5,358 research outputs found
Membrane Type 1 Matrix Metalloproteinase Regulates Monocyte Migration and Collagen Destruction in Tuberculosis
Tuberculosis (TB) remains a global pandemic and drug resistance is rising. Multicellular granuloma formation is the pathological hallmark of Mycobacterium tuberculosis infection. The membrane type 1 matrix metalloproteinase (MT1-MMP or MMP-14) is a collagenase that is key in leukocyte migration and collagen destruction. In patients with TB, induced sputum MT1-MMP mRNA levels were increased 5.1-fold compared with matched controls and correlated positively with extent of lung infiltration on chest radiographs (r = 0.483; p < 0.05). M. tuberculosis infection of primary human monocytes increased MT1-MMP surface expression 31.7-fold and gene expression 24.5-fold. M. tuberculosis-infected monocytes degraded collagen matrix in an MT1-MMP-dependent manner, and MT1-MMP neutralization decreased collagen degradation by 73%. In human TB granulomas, MT1-MMP immunoreactivity was observed in macrophages throughout the granuloma. Monocyte-monocyte networks caused a 17.5-fold increase in MT1-MMP surface expression dependent on p38 MAPK and G protein-coupled receptor-dependent signaling. Monocytes migrating toward agarose beads impregnated with conditioned media from M. tuberculosis-infected monocytes expressed MT1-MMP. Neutralization of MT1-MMP activity decreased this M. tuberculosis network-dependent monocyte migration by 44%. Taken together, we demonstrate that MT1-MMP is central to two key elements of TB pathogenesis, causing collagen degradation and regulating monocyte migration
Influência de fatores climáticos na decomposição de resÃduos culturais de milho e soja.
Estudos sobre a dinâmica da decomposição de resÃduos culturais, abordando os efeitos de fatores climáticos sobre o processo, como temperatura e umidade, são raros, principalmente os de longa duração, apesar de importantes para a compreensão de processos como a formação da matéria orgânica do solo. O objetivo deste trabalho foi estudar os impactos das temperaturas máxima e mÃnima, da quantidade de chuvas (precipitação) e da evaporação sobre a evolução da decomposição de resÃduos de milho e soja, em semeadura direta e convencional, utilizando-se dados de um ensaio de longa duração (12 anos) conduzido no campo experimental da Embrapa Soja, em Londrina, PR. Enquanto as temperaturas mostraram não ser um fator limitante à decomposição dos resÃduos, as maiores quantidades de chuvas foram diretamente relacionadas à s maiores taxas de decomposição dos resÃduos estudados, principalmente no sistema plantio convencional (PC).bitstream/item/33195/1/Boletim6.pd
Influência de fatores climáticos na decomposição de resÃduos culturais de aveia e trigo.
RESUMO: Os efeitos de fatores climáticos sobre a dinâmica da decomposição de resÃduos culturais, apesar de importantes para a compreensão de processos como a formação da matéria orgânica, são pouco conhecidos e estudados, sendo raros os estudos, principalmente os de longa duração. O objetivo deste trabalho foi avaliar os impactos das temperaturas máxima e mÃnima, da quantidade de chuvas (precipitação) e da evaporação sobre a evolução da decomposição de resÃduos de aveia e trigo, em semeadura direta e convencional, utilizando-se dados de um ensaio de longa duração (12 anos) conduzido no campo experimental da Embrapa Soja, em Londrina, PR. Enquanto as temperaturas mostraram não ser um fator limitante à decomposição dos resÃduos, as maiores quantidades de chuvas foram diretamente relacionadas à s maiores taxas de decomposição dos resÃduos estudados, principalmente no sistema plantio convencional. ABSTRACT: Climatic effect studies on residue decomposition are scarce in spite of its importance to understand the formation of the soil organic matter. The infl uence of maximum and minimum temperatures, rain and evaporation was studied on oat and wheat residues with emphasis on decay levels, considering tillage and no-tillage practices, over 12 years, in a clayish soil at the experimental fi eld of Embrapa Soybean, Londrina-PR, Brazil. While temperatures showed no limitations on decomposition of residues studied, rainfall was directly associated with high levels of residue decay. Decomposition levels were greater for tillage systems in both crops.bitstream/item/31995/1/Boletim5.pdf21. ed
Ionic liquids microemulsions: the key to Candida Antarctica lipase B superactivity
No abstract available
Quasi-one-dimensional system as a high-temperature superconductor
It is well-known that quasi-one-dimensional superconductors suffer from the
pairing fluctuations that significantly reduce the superconducting temperature
or even completely suppress any coherent behavior. Here we demonstrate that a
coupling to a robust pair condensate changes the situation dramatically. In
this case the quasi-one-dimensional system can be a high temperature
superconductor governed by the proximity to the Lifshitz transition at which
the Fermi level approaches the lower edge of the single-particle spectrum.Comment: 5 pages, 1 figur
Physical mechanisms of interface-mediated intervalley coupling in Si
The conduction band degeneracy in Si is detrimental to quantum computing
based on spin qubits, for which a nondegenerate ground orbital state is
desirable. This degeneracy is lifted at an interface with an insulator as the
spatially abrupt change in the conduction band minimum leads to intervalley
scattering. We present a theoretical study of the interface-induced valley
splitting in Si that provides simple criteria for optimal fabrication
parameters to maximize this splitting. Our work emphasizes the relevance of
different interface-related properties to the valley splitting.Comment: 4 pages, revised versio
Using emoji in response to customer reservation requests and service reviews
The use of paralinguistic cues—including emoji—in computer-mediated communication has become prevalent in recent years. Brands and service providers have also been using these cues in their communication strategies. And yet, research examining how such emoji use influences customers’ perception and behavior is still scarce. In two experiments (combined ), we tested if using emoji to reply to a customer request (restaurant reservation, Study 1) or online review (hotel experience, Study 2) influenced perceptions of the brands. The emoji used by the brand was always congruent with the valence of the situation. Results from both studies revealed that the presence (vs. absence) of emoji influenced consumers’ perception of the brand/service at several levels. Specifically, the restaurant/hotel was perceived to have a more informal communication style, have a warmer service, and be more modern. In Study 1, we also observed that emoji use had a positive impact on competence perception and reservation intentions. Importantly, these effects of emoji use were not moderated by the valence of the situation. Taken together, our results showed that emoji can influence different perceptions about brands and services and determine how customers relate to brands.info:eu-repo/semantics/publishedVersio
IMUNOTERAPIA COM VENENO DE HIMENÓPTEROS: A EXPERIÊNCIA DE UMA CONSULTA
Resumo: Na Europa a prevalência de alergia ao veneno de himenópteros estima-se em 20%. As reacções sistémicas graves são indicação para imunoterapia especÃfica com veneno de himenópteros após confirmação de atopia. Esta é eficaz em 91-100% dos casos de alergia ao veneno de vespa e 77-80% dos casos de alergia ao veneno de abelha. Apresentamos quatro casos clÃnicos de doentes com reacções sistémicas ao veneno de himenópteros que efectuaram imunoterapia. Três crianças apresentavam alergia ao veneno de abelha e uma ao veneno de vespa. Tinham IgE especÃfica para o veneno de himenópteros, classes IV a VI. A duração da imunoterapia variou entre quatro e sete anos, com diminuição da classe de IgE especÃfica em todos os doentes no final do tratamento. Três crianças tiveram contacto com o alergénio, durante ou após terminarem a imunoterapia, e nenhuma delas desencadeou uma reacção sistémica. A duração da imunoterapia continua a ser controversa. A ausência de reacção após contacto com o alergénio é sugestiva de sucesso do tratamento
- …