Separation and purification of biomacromolecules based on microfluidics

Separation and purification of biomacromolecules either in biopharmaceuticals and fine chemicals manufacturing, or in diagnostics and biological characterization, can substantially benefit from application of microfluidic devices. Small volumes of equipment, very efficient mass and heat transfer together with high process control result in process intensification, high throughputs, low energy consumption and reduced waste production as compared to conventional processing. This review highlights microfluidics-based separation and purification of proteins and nucleic acids with the focus on liquid-liquid extractions, particularly with biocompatible aqueous two-phase systems, which represent a cost-effective and green alternative. A variety of microflow set-ups are shown to enable sustainable and efficient isolation of target biomolecules both for preparative, as well as for analytical purposes.publishe

Modelling of L-DOPA Oxidation Catalyzed by Laccase

Enzymatic oxidation of 3,4-dihydroxyphenyl-L-alanine (L-DOPA) with laccase from Trametes versicolor was investigated. The highest enzyme activity at pH 5.4 and at 25 ºC was found. The reaction kinetics and the effect of dissolved oxygen concentration on the reaction rate were evaluated. A mathematical model, comprised of double-substrate Michealis-Menten kinetics and mass balances for L-DOPA and dissolved oxygen concentrations, was developed in order to describe and predict the process of L-DOPA oxidation. Kinetic parameters, , and were estimated and experimentally verified by a set of experiments with constant additional aeration for different initial concentrations of L-DOPA and dissolved oxygen. A significant increase in reaction rate was established at a higher oxygen concentration in the inlet gas. The developed model was used to investigate the influence of dissolved oxygen concentration on L-DOPA conversion

Modelling of L-DOPA Oxidation Catalyzed by Laccase

Enzymatic oxidation of 3,4-dihydroxyphenyl-L-alanine (L-DOPA) with laccase from Trametes versicolor was investigated. The highest enzyme activity at pH 5.4 and at 25 ºC was found. The reaction kinetics and the effect of dissolved oxygen concentration on the reaction rate were evaluated. A mathematical model, comprised of double-substrate Michealis-Menten kinetics and mass balances for L-DOPA and dissolved oxygen concentrations, was developed in order to describe and predict the process of L-DOPA oxidation. Kinetic parameters, , and were estimated and experimentally verified by a set of experiments with constant additional aeration for different initial concentrations of L-DOPA and dissolved oxygen. A significant increase in reaction rate was established at a higher oxygen concentration in the inlet gas. The developed model was used to investigate the influence of dissolved oxygen concentration on L-DOPA conversion

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Graph sampling with applications to estimating the number of pattern embeddings and the parameters of a statistical relational model

© 2018, The Author(s). Counting the number of times a pattern occurs in a database is a fundamental data mining problem. It is a subroutine in a diverse set of tasks ranging from pattern mining to supervised learning and probabilistic model learning. While a pattern and a database can take many forms, this paper focuses on the case where both the pattern and the database are graphs (networks). Unfortunately, in general, the problem of counting graph occurrences is #P-complete. In contrast to earlier work, which focused on exact counting for simple (i.e., very short) patterns, we present a sampling approach for estimating the statistics of larger graph pattern occurrences. We perform an empirical evaluation on synthetic and real-world data that validates the proposed algorithm, illustrates its practical behavior and provides insight into the trade-off between its accuracy of estimation and computational efficiency.status: publishe

Computational creativity in Slovenia

© 2018 Slovene Society Informatika. All rights reserved. Computational Creativity is a field of Artificial Intelligence that addresses processes that would be deemed creative if performed by a human. The field has been very active since 1999, and is now an established research field with its own International Conference on Computational Creativity (ICCC) conference series founded in 2010. This paper briefly surveys the field of Computational Creativity (CC) that is based on the analysis of ICCC conference papers, followed by a more detailed presentation of projects and selected contributions of Slovenian researchers to the field

Evaluation of Diffusion Coefficient Determination using a Microfluidic Device

A theoretical description of the convection-diffusion process in a homogeneous system enabling estimation of diffusion coefficients employing commercially available Y-junction microchannel is presented. A detailed numerical analysis based on finite volumes and finite differences, namely the explicit, implicit and Crank-Nicolson method, was performed and analyzed on the same domain in order to verify the proposed models. All numerical approaches provided stable solutions with certain numerical variations depending on the number of iterations defined by the mesh density. In addition, the method was validated with measurements of diffusion coefficients of some selected components in the short Y-junction microchannel. Benefits and possible pitfalls of this estimation method are discussed