HPLC/QTOF-MS metabolomics analysis applied to identify skin biomarkers of UVC-induced skin injury in mice and preventive effects of abietic acid

Abietic acid (AA) is a main constituent from pine resin, which has definite therapeutical effects for treating skin ulcers and tumor. Here, we explored the metabolome changes in skin tissues of mice with UVC-induced skin injury treated with AA by a HPLC-QTOF-MS/MS method. Model mice were induced with UVC irradiation. Skin histopathological changes were examined by routine HE staining. Metabolomic analysis technology and pattern recognition statistical method were applied to analyze the metabolites in the skin tissues of mice to study the therapeutic effect of AA on UVC-induced skin injury in mice. Ceramides, sphingosines, glycyl-L-glutamine, dihydroorotic acid, adenosine, dCMP and lyso-phosphatidylcholines can be used as biomarkers of UVC-induced skin injury. AA can improve the pathological tissue from the pathway of skin lipid and purine pyrimidine metabolism to achieve the therapeutic effect. AA can effectively treat UVC-induced skin injury in mice

Propriedades mecânicas da madeira resinada de Pinus elliottii / Mechanical properties of Pinus elliottii tapped wood

As propriedades mecânicas por flexão estática da madeira resinada de Pinus elliottii foram avaliadas por meio de testes destrutivos e não destrutivos. Para tanto, foram confeccionados corpos de prova de 10x10x200mm3 (radial, tangencial e longitudinal), levando em consideração dois fatores: lenho (juvenil, próximo à medula e adulto, próximo à casca) e resina, isto é, corpos de prova oriundos de toras com e sem estrias de resinagem. Para a avaliação não destrutiva, utilizou-se um aparelho de ultrassom com transdutores do tipo ponto seco, em que se pode calcular a velocidade da onda ultrassônica e consequentemente o módulo de elasticidade dinâmico (ED). Para obtenção do módulo de elasticidade (MOE) e do módulo de ruptura (MOR), realizou-se o ensaio destrutivo de flexão estática de três pontos. De posse das curvas de força x deformação, calculou-se a fragilidade do material. Os resultados confirmaram que o fator lenho foi significativo para as propriedades analisadas e o fator resina, em especial, para aumento do MOR e da massa específica. A fragilidade aumentou quando analisada a madeira juvenil e o fator resina quando incluso tendeu a aumentar a fragilidade no lenho adulto. O modelo de regressão múltiplo com variáveis Dummies, proposto para estimar o MOE pelo ED, foi significativo em 1% de probabilidade de erro (r2=0,75). Os resultados apresentados no presente trabalho mostraram que os fatores lenho e resina não afetaram negativamente as propriedades mecânicas da madeira de Pinus elliottii, em que, para o segundo fator, conclui-se, de maneira geral, que a madeira serrada oriunda de toras resinadas pode não representar danos significativos quando em serviço estrutural.

The mechanical properties for static bending of Pinus elliottii tapped wood were evaluated by nondestructive and destructive tests. To achieve this, samples measuring 10x10x200mm3 (thickness, width and length) were prepared considering two factors: wood (juvenile, near to pith and mature, near to bark) and rosin, i.e., samples from logs with and without tapping grooves. The nondestructive evaluation were performed using an ultrasound equipment with dry-point transducers in order to measure the ultrasonic velocity and, consequently, the dynamic modulus of elasticity (ED). The modulus of elasticity (MOE) and the modulus of rupture (MOR) were measured through static bending tests. The wood brittleness were determined through the analysis of force x deformation plots. The results confirmed the significance of wood factor for the properties analyzed and the factor rosin, especially for MOR and density. The brittleness increased for the juvenile wood and, when included the factor rosin, this property tends to increase for the mature wood. The multiple regression model with Dummies variables proposed to estimate MOE as a function of ED was significant at 1% of probability of error (r2=0.75). Moreover, the results showed that factor wood and factor rosin did not negatively affect the mechanical properties of Pinus elliotti wood. In general, the timber from tapped logs could not represent significant damages when in structural service.