Mapping the field of international comparative research in school social work

This article maps the field of international comparative research in school social work. For this purpose, a systematic literature review was conducted and subjected to a narrative synthesis. The review reveals 11 publications that are predominantly non-empirical, take mainly Asian, European, North American countries and Australia and New Zealand into account, and are focused on profession-related and sociopolitical aspects of school social work. A synthesis of school social work practice themes transcending national boundaries emerged from the findings, covering child-, family-, school-, and community-related issues. Accordingly, children are predominantly confronted with similar issues, irrespective of the place where they live, such as violence toward themselves, at home, in school, and in their community. Bearing in mind methodological challenges when carrying out comparative studies, recommendations include the conduct of practice-focused studies that generate new stimuli to improve already well-developed practices in a culturally appropriate way and enable mutual learning among school social workers

Development of Electrochemical Biosensors for Clinical Analysis

In this thesis, the beneficial properties of silver nanoparticles (AgNPs) are employed in the development of electrochemical assays for clinical analysis. AgNPs are the most abundant commercialized nanocompound with a production of 350 t per year. Besides their manifold uses based on their antibacterial, antiviral, antifungal and antimicrobial properties, e.g. in coating of medicinal products, they are also employed for various clinical biosensors. While most sensing applications rely on optical detection techniques such as surface plasmon resonance (SPR), surface-enhanced-Raman-scattering (SERS), metal-enhanced fluorescence (MEF) or fluorescence emission, there has been some research in the field of electrochemical biosensors using AgNPs, as well. They are used for modification of the electrode surface or less commonly as labels. The suitability for the use of the respective biosensor at the point-of-care (POC) was assessed carefully based on criteria like ease of handling, storage ability, cost, time consumption and need of sample pretreatment. Sandwich Immunoassay for NT-proBNP Detection The first experimental part of this work focuses on the benefit of using AgNPs as electrochemical label, instead of the more commonly employed gold nanoparticles (AuNPs). Using an electrochemical detection strategy with a sequence of oxidation and reduction reactions, lowest limits of detection (LODs) were reached for both metallic nanoparticles (mNPs). When exchanging gold with silver in a simple sandwich immunoassay for the blood biomarker N-terminal prohormone brain natriuretic peptide (NT-proBNP) on screen-printed carbon electrodes (SPCEs), the LOD is decreased by a factor of 6, while maintaining the same or better assay reliability and ease of surface functionalization. Moreover, the addition of hydrochloric acid, inevitable for the electrochemical detection of gold due the high Au stability, is removed. This makes the AgNP assay better suited for POC applications. In order to adjust the procedure better to the needs at the POC, i.e. ease of handling and miniaturization, while increasing the analytical performance, this assay was transferred into a microfluidic chip. The chip comprises the SPCE, double-sided adhesive tape with cut out channel design and a PMMA top with in- and outlet as well as a cavity on the inside. This renders it low-cost and easy to produce and enables the integration of all-dried reagents into one chip. The use of a trehalose matrix in combination with a suitable oxygen scavenger stabilizes the AgNPs against oxidation by air oxygen and renders the chips stable over 18 weeks at 4 °C. With a LOD of 0.26 ng·mL-1 in buffer and 0.56 ng·mL-1 in undiluted human serum, the microfluidic sensor exhibits a sensitivity below the clinically relevant threshold for chronic heart failure (HF) of 1 ng·mL-1. Also, the reproducibility is greatly increased with a mean standard deviation (SD) of 6% in comparison to the standard immunoassay with 15%. Aggregation Assay for Creatinine Detection The second experimental part shows the development of an electrochemical aggregation assay for the detection of the renal function biomarker creatinine. In neutral or slightly acidic medium, picric acid (PA) interacts selectively with the tautomeric form of creatinine, while creatinine molecules form hydrogen bonds among each other as well. AgNPs can be functionalized with PA via electrostatic interactions. These picric acid-modified AgNPs (PA-AgNPs) aggregate in the presence of creatinine and the grade of aggregation is a measure for the concentration of the analyte. This system was employed by others in combination with an optical detection. Here, an electrochemical detection via differential pulse voltammetry (DPV) is investigated, which is based on the increasing distance between AgNP and electrode surface upon aggregation. Different nanoparticle (NP) sizes and modifications were tested and 10 nm AgNPs modified with 10 μM PA are ideal for electrochemical detection and show effective aggregation. To render it accessible for POC strategies, the detection was transferred into an all-dried approach without any loss of performance. It was found that the sensitivity can be controlled by changes in the PA-AgNP to sample ratio making the assay easily adjustable to various matrices with different concentration ranges. With a 2:3 ratio, a LOD as low as 76 μM was reached with a mean SD of 12%. This system was also successfully applied in 1:10 diluted synthetic urine (surin) matrix covering a majority of the physiological range (0.4-2 mM in 1:10 diluted surin) without further optimization

Family predictors of physical activity change during the COVID-19 lockdown in preschool children in Germany

The COVID-19 pandemic is associated with crucial changes in children’s daily life including their physical activity (PA) and screen time (ST). Among preschool children, the family represents an important factor for sufficient PA levels by being the gatekeeper for PA. Thus, the aim of this study was to investigate the influence of the family environment, specifically SES, parental support, and having siblings on COVID-19-related changes of PA and ST behavior in 317 (170 boys, 147 girls) German preschool children using longitudinal data. Our results indicate a decline in total amount of sports-related PA, an increase in outdoor play, as well as an increase in leisure ST in preschool children. The changes in total amount of PA differed between children with different levels of parental support as well as in dependence on having siblings. Furthermore, levels of outdoor play and ST in preschool children were influenced by environmental factors like having access to their own garden. We conclude that the family environment (parental support as well as physical environment) is highly relevant for PA and ST levels in preschool children. To provide every child with PA opportunities during potential future lockdowns, restriction policies should be adapted and parents need sophisticated information about the importance of their support and thus the PA levels of their children

Wissensstandsanalyse zu Qualität, Verbraucherschutz und Verarbeitung ökologischer Lebensmittel

Zielsetzung des Projektes war es, den aktuellen Stand des Wissens zur Qualität und Verarbeitung ökologischer Lebensmittel sowie zum Verbraucherschutz aufzuzeigen und zu bewerten. Das Projektteam setzte sich aus Wissenschaftlern des Forschungsinstituts für biologischen Landbau (Deutschland und Schweiz), des Büros für Lebensmittelkunde, des Forschungsrings für Biologisch-Dynamische Wirtschaftsweise e.V. sowie des Fachgebiets Ökologische Lebensmittelqualität und Ernährungskultur der Universität Kassel zusammen. In dem zeitlich sehr begrenzten Projekt fokussierte die Arbeitsgruppe die Betrachtung auf folgende Themenkomplexe und Produktgruppen: Bereich Qualität - Ernährung - Sensorik - Ökospezifische Qualitäten - Authentizität und Rückverfolgbarkeit Bereich Verarbeitung - Rohwaren/Lagerung und Technologien für die Produktgruppen: -- Getreide -- Milch -- Fleisch -- Obst und Gemüse und Erzeugnisse aus diesen - Nachhaltigkeit im Unternehmen und entlang der Prozesskette - Verpackung Vorhandenes Wissen, aktuelle Fragestellungen und Entwicklungsrichtungen wurden nach thematisch angepassten Vorgehensweisen identifiziert und anhand internationaler Literatur und Experteninterviews diskutiert. Zu allen Themenkomplexen wurden kurze und allgemeinverständliche Reports erstellt, die einen schnellen und fundierten Überblick zum aktuellen Stand des Wissens und zu eventuellen Wissenslücken geben. Der Abschlussreport wurde in deutscher und englischer Sprache veröffentlicht. Insgesamt wurde festgestellt, dass in den betrachteten Themenkomplexen erheblicher Bedarf an Forschung und Entwicklung sowie an Wissenstransfer besteht. Neben einer Reihe von Detailfragen sind grundlegende Themen, wie beispielsweise das Anforderungsprofil an eine „ökologische Verarbeitung“, nicht hinreichend erforscht und geklärt. Diese Arbeiten sind jedoch Voraussetzung für die Bearbeitung von Detailthemen, da hier Aufgabenstellungen, Schwerpunktsetzungen und Methoden definiert werden

Peptide‐mediated surface coatings for the release of wound‐healing cytokines

Supporting the wound healing process by sending the appropriate cytokine signals can shorten healing time and overcome chronic inflammation syndromes. Even though adhesion peptides consisting of Arg-Gly-Asp (RGD) are commonly used to enhance cell-surface interactions, peptide-mediated cytokine delivery has not been widely exploited so far. Cytokines interact with high affinity with their cognitive receptors but also with sulfated glycosaminoglycans (GAGs), both of which form a base for incorporation of cytokines into functional biomaterials. Here, we report on a mussel-derived surface coating as a prospective cytokine delivery system using covalently bound heparin mimetics, receptor-derived chemokine-binding peptides, and heparin-binding peptides (HBP). The latter enabled non-covalent immobilization of heparin on the surface followed by chemokine binding and release, whereas the former allowed direct non-covalent chemokine immobilization. The peptide displayed excellent binding to custom-made polystyrene 96-well plates, enabling convenient testing of several compounds. Released chemokine successfully induced migration in Jurkat cells, especially for the non-covalent heparin immobilization approach using HBPs as evaluated in a transwell assay. In comparison, heparin-mimetic coatings, comprised of sulfated peptides and GAG derivatives, proved less efficient with respect to amount of immobilized chemokine and migratory response. Thus, our study provides a roadmap for further rational optimization and translation into clinics

Motivation and active travel in adolescent girls and boys in Germany – Findings from the ARRIVE study

Active travel (using an active mode of transport such as walking or cycling) contributes to the accumulation of daily physical activity and thus holds potential for promoting health. To promote active travel among adolescents an in-depth understanding of determinants from a sex/gender perspective is needed. Within Self-Determination Theory (SDT), it is proposed that the quality of an individuals’ motivation (i.e., the degree to which it is autonomous) determines the extent to which they engage in particular behaviors and perform them effectively. As part of the ARRIVE study, the aim of this research was to investigate the relationship between motivation and active travel in adolescent boys (N = 263, Mage = 12.92) and girls (N = 254, Mage = 13.21) from a nationwide German sample. Results showed significant group differences between male and female adolescents in the proportion of trips traveled actively, intrinsic motivation and amotivation. Logistic regression analyses demonstrated different relationships of the different types of motivation proposed within SDT on active travel behavior depending on sex/gender. In the total sample, integrated and identified regulation increased the odds of active travel (by 15.8 %, and 20.3 % respectively), whereas amotivation decreased the odds by 23.0 %. Intrinsic motivation and controlled forms of extrinsic motivation (i.e. introjected and external regulation) did not significantly change the odds of active travel. Separate sex/gender-specific analyses were conducted. For boys, only identified regulation significantly increased the odds of active travel (by 40.2 %) and amotivation significantly decreased the odds (by 18.8 %). In girls, integrated (by 25.3 %) and external (by 20.3 %) regulation significantly increased the odds of active travel, while amotivation (26.6 %) significantly decreased the odds. We conclude that disparities exist in the relationship among different regulation types with active travel behavior between adolescent boys and girls, and that findings contradictory to SDT might result from the specific context of traveling to a destination. Considering the regression analyses findings, future interventions to promote active travel among adolescents should incorporate sex/gender-sensitive development, because some behavioral regulations might not be equally effective among girls and boys

Hydrogel patterns in microfluidic devices by do-it-yourself UV-photolithography suitable for very large-scale integration

The interest in large-scale integrated (LSI) microfluidic systems that perform highthroughput biological and chemical laboratory investigations on a single chip is steadily growing. Such highly integrated Labs-on-a-Chip (LoC) provide fast analysis, high functionality, outstanding reproducibility at low cost per sample, and small demand of reagents. One LoC platform technology capable of LSI relies on specific intrinsically active polymers, the so-called stimuli-responsive hydrogels. Analogous to microelectronics, the active components of the chips can be realized by photolithographic micro-patterning of functional layers. The miniaturization potential and the integration degree of the microfluidic circuits depend on the capability of the photolithographic process to pattern hydrogel layers with high resolution, and they typically require expensive cleanroom equipment. Here, we propose, compare, and discuss a cost-efficient do-it-yourself (DIY) photolithographic set-up suitable to micro-pattern hydrogel-layers with a resolution as needed for very large-scale integrated (VLSI) microfluidics. The achievable structure dimensions are in the lower micrometer scale, down to a feature size of 20 µm with aspect ratios of 1:5 and maximum integration densities of 20,000 hydrogel patterns per cm. Furthermore, we demonstrate the effects of miniaturization on the efficiency of a hydrogel-based microreactor system by increasing the surface area to volume (SA:V) ratio of integrated bioactive hydrogels. We then determine and discuss a correlation between ultraviolet (UV) exposure time, cross-linking density of polymers, and the degree of immobilization of bioactive components. © 2020 by the authors

Parental perspectives on the decision-making process on transport mode choice in adolescents: a qualitative study with mothers and fathers

ObjectiveThe present study aims to understand the familial decision-making process on transport mode choice in adolescents with a focus on the parental perspective within this process.BackgroundActive travel contributes to adolescents’ overall physical activity and its positive health effects. Based on the social-learning theory, especially parents are assigned a central role for adolescents’ travel behavior. The aim of the present study was to examine how parents are involved in the decision-making process on transport mode choice in adolescents.MethodThe study is part of the cross-sectional mixed-methods ARRIVE study which includes semi-structured interviews with mothers (n = 12) and fathers (n = 7) of 11- to 14-year-old German adolescents. The interviews focused on travel behavior in adolescents and the decision-making process on transport mode choice from the parental perspective. All interviews were analyzed inductively using Thematic Analysis.ResultsOur study revealed that parents do not primarily decide for or against active travel in adolescents, but are mostly involved in the decision-making process, especially in case of a deviation from the main transport mode. Different forms of parental involvement in the decision-making process were identified. Some parents acted as main decision makers which is the highest form of involvement while others gave their children complete freedom of choose a transport mode for themselves. These parents accepted their child’s choice fully which shows a low involvement in the decision-making process.ConclusionThe results provide a deeper understanding of the familial decision-making process on travel behavior in adolescents. The results indicate an occasionally parental involvement in the decision-making process on the mainly used transport mode by adolescents, and that mothers and fathers are always involved when deviating from the main mode.ImplicationsFurther research should investigate changes in travel behavior from childhood to young adulthood to understand long-term travel decisions in families. Due to the findings that parents are often involved in the decision-making process on transport mode choice and that they mainly reported safety concerns as barriers to their children’s active travel, further research should focus especially on the social and physical environment of adolescents

Metabolic Activation of Benzo[a]pyrene by Human Tissue Organoid Cultures

Organoids are 3D cultures that to some extent reproduce the structure, composition and function of the mammalian tissues from which they derive, thereby creating in vitro systems with more in vivo-like characteristics than 2D monocultures. Here, the ability of human organoids derived from normal gastric, pancreas, liver, colon and kidney tissues to metabolise the environmental carcinogen benzo[a]pyrene (BaP) was investigated. While organoids from the different tissues showed varied cytotoxic responses to BaP, with gastric and colon organoids being the most susceptible, the xenobiotic-metabolising enzyme (XME) genes, CYP1A1 and NQO1, were highly upregulated in all organoid types, with kidney organoids having the highest levels. Furthermore, the presence of two key metabolites, BaP-t-7,8-dihydrodiol and BaP-tetrol-l-1, was detected in all organoid types, confirming their ability to metabolise BaP. BaP bioactivation was confirmed both by the activation of the DNA damage response pathway (induction of p-p53, pCHK2, p21 and γ-H2AX) and by DNA adduct formation. Overall, pancreatic and undifferentiated liver organoids formed the highest levels of DNA adducts. Colon organoids had the lowest responses in DNA adduct and metabolite formation, as well as XME expression. Additionally, high-throughput RT-qPCR explored differences in gene expression between organoid types after BaP treatment. The results demonstrate the potential usefulness of organoids for studying environmental carcinogenesis and genetic toxicology