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NGS Detects Extensive Genomic Alterations in Survivors of Irradiated Normal Human Fibroblast Cells
(2024)
Abstract
It is thought that cells surviving ionizing radiation exposure repair DNA double-strand breaks (DSBs) and restore their genomes. However, the recent biochemical and genetic characterization of DSB repair pathways reveals that only homologous recombination (HR) can function in an error-free manner and that the non-homologous end joining (NHEJ) pathways canonical NHEJ (c-NHEJ), alternative end joining (alt-EJ), and single-strand annealing (SSA) are error-prone, and potentially leave behind genomic scars and altered genomes. The strong cell cycle restriction of HR to S/ G2 phases and the unparalleled efficiency of c-NHEJ throughout the cell cycle, raise the intriguing question as to how far a surviving cell reaches after repairing the genome back to its pre-irradiation state. Indeed, there is evidence that the genomes of cells surviving radiation treatment harbor extensive genomic alterations. To directly investigate this possibility, we adopted next-generation sequencing (NGS) technologies and tested a normal human fibroblast cell line, 82-6 hTert, after exposure up to 6 Gy. Cells were irradiated and surviving colonies expanded and the cells frozen. Sequencing analysis using the Illumina sequencing platform and comparison with the unirradiated genome detected frequent genomic alterations in the six investigated radiation survivor clones, including translocations and large deletions. Translocations detected by this analysis and predicted to generate visible cytogenetic alterations were frequently (three out of five) confirmed using mFISH cytogenetic analysis. PCR analysis of selected deletions also confirmed seven of the ten examined. We conclude that cells surviving radiation exposure tolerate and pass to their progeny a wide spectrum of genomic alterations. This recognition needs to be integrated into the interpretation of biological results at all endpoints, as well as in the formulation of mathematical models of radiation action. NGS analysis of irradiated genomes promises to enhance molecular cytogenetics by increasing the spectrum of detectable genomic alterations and advance our understanding of key molecular radiobiological effects and the logic underpinning DSB repair. However, further developments in the technology will be required to harness its full potential.
Abstract
A low-cost plasma nozzle/setup was developed to allow demonstrations, and it invites hands-on experimentation with nonthermal plasmas of air and other gases. Several high-tech plasma applications, such as surface cleaning and activation, as well as mild but effective sterilization, will be explained and adapted to be eagerly explored by undergraduate and senior high school students. The results were surprisingly similar to those obtained with a commercial plasma treatment system. While the focus is on the experimental introduction to plasma physics and chemistry, it will be highlighted how a multidisciplinary approach enables the study and discussion of important concepts ranging from surface energies and contact angles to environmental or microbiological control.
Abstract
Electrospinning has been widely used as a versatile technique to generate nanofibers of various materials. It is also helpful in teaching topics ranging from macromolecular chemistry to physics, safety, and sustainability at various levels of difficulty and student involvement. Simple and safe hands-on experiments/manual assays can be realized for less than 30 euros to demonstrate polymer viscosity and nanofiber alignment and solubility. Students can further study (super)hydrophobicity and even upcycle packaging waste into useful filter materials but also improve the electrospinning setup from a manual assay to an inexpensive Arduino-based 3D printed research platform. Alternatively, the latter can be used for teacher demonstrations of more challenging experiments that can also be easily done using a commercial syringe-pump.
Abstract
Femtosecond laser-induced nano structuring offers a novel approach to enhance the performance of porous transport layers (PTLs) in anion-exchange membrane water electrolysis. By applying ultrashort laser pulses to nickel felts, distinct surface morphologies were generated, including high-spatial-frequency laser-induced periodic surface structures (HSFL-LIPSS), irregular ablated surfaces, and hybrid structures. Surface area analysis revealed increases of up to 4-fold for LIPSS, 6-fold for hybrid structures (LIPSS+Ablation), and 9-fold for ablated surfaces compared to untreated fibers. Electrochemical testing showed reduced overpotentials for laser-treated samples, comparable to state-of-the-art electrodes despite the absence of catalyst layers. Overpotentials could be reduced by up to 6.5 % at 10 mA cm−2 and by up to 9.6 % at 100 mA cm−2 compared to the unprocessed felt. Notably, ablated structures, with the highest surface areas, exhibited microcavities that may entrap oxygen bubbles, limiting active site and reaction rates. The LIPSS structures demonstrated the lowest activation losses and highest current density (1.32 A cm⁻² at 2.0 V) due to their periodic morphology and enhanced electrolyte flow, representing a 17 % improvement at 2.0 V compared to the untreated felts. Moreover, Tafel slopes down to 66 mV dec−1 denote a performant kinetic while oxidation charge measurements revealed pronounced peaks for laser-treated samples, with ablated surfaces achieving the highest charge of 16.76 ± 1.64 C cm⁻². Chronopotentiometry revealed the LIPSS structures showing the highest resistance to degradation among the structured samples.
These findings suggest femtosecond laser nano structuring as a promising method to improve PTL performance. Further application of catalyst layers could amplify the electrochemical efficiency of these advanced materials.
Abstract
The synergistic combination of various sorbitol-based organogelators with polyolefins allows the preparation of porous support structures for immobilized phase change materials (PCMs). Using a PCM as a solvent for the preparation leads to dimensionally stable composite materials with extremely high loading rates and low leakage of PCMs. Detailed investigations were performed on the kind of polyolefin support and its mass fraction concentration in the PCM, the temperature-dependent softening and failure under superimposed load, the efficiency of heat transport and the retention capacity over several melting/solidification cycles in various measurement setups. In particular, paraffin wax in combination with 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol (TBPMN) and ultrahigh molecular weight polyethylene (UHMWPE) showed the best results in terms of high dimensional stability, low leakage, excellent processability and competitive heat capacity. The herein-established one-step preparation method saves time and energy compared to the loading of pre-formed porous supports and improves application-related properties at the same time.
MARGE (Germany)
(2024)
Abstract
This case describes the difficulties of business succession from a successor’s perspective. The case is based on a real metalworking family business in an old industrial region in Germany. The key issues are challenges that, Michelle and Adrian, two second-generation successors within one company, face in teambuilding and finding their own place within the corporation and their team. The case is divided into two parts: Part 1 is a newspaper article about the succession process that points out stereotypes and writing styles in reporting on entrepreneurship/succession in the media. Part 2 is the succession story written from Michelle’s perspective and highlights challenges that female successors face in traditional male-dominated areas, for instance, when it comes to questions of balancing work and family needs. The case addresses issues relating to entrepreneurship and business succession classes, with sociological and psychological overtones.
Abstract
The aim of this chapter is to address the impact of formal and informal institutions on women’s entrepreneurship and to extend our understanding of issues influencing women-owned businesses and women’s entrepreneurship in the context of a transition economy, such as Georgia. Our work specifically addresses formal institutions, such as governmental initiatives, financial institutions, and business-relevant education. It also addresses informal institutions, such as women’s role in society, the use of informal networks of connections and acquaintances, and gift-giving practices. Drawing on results from an online focus group discussion with women entrepreneurs in Georgia, we provide initial insights into the critical constraints and supporting factors that local women entrepreneurs experience. Based on the interrelation of institutions and women’s entrepreneurship, we conclude that changes in formal institutions do not lead directly to changing informal institutions. Due to the lack of trust in formal institutions, women entrepreneurs are more likely to look for business development solutions outside the official frames, including illegal or unethical means of survival. Nevertheless, increased opportunities – induced by specific entrepreneurship policies and programs – encourage women to enter entrepreneurship. In addition to this, entrepreneurship enables women in Georgia to overcome gender discrimination issues, which is more prevalent in employment relationships in the local labor market than in entrepreneurial activities.
Abstract
Escape rooms have gained popularity across the globe, be it for entertainment, team building, or learning purposes. Solving puzzles has intrigued humanity since ancient times and playing games together facilitated intercultural encounters, encouraging mutual learning. This situated action builds on the idea of a mobile escape room within a suitcase, which when traveling shares previous encounters and collects new puzzles, thereby ever evolving. A suitcase will arrive in Sibu, Malaysia, with augmented reality stickers that entail puzzles created in Namibia. Visitors need to solve the puzzles to open the suitcase, which contains treats from Namibia, as well as materials to create new puzzles. Visitors participate in creating their own cultural puzzles, upload them to the augmented reality application, and thereby contribute to a new multicultural escape suitcase. The puzzles can also be played back at home, and the suitcase will continue evolving as it travels.
Abstract
Indigenous people across the globe have all too often been marginalised and not been considered in decisions that directly concern their life. We maintain the significance of incorporating indigenous perspectives in society to create a global dialogue through direct participation. In this light we propose a situated action in which our co-author from the Ju/’hoansi tribe, one of the San ethnicity in Southern Africa, digitally records semi-structured conversations with members of other indigenous communities at the conference and public spaces in Sibu. Then participants are engaged into a participatory exploration of processing the audio files into sound installations and soundscapes which “amplify indigenous voices“. We anticipate that the products can be reused for further initiatives in the different countries, raising awareness and calling for action on matters of concern for indigenous people.
Abstract
In this paper we present the co-design and implementation of an extended reality escape room with 26 primary school students. The aim of our study was to explore the co-design process with students and to co-create a playable escape room, providing an asymmetric immersive experience in which players collaborate. We realised the complexity of designing such an escape room with primary students. We share our experiences and learnings in regard to required capacities and skills of co-designers, and adjustment of complexity and timing to players. We also maintain that the integration of extended reality technologies into escape rooms requires further research to realise asymmetric co-located collaboration.