1,117 research outputs found

    ReaçÔes de Ortometalacão em Piridinas

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    In this paper we describe a powerful methodology for the regiospecific construction of polysubstituted aromatic and heteroaromatic compounds. The DoM reaction (direct ortho-metalation) comprises the deprotonation in position ortho of a aromatic or heteroaromatic containing DMG (directed metalation group) by strong bases, normally an alkyllithium reagent, leading to an ortho-lithiated species. These species, upon treatment with electrophilic reagents, gives 1,2 disubstituted products.

    Ethyl 2-[(carbamothioyl­amino)­imino]­propano­ate

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    The title compound, C6H11N3O2S, consists of a roughly planar mol­ecule (r.m.s deviation from planarity = 0.077 Å for the non-H atoms) and has the S atom in an anti position to the imine N atom. This N atom is the acceptor of a strongly bent inter­nal N—H⋯N hydrogen bond donated by the amino group. In the crystal, mol­ecules are arranged in undulating layers parallel to (010). The mol­ecules are linked via inter­molecular amino–carboxyl N—H⋯O hydrogen bonds, forming chains parallel to [001]. The chains are cross-linked by Ncarbazone—H⋯S and C—H⋯S inter­actions, forming infinite sheets

    Ethyl 2-[(carbamoyl­amino)­imino]­propano­ate hemihydrate

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    The title compound, C6H11N3O3·0.5H2O, has two independent mol­ecules and one mol­ecule of water in the asymmetric unit. The crystal packing is stabilized by inter­molecular N—H⋯N, O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds. These inter­actions form a two-dimensional array in the ab plane with a zigzag motif which has an angle close to 35° between the zigzag planes. The hydrogen bonding can be best described using the graph-set notation as N 1 = C(10)R 2 2(10)R 2 2(8) and N 2 = R 6 4(20)R 2 2(8)

    Diretrizes técnicas para produção pecuåria sustentåvel com årvores nativas: Carbono Nativo (CN).

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    A pecuĂĄria de corte brasileira, predominantemente realizada em pastagens, alĂ©m de ser um dos pilares da economia do paĂ­s, Ă© uma importante provedora de serviços ecossistĂȘmicos no contexto de mitigação das emissĂ”es de gases de efeito estufa. O Brasil tem assumido compromissos internacionais em favor da eficiĂȘncia produtiva em prol da sustentabilidade do setor agropecuĂĄrio. Por meio do "Plano Setorial de Mitigação e de Adaptação Ă s Mudanças ClimĂĄticas para a Consolidação de uma Economia de Baixa EmissĂŁo de Carbono na Agricultura", ou "Plano ABC (Agricultura de baixa emissĂŁo de carbono)", em nove anos (2010-2018), o PaĂ­s conseguiu evitar a emissĂŁo entre 100,21 milhĂ”es e 154,38 milhĂ”es de toneladas de CO2 eq. (equivalente de diĂłxido de carbono), alcançando de 68% a 105% da meta de mitigação estabelecida em 2015 (MAPA, 2018).ODS

    Histoplasmose crÎnica disseminada com lesÔes exclusivas na boca: relato de caso

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    We report a rare case of chronic disseminated histoplasmosis with several ulcerated lesions in the oral cavity in an alcoholic patient without human immunodeficiency virus infection, with no detectable signs and symptoms of systemic disease or extraoral manifestations. Histopathological analysis revealed chronic inflammatory process with granulomas containing Histoplasma-like organisms. The isolation of Histoplasma capsulatum provided the definitive diagnosis. Treatment with itraconazole resulted in complete remission of oral lesions. As far we aware, this is the second case report of oral histoplasmosis in an HIV negative patient described in Brazil.Reportamos um caso raro de histoplasmose crĂŽnica disseminada com diversas lesĂ”es ulceradas na cavidade oral de um paciente alcoĂłlatra, sem o vĂ­rus da imunodeficiĂȘncia humana, com nenhum outro sinal detectĂĄvel ou sintomas de doença sistĂȘmica ou manifestaçÔes extra-orais. AnĂĄlise histopatolĂłgica revelou processo inflamatĂłrio crĂŽnico com granulomas contendo organismos fĂșngicos. O isolamento do Histoplasma capsulatum forneceu o diagnĂłstico definitivo. Tratamento com itraconazol resultou numa remissĂŁo completa das lesĂ”es orais. De acordo com nosso conhecimento, este Ă© o segundo caso reportado de histoplasmose oral em um paciente HIV negativo descrito no Brasil

    Subversion of early innate antiviral responses during antibody-dependent enhancement of Dengue virus infection induces severe disease in immunocompetent mice

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    Dengue is a mosquito-borne disease caused by one of four serotypes of Dengue virus (DENV-1–4). Epidemiologic and observational studies demonstrate that the majority of severe dengue cases, dengue hemorrhagic fever and dengue shock syndrome (DHF/DSS), occurs predominantly in either individuals with cross-reactive immunity following a secondary heterologous infection or in infants with primary DENV infections born from dengue-immune mothers, suggesting that B-cell-mediated and antibody responses impact on disease evolution. We demonstrate here that B cells play a pivotal role in host responses against primary DENV infection in mice. After infection, ÎŒMT[superscript −/−] mice showed increased viral loads followed by severe disease manifestation characterized by intense thrombocytopenia, hemoconcentration, cytokine production and massive liver damage that culminated in death. In addition, we show that poly and monoclonal anti-DENV-specific antibodies can sufficiently increase viral replication through a suppression of early innate antiviral responses and enhance disease manifestation, so that a mostly non-lethal illness becomes a fatal disease resembling human DHF/DSS. Finally, treatment with intravenous immunoglobulin containing anti-DENV antibodies confirmed the potential enhancing capacity of subneutralizing antibodies to mediate virus infection and replication and induce severe disease manifestation of DENV-infected mice. Thus, our results show that humoral responses unleashed during DENV infections can exert protective or pathological outcomes and provide insight into the pathogenesis of this important human pathogen

    Synthesis and antimicrobial activity of amphiphilic carbohydrate derivatives

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    N-monoalkylated diamines were synthesised and treated with D-ribonolactone or D-gluconolactone. The resulting aldonamides were evaluated for their antimicrobial activity against S. aureus, E. coli, M. tuberculosis and C. albicans. Two hydrazides were also prepared from ribonohydrazide and their biological activity was compared to their amide analogues. All the ribono-derivatives displayed moderated antitubercular activity, and some of them were also active against S. aureus

    Azimuthal asymmetry in the risetime of the surface detector signals of the Pierre Auger Observatory

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    The azimuthal asymmetry in the risetime of signals in Auger surface detector stations is a source of information on shower development. The azimuthal asymmetry is due to a combination of the longitudinal evolution of the shower and geometrical effects related to the angles of incidence of the particles into the detectors. The magnitude of the effect depends upon the zenith angle and state of development of the shower and thus provides a novel observable, (sec⁡ξ)max(\sec \theta)_\mathrm{max}, sensitive to the mass composition of cosmic rays above 3×10183 \times 10^{18} eV. By comparing measurements with predictions from shower simulations, we find for both of our adopted models of hadronic physics (QGSJETII-04 and EPOS-LHC) an indication that the mean cosmic-ray mass increases slowly with energy, as has been inferred from other studies. However, the mass estimates are dependent on the shower model and on the range of distance from the shower core selected. Thus the method has uncovered further deficiencies in our understanding of shower modelling that must be resolved before the mass composition can be inferred from (sec⁡ξ)max(\sec \theta)_\mathrm{max}.Comment: Replaced with published version. Added journal reference and DO
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