23 research outputs found
Equal but not Similar? Historical perspectives on vocation-related paths to the university in Germany and Austria
Dem Anspruch der Öffnung der Hochschulen für beruflich Qualifizierte steht bislang im deutschsprachigen Raum eine geringe Nachfrage entsprechender Studierender gegenüber. Als mit ein Grund dafür wird im vorliegenden Beitrag die gesellschaftlich vorherrschende Überzeugung der Höherwertigkeit schulisch erworbener gegenüber beruflich erworbener Bildung geortet. Dieser Befund hat, so die These, nachweisbare Auswirkungen auf den historisch gewachsenen Zuschnitt von Hochschulzugangsformen und Bildungsinstitutionen. Der Autor und die Autorin beleuchten die historische Entwicklung alternativer, berufsbezogener Hochschulzugangswege in Deutschland und Österreich. Ein Schwerpunkt wird dabei auf rechtliche und praktische Zugangsbeschränkungen bzw. -erschwernisse gelegt. (DIPF/Orig.)In German-speaking countries, little use has been made of the right of access to universities for adults with vocational qualifications by these kinds of students. This article sees one reason for this in the idea prevalent in society that education acquired at school or at university is of higher value than vocational education. According to the thesis, this has had a measurable impact on the kind of forms of access to a university education and educational institutions that has evolved over time. The authors illuminate the historical development of alternative, vocation-related paths to a university education in Germany and Austria. Emphasis is placed on the legal and practical limitations to and difficulties with access. (DIPF/Orig.
Recent Trends in Applying Ortho-Nitrobenzyl Esters for the Design of Photo-Responsive Polymer Networks
Polymers with light-responsive groups have gained increased attention in the design of functional materials, as they allow changes in polymers properties, on demand, and simply by light exposure. For the synthesis of polymers and polymer networks with photolabile properties, the introduction o-nitrobenzyl alcohol (o-NB) derivatives as light-responsive chromophores has become a convenient and powerful route. Although o-NB groups were successfully exploited in numerous applications, this review pays particular attention to the studies in which they were included as photo-responsive moieties in thin polymer films and functional polymer coatings. The review is divided into four different sections according to the chemical structure of the polymer networks: (i) acrylate and methacrylate; (ii) thiol-click; (iii) epoxy; and (iv) polydimethylsiloxane. We conclude with an outlook of the present challenges and future perspectives of the versatile and unique features of o-NB chemistry
Digital light processing 3D printing of dynamic magneto-responsive thiol-acrylate composites
Additive manufacturing is one of the most promising processing techniques for fabricating customized 3D objects. For the 3D printing of functional and stimuli-triggered devices, interest is steadily growing in processing materials with magnetic properties. Synthesis routes for magneto-responsive soft materials typically involve the dispersion of (nano)particles into a non-magnetic polymer matrix. Above their glass transition temperature, the shape of such composites can be conveniently adjusted by applying an external magnetic field. With their rapid response time, facile controllability, and reversible actuation, magnetically responsive soft materials can be used in the biomedical field (e.g. drug delivery, minimally invasive surgery), soft robotics or in electronic applications. Herein, we combine the magnetic response with thermo-activated healability by introducing magnetic Fe3O4 nanoparticles into a dynamic photopolymer network, which undergoes thermo-activated bond exchange reactions. The resin is based on a radically curable thiol-acrylate system, whose composition is optimized towards processability via digital light processing 3D printing. A mono-functional methacrylate phosphate is applied as a stabilizer to increase the resins' shelf life by preventing thiol-Michael reactions. Once photocured, the organic phosphate further acts as a transesterification catalyst and activates bond exchange reactions at elevated temperature, which render the magneto-active composites mendable and malleable. The healing performance is demonstrated by recovering magnetic and mechanical properties after the thermally triggered mending of 3D-printed structures. We further demonstrate the magnetically driven movement of 3D-printed samples, which gives rise to the potential use of these materials in healable soft devices activated by external magnetic fields
Keratin Retraction and Desmoglein3 Internalization Independently Contribute to Autoantibody-Induced Cell Dissociation in Pemphigus Vulgaris
Pemphigus vulgaris (PV) is a potentially lethal autoimmune disease characterized by blister formation of the skin and mucous membranes and is caused by autoantibodies against desmoglein (Dsg) 1 and Dsg3. Dsg1 and Dsg3 are linked to keratin filaments in desmosomes, adhering junctions abundant in tissues exposed to high levels of mechanical stress. The binding of the autoantibodies leads to internalization of Dsg3 and a collapse of the keratin cytoskeleton-yet, the relevance and interdependence of these changes for loss of cell-cell adhesion and blistering is poorly understood. In live-cell imaging studies, loss of the keratin network at the cell periphery was detectable starting after 60 min of incubation with immunoglobulin G fractions of PV patients (PV-IgG). These rapid changes correlated with loss of cell-cell adhesion detected by dispase-based dissociation assays and were followed by a condensation of keratin filaments into thick bundles after several hours. Dsg3 internalization started at 90 min of PV-IgG treatment, thus following the early keratin changes. By inhibiting casein kinase 1 (CK-1), we provoked keratin alterations resembling the effects of PV-IgG. Although CK-1-induced loss of peripheral keratin network correlated with loss of cell cohesion and Dsg3 clustering in the membrane, it was not sufficient to trigger the internalization of Dsg3. However, additional incubation with PV-IgG was effective to promote Dsg3 loss at the membrane, indicating that Dsg3 internalization is independent from keratin alterations. Vice versa, inhibiting Dsg3 internalization did not prevent PV-IgG-induced keratin retraction and only partially rescued cell cohesion. Together, keratin changes appear very early after autoantibody binding and temporally overlap with loss of cell cohesion. These early alterations appear to be distinct from Dsg3 internalization, suggesting a crucial role for initial loss of cell cohesion in PV
Vat Photopolymerization 3D-Printing of Dynamic Thiol-Acrylate Photopolymers Using Bio-Derived Building Blocks
As an energy-efficient additive manufacturing process, vat photopolymerization 3D-printing has become a convenient technology to fabricate functional devices with high resolution and freedom in design. However, due to their permanently crosslinked network structure, photopolymers are not easily reprocessed or repaired. To improve the environmental footprint of 3D-printed objects, herein, we combine the dynamic nature of hydroxyl ester links, undergoing a catalyzed transesterification at elevated temperature, with an acrylate monomer derived from renewable resources. As a sustainable building block, we synthesized an acrylated linseed oil and mixed it with selected thiol crosslinkers. By careful selection of the transesterification catalyst, we obtained dynamic thiol-acrylate resins with a high cure rate and decent storage stability, which enabled the digital light processing (DLP) 3D-printing of objects with a structure size of 550 µm. Owing to their dynamic covalent bonds, the thiol-acrylate networks were able to relax 63% of their initial stress within 22 min at 180 °C and showed enhanced toughness after thermal annealing. We exploited the thermo-activated reflow of the dynamic networks to heal and re-shape the 3D-printed objects. The dynamic thiol-acrylate photopolymers also demonstrated promising healing, shape memory, and re-shaping properties, thus offering great potential for various industrial fields such as soft robotics and electronics
Towards automation of operando experiments: A case study in contactless conductivity measurements
Automation of experiments is a key component on the path of digitalisation in catalysis and related sciences. Here we present the lessons learned and caveats avoided during the automation of our contactless conductivity measurement set-up, capable of operando measurement of catalytic samples. We briefly discuss the motivation behind the work, the technical groundwork required, and the philosophy guiding our design. The main body of this work is dedicated to the detailing of the implementation of the automation, data structures, as well as the modular data processing pipeline. The open-source toolset developed as part of this work allows us to carry out unattended and reproducible experiments, as well as post-process data according to current best practice. This process is illustrated by implementing two routine sample protocols, one of which was included in the Handbook of Catalysis, providing several case studies showing the benefits of such automation, including increased throughput and higher
data quality. The datasets included as part of this work contain catalytic and operando conductivity data, and are self-consistent, annotated with metadata, and are available on a public repository in a machine-readable form. We hope the datasets as well as the tools and workflows developed as part of this work will be an useful guide on the path towards automation and digital catalysis
Spatially Resolved Cross-Linking Characterization by Imaging Low-Coherence Interferometry
A method to characterize cross-linking differences in polymers such as waveguide polymers has been developed. The method is based on the scan-free information acquisition utilizing a low-coherence interferometer in conjunction with an imaging spectrometer. By the introduction of a novel analyzing algorithm, the recorded spectral-phase data was interpreted as wavelength-dependent optical thickness which is matchable with the refractive index and therefore with the degree of cross-linking. In the course of this work, the method was described in its hardware and algorithmic implementation as well as in its accuracy. Comparative measurements and error estimations showed an accuracy in the range of 10−6 in terms of the refractive index. Finally, photo-lithographically produced samples with laterally defined cross-linking differences have been characterized. It could be shown, that differences in the optical thickness of ±1.5 μm are distinguishable
Patient-Related Predictors for Seeking and Receiving Obesity Surgery
Introduction
The decision for obesity surgery (OS) is complex and strongly driven by patients’ preference. This study aimed to examine patients' preference for OS before and after behavioral weight loss treatment (BWLT), associated patient characteristics, its role in predicting the receipt of OS after BWLT, and potential mediators.
Methods
Data of N = 431 adults with obesity starting a 1-year routine care obesity BWLT were analyzed. Patients were interviewed before (pre-BWLT) and after BWLT (post-BWLT) regarding their preference for OS, and anthropometric, medical, and psychological data were collected.
Results
Only a minority of patients (11.6%) had an explicit preference for OS pre-BWLT. Post-BWLT, the number of patients preferring OS significantly increased (27.4%). Patients with a constant or emerging preference for OS showed less favorable anthropometric, psychological, and medical characteristics than patients without or with a vanishing preference for OS. Patients' pre-BWLT preference for OS significantly predicted receiving OS post-BWLT. This association was mediated by higher body mass index pre- and post-BWLT, but not by less percentage total body weight loss (%TBWL) through BWLT.
Conclusion
Although the preference for OS pre-BWLT predicted the receipt of OS post-BWLT, it was not associated with %TBWL during BWLT. Further prospective studies with multiple assessment time points during BWLT may help to understand when and why patients’ attitude towards OS changes, and to identify possible mediators on the association between the preference and receipt of OS
Communication during the COVID-19 pandemic: evaluation study on self-perceived competences and views of health care professionals
PURPOSE
The aims of this study were to describe communication experiences while wearing a mask during COVID-19 pandemic in 2020, to identify possible mask-related barriers to COVID-19-adapted communications and to investigate whether the ABC mnemonic (A: attend mindfully; B: behave calmly; C: communicate clearly) might address these.
METHODS
This study was a cross-sectional, voluntary, web-based survey between January and February 2021. A 22-item survey was developed using the Surveymonkey platform and question styles were varied to include single choice and Likert scales. The respondents were also asked to view a short video presentation, which outlined the ABC mnemonic. CHERRIES (Checklist for Reporting Results of Internet E-Surveys) was used to ensure completeness of reporting. Diverging stacked bar charts were created to illustrate Likert scale responses.
RESULTS
We received 226 responses. The respondents were mostly women (60.2%) and the majority worked in a teaching hospital (64.6%). The majority of the respondents indicated issues related to lack of time during clinical encounters, uncertainty about how to adapt communication, lack of personal protective equipment, lack of communication skills and lack of information about how to adapt their own communication skills. In addition, the participants indicated acknowledging emotions and providing information using clear, specific, unambiguous, and consistent lay language while wearing a mask were among the main communication challenges created during the COVID-19 pandemic. Finally, the study showed significantly improved self-perceived competency regarding key communication after watching the short video presentation.
CONCLUSION
Effective communication in medical encounters requires both verbal and nonverbal skills