483 research outputs found

    In-situ laboratory X-ray diffraction applied to assess cement hydration

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    In-situ X-ray diffraction (XRD) is a powerful tool to assess the hydration of cementitious materials, providing time-resolved quantitative analysis with reasonable accuracy without disturbing sample. However, the lack of guidelines and well-established procedures for data collection and analysis is the limiting factor for spreading this technique. This paper discussed using in-situ laboratory XRD to assess cement hydration. The first part was dedicated to a literature review on the topic. Then, experimental strategies were discussed, and recommendations related to the data analysis routine were drawn; the advantages and limitations of this technique were also discussed. We can conclude that the critical factors for a successful analysis are the choice of an adequate experimental setup with good statistics and low measurement time, the proper consideration of different amorphous contributions in the XRD pattern, and a good data analysis routine. Independent techniques are highly recommended to support the in-situ XRD data.PID2020-114650RB-I0

    Evidence of a noncoding transcript of the RIPK2 gene overexpressed in head and neck tumor

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    Receptor-interacting proteins are a family of serine/threonine kinases, which integrate extra and intracellular stress signals caused by different factors, including infections, inflammation and DNA damage. Receptor-interacting serine/threonine-protein kinase 2 (RIP-2) is a member of this family and an important component of the nuclear factor NF-kappa-B signaling pathway. The corresponding human gene RIPK2 generates two transcripts by alternative splicing, the full-length and a short transcript. The short transcript has a truncated 5? sequence, which results in a predicted isoform with a partial kinase domain but able to transduce signals through its caspase recruitment domain. In this study, the expression of RIPK2 was investigated in human tissue samples and, in order to determine if both transcripts are similarly regulated at the transcriptional level, cancer cell lines were submitted to temperature and acid stresses. We observed that both transcripts are expressed in all tissues analyzed, with higher expression of the short one in tumor samples, and they are differentially regulated following temperature stress. Despite transcription, no corresponding protein for the short transcript was detected in tissues and cell lines analyzed. We propose that the shorter transcript is a noncoding RNA and that its presence in the cell may play regulatory roles and affect inflammation and other biological processes related to the kinase activity of RIP-2.Fil: Mancini Villagra, Ulises Maximiliano. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de BiotecnologĂ­a y BiologĂ­a Molecular; ArgentinaFil: da Cunha, Bianca R.. Universidade de Sao Paulo; BrasilFil: Polachini, Giovana M.. No especifĂ­ca;Fil: Tiago, Tiago Henrique. No especifĂ­ca;Fil: Carlos H. T. P. da Silva. Universidade de Sao Paulo; BrasilFil: Feitosa, Olavo A.. Universidade de Sao Paulo; BrasilFil: Fukuyama, Erica E.. Arnaldo Vieira de Carvalho Cancer Institute; BrasilFil: LĂłpez, Rossana V. M.. No especifĂ­ca;Fil: Dias Neto, Emmanuel. Universidade de Sao Paulo; BrasilFil: Nunes, Fabio D.. Universidade de Sao Paulo; BrasilFil: Severino, Patricia. Hospital Israelita Albert Einstein; BrasilFil: Tajara, Eloiza Helena Tajara. Universidade de Sao Paulo; Brasi

    Gene Expression Profiling during Early Acute Febrile Stage of Dengue Infection Can Predict the Disease Outcome

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    Background: We report the detailed development of biomarkers to predict the clinical outcome under dengue infection. Transcriptional signatures from purified peripheral blood mononuclear cells were derived from whole-genome gene-expression microarray data, validated by quantitative PCR and tested in independent samples. Methodology/Principal Findings: The study was performed on patients of a well-characterized dengue cohort from Recife, Brazil. The samples analyzed were collected prospectively from acute febrile dengue patients who evolved with different degrees of disease severity: classic dengue fever or dengue hemorrhagic fever (DHF) samples were compared with similar samples from other non-dengue febrile illnesses. The DHF samples were collected 2-3 days before the presentation of the plasma leakage symptoms. Differentially-expressed genes were selected by univariate statistical tests as well as multivariate classification techniques. The results showed that at early stages of dengue infection, the genes involved in effector mechanisms of innate immune response presented a weaker activation on patients who later developed hemorrhagic fever, whereas the genes involved in apoptosis were expressed in higher levels. Conclusions/Significance: Some of the gene expression signatures displayed estimated accuracy rates of more than 95%, indicating that expression profiling with these signatures may provide a useful means of DHF prognosis at early stages of infection. © 2009 Nascimento et al

    Benznidazole biotransformation and multiple targets in <i>Trypanosoma</i> cruzi revealed by metabolomics

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    &lt;b&gt;Background&lt;/b&gt;&lt;p&gt;&lt;/p&gt; The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn). Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methodology/Principal findings&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, Îł-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions/significance&lt;/b&gt;&lt;p&gt;&lt;/p&gt; Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi
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