447 research outputs found

    Combustion and fuel characterisation of wheat distillers dried grain with solubles (DDGS) and possible combustion applications

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    The present transition to a sustainable global energy system requires that biomass is increasingly combusted for heat and power production. Agricultural fuels considered include alkali-rich fuels with high phosphorus content. One such fuel is wheat distiller’s dried grain with solubles (wheat DDGS) from wheat-based ethanol production. Further increases in ethanol production may saturate the current market for wheat DDGS as livestock feed, and fuel uses are therefore considered. Fuel properties of wheat DDGS have been determined. The ash content (5.4 ± 1.6 %wt d.s.) is similar to many agricultural fuels. In comparison to most other biomass fuels the sulphur content is high (0.538 ± 0.232 %wt d.s.), and so are the contents of nitrogen (5.1 ± 0.6 %wt d.s.), phosphorus (0.960. ± 0.073 %wt d.s.) and potassium (1.30 ± 0.35 %wt d.s.). To determine fuel-specific combustion properties, wheat DDGS and mixes between wheat DDGS and logging residues (LR 60 %wt d.s. and DDGS 40 %wt d.s.), and wheat straw (wheat straw 50 %wt d.s., DDGS 50 %wt d.s.) were pelletized and combusted in a bubbling fluidised bed combustor (5 kW) and in a pellets burner combustor (20 kW). Pure wheat DDGS powder was also combusted in a powder burner (150 kW). Wheat DDGS had a high bed agglomeration and slagging tendency compared to other biomass fuels, although these tendencies were significantly lower for the mixture with the Ca-rich LR, probably reflecting the higher first melting temperatures of K–Ca/Mg-phosphates compared to K-phosphates. Combustion and co-combustion of wheat DDGS resulted in relatively large emissions of fine particles (<1 μm) for all combustion appliances. For powder combustion PMtot was sixteen times higher than from softwood stem wood. While the Cl concentrations of the fine particles from the the mixture of LR and wheat DDGS in fluidised bed combustion were lower than from combustion of pure LR, the Cl- and P-concentrations were considerably higher from the wheat DDGS mixtures combusted in the other appliances at higher fuel particle temperature. The particles from powder combustion of wheat DDGS contained mainly K, P, Cl, Na and S, and as KPO3 (i.e. the main phase identified with XRD) is known to have a low melting temperature, this suggests that powder combustion of wheat DDGS should be used with caution. The high slagging and bed agglomeration tendency of wheat DDGS, and the high emissions of fine particles rich in K, P and Cl from combustion at high temperature, mean that it is best used mixed with other fuels, preferably with high Ca and Mg contents, and in equipment where fuel particle temperatures during combustion are moderate, i.e. fluidised beds and possibly grate combustors rather than powder combustors

    The Effects of Vitamin D Deficiency on Neurodegenerative Diseases

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    Approximately 90% of the elderly population in the western countries has at least a mild to moderate vitamin D hypovitaminosis. Besides the well-known function of vitamin D in calcium homeostasis, it has been recently found that several enzymes and receptors involved in its homeostasis are expressed in the nervous system and brain suggesting also an important role in the brain homeostasis. Interestingly, epidemiological and clinical studies found reduced vitamin D level associated with an increased risk of several neurodegenerative disorders. In this chapter, we focus on a potential link between vitamin D and Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, prion disease, and motor neuron disease. Epidemiological studies were summarized, an overview of the known potential underlying pathomolecular mechanisms are given, and results from clinical studies dealing with vitamin D supplementation were presented. As an outlook, recent literature suggesting an impact of vitamin D on autism spectrum disease, depression, and schizophrenia are briefly discussed. In conclusion, the identification of an abundant vitamin D metabolism in the brain and the tight link between the increasing number of several neurological and mental disorders emphasize the need of further research making a clear recommendation of the intake and supplementation of vitamin D in a growing elderly population

    The Impact of Vitamin E and Other Fat-Soluble Vitamins on Alzheimer´s Disease

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    Alzheimer’s disease (AD) is the most common cause of dementia in the elderly population, currently affecting 46 million people worldwide. Histopathologically, the disease is characterized by the occurrence of extracellular amyloid plaques composed of aggregated amyloid-β (Aβ) peptides and intracellular neurofibrillary tangles containing the microtubule-associated protein tau. Aβ peptides are derived from the sequential processing of the amyloid precursor protein (APP) by enzymes called secretases, which are strongly influenced by the lipid environment. Several vitamins have been reported to be reduced in the plasma/serum of AD-affected individuals indicating they have an impact on AD pathogenesis. In this review we focus on vitamin E and the other lipophilic vitamins A, D, and K, and summarize the current knowledge about their status in AD patients, their impact on cognitive functions and AD risk, as well as their influence on the molecular mechanisms of AD. The vitamins might affect the generation and clearance of Aβ both by direct effects and indirectly by altering the cellular lipid homeostasis. Additionally, vitamins A, D, E, and K are reported to influence further mechanisms discussed to be involved in AD pathogenesis, e.g., Aβ-aggregation, Aβ-induced neurotoxicity, oxidative stress, and inflammatory processes, as summarized in this article

    Equity-Focused Decision-Making Lacks Guidance!

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    Learning Analytics are an academic field with promising usage scenarios for many educational domains. At the same time, learning analytics come with threats such as the amplification of historically grown inequalities. A range of general guidelines for more equity-focused learning analytics have been proposed but fail to provide sufficiently clear guidance for practitioners. With this paper, we attempt to address this theory–practice gap through domain-specific (physics education) refinement of the general guidelines We propose a process as a starting point for this domain-specific refinement that can be applied to other domains as well. Our point of departure is a domain-specific analysis of historically grown inequalities in order to identify the most relevant diversity categories and evaluation criteria. Through two focal points for normative decision-making, namely equity and bias, we analyze two edge cases and highlight where domain-specific refinement of general guidance is necessary. Our synthesis reveals a necessity to work towards domain-specific standards and regulations for bias analyses and to develop counter-measures against (intersectional) discrimination. Ultimately, this should lead to a stronger equity-focused practice in future

    Interprofessional education: a necessity in Alzheimer’s dementia care—a pilot study

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    Introduction: Interprofessional collaboration is seen as an indispensable prerequisite for high-quality health services and patient care, especially for complex diseases such as dementia. Thus, the current project aimed to extend interprofessional and competency-based education in the field of dementia care to the previously understudied therapy professions of nutrition, speech-language pathology, and physiotherapy. Methods: A three-day workshop was designed to provide specific learning objectives related to patient-centered dementia care, as well as competences for interprofessional collaboration. Teaching and learning approaches included case-based learning in simulated interprofessional case-conferences and peerteaching. A total of 42 students (n  =  20 nutrition therapy and counseling, n  =  8 speech-language pathology, n  =  14 physiotherapy), ranging from first to seventh semester, finished the whole workshop and were considered in data analysis. Changes in self-perceived attitudes toward interprofessional collaboration and education were measured by the German version of the UWE-IP. An in-house questionnaire was developed to evaluate knowledge and skills in the field of dementia, dementia management and interprofessional collaboration. Results: Participation in the workshop led to significant improvements in the total scores of the UWE-IP-D and the in-house questionnaire, as well as their respective subscales. Moderate to large effect sizes were achieved. All professions improved significantly in both questionnaires with large effect sizes. Significant differences between professions were found in the UWE-IP-D total score between students of speech-language pathology and physiotherapy in the posttest. Students of nutrition therapy and counseling revealed a significant lower level of self-perceived knowledge and skills in the in-house questionnaire pre- and post-testing. Discussion: The pilot-study confirms the effectiveness of interprofessional education to promote generic and interprofessional dementia care competencies and to develop positive attitudes toward interprofessional learning and collaboration in the therapy professions, thus increasing professional diversity in interprofessional education research. Differences between professions were confounded by heterogenous semester numbers and participation conditions. To achieve a curricular implementation, interprofessional education should be expanded to include a larger group of participants belonging to different professions, start early in the study program, and be evaluated over the long term

    Pazopanib, Cabozantinib, and Vandetanib in the Treatment of Progressive Medullary Thyroid Cancer with a Special Focus on the Adverse Effects on Hypertension

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    Medullary thyroid cancer (MTC) is a rare malignancy with a poor prognosis. First line therapy is surgery, which is the only curative method of the disease. However, in non-operable cases or with tumor progression and metastases, a systemic treatment is necessary. This form of cancer is often insensitive to conventional chemotherapy, but the use of tyrosine kinase inhibitors (TKIs), such as pazopanib, cabozantinib, and vandetanib, has shown promising results with an increase in progression-free survival and prolonged lifetime. Therefore, we focused on the pharmacological characteristics of TKIs, their mechanism of action, their application as a secondary treatment option for MTC, their efficacy as a cancer drug treatment, and reviewed the ongoing clinical trials. TKIs also act systemically causing various adverse events (AEs). One common AE of this treatment is hypertension, known to be associated with cardiovascular disease and can therefore potentially worsen the well-being of the treated patients. The available treatment strategies of drug-induced hypertension were discussed. The mechanism behind the development of hypertension is still unclear. Therefore, the treatment of this AE remains symptomatic. Thus, future studies are necessary to investigate the link between tumor growth inhibition and hypertension. In addition, optimized, individual treatment strategies should be implemented

    Positioning responsible learning analytics in the context of STEM identities of under-served students

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    Addressing 21st century challenges, professionals competent in science, technology, engineering, and mathematics (STEM) will be indispensable. A stronger individualisation of STEM learning environments is commonly considered a means to help more students develop the envisioned level of competence. However, research suggests that career aspirations are not only dependent on competence but also on STEM identity development. STEM identity development is relevant for all students, but particularly relevant for already under-served students. Focusing solely on the development of competence in the individualisation of STEM learning environments is not only harming the goal of educating enough professionals competent in STEM, but may also create further discrimination against those students already under-served in STEM education. One contemporary approach for individualisation of learning environments is learning analytics. Learning analytics are known to come with the threat of the reproduction of historically grown inequalities. In the research field, responsible learning analytics were introduced to navigate between potentials and threats. In this paper, we propose a theoretical framework that expands responsible learning analytics by the context of STEM identity development with a focus on under-served students. We discuss two major issues and deduce six suppositions aimed at guiding the use of as well as future research on the use of learning analytics in STEM education. Our work can inform political decision making on how to regulate learning analytics in STEM education to help providing a fair chance for the development of STEM identities for all students

    Methylxanthines and Neurodegenerative Diseases: An Update

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    Methylxanthines (MTX) are purine derived xanthine derivatives. Whereas naturally occurring methylxanthines like caffeine, theophylline or theobromine are widely consumed in food, several synthetic but also non-synthetic methylxanthines are used as pharmaceuticals, in particular in treating airway constrictions. Besides the well-established bronchoprotective effects, methylxanthines are also known to have anti-inflammatory and anti-oxidative properties, mediate changes in lipid homeostasis and have neuroprotective effects. Known molecular mechanisms include adenosine receptor antagonism, phosphodiesterase inhibition, effects on the cholinergic system, wnt signaling, histone deacetylase activation and gene regulation. By affecting several pathways associated with neurodegenerative diseases via different pleiotropic mechanisms and due to its moderate side effects, intake of methylxanthines have been suggested to be an interesting approach in dealing with neurodegeneration. Especially in the past years, the impact of methylxanthines in neurodegenerative diseases has been extensively studied and several new aspects have been elucidated. In this review we summarize the findings of methylxanthines linked to Alzheimer´s disease, Parkinson’s disease and Multiple Sclerosis since 2017, focusing on epidemiological and clinical studies and addressing the underlying molecular mechanisms in cell culture experiments and animal studies in order to assess the neuroprotective potential of methylxanthines in these diseases

    Unique Role of Caffeine Compared to Other Methylxanthines (Theobromine, Theophylline, Pentoxifylline, Propentofylline) in Regulation of AD Relevant Genes in Neuroblastoma SH-SY5Y Wild Type Cells

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    Methylxanthines are a group of substances derived from the purine base xanthine with a methyl group at the nitrogen on position 3 and different residues at the nitrogen on position 1 and 7. They are widely consumed in nutrition and used as pharmaceuticals. Here we investigate the transcriptional regulation of 83 genes linked to Alzheimer’s disease in the presence of five methylxanthines, including the most prominent naturally occurring methylxanthines—caffeine, theophylline and theobromine—and the synthetic methylxanthines pentoxifylline and propentofylline. Methylxanthine-regulated genes were found in pathways involved in processes including oxidative stress, lipid homeostasis, signal transduction, transcriptional regulation, as well as pathways involved in neuronal function. Interestingly, multivariate analysis revealed different or inverse effects on gene regulation for caffeine compared to the other methylxanthines, which was further substantiated by multiple comparison analysis, pointing out a distinct role for caffeine in gene regulation. Our results not only underline the beneficial effects of methylxanthines in the regulation of genes in neuroblastoma wild-type cells linked to neurodegenerative diseases in general, but also demonstrate that individual methylxanthines like caffeine mediate unique or inverse expression patterns. This suggests that the replacement of single methylxanthines by others could result in unexpected effects, which could not be anticipated by the comparison to other substances in this substance class
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