Frequent Graph Discovery : application to Line Drawing Document Images

In this paper a sequence of steps is applied to a graph representation of line drawings using concepts from data mining. This process finds frequent subgraphs and then association rules between these subgraphs. The distant aim is the automatic discovery of symbols and their relations, which are parts of the document model. The main outcome of our work is firstly an algorithm that finds frequent subgraphs in a single graph setting and secondly a modality to find rules and meta-rules between the discovered subgraphs. The searched structures are closed [1] and disjunct subgraphs. One aim of this study is to use the discovered symbols for classification and indexation of document images when a supervised approach is not at hand. The relations found between symbols can be used in segmentation of noisy and occluded document images. The results show that this approach is suitable for patterns, symbols or relation discovery

Frequent Graph Discovery: Application to Line Drawing Document Images

International audienceIn this paper a sequence of steps is applied to a graph representation of line drawings using concepts from data mining. This process finds frequent subgraphs and then association rules between these subgraphs. The distant aim is the automatic discovery of symbols and their relations, which are parts of the document model. The main outcome of our work is firstly an algorithm that finds frequent subgraphs in a single graph setting and secondly a modality to find rules and meta-rules between the discovered subgraphs. The searched structures are closed [1] and disjunct subgraphs. One aim of this study is to use the discovered symbols for classification and indexation of document images when a supervised approach is not at hand. The relations found between symbols can be used in segmentation of noisy and occluded document images. The results show that this approach is suitable for patterns, symbols or relation discovery

Engineering butylglyceryl-modified polysaccharides towards nanomedicines for brain drug delivery

Colloidal systems prepared from carbohydrates are subject of intense research due to their potential to enhance drug permeability through biological membranes, however their characteristics and performance are never compared directly. Here we report the results of a comparative investigation of a series of butylglyceryl-modified polysaccharides (chitosan, guar gum, and pullulan) that were formulated into nanoparticles and loaded with a range of model actives (Doxorubicin, Rhodamine B, Angiotensin II). Butylglyceryl-modified guar gum and corresponding pullulan nanocarriers were more stable at physiological pH compared to those obtained from modified chitosan, and studies of the in-vitro interactions with mouse brain endothelial cells (bEnd3) indicated an increased biological membrane permeability and lack of toxicity at application-relevant concentrations. No significant haemolytic effect was observed, and confocal microscopy and flow cytometry studies confirmed the efficient cellular uptake and cytoplasmic localisation of NPs. Most promising characteristics for brain drug delivery applications were demonstrated by butylglyceryl pullulan nanocarriers

Butylglyceryl pectin nanoparticles: synthesis, formulation and characterization

Pectin is a polysaccharide with very good gel forming properties that traditionally has found important applications in foods and pharmaceutical industries. Although less studied, chemical modifications of pectin leading to a decrease in its hydrophilicity can be useful for the development of novel drug carriers. To this aim, butylglyceryl pectins (P-OX4) were synthesized via functionalization with n-butylglycidyl ether and subsequently formed into nanoparticles. Chromatographic, spectroscopic, and thermal analytical methods were employed to characterize the novel butylglyceryl pectins (P-OX4) obtained, prior to their formulation into nanoparticles via nanoprecipitation. Nuclear magnetic resonance (NMR) and Fourier transform infrared (FT-IR) spectroscopy confirmed a degree of modification in these materials in the range 10.4−13.6%, and thermal stability studies indicated an increase in both the thermal decomposition onset and glass transition temperature values (compared to those of the original pectin). An increase in the molecular weight and a decrease in the viscosity of P-OX4, when compared to the starting material, were also observed. The resulting nanoformulations were investigated in terms of particle morphology, size and stability, and it was found that particles were roughly spherical, with their size below 300 nm, and a negative zeta potential (−20 to −26 mV, indicating good stability). Having demonstrated the ability to load Doxorubicin at the level of 10%, their potential in drug delivery applications warrants further investigations

Poly(alkyl methacrylate) tooth coatings for dental care: evaluation of the demineralisation-protection benefit using a time-resolved in vitro method

An in vitro method for the time-resolved quantification of acid-mediated tooth demineralisation has been developed and evaluated against putative non-permanent protective formulations based on a series of poly(alkyl methacrylate)s. Using a thermostatted carousel, dentally relevant substrates consisting of hydroxyapatite discs or sections of bovine teeth have been exposed to aqueous citric acid under controlled conditions, before and after being treated with the polymeric coatings. The dissolution of phosphate was monitored by the determination of 31P by Inductively Coupled Plasma—Mass Spectrometry and by the spectrophotometric phosphovanadomolybdate method. Dose-response plots constructed for both groups of treated substrates have revealed that the coatings significantly reduce erosion rates but are less effective at inhibiting tooth demineralisation than the standard fluoride treatment. The approach has enabled an evaluation of the erosion-protection efficiency of each coating