Quantum field theory approach to the optical conductivity of strained and deformed graphene

The computation of the optical conductivity of strained and deformed graphene is discussed within the framework of quantum field theory in curved spaces. The analytical solutions of the Dirac equation in an arbitrary static background geometry for one dimensional periodic deformations are computed, together with the corresponding Dirac propagator. Analytical expressions are given for the optical conductivity of strained and deformed graphene associated with both intra and interbrand transitions. The special case of small deformations is discussed and the result compared to the prediction of the tight-binding model.The authors acknowledge financial supportfrom the Brazilian agencies FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo) and CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico)

MELHORIA NA EFICIÊNCIA DA CLARIFICAÇÃO DE SUCO DE MARACUJÁ PELA COMBINAÇÃO DOS PROCESSOS DE MICROFILTRAÇÃO E ENZIMÁTICO

Este trabalho teve como objetivo a obtenção de suco clarificado de maracujá, utilizando a técnica de microfiltração. Introduziu-se a etapa de tratamento enzimático antes da microfiltração, visando aumentar a eficiência do processo pela redução da viscosidade e do teor de polpa do suco. Foram testadas três diferentes enzimas hidrolíticas em três níveis de concentração. Os resultados não mostraram diferenças significativas quanto ao Brix, pH e acidez das amostras de suco hidrolisado em relação ao suco integral. Observou-se efeito positivo da ação das enzimas na redução da viscosidade e do teor de polpa. A microfiltração foi realizada em sistema de membrana tubular com tamanho médio de poro equivalente a 0,3 µm e pressão transmembrana de 1,5 bar. O suco permeado apresentou-se límpido, isento de polpa e com qualidade e sanidade microbiológica. Tais resultados comprovaram a eficiência da microfiltração para clarificação e estabilização de sucos de frutas. IMPROVEMENT IN THE EFFICIENCY OF PASSION FRUIT JUICE CLARIFICATION BY THE COMBINATION OF MICROFILTRATION AND ENZYMATIC PROCESSES Abstract This work had as objective the obtention of clarified passion fruit juice by using the microfiltration technique. A step of enzymatic treatment was introduced before microfiltration, aiming to enhance process efficiency by reduction of viscosity and pulp content of the juice. Three different hidrolytic enzymes were tested in three concentration levels. The results didnt demonstrate significant differences in Brix, pH and acidity of the hidrolyzed juice samples in relation to the concentrated juice. Positive effect was observed in the action of the enzymes in the reduction of viscosity and pulp content. The microfiltration was realized in a tubular membrane system with average size of the pore equivalent to 0.3 m and transmembrane pressure of 1.5 bar. The permeate juice was clear, free from pulp and with good micribiological quality. Such results proved the efficiency of microfiltration for clarification and stabilization of fruit juices

Capsaicin cyclodextrin complex enhances mepivacaine targeting and improves local anesthesia in inflamed tissues

Acidic environments, such as in inflamed tissues, favor the charged form of local anesthetics LA . Hence, these drugs show less cell permeation and diminished potency. Since the analgesic capsaicin CAP triggers opening of the TRPV1 receptor pore, its combination with LAs could result in better uptake and improved anesthesia. We tested the above hypothesis and report here for the first time the analgesia effect of a two drug combination LA and CAP on an inflamed tissue. First, CAP solubility increased up to 20 times with hydroxypropyl beta cyclodextrin HP amp; 946; CD , as shown by the phase solubility study. The resulting complex HP amp; 946; CD CAP showed 1 1 stoichiometry and high association constant, according to phase solubility diagrams and isothermal titration calorimetry data. The inclusion complex formation was also confirmed and characterized by differential scanning calorimetry DSC , X ray diffraction, and 1H NMR. The freeze dried complex showed physicochemical stability for at least 12 months. To test in vivo performance, we used a pain model based on mouse paw edema. Results showed that 2 mepivacaine injection failed to anesthetize mice inflamed paw, but its combination with complexed CAP resulted in pain control up to 45 min. These promising results encourages deeper research of CAP as an adjuvant for anesthesia in inflamed tissues and cyclodextrin as a solubilizing agent for targeting molecules in drug deliver