Resumen En el texto se presentan dos modelos insumo-producto con inoperabilidad que analizan los efectos de la pandemia de Covid-19 en México, ambos utilizan desarrollos metodológicos recientes en los que se realizaron aportaciones en su especificación. El primero, un modelo estático, genera un índice de vulnerabilidad de las ramas económicas, produciendo su prelación para la atención con instrumentos de política económica. El segundo, un modelo dinámico, estima posibles trayectorias de recuperación económica de los sectores, su posible duración, y sus capacidades de resiliencia frente a fenómenos de persistencia de la pandemia. Los modelos se ajustan a los indicadores de corto plazo que produce el INEGI, reflejando un comportamiento heterogéneo entre los sectores; algunos con una tendencia de mediano plazo a no regresar a su capacidad productiva normal.

Abstract The article presents two input-out models with inoperability that analyze the effects of the Covid-19 pandemic in Mexico. Both use methodological developments in which contributions were made in their specification. The first, a static model, generates a vulnerability index of the economic branches, establishing their priority for attention with economic policy instruments. The second, a dynamic model, estimates possible trajectories of economic recovery of the sectors, their possible duration, and their resilience capacities in the face of persistent phenomena of the pandemic. The models are adjusted to the short-term indicators produced by the INEGI, reflecting a heterogeneous behavior between the sectors; some have a medium-term tendency not to return to their normal productive capacity.

Resumo Objetivou-se desenvolver, caracterizar e avaliar in vitro biomateriais compósitos de quitosana com hidroxiapatita (CHI/HA) para atuarem como substitutos ósseos. As quitosanas de baixa (L-CHI) e média (M-CHI) massa molecular foram previamente caracterizadas por gravimetria, viscosimetria e espectrofotometria ultravioleta. Os compósitos de CHI/HA foram produzidos por precipitação in situ, seguida de centrifugação (micropartículas) ou spray drying (nanopartículas), e caracterizados por microscopia eletrônica de varredura, espectroscopia de infravermelho com transformada de Fourier e difração de raios X. A citotoxicidade in vitro foi determinada por teste de viabilidade celular. L-CHI e M-CHI apresentaram, respectivamente, 15,7% e 16,4% de umidade, 0,51% e 0,18% de cinzas, 79,5% e 77,7% de grau de desacetilação e 4,18.104 e 17,3.104 de massa molecular média viscosimétrica. Os compósitos exibiram grupos característicos dos materiais de origem e escassa citotoxicidade. Concluiu-se que as técnicas foram eficazes para produção dos biomateriais, com características físico-químicas e biológicas adequadas para utilização nas terapias ósseas.

Abstract It was aimed to develop, characterize and evaluate in vitro the biomaterial composites of chitosan with hydroxyapatite (CHI/HA) to be applied as bone substitutes. Chitosans of low (L-CHI) and medium (M-CHI) molecular weight were previously characterized by the gravimetry, viscosimetry and ultraviolet spectrophotometry. The composites of CHI/HA were produced by in situ precipitation, followed by centrifugation (microparticles) or spray drying (nanoparticles), and characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and X-ray diffraction. In vitro cytotoxicity was determined by the cell viability test. The L-CHI and M-CHI presented, respectively, 15.7% and 16.4% of humidity, 0.51% and 0.18% ash, 79.5% and 77.7% deacetylation degree, and 4.18x104 and 17.3x104 mean molecular weight by viscosimetry. The composites exhibited characteristic groups of the source materials and scarce cytotoxicity. It was concluded that the techniques were effective for the production of biomaterials, with adequate physicochemical and biological characteristics for use in bone therapies.