88 research outputs found
Evaluation of anti-estrogenic or estrogenic activities of aqueous root extracts of Gunnera manicata L.
Gunnera perpensa (Gunneraceae) is an African plant widely used in traditional medicine. This species is known for its activity involving the female reproductive system, such as inducing or increasing labor, treating female infertility, expelling the placenta and/or preventing post-partum hemorrhage. These properties are probably due to (z)-venusol, a majoritary compound, and its action in conjunction with substances in the whole extract and other natural products. In southern Brazil, a native species Gunnera manicata L. that also belongs to Gunneraceae can be found. In spite of the traditional use of G. perpensa, there is no pharmacological and phytochemical information regarding the South American Gunnera species. Therefore, the aim of this study was to investigate the activity of Brazilian G. manicata aqueous extracts on the reproductive system of immature female Wistar rats through a uterotrophic assay and to verify the presence of (z)-venusol by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Data were analyzed by analysis of variance (ANOVA) and Bonferroni´s post-hoc test (p< 0.01). Results obtained shown that G. manicata extracts did not present in vivo anti or estrogenic activity. Furthermore, (z)-venusol compound was not found. This study represents the first preliminary screening done on the South American G. manicata species.Gunnera perpensa (Gunneraceae) é uma planta de origem africana extensamente utilizada na medicina tradicional do país. Esta espécie é conhecida por suas atividades no sistema reprodutor feminino, como indução ou aumento do trabalho de parto, tratamento da infertilidade em mulheres, expulsão da placenta e/ou impedimento de hemorragia pós-parto. Tais atividades devem-se, provavelmente, ao sinergismo existente entre o (z)-venusol, composto majoritário, e outros compostos presentes na planta. No sul do Brasil, encontra-se uma espécie nativa, Gunnera manicata L., pertencente à família Gunneraceae. Apesar do uso tradicional de G. perpensa, não há informações farmacológicas e fitoquímicas a respeito da espécie sul Americana de Gunnera. Assim, o objetivo deste estudo foi investigar a atividade de extratos aquosos da espécie brasileira G. manicata no sistema reprodutor de ratas Wistar imaturas através de ensaio uterotrófico e verificar a presença do composto (z)-venusol utilizando-se cromatografia líquida acoplada a espectrômetro de massas em tandem (CL-EM/EM). Para a análise estatística, utilizou-se ANOVA/Bonferroni (
Composites based on PDMS and graphite flakes for thermoelectric sensing applications
[Excerpt] Thermoelectric (TE) devices are utilized for thermal energy harvesting, local cooling or heating, and temperature sensing. They have no mechanical structures, can be made flexible and present long operating lifetimes, making them useful for the Internet of Things (IoT) and wearable electronics.[...]This work was financed by national funds from FCT-Fundação para a Ciência e a Tecnologia,
I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the
Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication–i3N, and
by projects PTDC/NAN-MAT/32558/2017 and PTDC/CTM-PAM/4241/2020. E.V. thanks the FCT Fundação para a Ciência e a Tecnologia, I.P., under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020. J.F. thanks the support from FCTFundação para a Ciência e a Tecnologia, I.P. through the PhD scholarship SFRH/BD/121679/2016
(Joana Figueira). This work has received funding from the European Union’s Horizon 2020 Research
and Innovation Programme under the Grant Agreements Nos: 640598 (ERC-2014-STG NEW-FUN),
952169 (SYNERGY, H2020-WIDESPREAD-2020-5, CSA), and 101008701 (EMERGE, H2020-INFRAIA2020-1)
Investigation of single phase Cu2ZnSnxSb1-xS4 compounds processed by mechanochemical synthesis
ABSTRACT: The copper zinc tin sulfide (CZTS) compound is a promising candidate as an alternative absorber material for thin-film solar cells. In this study, we investigate the direct formation of Cu1.92ZnSnx(Sb1-x)S-4 compounds [CZT(A)S], with x = 1, 0.85, 0.70, and 0.50, via a mechanochemical synthesis (MCS) approach, starting from powders of the corresponding metals, zinc sulfide, and sulfur. The thermal stability of the CZT(A)S compounds was evaluated in detail by in situ synchrotron high-energy x-ray diffraction measurements up to 700 degrees C. The CZT(A)S compounds prepared via MCS revealed a sphalerite-type crystal structure with strong structural stability over the studied temperature range. The contribution of the MCS to the formation of such a structure at room temperature is analyzed in detail. Additionally, this study provides insights into the MCS of CZTS-based compounds: the possibility of a large-scale substitution of Sn by Sb and the production of single phase CZT(A)S with a Cupoor/Zn-poor composition. A slight increase in the band gap from 1.45 to 1.49-1.51 eV was observed with the incorporation of Sb, indicating that these novel compounds can be further explored for thin-film solar cells.info:eu-repo/semantics/publishedVersio
Prediction of sunlight-driven CO2 conversion: producing methane from photovoltaics, and full system design for single-house application
ABSTRACT: CO2 capture and utilization (CCU) technologies are being immensely researched as means to close the anthropogenic carbon cycle. One approach known as artificial photosynthesis uses solar energy from photovoltaics (PV), carbon dioxide and water to generate hydrocarbon fuels, being methane (CH4) a preferential target due to the already in place infrastructures for its storage, distribution and consumption. Here, a model is developed to simulate a direct (1-step) solar methane production approach, which is studied in two scenarios: first, we compare it against a more conventional 2-step methane production route, and second, we apply it to address the energetic needs of concept buildings with usual space and domestic hot water heating requirements. The analysed 2-step process consists in the PV-powered synthesis of an intermediate fuel - syngas - followed by its conversion to CH4 via a Fischer -Tropsch (methanation) process. It was found that the 1-step route could be adequate to a domestic, small scale use, potentially providing energy for a single-family house, whilst the 2-step can be used in both small and large scale applications, from domestic to industrial uses. In terms of overall solar-to-CH4 energy efficiency, the 2-step method reaches 13.26% against the 9.18% reached by the 1-step method. Next, the application of the direct solar methane technology is analysed for domestic buildings, in different European locations, equipped with a combination of solar thermal collectors (STCs) and PV panels, in which the heating needs that cannot be fulfilled by the STCs are satisfied by the combustion of methane synthesized by the PV-powered electrolyzers. Various combinations of situations for a whole year were studied and it was found that this auxiliary system can produce, per m(2) of PV area, in the worst case scenario 23.6 g/day (0.328 kWh/day) of methane in Stockholm, and in the best case scenario 47.4 g/day (0.658 kWh/day) in Lisbon.info:eu-repo/semantics/publishedVersio
Estratégias fotónicas para fotovoltaico : novos avanços para além da ótica
CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: Estruturas fotónicas com tamanhos comparáveis aos comprimentos de onda da luz solar são as soluções preferenciais para melhorar a eficiência de dispositivos fotovoltaicos através de aprisionamento de luz. As micro-estruturas fotónicas aqui desenvolvidas operam no regime de ótica de ondas, pelo que foram construídos modelos eletromagnéticos que permitiram encontrar os parâmetros ótimos para aplicação no contacto frontal de diferentes tipos de tecnologias, nomeadamente em células de filme fino baseadas em silício ou perovskite. Desta forma, foram obtidas diferentes arquiteturas fotónicas de células, demonstrando melhoras de até 50% na eficiência relativamente a células de referência planas. Os resultados mostram que as vantagens da aplicação de estruturas fotónicas não estão só limitadas a ganhos óticos de melhora da absorção, mas também possibilitam outros benefícios importantes tais como: ganhos elétricos devido à melhora dos contactos transparentes, e melhor desempenho em condições ambientais devido a um encapsulamento avançado dos dispositivos que confere até propriedades de auto-limpeza dos mesmos.ABSTRACT: Photonic structures with dimensions comparable to the sunlight wavelengths are now regarded as the preferential solutions to enhance the efficiency of photovoltaic devices via light trapping. The photonic microstructures operate in the regime of wave-optics, so electromagnetic models were constructed that were capable of determining the optimal parameters for application in the front contact of different photovoltaic technologies, namely in thin film solar cells based in silicon or perovskite materials. In this way, distinct photonic cell architectures were obtained, showing efficiency improvements up to 50% with respect to planar reference solar cells. The results demonstrate that the advantages in the application of the photonic structures are not just limited to optical gains related with light absorption enhancement, but also enable other important benefits such as: electrical gains due to the improvement of the front contact conductance, and better environmental/outdoor performance due to an advanced micro-structured encapsulation that even allows self-cleaning properties.info:eu-repo/semantics/publishedVersio
Age-Related Effects of COVID-19 Pandemic on Mechanical Reperfusion and 30-Day Mortality for STEMI : Results of the ISACS-STEMI COVID-19 Registry
Background: The constraints in the management of patients with ST-segment elevation
myocardial infarction (STEMI) during the COVID-19 pandemic have been suggested to have severely
impacted mortality levels. The aim of the current analysis is to evaluate the age-related effects of
the COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI within the
registry ISACS-STEMI COVID-19. Methods: This retrospective multicenter registry was performed
in high-volume PPCI centers on four continents and included STEMI patients undergoing PPCI
in March–June 2019 and 2020. Patients were divided according to age (< or ≥75 years). The main
outcomes were the incidence and timing of PPCI, (ischemia time longer than 12 h and door-to-balloon
longer than 30 min), and in-hospital or 30-day mortality. Results: We included 16,683 patients
undergoing PPCI in 109 centers. In 2020, during the pandemic, there was a significant reduction in
PPCI as compared to 2019 (IRR 0.843 (95%-CI: 0.825–0.861, p < 0.0001). We found a significant agerelated reduction (7%, p = 0.015), with a larger effect on elderly than on younger patients. Furthermore,
we observed significantly higher 30-day mortality during the pandemic period, especially among the
elderly (13.6% vs. 17.9%, adjusted HR (95% CI) = 1.55 [1.24–1.93], p < 0.001) as compared to younger
patients (4.8% vs. 5.7%; adjusted HR (95% CI) = 1.25 [1.05–1.49], p = 0.013), as a potential consequence
of the significantly longer ischemia time observed during the pandemic. Conclusions: The COVID-19
pandemic had a significant impact on the treatment of patients with STEMI, with a 16% reduction in
PPCI procedures, with a larger reduction and a longer delay to treatment among elderly patients,
which may have contributed to increase in-hospital and 30-day mortality during the pandemic
Age-Related Effects of COVID-19 Pandemic on Mechanical Reperfusion and 30-Day Mortality for STEMI: Results of the ISACS-STEMI COVID-19 Registry
Background: The constraints in the management of patients with ST-segment elevation myocardial infarction (STEMI) during the COVID-19 pandemic have been suggested to have severely impacted mortality levels. The aim of the current analysis is to evaluate the age-related effects of the COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI within the registry ISACS-STEMI COVID-19. Methods: This retrospective multicenter registry was performed in high-volume PPCI centers on four continents and included STEMI patients undergoing PPCI in March-June 2019 and 2020. Patients were divided according to age (= 75 years). The main outcomes were the incidence and timing of PPCI, (ischemia time longer than 12 h and door-to-balloon longer than 30 min), and in-hospital or 30-day mortality. Results: We included 16,683 patients undergoing PPCI in 109 centers. In 2020, during the pandemic, there was a significant reduction in PPCI as compared to 2019 (IRR 0.843 (95%-CI: 0.825-0.861, p < 0.0001). We found a significant age-related reduction (7%, p = 0.015), with a larger effect on elderly than on younger patients. Furthermore, we observed significantly higher 30-day mortality during the pandemic period, especially among the elderly (13.6% vs. 17.9%, adjusted HR (95% CI) = 1.55 [1.24-1.93], p < 0.001) as compared to younger patients (4.8% vs. 5.7%; adjusted HR (95% CI) = 1.25 [1.05-1.49], p = 0.013), as a potential consequence of the significantly longer ischemia time observed during the pandemic. Conclusions: The COVID-19 pandemic had a significant impact on the treatment of patients with STEMI, with a 16% reduction in PPCI procedures, with a larger reduction and a longer delay to treatment among elderly patients, which may have contributed to increase in-hospital and 30-day mortality during the pandemic
Gender Difference in the Effects of COVID-19 Pandemic on Mechanical Reperfusion and 30-Day Mortality for STEMI: Results of the ISACS-STEMI COVID-19 Registry
Background. Several reports have demonstrated the impact of the COVID-19 pandemic on
the management and outcome of patients with ST-segment elevation myocardial infarction (STEMI).
The aim of the current analysis is to investigate the potential gender difference in the effects of the
COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI patients within the
ISACS-STEMI COVID-19 Registry. Methods. This retrospective multicenter registry was performed
in high-volume primary percutaneous coronary intervention (PPCI) centers on four continents and
included STEMI patients undergoing PPCIs in March–June 2019 and 2020. Patients were divided
according to gender. The main outcomes were the incidence and timing of the PPCI, (ischemia time
≥ 12 h and door-to-balloon ≥ 30 min) and in-hospital or 30-day mortality. Results. We included
16683 STEMI patients undergoing PPCIs in 109 centers. In 2020 during the pandemic, there was a
significant reduction in PPCIs compared to 2019 (IRR 0.843 (95% CI: 0.825–0.861, p < 0.0001). We did
not find a significant gender difference in the effects of the COVID-19 pandemic on the numbers of
STEMI patients, which were similarly reduced from 2019 to 2020 in both groups, or in the mortality
rates. Compared to prepandemia, 30-day mortality was significantly higher during the pandemic
period among female (12.1% vs. 8.7%; adjusted HR [95% CI] = 1.66 [1.31–2.11], p < 0.001) but not
male patients (5.8% vs. 6.7%; adjusted HR [95% CI] = 1.14 [0.96–1.34], p = 0.12). Conclusions. The
COVID-19 pandemic had a significant impact on the treatment of patients with STEMI, with a
16% reduction in PPCI procedures similarly observed in both genders. Furthermore, we observed
significantly increased in-hospital and 30-day mortality rates during the pandemic only among
females. Trial registration number: NCT 04412655
Impact of Smoking Status on Mortality in STEMI Patients Undergoing Mechanical Reperfusion for STEMI : Insights from the ISACS–STEMI COVID-19 Registry
The so-called “smoking paradox”, conditioning lower mortality in smokers among STEMI
patients, has seldom been addressed in the settings of modern primary PCI protocols. The ISACS–
STEMI COVID-19 is a large-scale retrospective multicenter registry addressing in-hospital mortality,
reperfusion, and 30-day mortality among primary PCI patients in the era of the COVID-19 pandemic.
Among the 16,083 STEMI patients, 6819 (42.3%) patients were active smokers, 2099 (13.1%) previous smokers, and 7165 (44.6%) non-smokers. Despite the impaired preprocedural recanalization
(p < 0.001), active smokers had a significantly better postprocedural TIMI flow compared with nonsmokers (p < 0.001); this was confirmed after adjustment for all baseline and procedural confounders,
and the propensity score. Active smokers had a significantly lower in-hospital (p < 0.001) and 30-day
(p < 0.001) mortality compared with non-smokers and previous smokers; this was confirmed after
adjustment for all baseline and procedural confounders, and the propensity score. In conclusion, in
our population, active smoking was significantly associated with improved epicardial recanalization
and lower in-hospital and 30-day mortality compared with previous and non-smoking histor
Results of the ISACS-STEMI COVID-19 Registry
Publisher Copyright: © 2023 by the authors.Background. Several reports have demonstrated the impact of the COVID-19 pandemic on the management and outcome of patients with ST-segment elevation myocardial infarction (STEMI). The aim of the current analysis is to investigate the potential gender difference in the effects of the COVID-19 pandemic on mechanical reperfusion and 30-day mortality for STEMI patients within the ISACS-STEMI COVID-19 Registry. Methods. This retrospective multicenter registry was performed in high-volume primary percutaneous coronary intervention (PPCI) centers on four continents and included STEMI patients undergoing PPCIs in March–June 2019 and 2020. Patients were divided according to gender. The main outcomes were the incidence and timing of the PPCI, (ischemia time ≥ 12 h and door-to-balloon ≥ 30 min) and in-hospital or 30-day mortality. Results. We included 16683 STEMI patients undergoing PPCIs in 109 centers. In 2020 during the pandemic, there was a significant reduction in PPCIs compared to 2019 (IRR 0.843 (95% CI: 0.825–0.861, p < 0.0001). We did not find a significant gender difference in the effects of the COVID-19 pandemic on the numbers of STEMI patients, which were similarly reduced from 2019 to 2020 in both groups, or in the mortality rates. Compared to prepandemia, 30-day mortality was significantly higher during the pandemic period among female (12.1% vs. 8.7%; adjusted HR [95% CI] = 1.66 [1.31–2.11], p < 0.001) but not male patients (5.8% vs. 6.7%; adjusted HR [95% CI] = 1.14 [0.96–1.34], p = 0.12). Conclusions. The COVID-19 pandemic had a significant impact on the treatment of patients with STEMI, with a 16% reduction in PPCI procedures similarly observed in both genders. Furthermore, we observed significantly increased in-hospital and 30-day mortality rates during the pandemic only among females. Trial registration number: NCT 04412655.publishersversionpublishe
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