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The aim of this study was to analyze the effectiveness of UV-C light (0-10.6â¯kJ/m2) assisted by mild heat treatment (50⯰C) on the inactivation of Saccharomyces cerevisiae KE 162 in peptone water and fresh carrot-orange juice blend (pH: 3.8; 9.8°Brix; 707 NTU; absorption coefficient: 0.17â¯cm-1). Yeast induced damage by single UV-C and mild heat (H) and the combined treatment UV-C/H, was investigated by flow cytometry (FC) and transmission electron microscopy (TEM). When studying induced damage by FC, cells were labeled with fluorescein diacetate (FDA) and propidium iodide (PI) to monitor membrane integrity and esterase activity. UV-C/H provoked up to 4.7 log-reductions of S. cerevisiae; whereas, only 2.6-3.3 log-reductions were achieved by single UV-C and H treatments. FC revealed a shift with treatment time from cells with esterase activity and intact membrane to cells with permeabilized membrane. This shift was more noticeable in peptone water and UV-C/H treated juice. In the UV-C treated juice, double stained cells were detected, suggesting the possibility of being sub-lethally damaged, with compromised membrane but still metabolically active. TEM images of treated cells revealed severe damage, encompassing coagulated inner content, disorganized lumen and cell debris. FC and TEM provided additional information regarding degree and type of damage, complementing information revealed by the traditional plate count technique.
Assuntos
Citrus sinensis/microbiologia , Daucus carota/microbiologia , Conservação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/efeitos da radiação , Citrus sinensis/química , Daucus carota/química , Citometria de Fluxo , Temperatura Alta , Viabilidade Microbiana/efeitos da radiação , Microscopia Eletrônica de Transmissão , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/ultraestrutura , Raios UltravioletaRESUMO
In this study, we achieved the biosynthesis of novel 7-8 nm iron-oxide nanoparticles in the presence of different concentrations (5 to 50% w/v) of commercial white quinoa extract. Initially, quinoa extract was prepared at various concentrations by a purification route. The biosynthesis optimization was systematically monitored by X-ray diffraction, and the Rietveld quantitative analysis showed the presence of goethite (5 to 10 wt.%) and maghemite phases. The first phase disappeared upon increasing the organic loading (40 and 50% w/v). The organic loading was corroborated by thermogravimetric measurements, and it increased with quinoa extract concentration. Its use reduces the amount of precipitation agent at high quinoa extract concentrations with the formation of magnetic nanoparticles with hard ferrimagnetic character (42 and 11 emu g-1). The enrichment of hydroxyl groups and the negative zeta potential above pH = 7 were corroborated by a reduction in the point of zero charge in all the samples. For alkaline values, the zeta potential values were above the stability range, indicating highly stable chemical species. The evidence of hydroxyl and amide functionalization was qualitatively observed using infrared analysis, which showed that the carboxyl (quercetin/kaempferol), amide I, and amide III chemical groups are retained after biosynthesis. The resultant biosynthesized samples can find applications in environmental remediation due to the affinity of the chemical agents present on the particle surfaces and easy-to-handle them magnetically.
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[This corrects the article DOI: 10.1371/journal.pone.0249661.].
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The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the coronavirus disease 2019 (COVID-19) pandemic. Of particular interest for this topic are the signaling cascades that regulate cell survival and death, two opposite cell programs whose control is hijacked by viral infections. The AKT and the Unfolded Protein Response (UPR) pathways, which maintain cell homeostasis by regulating these two programs, have been shown to be deregulated during SARS-CoVs infection as well as in the development of cancer, one of the most important comorbidities in relation to COVID-19. Recent evidence revealed two way crosstalk mechanisms between the AKT and the UPR pathways, suggesting that they might constitute a unified homeostatic control system. Here, we review the role of the AKT and UPR pathways and their interaction in relation to SARS-CoV-2 infection as well as in tumor onset and progression. Feedback regulation between AKT and UPR pathways emerges as a master control mechanism of cell decision making in terms of survival or death and therefore represents a key potential target for developing treatments for both viral infection and cancer. In particular, drug repositioning, the investigation of existing drugs for new therapeutic purposes, could significantly reduce time and costs compared to de novo drug discovery.
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COVID-19 , Neoplasias , Humanos , Neoplasias/genética , Proteínas Proto-Oncogênicas c-akt , SARS-CoV-2 , Regulação para CimaRESUMO
Background: The prevailing health and biomedical sciences (HBMS) research agenda, not only determined by leading academic institutions but also by large pharmaceutical companies, has been shown to prioritize the exploration of novel pharmacological interventions over the study of the socio-environmental factors influencing illness onset and progression. The aim of this investigation is to quantitatively explore whether and to what extent the prevailing international HBMS research agenda and the key actors setting this agenda influence research in non-core countries. Methods: We used the Web of Science database and the CorText platform to proxy the HBMS research agenda of a prestigious research institution from Latin America: Argentina's National Research Council (CONICET). We conducted a bibliometric and lexical analysis of 16,309 HBMS academic articles whereby CONICET was among the authors' affiliations. The content of CONICET's agenda was represented through co-occurrence network maps of the most frequent concatenation of terms found in titles, keywords, and abstracts. We compared our findings with previous reports on the international HBMS research agenda. Results: In line with the results previously reported for the prevailing international agenda, we found that terms linked to molecular biology and cancer research hegemonize CONICET's HBMS research agenda, whereas terms connecting HBMS research with socio-environmental cues are marginal. However, we also found differences with the international agenda: CONICET's HBMS agenda shows a marginal presence of terms linked to translational medicine, while terms associated with categories such as pathogens, plant research, agrobiotechnology, and food industry are more represented than in the prevailing agenda. Conclusions: CONICET's HBMS research agenda shares topics, priorities, and methodologies with the prevailing HBMS international research agenda. However, CONICET's HBMS research agenda is internally heterogeneous, appearing to be mostly driven by a combination of elements that not only reflect academic dependency (the adoption of the prevailing research agenda by non-core research institutions) but also local economic determinants associated with Argentina's place in the international division of labor as an exporter of primary goods.
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BACKGROUND: Conflicts of interest in biomedical research can influence research results and drive research agendas away from public health priorities. Previous agenda-setting studies share two shortfalls: they only account for direct connections between academic institutions and firms, as well as potential bias based on researchers' personal beliefs. This paper's goal is to determine the key actors and contents of the prevailing health and biomedical sciences (HBMS) research agenda, overcoming these shortfalls. METHODS: We performed a bibliometric and lexical analysis of 95,415 scientific articles published between 1999 and 2018 in the highest impact factor journals within HBMS, using the Web of Science database and the CorText platform. HBMS's prevailing knowledge network of institutions was proxied with network maps where nodes represent affiliations and edges the most frequent co-authorships. The content of the prevailing HBMS research agenda was depicted through network maps of prevalent multi-terms found in titles, keywords, and abstracts. RESULTS: The HBMS research agendas of large private firms and leading academic institutions are intertwined. The prevailing HBMS agenda is mostly based on molecular biology (40% of the most frequent multi-terms), with an inclination towards cancer and cardiovascular research (15 and 8% of the most frequent multi-terms, respectively). Studies on pathogens and biological vectors related to recent epidemics are marginal (1% of the most frequent multi-terms). Content of the prevailing HBMS research agenda prioritizes research on pharmacological intervention over research on socio-environmental factors influencing disease onset or progression and overlooks, among others, the study of infectious diseases. CONCLUSIONS: Pharmaceutical corporations contribute to set HBMS's prevailing research agenda, which is mainly focused on a few diseases and research topics. A more balanced research agenda, together with epistemological approaches that consider socio-environmental factors associated with disease spreading, could contribute to being better prepared to prevent and treat more diverse pathologies and to improve overall health outcomes.
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Pesquisa Biomédica/normas , Publicações/normas , Autoria/normas , Bibliometria , Conflito de Interesses , Bases de Dados Factuais , HumanosRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0249661.].
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El Metapneumovirus humano (hMPV) constituye una importante causa de Infecciones Respiratorias Agudas (IRAs) en niños hospitalizados. En Paraguay, las IRAs están entre las primeras causas de hospitalización durante la infancia, siendo los virus los principales agentes causales. Sin embargo, aún persiste una alta proporción de casos sin etiología identificada. La pandemia de Influenza en el año 2009, condujo a una intensificación de la vigilancia de las infecciones respiratorias, lo cual permitió al mismo tiempo la búsqueda de otros virus como el hMPV. Nuestro objetivo fue detectar hMPV en niños hospitalizados por IRAs en Paraguay durante el año 2009. Fueron estudiadas 240 muestras respiratorias de niños < 5 años internados por IRAs en Paraguay durante el año 2009, que habían resultado negativas para otros virus respiratorios. Fue utilizado el reactivo LightMix Kit human MPV de TIBMOLBIOL, para la detección del gen N de hMPV por PCR en Tiempo Real, siguiendo el procedimiento indicado por el fabricante. De las 240 muestras estudiadas, 29 (12%) resultaron positivas para hMPV, con la mayor detección en julio y agosto; predominando en mayores de 1 año. Los principales signos y síntomas fueron tos, fiebre y dificultad respiratoria; y las complicaciones más frecuentes neumonía y bronquiolitis. Estos resultados proveen las primeras evidencias en Salud Pública, de la importancia del hMPV asociado a niños hospitalizados por IRAs en Paraguay.
Human metapneumovirus (hMPV) is a significant cause of acute respiratory infection (ARI) in hospitalized children. In Paraguay, ARI is one of the leading causes of childhood hospitalization, with viruses being the primary causal agents. However, a large number of cases of unknown etiology remain. The influenza pandemic of 2009 led to intensified vigilance concerning respiratory infections and more thorough efforts to confirm the presence of viruses such as hMPV. Our objective was to detect hMPV in children hospitalized for ARI in Paraguay during 2009. We studied respiratory samples from 240 children age < 5 years hospitalized for IRAs in Paraguay during 2009 who had tested negative for other respiratory viruses. We used the hMPV-reactive LightMix® kit from TIB MOLBIOL for the detection of the nucleoprotein (N) gene by real-time PCR according to manufacturer-specified procedures. Of the 240 samples studied, 29 (12%) were positive for hMPV, with the highest rates detected in July and August (winter) predominating in children over 1 year of age. The most common signs and symptoms were cough, fever, and respiratory distress; while the most common complications were pneumonia and bronchiolitis. These results provide the first evidence concerning the prevalence of hMPV in children hospitalized for ARI in Paraguay.
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El Metapneumovirus humano (hMPV) constituye una importante causa de Infecciones Respiratorias Agudas (IRAs) en niños hospitalizados. En Paraguay, las IRAs están entre las primeras causas de hospitalización durante la infancia, siendo los virus los principales agentes causales. Sin embargo, aún persiste una alta proporción de casos sin etiología identificada. La pandemia de Influenza en el año 2009, condujo a una intensificación de la vigilancia de las infecciones respiratorias, lo cual permitió al mismo tiempo la búsqueda de otros virus como el hMPV. Nuestro objetivo fue detectar hMPV en niños hospitalizados por IRAs en Paraguay durante el año 2009. Fueron estudiadas 240 muestras respiratorias de niños <5 años internados por IRAs en Paraguay durante el año 2009, que habían resultado negativas para otros virus respiratorios. Fue utilizado el reactivo LightMix Kit human MPV de TIBMOLBIOL, para la detección del gen N de hMPV por PCR en Tiempo Real, siguiendo el procedimiento indicado por el fabricante. De las 240 muestras estudiadas, 29 (12%) resultaron positivas para hMPV, con la mayor detección en julio y agosto; predominando en mayores de 1 año. Los principales signos y síntomas fueron tos, fiebre y dificultad respiratoria; y las complicaciones más frecuentes neumonía y bronquiolitis. Estos resultados proveen las primeras evidencias en Salud Pública, de la importancia del hMPV asociado a niños hospitalizados por IRAs en Paraguay.