381023 research outputs found
Sort by
Metal-organic frameworks for sustainable transformations in renewables valorization
No full textThe world witnesses a racing towards making materials that "benefit society”. Today there is a rising interest in sustainable production for producing platform chemicals and renewable fuels, which can be used together with fossil fuels or can even replace them entirely. Renewable biomass is an ideal alternative, as it is abundant and relatively cheap. However, a reliable method of producing bio-based platform chemicals at substantial yield remains a bottleneck for extending their production to an industrial scale. Thus, researchers persist to heterogeneous catalysts and non-conventional heating technologies to develop sustainable processes for producing added-value chemicals and fuels. Selecting biomass conversion technology is very challenging and depends on the nature of the biomass, the volume available, the reliability and the risk of failure from immature technologies.
Hence, this thesis investigated several concepts in detail using two benchmark reactions, i.e. furfural production and aldol condensation. Firstly, structure-catalytic property relationships for several MOFs were investigated; secondly, the potential of MOFs as microwave-responsive catalysts was examined; and finally, the potential benefits of microwave irradiation for chemical conversion have been quantified
Rethinking our habits : development and effects of interventions to promote mindful sharenting
No full textThis chapter enhances our understanding of the influencer sharenting phenomenon by consolidating insights previously explored in the book. It delves deeper into the influence of contextual factors and cognitive biases, illustrating how these elements contribute to influencer parents' tendency to underestimate the risks associated with sharenting. This chapter also delineates the ecosystem in which influencer parents operate and the various factors that contribute to their inclination to prioritise short-term gains over the long-term downsides associated with sharenting behaviour. We examine existing interventions aimed at sensitising and supporting (influencer) parents regarding their sharenting behaviours and discuss the effectiveness of a Flemish intervention with a central focus on influencer sharenting. To conclude, the chapter offers inspiration for future interventions, underscoring the importance of considering diverse stakeholders beyond parents. We provide insights into the complexities of altering (influencer) sharenting behaviour and the challenges and opportunities for promoting online safety and long-term well-being of children. This comprehensive approach seeks to inform future research and intervention efforts, focusing on fostering collaborative and holistic strategies to address the evolving landscape of influencer sharenting in the digital age
One big happy family? The legal implications of commercial sharenting
No full textThis chapter explores the phenomenon of commercial sharenting from a legal perspective. While sharenting can have benefits, such as connecting with friends and family and providing a platform for expression, it also poses significant risks to children’s rights. The underlying business model of the platform economy, which rewards views and clicks with monetary compensation, especially for family influencers, has created a landscape in which the privacy, dignity and safety of children are potentially at risk. First, the chapter discusses the positive and negative impacts of sharenting on the rights of both parents and children. To do so, it draws upon the United Nations children’s rights framework and examines the duties of States to provide guidance to parents about their role in safeguarding children’s rights on digital platforms, the importance of the evolving capacities of the child and parents’ right to freedom of expression. In a second part, the chapter analyses relevant French legislation introducing rules which may affect commercial sharenting. Through this examination, we aim to offer insights into how legal frameworks can balance the interests of parents and children in the context of commercial sharenting while ensuring the protection of children's rights
Long-term outcomes of hypospadias : urological and psychosexual function and endocrine-reproductive capacity
No full textMale genital development is a complex process requiring the intricate and delicate interaction of genetic, hormonal and mechanical factors. It is therefore unsurprising that male genital development frequently hampers, commonly presenting with some form of hypospadias. Although roughly 1/200 newborn males is born with hypospadias, very little is known regarding their long-term outcomes. This gap in knowledge renders surgical, endocrine, fertility and genetic counseling of patients and parents difficult. Performing long-term outcome studies is imperative to be able to provide tailored follow-up and guidance to men born with hypospadias and their parents.
The main aim of this PhD thesis was to explore the outcome of young men born with various forms of non-syndromic hypospadias and elucidate the genetic factors underlying the development of hypospadias.
The first part of the thesis reports the androgen receptor (AR) expression in 428 human foreskin samples, of which 197 from boys who underwent hypospadias repair. Immunohistochemical AR staining was assessed using the mQuicks. This new semi-quantitative method was based on the Quick score used to assess receptor status in breast cancer. Our results showed no differences in AR expression between boys born with hypospadias, versus healthy controls, nor versus boys with buried penis. Instead, age was found to be the principle determinant of AR expression, correlating with the phases in life during which there are high androgen levels (i.e. minipuberty and puberty). Although we failed to find differences in AR expression, these data do not exclude impaired AR functionality or downstream defects. However, based on our data, when exploring the role of the AR in the development of hypospadias, strict age matching appears to be crucial.
The following parts mainly used the cross-sectional data of a large cohort of 193 adolescents and young adults born with various forms of non-syndromic
10
hypospadias compared to 50 healthy male peers. The data of this cross-sectional study were divided into three sections.
The first part explored the psychosexual outcome and patient and parental satisfaction after hypospadias repair. The overall psychosexual outcome did not show large differences with the control group. However, a negative impact of surgical re-interventions was seen. In addition, patients were generally more content with their genital appearance compared to the physician. As a conclusion we recommend, a restrictive attitude towards re-interventions for non-functional problems. Mild erectile and ejaculatory problems were seen in 10% of cases, but appeared unrelated to any patient or surgical factors. The majority of patients and parents were content with the childhood hypospadias repair. However, many parents indicated that they had experienced the entire diagnostic and therapeutic process as very stressful, warranting the organization of early psychological support for parents who need it.
The second part assessed the surgical and urological outcome of the same cohort. Re-interventions were needed in 39.2%, whereas suboptimal urinary and/or sexual outcomes were found in 52.9% of cases. Several factors were found to be associated with more re-interventions and poor urological outcomes. Our data support the organization of a specialized urology team for hypospadias repair and deferral of hypospadias repair until the age of at least 12 months. Smaller adult stretched penile lengths and more severe hypospadias were also associated with worse outcomes and warrant a cautious approach in order to avoid complications. Our data also support the routine use of uroflowmetry during follow-up well into adulthood, as suboptimal voiding was common.
The third part explored the endocrine outcome and semen characteristics, as well as the genetic mechanisms involved in the development of hypospadias and poor outcomes in some. Additional data focusing on growth, hormone levels during minipuberty and puberty in boys born small for gestational age (SGA) and appropriate for gestational age (AGA) with severe
11
hypospadias were provided through a supplementary retrospective study using the I-DSD registry. These studies revealed poor growth in those born SGA with hypospadias at three times the rate as what has been reported in the overall SGA population (i.e. 30%). Hormone levels during minipuberty suggested infantile Leydig cell dysfunction in SGA children, whereas evidence was found of subclinical adult Leydig cell dysfunction in the entire hypospadias population. In addition, low sperm counts were a point of concern in hypospadias cases, especially in those born SGA or AGA with complex hypospadias (60% and 30%, respectively). The cause of the frequent testicular dysfunction in men born with hypospadias appeared to be multifactorial and largely dependent on environmental and perhaps epigenetic factors as no mono- or oligogenic causes were identified in the genetic study
Psychometric approaches for designing personality inventories for large-scale assessment
No full textDeveloping delineation guidelines for the lymphatic target volumes in ‘prone crawl’ radiotherapy treatment position for breast cancer patients
No full textThis project focuses on the promising new 'prone crawl' position for breast cancer radiotherapy. This position places the patient in prone, with the arm on the treated side alongside the body. The other arm is extended above the head, resembling a phase from crawl swimming. In prone position, the breast can hang free, away from organs at risk and by placing the arm alongside the body, the radiation beam can still reach the axillary lymph nodes. Preliminary data showed reduced radiation dosages in lungs, non-treated breast, thyroid and oesophagus, compared to the regularly used supine position. After proving the potential of this new position, it is important to optimize it for widespread clinical use.
An important part of radiation therapy is the delineation of the target tissue (the tumour or the lymphatic system, if cancer cells have infiltrated the lymphatics) and the organs at risk. The goal of radiotherapy is to kill tumour cells by hitting them with a high energy beam. This beam is guided by the delineations and it is therefore really important that delineations are performed accurately, since the beam will also kill healthy cells and it could cause damage to organs at risk (like the heart and lungs) if it misses the target area. To ensure that delineations are performed according to a universal standard and to guarantee that every patient gets the same quality of treatment across different centres, delineation guidelines exist to guide the radiation oncologist when performing delineations. Since the prone crawl position is still very new, no position specific guidelines existed and as such, making these position specific guidelines was the goal of the PhD.
Since the lymphatics are in the submillimetre size range and they are soft tissues, they cannot directly be visualised on the CT scans used for treatment planning. Instead, the current delineation guidelines contain reference structures like muscles and blood vessels, that are visible on patient CT scans. Since nobody ever completely visualised the lymphatic system in the target area, complete with spatial relations with the reference structures that are used on CT, it seemed very interesting to try and provide a map of the lymphatic system and base the new delineation guidelines for the prone crawl position on the actual location of these lymphatics. Therefore, the PhD was divided into 2 parts.
The first part focused on finding a methodology to visualise the lymphatics on CT images by injecting radiographic contrast agents. The second part of the PhD focused on setting up the actual delineation guidelines and developing a methodology specifically for this purpose.
The experiments performed during the PhD yielded 3 papers for the first part and another 3 papers for the second part. Position specific delineations were developed and they are currently being used at the radiotherapy department. Apart from this, the methodologies that were developed during this PhD will also be useful for future guideline development studies and future lymphatic mapping efforts. This thesis may to date even be the only document that thoroughly discusses the possibility of retrograde lymphatic injection
Temporal effects of chemical and physical stressors on marine zooplankton : a molecular approach
No full textOceans and seas are often perceived as the last wilderness on the planet. However, anthropogenic actions are already impacting these ecosystems, ranging from the coasts and the sea surface to the open ocean and the deep sea floor. Marine ecosystems are currently affected by multiple human activities, such as eutrophication, overfishing, the introduction of non-indigenous species, the contamination by hazardous chemicals and (micro)plastics, etc., in addition to climate change, leading to impaired environmental conditions. Evidence is growing that these changing environmental conditions have negative effects on the biodiversity and functioning of marine food webs. Due to their rapid responses to environmental variation, planktonic organisms are used as bio-indicators of ecosystem changes. With the need for better understanding the impact of a changing environment on zooplankton communities, zooplankton monitoring programs have been carried out in the marine environment globally since the early 20th century. Most zooplankton monitoring studies focus mainly on variability in biodiversity and biomass. However, this approach is hindered by challenges in the identification, which is time-consuming, complicated and requires biological expertise. A combination of new technologies and techniques, together with classical in situ and laboratory studies, could improve our understanding of such biodiversity patterns by assessing the health and physiology of marine plankton. In this thesis, we aimed to apply molecular methods to investigate spatiotemporal patterns in zooplankton dynamics, as well as to investigate the influence of environmental variation and stressors on these dynamics