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Echocardiography-guided Injection for Targeted and Reliable Intramyocardial Stem Cell Delivery in a Rat Model of Myocardial Infarction
No full textEchocardiography-guided intramyocardial injection (EGI) is a minimally invasive technique for delivering stem cell therapies in preclinical myocardial infarction (MI) models. Compared to traditional open-chest approaches, EGI offers improved clinical translatability, reduced invasiveness, and minimized physiological impact on the animal. While EGI is well established in murine models, its application in rats remains limited due to anatomical and technical challenges. In particular, thinning of the left ventricular anterior wall (LVAW) in infarcted and peri-infarct regions complicates safe and accurate myocardial delivery, as wall thickness can fall below the needle bevel size of commonly used 27 G or 28 G needles, increasing the risk of ventricular perforation or failed delivery. To address this limitation, we optimized a protocol for EGI in rat MI models using 29 G Spinocan needles. The smaller-diameter, longer needle enables precise targeting of thin myocardial tissue, minimizing damage and enhancing injection accuracy, independent of LVAW thickness. This technique is compatible with standard transthoracic echocardiography platforms and eliminates the need for thoracotomy, allowing longitudinal studies in the same animal. Our refined method enables robust, reproducible delivery of therapeutic agents into viable myocardium adjacent to the infarct zone, where regenerative therapies are most effective. By improving safety and targeting precision, this approach increases the translational relevance of preclinical cardiac research and supports the development of standardized protocols across laboratories.We thank Kim Nijsten for assistance with fluorescence imaging. This work was financially supported by a Flanders Innovation & Entrepreneurship (VLAIO) Baekeland Mandate (HBC.2021.0811)
Crack Monitoring in Dapped-End Beams: A Study of Sensor Technologies under Corrosive Conditions and Numerical Modelling of Crack Formation
No full textVerouderende bruginfrastructuur brengt aanzienlijke veiligheidsrisico’s met zich mee, vooral door corrosie die scheuren veroorzaakt in balken met een inkeping aan het uiteinde. Traditionele monitoringssystemen werken vaak onbetrouwbaar in corrosieve omgevingen, wat de noodzaak voor duurzame sensortechnologieën benadrukt die scheur- en roestvorming op lange termijn kunnen detecteren.
Als eerste stap is er een literatuuronderzoek uitgevoerd naar sensortechnologieën die bestand zijn tegen corrosie. Dit leidde tot de keuze voor Fiber Bragg Grating- (FBG) sensoren, vanwege hun hoge precisie, stabiliteit op lange termijn en weerstand tegen corrosieve omgevingen. Als tweede richt dit onderzoek zich op het monitoren van corrosie-geïnduceerde scheuren in balken met een inkeping aan het uiteinde door het ontwikkelen van DIANA-eindige-elementenmodellen. Acht verschillende modellen werden ontwikkeld, elk met een andere treksterkte van de wapening volgens de Eurocode-classificaties en een verschillende wapeningsconfiguratie.
De analyse toont aan dat de scheurpatronen grotendeels overeenkomen, maar het theoretische model faalt eerder en vertoont meer kleine scheuren door de lagere betonsterkte.
Dit onderzoek biedt een basis voor het beoordelen van de nauwkeurigheid van scheurvoorspellingen en de integratie van corrosiebestendige sensoren. Dit is essentieel vanwege de beperkte kennis van dit soort balken, vooral wat betreft structurele berekeningen en scheurgedrag, die cruciaal zijn voor het verbeteren van de veiligheid
Correction: Use of the non-paretic arm reflects a habitual behaviour in chronic stroke
No full textCorrection to: Journal of NeuroEngineering and Rehabilitation (2025) 22:135 h t t p s : / / d o i. o r g / 1 0. 1 1 8 6 / s 1 2 9 8 4-0 2 5-0 1 6 6 1-5 In the sentence beginning 'Our results demonstrate that not using the ... in demanding (e.g. time-limited) situations. ' in the Conclusions heading under the Abstract section of this article [1], The word "not" needs to be deleted from the sentence. The corrected sentence is 'Our results demonstrate that using the non-paretic arm may reflect a habit response that is more readily triggered in demanding (e.g. time-limited) situations. ' The original article has been corrected. References 1. Sporn S, Bonyadi E, Fathana R, et al. Use of the non-paretic arm reflects a habitual behaviour in chronic stroke. J Neuroeng Rehabil. 2025;22:135. h t t p s : / / d o i. o r g / 1 0. 1 1 8 6 / s 1 2 9 8 4-0 2 5-0 1 6 6 1-5
Next-generation kesterite thin-film solar cells: development, characterization and modeling
No full textIn order to cope with the ever-growing energy demand while cutting down
greenhouse gas emissions, solar power must be deployed at the largest
extent possible. This requires the widespread installation of photovoltaic
technologies beyond utility-scale to comply with the greater integrability
and adaptability needed in emerging markets. Thin-film solar cells
based on chalcogenide compounds hold highly encouraging promises for
such applications, due to their versatile architecture and tuneable properties.
Among them, kesterite materials with the Cu2ZnSn(S,Se)4 crystalline
structure provide an interesting alternative based on Earth-abundant elements
and compatible with low-cost processes, making them a promising
solution with reduced carbon footprint and cost. Yet, their performance
must be increased to align their competitiveness with commercial technologies.
Reaching this objective entails to resolve their still too significant
deficit in open-circuit voltage, which is the main culprit for their limited efficiency
around 15% for the highest-performing devices. The physical origin
of these losses is manifold: control of the kesterite phase and composition
in a uniform fashion, regulation of its crystalline quality to favour low disorder,
monitoring of the growth environment and conditions enabling weakly
defective materials and interfaces, as well as preserving all these aspects
when tuning the absorber bandgap for relevant applications, among others.
This thesis aims at tackling these challenges on different levels.
First of all, it is demonstrated through an extensive review of the literature
that germanium (Ge) alloying constitutes a promising strategy to
enhance the quality of kesterite thin films by overcoming intrinsic electronic
limitations related to tin (Sn) while promoting superior structural
morphology. On top of this, this approach also allows to control the absorber
bandgap, which contributes to a greater versatility of the kesterite
compounds. Still, most studies have focused on low to moderate proportions
of Ge corresponding to a narrow bandgap range not yet matching the
specifications of emerging applications. This highlights the need to pursue
the exploration of the broad Ge compositional domain. The importance of
the kesterite deposition process is also detailed, showing the greater potential
of solution-based routes allowing finer control of composition and
phases at the lab scale, thus providing conditions for high efficiency. In
comparison, samples from the presented starting baseline, deposited via
sequential physical processes, exhibit limited performance with symptoms
of low opto-electronic kesterite quality and device non-ideality.
Following this, a molecular ink chemical route in ambient environment
is developed to allow flexible Ge alloying in high-quality single-phase thinfilm kesterite absorbers. Remarkably, this updated baseline enables to
tune the kesterite bandgap without compromising material quality. In
particular, narrow band tails associated to mitigated open-circuit voltage
radiative losses are ensured for a broad bandgap range in which the device
performance potential is therefrom augmented. Resolving this prerequisite
for photovoltaic absorbers is however only one of the main steps in
the development of a solar cell technology. Indeed, non-radiative losses
leading to low minority carrier lifetime remain an even more critical challenge
to be tackled. It originates from the numerous intrinsic point defects
in the kesterite lattice, the exact nature, location and dominance of
which remain partly undetermined. It is therefore essential to pinpoint
the underlying mechanism responsible for defect-assisted recombination
and the associated performance losses. This is especially relevant for the
next-generation devices based on multinary-alloyed solution-processed
kesterite absorbers which are presently leading the way towards future
efficiency breakthroughs.
Eventually, based on the study of temperature- and light intensitydependent
current-voltage measurements confronting analytical models
and SCAPS-1D simulations, the closer-to-ideal behaviour of state-of-theart
kesterite devices is demonstrated as a consequence of weaker band
tailing and bandgap and potential fluctuations. The close agreement with
the single diode formalism combined with the observed dark and light reconciliation
allow to gauge the various contributions to the open-circuit voltage
deficit. The dominant loss mechanism is hypothesized to be a defectrich
kesterite layer at the interface with the buffer, highlighting the diode
ideality factor and saturation current density as the primary causes of
restrained performance. Light is also shed on carrier trapping-detrapping
via shallow defect states as the mechanism behind shunt leakage currents,
also contributing to lower efficiency. The applicability of this whole analysis
extends across various samples, which emphasizes its potential to
support further enhancements of next-generation kesterite solar cells.Doctoral dissertation submitted to obtain the degrees of-Doctor of Engineering Technology | UHasselt-Docteur en Sciences de l'ingénieur et technologie | UCLouvai
Delayed interventricular septum perforation with mitral chordal rupture after left bundle branch area pacing
No full textFund for Scientific Research Flanders [FWO 11PGA24N
Identifying rehabilitation needs as part of secondary prevention in individuals with atrial fibrillation-a Delphi consensus study
No full textAims This study aimed to establish general consensus on a systematic needs assessment model to determine eligibility for cardiac rehabilitation (CR) as part of secondary prevention in individuals with atrial fibrillation (AF). Specific objectives included identifying relevant needs assessment criteria and establishing consensus on referral criteria.Methods and results A Delphi study was conducted following the ACCORD guidelines (ACcurate COnsensus Reporting Document) with participation of an international, multi-disciplinary expert panel including physicians, nurses, and other healthcare professionals, across primary and secondary care as well as academic research. The panel also included six people who had AF themselves. The Delphi process involved three iterative rounds of surveys and a video meeting to determine needs assessment criteria and facilitate consensus. Data collection included qualitative feedback and quantitative voting on proposed criteria. Sixty-nine experts participated. There was high agreement on the importance of the study, which identified 12 needs assessment criteria related to AF symptom burden, health-related quality of life, anxiety, medicine adherence, and various risk factors. Whilst there was agreement on the needs assessment model, experts noted that referral criteria should be flexible and tailored to local healthcare settings, emphasizing that each individual's situation is unique.Conclusion This Delphi study established a needs assessment model that can be adapted to local contexts for individuals with AF. More research is needed to refine referral criteria and ensure effective implementation of individually tailored CR strategies. This study aimed to create a model that helps healthcare providers assess the needs of individuals with atrial fibrillation to determine their eligibility for cardiac rehabilitation as part of secondary prevention. The key findings were:An expert panel identified 12 important criteria for assessing the needs of individuals with atrial fibrillation, including factors such as symptom burden, quality of life, anxiety, medicine adherence, and various risk factors.Whilst there was high agreement on the needs assessment model, experts noted that referral criteria should be flexible and tailored to local healthcare settings, emphasizing that each individual's situation is unique.Funding
This project is part of a PhD study, which is partially funded by a PhD faculty scholarship from the University of Southern Denmark (no Grant number), a PhD scholarship from the Region of Southern Denmark (grant number: J.no.: 21/58092), and the fund to support independent, strategic clinical research in the Region of Southern Denmark (grant number: J.no.: 2024-0022).
Acknowledgements
We would like to thank Anton Pottegaard (Denmark) for inspiring us with the idea to conduct an international Delphi process. Moreover, we would like to thank all experts who participated in the study, with special appreciation to those who consistently responded to the surveys. A special thanks to Hein Heidbuchel (Belgium) and additional Danish participants: Andi Albertsen, Anja Skov, Anne-Marie Hedegaard, Claus Tveskov, Dagmar Lybak Sieg, Jesper Eilsø, Jonas Bjerring Olesen, Kirsten Gerholt, Louise Huang Juul, Margit Brinck, Robert Bedsted, and Ulla Dam-Schmidt for their valuable inputs during the development of the assessment model
The term 'athlete's heart' encapsulates both male and female athletic hearts if indexed correctly
No full textWhat Others Afford: Sociotechnical shaping of normative processes on social media platforms
No full textSocial media platforms increasingly delegate content moderation responsibilities to
users, yet we have limited understanding of how platform architectures shape users'
capacity to govern each other through social norms. This thesis examines how social
media users collectively negotiate what constitutes acceptable behavior and content
through platform-mediated normative processes.
Drawing on social norm theory and affordance research, this study develops the concept
of ‘social norm affordances’ that enable users to shape other users' behavior. Through
platform audits, qualitative interviews, and theoretical synthesis across multiple
platforms, the research identifies first four, later condensed to three key affordances,
which can operate as two-stage shaping phenomena. Platforms thereby mediate users'
capacity to shape other users' experiences, which is subject to users’ impression of what
norms they should comply with. This research reveals how the mechanisms of social
norm affordances influence the capacity for user self-governance through normative
contestation.
These insights have implications for platform design, content moderation policy, and
understanding the conditions under which users can effectively deal with contemporary
issues like hatespeech, radicalization and disinformation in digital environments
The impact of greening interventions in school grounds on social behavior and cognitive performance among primary school children
No full textBackground Green spaces have been identified as beneficial for children's mental health, as well as cognitive performance, however, less is known about the role of biodiversity within these environments. Here, we study the impact of greening schoolyards, especially with regard to biodiversity enrichment, on children's behavior, emotion recognition, cognitive performance and mental effort, and attentional bias, compared to observations in control schools.Methods This study employs an interventional design, including two intervention and two control schools located in Belgium and the Netherlands. Data was collected from 169 children aged 7-12 years, assessing cognitive performance using a battery of cognitive tasks combined with eye tracking, as well as socio-emotional wellbeing via eye tracking and validated questionnaires. Baseline measurements were followed up every 6 months for 2 years.Findings Selective attention in the Stroop test and mental effort, as indicated by enlarged pupil diameters during cognitive tasks, increased more over time in the intervention group compared to the control group as schoolyard greening progressed. The intervention was associated with improved scores on prosocial behavior over time. These associations were independent of sex, age, country, education level of the household, the capacity to manage household incomes, and season. Attentional bias towards the emotion of happiness using eye-tracking did not show a significant difference in changes over time between intervention and control groups.Interpretation These findings suggest that a green, more biodiverse school environment could improve children's cognitive and emotional functioning, highlighting the importance of designing schoolyard green spaces that enhance both nature contact and biodiversity as a valuable public health initiative.Funding
The author(s) declare that financial support was received for the research and/or publication of this article. This research was funded by Dutch Provincie Limburg grant number Provincie Limburg: 2021/170 and the Belgian Province. The authors acknowledge funding from the Special Research Fund (BOF 2021 KP) from Hasselt University Research Foundation Flanders (FWO, G026222N and G059219).
Acknowledgments
We are thankful to all participating children and parents. We alsoare very grateful for the cooperation with the participating schools. We acknowledge several colleagues for assistance with the research in the schools. We also would like to thank Dr. Silvie Daniëls for thinking along, her enthusiasm, and critical input on the design of the study. We are also grateful for the input of the ‘Provinciaal Natuurcentrum Limburg.’ Additionally, we would like to thank Sam Ottoy and Timon Smeets for their input