Development of an electrochemical aptasensor for the detection of human osteopontin

Electrochemical aptasensors, an emerging technology, enables the detection of protein biomarkers, which may be indicative of tumour activity. Osteopontin is a protein present in body fluids, being a possible biomarker since its overexpression has been related with breast cancer progression. An \RNA\ aptamer, described in the literature, with affinity for human osteopontin, was synthetized, immobilized in a microelectrode gold surface and used for development electrochemical aptasensor for human \OPN\ detection in standard solutions. Cyclic voltammetry results showed that this aptasensor allowed detecting human osteopontin with a detection limit of 8 nM, showing a satisfactory selectivity towards the target in the presence of others proteins, except for thrombin

Automatic two-plane balancing for rigid rotors

Abstract We present an analysis of a two-plane automatic balancing device for rigid rotors. Ball bearings, which are free to travel around a race, are used to eliminate imbalance due to shaft eccentricity or misalignment. The rotating frame is used to derive autonomous equations of motion and the symmetry breaking bifurcations of this system are investigated. Stability diagrams in various parameter planes show the coexistence of a stable balanced state with other less desirable dynamics

Descrição de uma forma autossômica dominante de síndrome de Kabuki por mutação no gene MLL2

Aims: Although there are more than 400 cases of Kabuki syndrome described in the literature, it is believed that this syndrome is under-diagnosed. Most cases occur sporadically, despite cases with autosomal dominant familial transmission being described. Here we describe three cases identified in the same family. Cases description: A family (mother and two children) was diagnosed with Kabuki syndrome. The three patients show the typical characteristics (facial appearance, musculoskeletal abnormalities, cognitive impairment, growth retardation and peculiar dermatoglyphic pattern) associated with other anomalies described in the syndrome (congenital heart disease and increased susceptibility to infections). Genetic studies revealed a nonsense mutation c.14710 C > T (p.Arg4904X) in the MLL2 gene in the three members of the family. Conclusions: With the description of another case of familial Kabuki syndrome, the authors wish to illustrate the autosomal dominant inheritance with variable expressivity, which are present in this situation, and to alert to the need for a rigorous clinical and molecular evaluation of the affected patient’s relatives, allowing appropriate genetic counseling

Assessment of fructooligosaccharides production from sucrose in aqueous and aqueous-organic systems using immobilized inulinase from Kluyveromyces marxianus NRRL Y-7571

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This work investigated the fructooligosaccharides (FOS) synthesis by immobilized inulinase obtained from Kluyveromyces marxianus NRRL Y-7571 in aqueous and aqueous-organic systems using sucrose as substrate. The sequential strategy of experimental design was used to optimize the FOS conversion in both systems. For the aqueous-organic system, a 2(6-2) fractional design was carried out to evaluate the effects of temperature, sucrose concentration, pH, aqueous/organic ratio, enzyme activity, and polyethylene glycol concentration. For the aqueous system, a central composite design for the enzyme activity and the sucrose concentration was carried out. The highest fructooligosaccharides yield (Y-FOS) for the aqueous-organic system was 18.2 +/- S0.9 wt%, at 40 degrees C, pH 5.0, sucrose concentration of 60% (w/w), enzyme activity of 4 U.mL(-1) and aqueous/organic ratio of 25/75 wt%. The highest Y-FOS for the aqueous system was 14.6 +/- 0.9 wt% at 40 degrees C, pH 5.0, sucrose concentration of 60 wt%, and enzyme activity of 4.0 U.mL(-1).322245249Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

On finding minimal absent words

<p>Abstract</p> <p>Background</p> <p>The problem of finding the shortest absent words in DNA data has been recently addressed, and algorithms for its solution have been described. It has been noted that longer absent words might also be of interest, but the existing algorithms only provide generic absent words by trivially extending the shortest ones.</p> <p>Results</p> <p>We show how absent words relate to the repetitions and structure of the data, and define a new and larger class of absent words, called minimal absent words, that still captures the essential properties of the shortest absent words introduced in recent works. The words of this new class are minimal in the sense that if their leftmost or rightmost character is removed, then the resulting word is no longer an absent word. We describe an algorithm for generating minimal absent words that, in practice, runs in approximately linear time. An implementation of this algorithm is publicly available at <url>ftp://www.ieeta.pt/~ap/maws</url>.</p> <p>Conclusion</p> <p>Because the set of minimal absent words that we propose is much larger than the set of the shortest absent words, it is potentially more useful for applications that require a richer variety of absent words. Nevertheless, the number of minimal absent words is still manageable since it grows at most linearly with the string size, unlike generic absent words that grow exponentially. Both the algorithm and the concepts upon which it depends shed additional light on the structure of absent words and complement the existing studies on the topic.</p

Combined use of phosphonium-erythrosin B-based nanoGUMBOS, UV–Vis spectroscopy, and chemometrics for discrimination and quantification of proteins

Nanoparticles derived from a group of uniform materials based on organic salts (nanoGUMBOS) are considered promising candidates for protein analysis due to their facile synthesis in aqueous media and high tunability. In this study, a phosphonium-erythrosin B-based nanoGUMBOS (i.e., [P4444]2[EB]) was prepared using an ultrasound-assisted reprecipitation method, and its ability to discriminate and quantify proteins was evaluated. Sonication time (30 s, 5 min, and 15 min) and cyclodextrin templating (α-, 2-HP-β-, and γ-CD) were investigated for their effects on discrimination performance of synthesized nanomaterial. Six proteins (albumin, hemoglobin, trypsin, catalase, lysozyme, and cytochrome c) with different abundance levels and physicochemical properties were selected as target analytes. Absorbance response patterns generated from interactions between [P4444]2[EB] nanoGUMBOS and proteins were analyzed using partial least squares discriminant analysis. Percentages of correct protein discrimination ranged from 94.6 to 99.6%, with the latter being the best result obtained using non-templated nanoGUMBOS formed after 5 min sonication. Under optimized conditions, it was possible to discriminate all protein samples with percentages of correct assignments greater than 90% for concentrations as low as 2.0 μg mL−1. The discrimination capability of synthesized nanoGUMBOS was further evaluated using mixtures of different ratios of lysozyme, cytochrome c, and hemoglobin. Finally, partial least squares models were developed for protein quantification and the best performance was observed for albumin. Results support potential use of [P4444]2[EB] nanoGUMBOS in combination with ultraviolet–visible spectroscopy and chemometrics for qualitative and quantitative analyses of individual proteins and mixtures of proteins.info:eu-repo/semantics/publishedVersio