1,153 research outputs found
ReaçÔes de Ortometalacão em Piridinas
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-[(carbamothioylÂamino)Âimino]ÂpropanoÂate
The title compound, C6H11N3O2S, consists of a roughly planar molÂecule (r.m.s deviation from planarity = 0.077â
Ă
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 interÂnal NâHâŻN hydrogen bond donated by the amino group. In the crystal, molÂecules are arranged in undulating layers parallel to (010). The molÂecules are linked via interÂmolecular aminoâcarboxyl NâHâŻO hydrogen bonds, forming chains parallel to [001]. The chains are cross-linked by NcarbazoneâHâŻS and CâHâŻS interÂactions, forming infinite sheets
Ethyl 2-[(carbamoylÂamino)Âimino]ÂpropanoÂate hemihydrate
The title compound, C6H11N3O3·0.5H2O, has two independent molÂecules and one molÂecule of water in the asymmetric unit. The crystal packing is stabilized by interÂmolecular NâHâŻN, OâHâŻO, NâHâŻO and CâHâŻO hydrogen bonds. These interÂactions 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).
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
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
From traditionally extensive to sustainably intensive: a review on the path to a sustainable and inclusive beef farming in Brazil
Brazil is the second largest beef producer and a leading exporter, contributing to some 3000 t CWE in global markets (27.7% of market share). The sector has experienced substantial development, but yields remain far below potential, and there are growing concerns regarding land use change and greenhouse gas emissions. The need for sustainable technologies, such as sound pasture management and integrated farming systems, is evident, but adoption may be low amongst farmers unable to keep up with technological advances. This article describes the historical developments of Brazilian beef farming towards sustainability and discusses possible socioenvironmental outcomes. We combined an extensive literature review, public data, and our own insights as senior researchers to achieve that. The trajectory shown here evidenced the technological intensification of Brazilian beef farming, with strong support of public policies for decarbonizing agriculture. Nonetheless, the pace of this transition may affect small to medium farmers with limited access to information, technologies, and credit. Our recommendations involve a broad program of technical assistance and training on sustainable technologies, including financial and digital literacy. A novel approach to financing farmers is suggested to support a sustainable and inclusive transition in beef farming in Brazil
Subversion of early innate antiviral responses during antibody-dependent enhancement of Dengue virus infection induces severe disease in immunocompetent mice
Dengue is a mosquito-borne disease caused by one of four serotypes of Dengue virus (DENV-1â4). 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 â/â] 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
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
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,
, sensitive to the mass composition of cosmic rays
above 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 .Comment: Replaced with published version. Added journal reference and DO
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