Extracytoplasmic function (ECF) sigma factors are key transcriptional regulators that prokaryotes have evolved to respond to environmental challenges. Streptomyces tsukubaensis harbours 42 ECFs to ...reprogram stress-responsive gene expression. Among them, SigG1 features a minimal conserved ECF σ
-σ
architecture and an additional C-terminal extension that encodes a SnoaL_2 domain, which is characteristic for ECF σ factors of group ECF56. Although proteins with such domain organisation are widely found among Actinobacteria, the functional role of ECFs with a fused SnoaL_2 domain remains unknown. Our results show that in addition to predicted self-regulatory intramolecular amino acid interactions between the SnoaL_2 domain and the ECF core, SigG1 activity is controlled by the cognate anti-sigma protein RsfG, encoded by a co-transcribed sigG1-neighbouring gene. Characterisation of ∆sigG1 and ∆rsfG strains combined with RNA-seq and ChIP-seq experiments, suggests the involvement of SigG1 in the morphological differentiation programme of S. tsukubaensis. SigG1 regulates the expression of alanine dehydrogenase, ald and the WhiB-like regulator, wblC required for differentiation, in addition to iron and copper trafficking systems. Overall, our work establishes a model in which the activity of a σ factor of group ECF56, regulates morphogenesis and metal-ions homeostasis during development to ensure the timely progression of multicellular differentiation.
A ciência das redes é um campo multidisciplinar que oferece um arcabouço amplo para se estudar propriedades estatísticas de uma variedade de fenômenos. No cerne do seu sucesso, está o fato de que os ...sistemas, por mais complexos que sejam seus constituintes ou interações, podem ser representados por um simples grafo, um conjunto de nós conectados por arestas. Nesta abordagem, processos de natureza muito diferentes, como a internet, colaborações científicas, ou redes de proteínas, se tornam semelhantes do ponto de vista da rede, o que nos permite não somente entender de maneira unificada as redes naturais mas também otimizar e projetar redes artificiais mais eficientes. Dentro deste contexto, este artigo tem dois objetivos. Primeiramente, apresentar os principais conceitos da ciência das redes, tais como grafos, propriedade de mundo pequeno, distribuição de conectividade entre outros, assim como alguns dos principais modelos de redes já propostos. O segundo objetivo é aplicar este ferramental para analisar uma rede real, mais precisamente a rede de pesquisadores do Instituto Nacional de Ciência e Tecnologia de Informação Quântica. Nossos resultados mostram que do ponto de vista estatístico a rede estudada é bem descrita por uma lei de potência truncada, com um alto grau de interconectividade entre os participantes. Um aglomerado, formado por 8 comunidades menores, contém 85 % dos cientistas da rede. O número médio de colaborações da rede é próximo de 5 e a média de artigos publicados está acima de 13 durante o período de duração do projeto. A rede possui um alto grau de agregação, com valor de ⟨ C ⟩ = 0.4, mostrando que os colaboradores de um dado cientista também tendem a colaborar entre si.
Network science is a multidisciplinary field that offers a broad framework for studying statistical properties of a variety of phenomena. At the core of its success is the fact that systems, in spite of the complexity of their constituents or interactions, can be represented as a simple graph, a set of nodes connected by edges. In this approach, processes of a very different nature, such as the internet, scientific collaborations, or protein networks, become similar from a network point of view, which allows not only to understand natural networks in a unified way, but also to optimize and design more efficient artificial networks. Within this context, this article has two objectives. First, present the main concepts of network science, such as graphs, the small-world property, connectivity distribution, among others, as well as some of the main network models proposed in the literature. The second objective is to apply network science to analyze a real network, more precisely the network of researchers from the National Institute of Science and Technology of Quantum Information. Our results show that from a statistical point of view the studied network is well described by a truncated power law, with a high degree of interconnectivity among the participants. A cluster, formed by 8 smaller communities, contains 85 % of the network’s scientists. The network’s average number of collaborations is close to 5 and the average of articles published is above 13 in the analyzed period of time. The network has a high clustering coefficient, with a value of ⟨ C ⟩ = 0.4, showing that the collaborators of a given scientist also tend to collaborate with each other.
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•Sequential two-step high pressure solvent extractions of walnut husks were performed.•scCO2 extracts presented high contents of 1,4-naphthoquinone.•Subcritical CO2/ethanol/H2O ...extracts presented high contents of juglone.•Walnut husks extracts can be valorized by their phenolic contents and antioxidant activities.
Walnut husks, an abundant agroindustrial residue/waste rich in several bioactive phytochemicals, were subjected to a two-step high pressure solvent extraction methodology using supercritical CO2 (1st step) and a subcritical homogeneous liquid mixture of CO2/ethanol/H2O (0.69:0.28:0.03, molar fractions) (2nd step). Extractions were performed at 35 °C and 45 °C, and from ˜10 MPa up to ˜30 MPa. GC–MS analysis revealed that the most abundant compounds in CO2 extracts were alkanes, terpenes, oxygenated terpenes and alkaloids. The amounts of juglone plus 1,4-naphthoquinone in the 1st and 2nd step extracts were in the 0.33-0.88 mg/g and 0.65–2.77 mg/g range, respectively, and those of total phenols in 2nd step extracts were in the 71.5–116.8 mg GAE/g range. High antioxidant activities were obtained independently of juglone and 1,4-naphtoquinone contents, thus indicating the potential of the applied high pressure methodology to obtain selective extracts for valuable pharmaceutical, agricultural and food applications.
Objective
To understand whether thyroid cells can be directly infected by the SARS-CoV-2 virus and to establish a putative correlation with the expression of the host entry machinery: ACE-2, TMPRSS2, ...and furin.
Methods
We assessed the presence of SARS-CoV-2 virus at the gene level by RT-PCR, viral RNA transcripts localization by
in situ
hybridization, and by detecting viral proteins by immunohistochemistry for the nucleocapsid and the spike proteins. Furthermore, we also described the immunoexpression of key host factors for virus entry in the COVID-19 thyroid samples.
Results
We performed RT-PCR for SARS-CoV-2 in all autopsy specimens and detected viral genome positivity in 13 of 15 thyroid tissues and in a lung specimen. In 9 of the 14 positive samples, we were also able to confirm SARS-CoV-2 signal by
in situ
hybridization. Immunohistochemistry for the viral nucleocapsid and spike protein was also positive for ten and nine of the RT-PCR-positive cases, respectively, but revealed a lower sensitivity. We also described, for the first time in a COVID-19 series, the immunohistochemical expression of ACE-2, TMPRSS2, and furin in the thyroid.
Conclusions
Our results obtained in thyroid specimens from deceased COVID-19 patients indicate that thyrocytes can be directly infected by SARS-CoV-2 since we detected the presence of SARS-CoV-2 genome in follicular cells. Nevertheless, we did not find a clear correlation between the presence of viral genome and the expression of the host factors for virus entry, namely ACE-2, TMPRSS2, and furin.
SARS-CoV-2 pandemics have been massively characterized on a global scale by the rapid generation of in-depth genomic information. The main entry gate of SARS-CoV-2 in human cells is the ...angiotensin-converting enzyme 2 (ACE2) receptor. The expression of this protein has been reported in several human tissues, suggesting a correlation between SARS-CoV-2 organotropism and ACE2 distribution. In this study, we selected (a series of) 90 patients who were submitted to surgery for tumor removal between the beginning of the SARS-CoV-2 pandemic and the closure of operating rooms (by the end of March 2020) in two different countries-Portugal and Brazil. We evaluated the expressions of ACE2 and furin (another important factor for virus internalization) in colon (
= 60), gastric (
= 19), and thyroid (
= 11) carcinomas. In a subseries of cases with PCR results for SARS-CoV-2 detection in the peri-operatory window (
= 18), we performed different methodological approaches for viral detections in patient tumor samples. Our results show that colon and gastric carcinomas display favorable microenvironments to SARS-CoV-2 tropism, presenting high expression levels of ACE2 and furin. From the subseries of 18 cases, 11 tested positive via PCR detection performed in tumor blocks; however, a direct association between the ACE2 expression and SARS-CoV-2 infection was not demonstrated in cancer cells using histology-based techniques, such as immunohistochemistry or in situ hybridization. This study raises the possibility of ACE2-mediated viral tropism in cancer tissues to be clarified in future studies.
Este artigo apresenta os resultados de uma pesquisa realizada em 14 maternidades públicas do Estado do Tocantins onde foram entrevistadas 56 mulheres por meio de entrevista semiestruturada. O estudo ...teve como objetivo identificar as percepções das mulheres sobre violência obstétrica no processo de parto. A percepção das mulheres sobre violência obstétrica apresentou-se relacionada à falta de qualidade e acolhimento na assistência, destacando a ocorrência de expressões diversas de violência obstétrica como negligência, violência física, verbal, psicológica. Constatou-se o descumprimento de normativas importantes, a não utilização das recomendações baseadas em evidências científicas e a violação dos principais direitos das parturientes, configurando a magnitude da violência obstétrica e a necessidade da melhoria dos serviços.
This article presents the results of a survey conducted in 14 public maternity wards of the State of Tocantins, where 56 women were interviewed by means of a semi-structured interview. The study aimed to identify women’s perceptions about violence in the obstetric delivery process. The perception of women about obstetric violence appeared to be related to the lack of quality and reception in care, highlighting the occurrence of various expressions of obstetric violence such as neglect, physical, verbal, psychological violence. A breach in important regulations, the non-utilization of recommendations based on scientific evidence and the breach of the main rights of parturient women were found, setting the magnitude of the violence and the need for improving obstetric services.
The oxidative stress response is a key mechanism that microorganisms have to adapt to changeling environmental conditions. Adaptation is achieved by a fine-tuned molecular response that extends its ...influence to primary and secondary metabolism. In the past, the role of the intracellular redox status in the biosynthesis of tacrolimus in Streptomyces tsukubaensis has been briefly acknowledged. Here, we investigate the impact of the oxidative stress response on tacrolimus biosynthesis in S. tsukubaensis. Physiological characterization of S. tsukubaensis showed that the onset of tacrolimus biosynthesis coincided with the induction of catalase activity. In addition, tacrolimus displays antioxidant properties and thus a controlled redox environment would be beneficial for its biosynthesis. In addition, S. tsukubaensis ∆ahpC strain, a strain defective in the H2O2-scavenging enzyme AhpC, showed increased production of tacrolimus. Proteomic and transcriptomic studies revealed that the tacrolimus over-production phenotype was correlated with a metabolic rewiring leading to increased availability of tacrolimus biosynthetic precursors. Altogether, our results suggest that the carbon source, mainly used for cell growth, can trigger the production of tacrolimus by modulating the oxidative metabolism to favour a low oxidizing intracellular environment and redirecting the metabolic flux towards the increase availability of biosynthetic precursors.
Introduçao: A espiritualidade em pacientes que vivem com HIV ajuda a enfrentar os pensamentos negativos causados pela doença. O estudo objetiva conhecer o impacto da espiritualidade na vida das ...mulheres que vivem com HIV. Materials e Métodos: Pesquisa qualitativa sobre historias de vida temáticas. A amostra está composta por sete mulheres que foram diagnosticada com HIV/AIDS há mais de um ano. Para a compilaçao dos dados, foi utilizada uma entrevista semiestruturada com perguntas sobre o contexto social, a situaçao sociodemográficas e clínica, a religiao e a espiritualidade. Para a análise dos dados, aplicou-se a técnica de análise de conteúdos. Os resultados se organizaram em duas categorias: a busca da força na espiritualidade e a esperança de cura. Resultados: Em momentos de angústia causados pelo HIV/AIDS, todas as entrevistas recorreram a espiritualidade através da oraçao e mesmo â materializaçao da presença de Deus como estratégias para fazer face â doença. O anseio de cura mediante revelaçöes divinas se expressa nos discursos dos entrevistados. Discussāo: Segundo as histórias de vida das entrevistadas, a figura divina deu-lhes fortaleza para enfrentar os desafios gerados pelo HIV/AIDS. Conclusoes: Esta pesquisa permitiu comprovar que a espiritualidade está presente nas vidas das mulheres portadoras de HIV e que mitiga as adversidades causadas pela doença.
Steady technological advances and recent milestones such as intercontinental quantum communication and the first implementation of medium-scale quantum networks are paving the way for the ...establishment of the quantum internet, a network of nodes interconnected by quantum channels. Here we build upon recent models for quantum networks based on optical fibers by considering the effect of a non-uniform distribution of nodes, more specifically based on the demographic data of the federal states in Brazil. We not only compute the statistical properties of this more realistic network, comparing its features with previous models but also employ it to compute the repetition rates for entanglement swapping, an essential protocol for quantum communication based on quantum repeaters.
•Developed a quantum network model using optical fibers, incorporating the impact of a non-uniform node distribution.•Analyzed the statistical properties of such quantum network, leveraging demographic and geographical data from Brazil.•Applied the developed model to compute repetition rates for entanglement swapping.
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