine species—with a focus on the challenges and opportunities associated with 3DCP prefabrication for such a complex topographical context. We first discuss the benefits and disadvantages of 3DCP over traditional methods for retrofitting strategies with the support of state-of-the-art literature review. We then present a methodology for an experimental case study, organized in three stages: (1) a photogrammetric survey and digital reconstruction of the site´s rocky landscape, (2) the creation of a tool to generate and optimize custom-fit slabs based on their location on site, intended use and role in the protection of the natural ecosystem, and (3) the robotic fabrication of these slabs through 3DCP. Finally, we present our key findings, revealing that 3DCP offers a viable and more efficient alternative for appropriating and revitalizing sites with a disorderly and highly complex topography.This work is co-funded by the European Regional Development Fund (ERDF) through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) of the Portugal 2020 Program [Project No. 47108, “SIFA”; Funding Reference: POCI-01-0247-FEDER-047108. It is co-financed by the Project Lab2PT—Landscapes, Heritage and Territory laboratory—UIDB/04509/2020 through FCT—Fundação para a Ciência e a Tecnologia and by FCT Doctoral Grant with the reference SFRH/BD/145832/2019
Postischemic stunned myocardium does not alter cardiac response to an elevation in contractile frequency
OBJECTIVE:To assess the influence of the postischemia/reperfusion stunned myocardium (PIRSM) on the inotropic and lusitropic effects of heart rate (HR). METHODS: Nine preparations of isolated dog hearts in isovolumic contraction and nourished by the arterial blood of another dog underwent heart rate elevation from 60 bpm to 200 bpm, in 20-bpm stages. The following variables were assessed before (B) and after (A) ischemia (15 min) and reperfusion (30 min): the pressure developed during contraction (PD), its first positive (+dP/dt) and negative (-dP/dt) derivative, the time of maximum pressure (TMP), the pressure at rest (Pr), and the time necessary for the developed pressure to decrease by 90% of its maximum value (time for relaxation - TR90%). RESULTS: The stimulating effects of HR elevation on inotropism and relaxation were similar before and after ischemia/reperfusion as follows: +dP/dt values increased, TMP decreased, -dP/dt values were intensified, and TR90% decreased. The values of PD did not change, and Pr increased. CONCLUSION: The results confirmed the positive inotropic effect of HR elevation (Bowditch effect) and the depressive action of ischemia/reperfusion. They also evidenced that PIRSM does not alter the stimulating action of the Bowditch effect, in accordance with the current concept that PIRSM does not impair calcium myocardial kinetics, favoring the prevalent hypothesis that the decrease in the contractile capacity after ischemia/reperfusion depends on the reduction of the myofilament responsiveness to calcium.OBJETIVO: Analisar a influência da depressão miocárdica pós-isquemia/reperfusão (DMPIR) sobre os efeitos inotrópico e lusitrópico promovidos pela freqüência cardíaca (FC). MÉTODOS: Nove preparações de coração isolado de cães nutrido pelo sangue arterial de um outro cão e contraindo isovolumetricamente tiveram a freqüência cardíaca elevada de 60 bpm a 200 bpm, em etapas de 20 bpm. Foram avaliadas as variáveis antes (C) e depois (D) da isquemia (15 min) e reperfusão (30 min): a pressão desenvolvida durante a contração (PD), sua 1ª derivada positiva (+dP/dt) e negativa (-dP/dt), o tempo de pressão máxima (TPM), a pressão de repouso (Pr) e o tempo para a pressão desenvolvida regredir em 90% de seu valor máximo (TR90%). RESULTADOS: Os efeitos estimulantes da elevação da FC sobre o inotropismo e o relaxamento foram semelhantes em C e em D: houve aumento dos valores da +dP/dt, redução do TPM, acentuação da -dP/dt e diminuição do TR90%. A PD não sofreu alteração e a Pr se elevou. CONCLUSÃO: Os resultados confirmaram o efeito inotrópico positivo da elevação da FC (efeito Bowditch) e a ação depressora da isquemia/reperfusão. Evidenciaram ainda que a DMPIR não altera a ação estimulante do efeito Bowditch. Os resultados se adequam ao conceito vigente de que a DMPIR não compromete a cinética miocárdica do cálcio, favorecendo, a hipótese prevalente de que o decaimento da capacidade contrátil pós-isquemia/reperfusão depende de redução da responsividade dos miofilamentos ao cálcio.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Fisiologia CardiovascularUNIFESP, EPM, Fisiologia CardiovascularSciEL
Evaluating the impact of extreme temperature based indices in the 2003 heatwave excessive mortality in Portugal
This paper analyses the impact of the 2003 European heatwave on excessive human mortality in Portugal, a country that presents a relatively high level of exposure to heatwave events. A total of 2399 excessive deaths are estimated in continental Portugal, which implies an increase of 58% over the expected deaths. When these values are split by gender, it is seen that women increase (79%), was considerably higher than that recorded for men (41%). The increment of mortality due to this heatwave was detected for all the 18 districts of the country, but its magnitude was significantly higher in the inner districts close to the Spanish border. When we split by gender all districts reveal significant mortality increments for women, while the impact in men’s excess deaths is not significant over 3 districts. Several temperature derived indices were used and evaluated in their capacity to explain, at the regional level, the excessive mortality (ratio between observed and expected deaths) by gender. It is shown that the best relationship is found for the total exceedance of extreme days, an index combining the length of the heatwave and its intensity. Both variables hold a linear relationship with r = 0.79 for women and a poorer adjustment (r = 0.50) for men. Additionally, availability of mortality data split by age also allowed obtaining detailed information on the structure of the population in risk, namely by showing that statistically significant increments are concentrated in the last three age classes (45–64, 65–74 and 75 or more). The use of air conditioning systems in some Portuguese hospitals had a major impact on the decrease (up to 40%) in excessive mortality values. A finer approach is relevant for prevention strategies, since it allows to identify better the target population of any preventive strategy regional and national authorities may be interested to implement
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