299 research outputs found

    Experimental alteration of a meteoritic model-glass in different media

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    A meteoritic model-glass has been altered under oxidizing conditions in different media (water and sulfuric acid) at 80℃ and 0℃. The reactions were followed by analysis of solutions and solids (XRD, FTIR, SEM, TEM). After reaction, all the elements were detected in solution, at different levels of concentration related to the medium. The most aggressive media were sulfuric acid at pH 1 for 80℃ and 0℃ runs. In such alteration conditions, the surface of the solid evolved rapidly according to the temperature. At 80℃, one noticed the development of a Si-rich layer containing calcium and sulfate ions which combined to form gypsum. At 0℃, only smooth surface with etch pits and scarce gypsum crystals were observed. In contact with glass, ultramicrotomed thin-sections studied by TEM revealed the presence of two kinds of products : Fe-Al silicate phases (in deionized water and H_2SO_4 solution with pH_4) and a high-silica content layer (H_2SO_4 solution with pH1,at 80℃)

    Optimising DNA binding to carbon nanotubes by non-covalent methods

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    The use of carbon nanotubes as a gene delivery system has been extensively studied in recent years owing to its potential advantages over viral vectors. To achieve this goal, carbon nanotubes have to be functionalized to become compatible with aqueous media and to bind the genetic material. To establish the best conditions for plasmid DNA binding, we compare the dispersion properties of single-, double- and multi-walled carbon nanotubes (SWCNTs, DWCNTs and MWCNTs, respectively) functionalized with a variety of surfactants by non-covalent attachment. The DNA binding properties of the functionalized carbon nanotubes were studied and compared by electrophoresis. Furthermore, a bilayer functionalization method for DNA binding on SWCNTs was developed that utilized RNA-wrapping to solubilize the nanotubes and cationic polymers as a bridge between nanotubes and DNA

    Myositis autoantibodies in Korean patients with inflammatory myositis: Anti-140-kDa polypeptide antibody is primarily associated with rapidly progressive interstitial lung disease independent of clinically amyopathic dermatomyositis

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    <p>Abstract</p> <p>Background</p> <p>To investigate the association between myositis autoantibodies and clinical subsets of inflammatory myositis in Korean patients.</p> <p>Methods</p> <p>Immunoprecipitation was performed using the sera of classic polymyositis (PM) (n = 11) and dermatomyositis (DM) (n = 38) patients who met the Bohan and Peter criteria for definite inflammatory myositis. A panel of defined myositis autoantibodies was surveyed to investigate the association between each autoantibody and clinical subsets of inflammatory myositis.</p> <p>Results</p> <p>Either MSAs, anti-p140, or anti-p155/140 antibodies were found in 63.3% (31/49) of the study subjects. Anti-140-kDa-polypeptide (anti-p140) (18.4%, 9/49) and anti-155/140-kDa polypeptide (anti-p155/140) (16.3%, 8/49) antibodies were the most common, followed by anti-Mi2 (14.3%, 7/49), anti-ARS (12.2%, 6/49) and anti-SRP (2.0%, 1/49) antibodies. All MSAs and anti-p140 and anti-p155/140 antibodies were mutually exclusive. Anti-p140 (23.7%, 9/38), anti-p155/140 (21.1%, 8/38), and anti-Mi2 (18.4%, 3/38) antibodies were found exclusively in DM patients. Anti-p140 antibody was associated with rapidly progressive interstitial lung disease (ILD) (p = 0.001), with a sensitivity of 100.0% (4/4) and a specificity of 85.3% (29/34) in DM patients. Anti-p155/140 antibody was associated with cancer-associated DM (p = 0.009), with a sensitivity of 55.6% (5/9) and a specificity of 89.7% (26/29). Cancer-associated survival was significantly worse when anti-p155/140 antibody was present (19.2 ± 7.6 vs. 65.0 ± 3.5 months, p = 0.032). Finally, anti-ARS antibodies were associated with stable or slowly progressive ILD in PM and DM patients (p = 0.005).</p> <p>Conclusions</p> <p>Anti-p140 and anti-p155/140 antibodies were commonly found autoantibodies in Korean patients with inflammatory myositis. Despite the lack of clinically amyopathic DM patients in the study subjects, a strong association was observed between anti-p140 antibody and rapidly progressive ILD. Anti-p155/140 antibody was associated with cancer-associated myositis and poor survival.</p

    A Conditional Zebrafish MITF Mutation Reveals MITF Levels Are Critical for Melanoma Promotion vs. Regression In Vivo

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    The microphthalmia-associated transcription factor (MITF) is the “master melanocyte transcription factor” with a complex role in melanoma. MITF protein levels vary between and within clinical specimens, and amplifications and gain- and loss-of-function mutations have been identified in melanoma. How MITF functions in melanoma development and the effects of targeting MITF in vivo are unknown because MITF levels have not been directly tested in a genetic animal model. Here, we use a temperature-sensitive mitf zebrafish mutant to conditionally control endogenous MITF activity. We show that low levels of endogenous MITF activity are oncogenic with BRAFV600E to promote melanoma that reflects the pathology of the human disease. Remarkably, abrogating MITF activity in BRAFV600Emitf melanoma leads to dramatic tumor regression marked by melanophage infiltration and increased apoptosis. These studies are significant because they show that targeting MITF activity is a potent antitumor mechanism, but also show that caution is required because low levels of wild-type MITF activity are oncogenic

    The hypotensive effect of acute and chronic AMP-activated protein kinase activation in normal and hyperlipidemic mice

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    AMP-activated protein kinase (AMPK) is present in the arterial wall and is activated in response to cellular stressors that raise AMP relative to ADP/ATP. Activation of AMPK in vivo lowers blood pressure but the influence of hyperlipidemia on this response has not been studied. ApoE-/- mice on high fat diet for 6 weeks and age-matched controls were treated with the AMPK activator, AICAR daily for two weeks. Under anesthesia, the carotid artery was cannulated for blood pressure measurements. Aortic tissue was removed for in vitro functional experiments and AMPK activity was measured in artery homogenates by Western blotting. ApoE-/- mice had significantly raised mean arterial pressure; chronic AICAR treatment normalized this but had no effect in normolipidemic mice, whereas acute administration of AICAR lowered mean arterial pressure in both groups. Chronic AICAR treatment increased phosphorylation of AMPK and its downstream target acetyl-CoA carboxylase in normolipidemic but not ApoE-/- mice. In aortic rings, AMPK activation induced vasodilation and an anticontractile effect, which was attenuated in ApoE-/- mice. This study demonstrates that hyperlipidemia dysregulates the AMPK pathway in the arterial wall but this effect can be reversed by AMPK activation, possibly through improving vessel compliance

    Comparison of Pulmonary Involvement Between Patients Expressing Anti-PL-7 and Anti-Jo-1 Antibodies

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    Anti-PL-7 is an anti-tRNA synthetase antibody, and interstitial lung disease (ILD) is the most frequent complication of anti-PL-7-associated antisynthetase syndrome. However, the features of ILD have not been fully elucidated. The present study retrospectively compares 7 and 15 patients who were positive for anti-PL-7 and anti-Jo-1 antibodies, respectively. The features of ILD did not significantly differ between the two groups, but the ratio of lymphocytes in bronchoalveolar lavage fluid was higher in the Jo-1 than in the PL-7 group. High-resolution computed tomography revealed nonspecific interstitial pneumonia in all patients in the PL-7 group and organizing pneumonia in four of the 15 patients in the Jo-1 group. These findings suggest that pulmonary complications slightly differ between patients expressing anti-PL-7 and anti-Jo-1 antibodies. Further studies are required to clarify the features of ILD associated with PL-7

    Identification of the Homeobox Protein Prx1 (MHox, Prrx-1) as a Regulator of Osterix Expression and Mediator of Tumor Necrosis Factor α Action in Osteoblast Differentiation

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    Tumor necrosis factor α (TNF-α) promotes bone loss and inhibits bone formation. Osterix (Osx, SP7) is a transcription factor required for osteoblast (OB) differentiation because deletion results in a cartilaginous skeleton. We previously described a TNF suppressor element in the Osx promoter that was used to isolate nuclear proteins mediating TNF inhibition of OB differentiation. Nuclear extracts from TNF-treated pre-OBs were incubated with the TNF suppressor element for protein pull-down, and tryptic fragments were analyzed by mass spectrometry. Chromatin immunoprecipitation (ChIP) assay confirmed eight bound transcription factors. One protein, the paired related homeobox protein (Prx1), had been shown previously to have a critical role in limb bud formation and skeletal patterning. PCR revealed Prx1 expression in primary stromal cells (MSCs), C3H10T1/2 cells, and MC3T3 preosteoblasts. TNF stimulated a 14-fold increase in mRNA for Prx1, rapid cell accumulation in MC3T3 cells, and expression in periosteal and trabecular lining cells in vivo. Transient expression of Prx inhibited transcription of Osx and RUNX2. Expression of the Prx1b isoform or Prx2 decreased Osx and RUNX2 mRNA and OB differentiation in preosteoblasts. Silencing of Prx1 with siRNA abrogated TNF suppression of Osx mRNA and increased basal Osx expression. Electrophoretic mobility shift revealed Prx1b as the preferred isoform binding the Osx promoter. These results identify the homeobox protein Prx1 as an obligate mediator of TNF inhibition of Osx and differentiation of OB progenitors. Activation of Prx1 by TNF may contribute to reduced bone formation in inflammatory arthritis, menopause, and aging. © 2011 American Society for Bone and Mineral Research

    Metanarrativa : feci quod potui (medalha, moeda & objetos)

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    A ideia para esta publicação ocorreu durante o verão de 2019 na sequência dos trabalhos preparatórios para a montagem da exposição individual, Feci quod potui — Medalha, Moeda & Objetos, que decorreu entre 12 e 27 de Setembro na Galeria da Faculdade de Belas-Artes da Universidade de Lisboa (FBAUL). A exposição que contou com a curadoria de Andreia Pereira e com o apoio logístico e museográfico do Designer João Rocha, do Projetlab/FBAUL, pretendeu assinalar os 25 anos da minha produção medalhística, iniciada, precisamente, em 1994/95, no Convento de S. Francisco, no âmbito da Unidade Curricular lecionada pelo Professor Hélder Batista (regente) e pelo seu Assistente Prof. João Duarte. O projeto para essa exposição antológica foi motivado por três aspetos: quis aproveitar a oportunidade para divulgar a minha obra, que alcançara visibilidade e prestigio internacional, mas que é relativamente pouco conhecida a nível nacional; homenagear de modo singelo a memória do professor Hélder, que me havia convidado para ser o curador da mostra de medalha construída agendada para o mesmo espaço mas que a fatalidade da sua partida impediu de se efetivar1; o derradeiro motivo foi o de cativar as novas gerações para a prática da medalhística, arte cujo ensino e dinamismo trouxe o maior prestigio a Portugal como o demonstram, por exemplo, a atribuição em 1998 do prémio J. Sanford Saltus Award for Outstanding Achievement in the Art of the Medal, ao Professor Hélder Batista e em 2011 ao João Duarte.Ciente do legado que me foi transmitido, enquanto regente da U. C. de Medalhística desde (2016-17) senti-me na obrigação de dar continuidade a esse trabalho tanto no âmbito do ensino quanto no da divulgação dessa forma de expressão artística, preconceituosamente, encarada como arte menor.A escolha do nome — metanarrativa — deriva de um olhar pessoal sobre a minha obra onde, paralelamente ao contexto específico de cada objeto, subsiste um fundo subliminar ou, discurso paralelo, hipertextual, simbioticamente relacionado com o território da medalha enquanto expressão artística contemporânea. Diria que a dimensão metanarrativa tem sido um farol cuja luz tem sondado as possibilidades poéticas dos materiais (pedra, madeira, bronze, cobre, latão, alumínio, aço carbono, aço inox, zinco, estanho, chumbo, couro, acrílico, cera, policarbonato, poliuretano, vinil, termolaminado, poliéster, plástico...) visando expandir o campo de intervenção da medalhística ao mesmo tempo que encontra na vanguarda dos procedimentos tecnológicos os métodos para a sua reprodutibilidade; é na multiplicidade serial que a medalhística se singulariza em contraste com a escultura. À semelhança da obra prolixa e multifacetada, a organização desta publicação reflete também, a heterogeneidade das abordagens. Sem querer categorizar, diria que o miolo é constituído por testemunhos e ensaios que assinalam a multiplicidade da relação artística e pessoal no âmbito da medalhística. A complementar o generoso contributo dos diversos autores propus-me escrever o texto final onde continuei a investigação sobre a “metanarrativa”2 na escultura.Aqui chegado diria que reconheço, neste livro, um objeto híbrido, heterogéneo e polimorfo, sinónimo quiçá, de quem se arrisca a procurar caminhos por descobrir.info:eu-repo/semantics/publishedVersio

    The influence of non-steroidal anti-inflammatory drugs and paracetamol used for pain control of orthodontic tooth movement: a systematic review

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    ABSTRACT The present study aimed to perform a systematic literature review to determine if there is a non-steroidal anti-inflammatory drug (NSAID) that interferes less within tooth movement. This research was performed according to the PRISMA statement. Articles were searched in eight electronic databases (PubMed, Scopus, Embase, Web of Science, LILACS, SciELO, Google Scholar, and Open Grey). Only experimental studies on male Wistar rats were selected, which included experiments related to the influence of NSAIDs on orthodontic movement. Studies in animals with pathological conditions, literature review articles, letters to the editor and/or editorials, case reports, abstracts, books, and book chapters were excluded. Each of the steps of this systematic literature review was performed by two examiners independently. Results: the total sample consisted of 505 articles, from which 6 studies were eligible after a qualitative analysis. From the drugs assessed, paracetamol was unanimous for not interfering within orthodontic movement when compared to the control group. However, drugs such as aspirin, ibuprofen, sodium diclofenac, and selective cyclooxygenase-2 inhibitors caused a reduction in tooth movement when compared to the control group. Conclusion: paracetamol could be considered the drug of choice for pain relief because it interferes less within tooth movement

    Expression of osterix Is Regulated by FGF and Wnt/β-Catenin Signalling during Osteoblast Differentiation

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    Osteoblast differentiation from mesenchymal cells is regulated by multiple signalling pathways. Here we have analysed the roles of Fibroblast Growth Factor (FGF) and canonical Wingless-type MMTV integration site (Wnt/β-Catenin) signalling pathways on zebrafish osteogenesis. We have used transgenic and chemical interference approaches to manipulate these pathways and have found that both pathways are required for osteoblast differentiation in vivo. Our analysis of bone markers suggests that these pathways act at the same stage of differentiation to initiate expression of the osteoblast master regulatory gene osterix (osx). We use two independent approaches that suggest that osx is a direct target of these pathways. Firstly, we manipulate signalling and show that osx gene expression responds with similar kinetics to that of known transcriptional targets of the FGF and Wnt pathways. Secondly, we have performed ChIP with transcription factors for both pathways and our data suggest that a genomic region in the first intron of osx mediates transcriptional activation. Based upon these data, we propose that FGF and Wnt/β-Catenin pathways act in part by directing transcription of osx to promote osteoblast differentiation at sites of bone formation
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