Immobilization of Laccase in Alginate Beads

The elimination or degradation of micropollutants from wastewater is becoming ever more important nowadays. Using oxidoreductase enzymes to treat different micropollutants seems a promising solution. However, the viability of the process is highly dependent on the availability and stability of the applied enzymes. In order to improve the stability and provide faster reaction rates, enzymes can be immobilized in various carriers. Properties such as simple production, easy retention and biodegradable carrier material are advantageous, e.g. entrapping laccase in alginate beads. This paper shows the results of the preparation and characterization of immobilized laccase entrapped in calcium alginate beads. The technique of adding a mixture of sodium alginate and laccase dropwise into calcium chloride has been applied, improved and standardized to produce laccase-containing beads of uniform size and activity. For the purpose of characterization, a widely used substrate, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, was used to evaluate the performance of the laccase-containing alginate beads. In addition to the characterization of the laccase-containing alginate beads, the enzyme kinetic constants (= 26.43 µM, ax = 0.23 µM/min) were determined. The reduction in the activity during storage has been described by a decay constant (0.26 d−1 ) that provides information concerning the design constraints of the process. Results will be used to test the method in terms of the removal of organic micropollutants in continuous systems

Balancing identity, construction, and rules : family relationship negotiations during first-generation succession in family businesses

This article identifies how relationship-regulation processes between family members support or hinder the succession process in family businesses during first-generation succession. We analyzed interviews with incumbents and successors from twelve first- generation family firms. We found that intrafamily succession is driven by relational negotiation processes organized around three main domains: negotiating the shared identity of the incumbent and successor, their shared construction regarding succession, and shaping the family rules that frame the process. In the proposed theoretical model, their common construction is represented by the metaphor of a bridge built ‘brick by brick’ as a result of their relationship regulation processes. Relationship negotiations around shared identity served as a basis for their common construction, while negotiations on family rules shaped its framework. Findings suggest a dynamic and relationship-oriented approach to succession wherein the role of planning is not central and relationship negotiations regulate the achievement of the succession

Dynamical Backaction Magnomechanics

Dynamical backaction resulting from radiation pressure forces in optomechanical systems has proven to be a versatile tool for manipulating mechanical vibrations. Notably, dynamical backaction has resulted in the cooling of a mechanical resonator to its ground-state, driving phonon lasing, the generation of entangled states, and observation of the optical-spring effect. In certain magnetic materials, mechanical vibrations can interact with magnetic excitations (magnons) via the magnetostrictive interaction, resulting in an analogous magnon-induced dynamical backaction. In this article, we directly observe the impact of magnon-induced dynamical backaction on a spherical magnetic sample's mechanical vibrations. Moreover, dynamical backaction effects play a crucial role in many recent theoretical proposals; thus, our work provides the foundation for future experimental work pursuing many of these theoretical proposals.Comment: Accepted version with appendice

Research Update: Focused ion beam direct writing of magnetic patterns with controlled structural and magnetic properties

Focused ion beam irradiation of metastable Fe78Ni22 thin films grown on Cu(100) substrates is used to create ferromagnetic, body-centered cubic patterns embedded into paramagnetic, face-centered-cubic surrounding. The structural and magnetic phase transformation can be controlled by varying parameters of the transforming gallium ion beam. The focused ion beam parameters such as the ion dose, number of scans, and scanning direction can be used not only to control a degree of transformation but also to change the otherwise four-fold in-plane magnetic anisotropy into the uniaxial anisotropy along a specific crystallographic direction. This change is associated with a preferred growth of specific crystallographic domains. The possibility to create magnetic patterns with continuous magnetization transitions and at the same time to create patterns with periodical changes in magnetic anisotropy makes this system an ideal candidate for rapid prototyping of a large variety of nanostructured samples. Namely, spin-wave waveguides and magnonic crystals can be easily combined into complex devices in a single fabrication ste

Reaction of β-Bromo-β,γ-unsaturated Pyrroline Nitroxide Aldehydes and Nitriles with Aromatic N-Binucleophiles and S-Binucleophiles

Reactions of β-bromo-β,γ-unsaturated pyrroline nitroxide aldehyde (1) or nitrile (4) or their diamagnetic forms (5, 6) with 2-aminothiophenol or 2-mercaptobenzimidazole were evaluated. The reaction could be reproduced more easily with the application of O-acetyl derivatives of nitroxides to generate 2- substituted-benzothiazole, pyrrolo[3,4-b]benzo[1,5]tiazepine scaffolds with 2-aminothiophenol and benzimidazo[2,1-b]pyrrolo[3,4-e]-[1,3]thiazine scaffold with 2-mercaptobenzimidazole

Fructose, glucocorticoids and adipose tissue: Implications for the metabolic syndrome

The modern Western society lifestyle is characterized by a hyperenergetic, high sugar containing food intake. Sugar intake increased dramatically during the last few decades, due to the excessive consumption of high-sugar drinks and high-fructose corn syrup. Current evidence suggests that high fructose intake when combined with overeating and adiposity promotes adverse metabolic health effects including dyslipidemia, insulin resistance, type II diabetes, and inflammation. Similarly, elevated glucocorticoid levels, especially the enhanced generation of active glucocorticoids in the adipose tissue due to increased 11β-hydroxysteroid dehydrogenase 1 (11β -HSD1) activity, have been associated with metabolic diseases. Moreover, recent evidence suggests that fructose stimulates the 11β -HSD1-mediated glucocorticoid activation by enhancing the availability of its cofactor NADPH. In adipocytes, fructose was found to stimulate 11β -HSD1 expression and activity, thereby promoting the adipogenic effects of glucocorticoids. This article aims to highlight the interconnections between overwhelmed fructose metabolism, intracellular glucocorticoid activation in adipose tissue, and their metabolic effects on the progression of the metabolic syndrome. © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license

Predictions of alpha-decay half-lives based on potentials from self-consistent mean-field models

We present a microscopic model for the calculation of alpha-decay half lives employing potentials obtained from relativistic and non-relativistic self-consistent mean-field models. The nuclear and Coulomb potentials are used to obtain the tunneling probability and, in one model variant, also the knocking frequency. The model contains only one parameter. We compare this approach employing several modern mean-field parametrizations to experimental data and to the semi-empirical Viola-Seaborg systematics. We extrapolate our model to superheavy nuclei where assumptions entering semi-empirical approaches might lose validity.Comment: latex, 15 pages, 4 eps figures, accepted for publication in Nucl. Phys.

Species-Specific Glucose-6-Phosphatase Activity in the Small Intestine-Studies in Three Different Mammalian Models

Besides the liver, which has always been considered the major source of endogenous glucose production in all post-absorptive situations, kidneys and intestines can also produce glucose in blood, particularly during fasting and under protein feeding. However, observations gained in different experimental animals have given ambiguous results concerning the presence of the glucose-6-phosphatase system in the small intestine. The aim of this study was to better define the species-related differences of this putative gluconeogenic organ in glucose homeostasis. The components of the glucose-6-phosphatase system (i.e., glucose-6-phosphate transporter and glucose-6-phosphatase itself) were analyzed in homogenates or microsomal fractions prepared from the small intestine mucosae and liver of rats, guinea pigs, and humans. Protein and mRNA levels, as well as glucose-6-phosphatase activities, were detected. The results showed that the glucose-6-phosphatase system is poorly represented in the small intestine of rats; on the other hand, significant expressions of glucose-6-phosphate transporter and of the glucose-6-phosphatase were found in the small intestine of guinea pigs and homo sapiens. The activity of the recently described fructose-6-phosphate transporter-intraluminal hexose isomerase pathway was also present in intestinal microsomes from these two species. The results demonstrate that the gluconeogenic role of the small intestine is highly species-specific and presumably dependent on feeding behavior (e.g., fructose consumption) and the actual state of metabolism