811 research outputs found

    Design e adoção tardia

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    Atualmente no Brasil, muitas crianças vivem em abrigos, à espera da adoção. O número de pretendentes a adotar é muito maior que o de crianças disponíveis, e mesmo assim, crianças continuam sem uma família. Esse agravante se dá em virtude do restrito perfil exigido pela maioria dos pretendentes. Com a crença que o design possa interferir nesse cenário, conscientizando os pretendentes sobre a importância da adoção tardia, o presente trabalho evidencia o processo de desenvolvimento de um projeto gráfico, que tem como ferramenta principal para a construção do processo criativo a técnica de lettering. A escolha dessa técnica surgiu da associação entre essas crianças (as quais, no passado eram vistas pela sociedade, como futuros vândalos) e o lettering que também era visto de forma negativa (vandalismo e depreciação do espaço público), sendo que as duas, nos dias atuais, já são vistas de maneira diferente pela sociedade, embora o preconceito ainda permaneça entre algumas pessoas. O trabalho contou com a metodologia projetual de Bruno Munari (1998), juntamente com uma coleta de entrevistas semiestruturadas com profissionais da área e pais adotivos, que colaboraram para um melhor entendimento acerca da realidade do tema. A união destas informações com o referencial teórico anterior, ofereceu uma direção assertiva ao trabalho, que teve seu desenvolvimento criativo e construção do projeto norteados pelas potenciais frases que surgiram nos próprios depoimentos dos participantes.Currently, in Brazil, many children live in shelters, waiting for adoption. The number of suitors in the queue to adopt is much higher than that of available children, and even so, children continue without a family. This aggravation comes from the restricted profile demanded by the majority of the suitors. Believing that design may interfere on this scenario, making applicants aware of the importance of late adoption, making the applicants aware of the importance of late adoption, this work emphasizes on the process of development of a graphic project, which has the lettering technique as main tool for the creative process. The choice of this technique came from the association among these children (which in the past were seen by society as future vandals), and the lettering that was also seen in a negative way (vandalism and depreciation of public space), being both, currently, already seen differently by the society, but prejudice still remains on some people. The work relied on the design methodology of Bruno Munari (1998), along with a collection of semi structured interviews with professionals from the area and adoptive parents, who collaborated to better understand the reality of the topic.The union of these information, with the previous theoretical reference, offered an assertive direction to the work, finding in the statements phrases in potential that guided the creative development and the construction of the project

    TET-mediated oxidation of methylcytosine causes TDG or NEIL glycosylase dependent gene reactivation

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    The discovery of hydroxymethyl-,formyl- and carboxylcytosine, generated through oxidation of methylcytosine by TET dioxygenases, raised the question how these modifications contribute to epigenetic regulation. As they are subjected to complex regulation in vivo, we dissected links to gene expression with in vitro modified reporter constructs. We used an Oct4 promoter-driven reporter gene and demonstrated that in vitro methylation causes gene silencing while subsequent oxidation with purified catalytic domain of TET1 leads to gene reactivation. To identify proteins involved in this pathway we screened for TET interacting factors and identified TDG, PARP1, XRCC1 and LIG3 that are involved in base-excision repair. Knockout and rescue experiments demonstrated that gene reactivation depended on the glycosylase TDG, but not MBD4, while NEIL1, 2 and 3 could partially rescue the loss of TDG. These results clearly show that oxidation of methylcytosine by TET dioxygenases and subsequent removal by TDG or NEIL glycosylases and the BER pathway results in reactivation of epigenetically silenced genes

    Systematic analysis of the binding behaviour of UHRF1 towards different methyl- and carboxylcytosine modification patterns at CpG dyads

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    The multi-domain protein UHRF1 is essential for DNA methylation maintenance and binds DNA via a base-flipping mechanism with a preference for hemi-methylated CpG sites. We investigated its binding to hemi- and symmetrically modified DNA containing either 5-methylcytosine (mC), 5-hydroxymethylcytosine (hmC), 5-formylcytosine (fC), or 5-carboxylcytosine (caC). Our experimental results indicate that UHRF1 binds symmetrically carboxylated and hybrid methylated/carboxylated CpG dyads in addition to its previously reported substrates. Complementary molecular dynamics simulations provide a possible mechanistic explanation of how the protein could differentiate between modification patterns. First, we observe different local binding modes in the nucleotide binding pocket as well as the protein's NKR finger. Second, both DNA modification sites are coupled through key residues within the NKR finger, suggesting a communication pathway affecting protein-DNA binding for carboxylcytosine modifications. Our results suggest a possible additional function of the hemi-methylation reader UHRF1 through binding of carboxylated CpG sites. This opens the possibility of new biological roles of UHRF1 beyond DNA methylation maintenance and of oxidised methylcytosine derivates in epigenetic regulation

    TET-mediated oxidation of methylcytosine causes TDG or NEIL glycosylase dependent gene reactivation

    Get PDF
    The discovery of hydroxymethyl-,formyl- and carboxylcytosine, generated through oxidation of methylcytosine by TET dioxygenases, raised the question how these modifications contribute to epigenetic regulation. As they are subjected to complex regulation in vivo, we dissected links to gene expression with in vitro modified reporter constructs. We used an Oct4 promoter-driven reporter gene and demonstrated that in vitro methylation causes gene silencing while subsequent oxidation with purified catalytic domain of TET1 leads to gene reactivation. To identify proteins involved in this pathway we screened for TET interacting factors and identified TDG, PARP1, XRCC1 and LIG3 that are involved in base-excision repair. Knockout and rescue experiments demonstrated that gene reactivation depended on the glycosylase TDG, but not MBD4, while NEIL1, 2 and 3 could partially rescue the loss of TDG. These results clearly show that oxidation of methylcytosine by TET dioxygenases and subsequent removal by TDG or NEIL glycosylases and the BER pathway results in reactivation of epigenetically silenced genes

    Dynamics of DNA Replication Factories in Living Cells

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    DNA replication occurs in microscopically visible complexes at discrete sites (replication foci) in the nucleus. These foci consist of DNA associated with replication machineries, i.e., large protein complexes involved in DNA replication. To study the dynamics of these nuclear replication foci in living cells, we fused proliferating cell nuclear antigen (PCNA), a central component of the replication machinery, with the green fluorescent protein (GFP). Imaging of stable cell lines expressing low levels of GFP-PCNA showed that replication foci are heterogeneous in size and lifetime. Time-lapse studies revealed that replication foci clearly differ from nuclear speckles and coiled bodies as they neither show directional movements, nor do they seem to merge or divide. These four dimensional analyses suggested that replication factories are stably anchored in the nucleus and that changes in the pattern occur through gradual, coordinated, but asynchronous, assembly and disassembly throughout S phase

    Synthesis and Characterisation of Hierarchically Structured Titanium Silicalite‐1 Zeolites with Large Intracrystalline Macropores

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    The successful synthesis of hierarchically structured titanium silicalite‐1 (TS‐1) with large intracrystalline macropores by steam‐assisted crystallisation of mesoporous silica particles is reported. The macropore topology was imaged in 3D by using electron tomography and synchrotron radiation‐based ptychographic X‐ray computed tomography, revealing interconnected macropores within the crystals accounting for about 30 % of the particle volume. The study of the macropore formation mechanism revealed that the mesoporous silica particles act as a sacrificial macropore template during the synthesis. Silicon‐to‐titanium ratio of the macroporous TS‐1 samples was successfully tuned from 100 to 44. The hierarchically structured TS‐1 exhibited high activity in the liquid phase epoxidation of 2‐octene with hydrogen peroxide. The hierarchically structured TS‐1 surpassed a conventional nano‐sized TS‐1 sample in terms of alkene conversion and showed comparable selectivity to the epoxide. The flexible synthesis route described here can be used to prepare hierarchical zeolites with improved mass transport properties for other selective oxidation reactions

    Candida albicans β-Glucan Differentiates Human Monocytes Into a Specific Subset of Macrophages

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    β-Glucan derived from cell walls of Candida albicans is a potent immune modulator. It has been shown to induce trained immunity in monocytes via epigenetic and metabolic reprogramming and to protect from lethal sepsis if applied prior to infection. Since β-glucan-trained monocytes have not been classified within the system of mononuclear phagocytes we analyzed these cells metabolically, phenotypically and functionally with a focus on monocyte-to-macrophage differentiation and compared them with naïve monocytes and other types of monocyte-derived cells such as classically (M1) or alternatively (M2) activated macrophages and monocyte-derived dendritic cells (moDCs). We show that β-glucan inhibits spontaneous apoptosis of monocytes independent from autocrine or paracrine M-CSF release and stimulates monocyte differentiation into macrophages. β-Glucan-differentiated macrophages exhibit increased cell size and granularity and enhanced metabolic activity when compared to naïve monocytes. Although β-glucan-primed cells expressed markers of alternative activation and secreted higher levels of IL-10 after lipopolysaccharide (LPS), their capability to release pro-inflammatory cytokines and to kill bacteria was unaffected. Our data demonstrate that β-glucan priming induces a population of immune competent long-lived monocyte-derived macrophages that may be involved in immunoregulatory processes

    Hepatobiliary long-term consequences of COVID-19: dramatically increased rate of secondary sclerosing cholangitis in critically ill COVID-19 patients

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    BACKGROUND: Increasing evidence suggests that secondary sclerosing cholangitis (SSC), which can lead to cirrhosis or liver failure, may be a hepatobiliary long-term complication of COVID-19. The aim of this study was to estimate the frequency and outcome of this COVID-19 sequela and to identify possible risk factors. METHODS: This observational study, conducted at University Hospital Charité Berlin and Unfallkrankenhaus Berlin, Germany, involved hospitalized patients with COVID-19 pneumonia, including 1082 ventilated COVID-19 patients. We compared COVID-19 patients who developed SSC with a COVID-19 control group by univariate and multivariate analyses. RESULTS: SSC occurrence after COVID-19 was observed exclusively in critically ill patients with invasive ventilation, albeit with extreme clustering among them. One in every 43 invasively ventilated COVID-19 patients developed this complication. Risk factors preceding the development of secondary sclerosing cholangitis in critically ill COVID-19 patients (SSC-CIP) were signs of systemic reduced blood oxygen supply (e.g., low PaO(2)/FiO(2), ischemic organ infarctions), multi-organ failure (high SOFA score) at admission, high fibrinogen levels and intravenous ketamine use. Multivariate analysis confirmed fibrinogen and increased plasma lactate dehydrogenase as independent risk factors associated with cholangiopathy onset. The 1-year transplant-free survival rate of COVID-19-associated SSC-CIP was 40%. CONCLUSIONS: COVID-19 causes SSC-CIP in a substantial proportion of critically ill patients. SSC-CIP most likely develops due to severe tissue hypoxia and fibrinogen-associated circulatory disturbances. A significant increase of patients with SSC-CIP is to be expected in the post-COVID era

    Scalable, ultra-resistant structural colors based on network metamaterials

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    Structural colors have drawn wide attention for their potential as a future printing technology for various applications, ranging from biomimetic tissues to adaptive camouflage materials. However, an efficient approach to realize robust colors with a scalable fabrication technique is still lacking, hampering the realization of practical applications with this platform. Here, we develop a new approach based on large-scale network metamaterials that combine dealloyed subwavelength structures at the nanoscale with lossless, ultra-thin dielectric coatings. By using theory and experiments, we show how subwavelength dielectric coatings control a mechanism of resonant light coupling with epsilon-near-zero regions generated in the metallic network, generating the formation of saturated structural colors that cover a wide portion of the spectrum. Ellipsometry measurements support the efficient observation of these colors, even at angles of 70°. The network-like architecture of these nanomaterials allows for high mechanical resistance, which is quantified in a series of nano-scratch tests. With such remarkable properties, these metastructures represent a robust design technology for real-world, large-scale commercial applications
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