In modern measurement and control systems, the available time and resources are often not only limited, but could change during the operation of the system. In these cases, the so called anytime algorithms could be used advantageously. While diflerent soft computing methods are wide-spreadly used in system modeling, their usability in these cases are limited, because the lack of an universal method for the determination of the needed complexity often results in huge and redundant neural networks1 fuzzy rule-bases. This paper proposes a possible way to carry out anytime information processing in fuzzy systems or neural networks, with the help of the Singular Value Decomposition (SVD)-based complexity reduction algorithm.
Introduction: 3-Nitropropionic acid (3-NPA) is a toxic compound that can accumulate in esterified form in the Fabaceae family. In the Lotae tribe, many species have been identified as 3-NPA producers (e.g., Securigera varia), while some of the genetically close Lotae plants were formerly reported as 3-NPA-free (e.g., Lotus corniculatus and Anthyllis vulneraria). These plants are used as forage and have a tradition in ethnomedicine, also, the extracts of A. vulneraria are used in cosmetics.Objectives: Our aim was to investigate the 3-NPA content of these selected Fabaceae species and to develop a validated quantitative method to evaluate 3-NPA concentrations in extracts of different herbal parts and cosmetic products.
Materials and Methods:A UHPLC-ESI-Orbitrap-MS/MS method was applied for detection and identification of 3-NPA derivatives in the form of glucose esters. For the quantitative analysis, an optimized sample processing method was developed.The free 3-NPA content was determined using HPLC-ESI-MS/MS.Results: 3-NPA esters could be detected in all three species, but their quantity showed a high variation. S. varia contained 0.5-1.0 g/100 g of 3-NPA, while in L. corniculatus samples only trace quantities were detectable, below the LOQ (25 ng/ml). Most of the A. vulneraria samples showed similarly low concentrations, but one sample had 3-NPA levels comparable to S. varia. 3-NPA could not be detected in the tested cosmetics containing A. vulneraria extracts.Conclusions: Using highly sensitive analytical methods, new 3-NPA-containing species were identified. The developed validated quantitative method is suitable for the determination of 3-NPA concentrations in herbal samples.
The production of active pharmaceutical ingredients (APIs) and fine chemicals is accelerating due to the advent of novel microreactors and new materials for immobilizing customized biocatalysts that permit long-term use in continuous-flow reactors. This work studied the scalability of a tunable U-shape magnetic nanoparticles (MNPs)-based microreactor. The reactor consisted of a polytetrafluoroethylene tube (PTFE) of various inner diameters (ID = 0.75 mm, 1.50 mm, or 2.15 mm) and six movable permanent magnets positioned under the tube to create reaction chambers allowing the fluid reaction mixture to flow through and above the enzyme-loaded MNPs anchored by permanent magnets. The microreactors with various tube sizes and MNP capacities were tested with the preparative scale kinetic resolution of the drug-like alcohols 4-(3,4-dihydroisoquinolin-2(1H)-yl)butan-2-ol (±)-1a and 4-(3,4-dihydroquinolin-1(2H)-yl)butan-2-ol (±)-1b, utilizing Lipase B from Candida antarctica immobilized covalently onto MNPs, leading to highly enantioenriched products [(R)-2a,b and (S)-1a,b]. The results in the U-shape MNP flow reactor were compared with reactions in the batch mode with CaLB-MNPs using similar conditions. Of the three different systems, the one with ID = 1.50 mm showed the best balance between the maximum loading capacity of biocatalysts in the reactor and the most effective cross-section area. The results showed that this U-shaped tubular microreactor might be a simple and flexible instrument for many processes in biocatalysis, providing an easy-to-set-up alternative to existing techniques.
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