Early Devonian organic-walled phytoplankton from the Ponta Grossa Formation, Paraná Basin, Braz

peer reviewe

Critical point network for drainage between rough surfaces

In this paper, we present a network method for computing two-phase flows between two rough surfaces with significant contact areas. Low-capillary number drainage is investigated here since one-phase flows have been previously investigated in other contributions. An invasion percolation algorithm is presented for modeling slow displacement of a wetting fluid by a non wetting one between two rough surfaces. Short-correlated Gaussian process is used to model random rough surfaces.The algorithm is based on a network description of the fracture aperture field. The network is constructed from the identification of critical points (saddles and maxima) of the aperture field. The invasion potential is determined from examining drainage process in a flat mini-channel. A direct comparison between numerical prediction and experimental visualizations on an identical geometry has been performed for one realization of an artificial fracture with a moderate fractional contact area of about 0.3. A good agreement is found between predictions and observations

Silver(I) and Copper(II) Complexes of 1,10-Phenanthroline-5,6-Dione Against Phialophora Verrucosa: A Focus on the Interaction With Human Macrophages and Galleria Mellonella Larvae

Phialophora verrucosa is a dematiaceous fungus that causes mainly chromoblastomycosis, but also disseminated infections such as phaeohyphomycosis and mycetoma. These diseases are extremely hard to treat and often refractory to current antifungal therapies. In this work, we have evaluated the effect of 1,10-phenanthroline-5,6-dione (phendione) and its metal-based complexes, [Ag (phendione)2]ClO4 and [Cu(phendione)3](ClO4)2.4H2O, against P. verrucosa, focusing on (i) conidial viability when combined with amphotericin B (AmB); (ii) biofilm formation and disarticulation events; (iii) in vitro interaction with human macrophages; and (iv) in vivo infection of Galleria mellonella larvae. The combination of AmB with each of the test compounds promoted the additive inhibition of P. verrucosa growth, as judged by the checkerboard assay. During the biofilm formation process over polystyrene surface, sub-minimum inhibitory concentrations (MIC) of phendione and its silver(I) and copper(II) complexes were able to reduce biomass and extracellular matrix production. Moreover, a mature biofilm treated with high concentrations of the test compounds diminished biofilm viability in a concentration-dependent manner. Pre-treatment of conidial cells with the test compounds did not alter the percentage of infected THP-1 macrophages; however, [Ag(phendione)2]ClO4 caused a significant reduction in the number of intracellular fungal cells compared to the untreated system. In addition, the killing process was significantly enhanced by post-treatment of infected macrophages with the test compounds. P. verrucosa induced a typically cell density-dependent effect on G. mellonella larvae death after 7 days of infection. Interestingly, exposure to the silver(I) complex protected the larvae from P. verrucosa infection. Collectively, the results corroborate the promising therapeutic potential of phendione-based drugs against fungal infections, including those caused by P. verrucosa

Essential oil of Thymus vulgaris: preparation of pharmaceutical mouthwash formulation and in vitro evaluation of the bacterial plaque-inhibiting properties

O objetivo deste estudo foi avaliar in vitro o efeito do óleo essencial de Thymus vulgaris (tomilho) puro ou incorporado em uma formulação farmacêutica de uso oral (enxaguatório bucal), frente ao Streptococcus mutans (ATCC 25175), determinando-se sua concentração inibitoria minima (CIM) e o efeito na formação da placa bacteriana. A CIM obtida para o óleo essencial de tomilho foi de 100 μg/mL (1 %). Procedeu-se o desenvolvimento de enxaguatório bucal com efeito antiplaca contendo o óleo essencial comercial de tomilho. As análises da formação da placa bacteriana (ensaios microbiológicos, análise macroscópica de aderência e análises por MEV) confirmaram a eficácia destas novas formulações de enxaguatórios, sem álcool, contendo óleo essencial de T. vulgaris como agentes antiplaca bacteriana com possível emprego na odontologia preventiva. A caracterização química do óleo essencial bioativo foi realizada por CG-MS, verificando-se a presença de carvacrol, p-cimeno e α-pineno como constituintes majoritáriosThe aim of this study was to evaluate the in vitro effect of the essential oil of Thymus vulgaris (thyme) pure or incorporate in a alcohol-free pharmaceutical mouthwash formulation, against Streptococcus mutans (ATCC 25175), being determined the Minimal Inhibitory Concentration (MIC) and the effect in the bacterial plate formation. The MIC value obtained for the essential oil was 100 μg/mL (1 %). The mouthwash pharmaceutical formulation containing commercial essential oil of T. vulgaris was preparated. Microbiological and macroscopic analysis as well as analyses for MEV confirmed the effectiveness of this new alcohol-free mouthwash formulation containing essential oil of T. vulgaris as agent with plaqueinhibiting properties and possible application in the preventive dentistry. The chemical characterization of the bioactive essential oil was accomplished by CG-MS, being verified the presence of carvacrol, p-cimene and α- pinene as major constituents.Colegio de Farmacéuticos de la Provincia de Buenos Aire