37 research outputs found
Preparation of Dispersed Particle Gel (DPG) through a Simple High Speed Shearing Method
No full textDispersed particle gel (DPG) has been first successfully prepared using cross-linked gel systems through a simple high speed shearing method with the aid of a colloid mill at room temperature. The gel microstructure and particle size were investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), and dynamic light scattering (DLS) measurements. The results clearly show that the prepared DPG particles have highly uniformly spherical structures with an average size of 2.5 μm. A possible mechanism for the formation of DPG has been put forward and discussed in details. The high speed shearing method is considered to be the simple and rapid method for the preparation of DPG
Lanthanide ions induce hydrolysis of hemoglobin-bound 2,3-diphosphoglycerate (2,3-DPG), conformational changes of globin and bidirectional changes of 2,3-DPG-hemoglobin’s oxygen affinity
No full textAbstractThe changes in structure and function of 2,3-diphosphoglycerate-hemoglobin (2,3-DPG-Hb) induced by Ln3+ binding were studied by spectroscopic methods. The binding of lanthanide cations to 2,3-DPG is prior to that to Hb. Ln3+ binding causes the hydrolysis of either one from the two phosphomonoester bonds in 2,3-DPG non-specifically. The results using the ultrafiltration method indicate that Ln3+ binding sites for Hb can be classified into three categories: i.e. positive cooperative sites (NI), non-cooperative strong sites (NS) and non-cooperative weak sites (NW) with binding constants in decreasing order: KI>KS>KW. The total number of binding sites amounts to about 65 per Hb tetramer. Information on reaction kinetics was obtained from the change of intrinsic fluorescence in Hb monitored by stopped-flow fluorometry. Fluctuation of fluorescence dependent on Ln3+ concentration and temperature was observed and can be attributed to the successive conformational changes induced by Ln3+ binding. The results also reveal the bidirectional changes of the oxygen affinity of Hb in the dependence on Ln3+ concentration. At the range of [Ln3+]/[Hb]<2, the marked increase of oxygen affinity (P50 decrease) with the Ln3+ concentration can be attributed to the hydrolysis of 2,3-DPG, while the slight rebound of oxygen affinity in higher Ln3+ concentration can be interpreted by the transition to the T-state of the Hb tetramer induced by Ln3+ binding. This was indicated by the changes in secondary structure characterized by the decrease of α-helix content
Restoring the oncosuppressor activity of microRNA-34a in glioblastoma using a polyglycerol-based polyplex
No full textAbstractGlioblastoma multiforme (GBM) is the most common and aggressive primary neoplasm of the brain. Poor prognosis is mainly attributed to tumor heterogeneity, invasiveness, and drug resistance. microRNA-based therapeutics represent a promising approach due to their ability to inhibit multiple targets. In this work, we aim to restore the oncosuppressor activity of microRNA-34a (miR-34a) in GBM. We developed a cationic carrier system, dendritic polyglycerolamine (dPG-NH2), which remarkably improves miRNA stability, intracellular trafficking, and activity. dPG-NH2 carrying mature miR-34a targets C-MET, CDK6, Notch1 and BCL-2, consequently inhibiting cell cycle progression, proliferation and migration of GBM cells. Following complexation with dPG-NH2, miRNA is stable in plasma and able to cross the blood–brain barrier. We further show inhibition of tumor growth following treatment with dPG-NH2–miR-34a in a human glioblastoma mouse model. We hereby present a promising technology using dPG-NH2–miR-34a polyplex for brain-tumor treatment, with enhanced efficacy and no apparent signs of toxicity
Approximation properties of primal discontinuous Petrov-Galerkin method on general quadrilateral meshes
No full textAbstract
We consider the approximation properties of primal discontinuous Petrov-Galerkin (DPG) method on quadrilateral meshes. We show how the previous convergence results as well as the Aubin-Nitsche type duality arguments can be extended to cover arbitrary convex quadrilateral elements with bilinear isomorphisms. The arguments are based on the approximation theory of quadrilateral vector finite element spaces associated to the numerical flux variable of the DPG approximation. The theoretical results are validated by a numerical experiment that features also a comparison between the primal DPG method and a conventional least squares finite element method with the same number of degrees of freedom.Abstract
We consider the approximation properties of primal discontinuous Petrov-Galerkin (DPG) method on quadrilateral meshes. We show how the previous convergence results as well as the Aubin-Nitsche type duality arguments can be extended to cover arbitrary convex quadrilateral elements with bilinear isomorphisms. The arguments are based on the approximation theory of quadrilateral vector finite element spaces associated to the numerical flux variable of the DPG approximation. The theoretical results are validated by a numerical experiment that features also a comparison between the primal DPG method and a conventional least squares finite element method with the same number of degrees of freedom
Surfactant-stabilized copper paticles for low-temperature sintering: Paste preparation using a milling with small zirconia beads : Effect of pre-treatment with the disperse medium
No full textCopper paste is considered as a promising candidate for printed electronics in replacement for silver paste. This is owing to copper which has anti-electromigration property, lower cost, and similar conductivity and compared with silver. We synthesize a copper nanoparticle (NP) paste that can be sintered at low temperature for high conductivity. The copper NP paste composes of 50 wt% copper NPs and dipropylene glycol (DPG) as the disperse medium. The effect of DPG coating and various conditions of milling with small beads on improving the dispersity of copper NPs has been investigated. The optimum conditions for milling are at 1000 and 2000 rpm for 30 min. This results in a volume resistivity of 6.62 x 10(-6) Omega.cm after sintering the copper NP paste at 200 degrees C. (C) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved
A personalised newsplatform for de Volkskrant: Discovering the possibilities of the collaboration between journalists and algorithms at de Volkskrant and DPG Media
No full textThis master thesis for Strategic Product Design at the TU Delft presents a design for a personalised Volkskrant-app. The goal of this project was to explore the different possibilities of personalisation and see how it could help de Volkskrant fulfil its mission to enrich their reader’s life through news. Why?During my whole project I have involved readers, journalists and the product developers at DPG Media. Within the theory analysis, interviews and conversations I had with these stakeholders I have identified four reasons for implementing personalisation in the digital news distribution product of the Volkskrant:Facilitating the fulfilment of the diverse reader needs of the subscribers.The current home feed of the app and website of de Volkskrant mainly focus on the update-me need. Developing the platform of de Volkskrant into a product that takes full advantage of the possibilities of digital news distribution.The current digital news distribution product offer of de Volkskrant is still seen as a digital translation of the physical newspaper. It is time to look at what digital developments can offer something different. Offering an extra service for the users of the platform of de VolkskrantThe rise of competitive platforms for news put pressure on the business model of de Volkskrant. Personalisation could offer an extra service to bind readers to the app of de Volkskrant. Limiting the news overload that readers experience in current day and age. De Volkskrant should help subscribers to find the articles they look for and offer a clear overview.How?To create an algorithm that would facilitate more needs of the readers, I came up with co-curation of the news. The digital news will now be curated by both journalists and an algorithm, both having a different responsibility:Journalists: Delivering on the promise of creating the most relevant news events and productions that make de Volkskrant stand out. Algorithms: Bringing the niche articles to the right readers by fulfilling their personal habits, deepening their knowledge in specific topics and surprising them with suggestions out of their filter bubble. What?The final design proposes two newly designed interfaces for the app of de Volkskrant. Focusing on two scenarios: Getting the right article to the right reader: the home feedThe newly designed home feed is co-curated. A horizontal scroll bar was added to the home feed saying ‘de belangrijkste verhalen voor jou’ - the most important stories for you. This addition is based on three key principles for personalisation: transparency, autonomy and diversity. The horizontal scroll bar is distinctive because of its look, title and scrolling direction, allowing the users to dive into it or leave it out in their session.Strategic Product Desig
‘The environment was like they were in the pub but with no alcohol’ - A process evaluation of engagement and sustainability in Men on the Move an Irish community-based physical activity intervention
No full textMen’s health and life expectancy, particularly for those men from lower socioeconomic groups, remains an issue of concern in Ireland. This concern is reflected in the recent National Men’s Health Action Plan where important priority has been placed on finding appropriate ways to garner sustained involvement in health promotion interventions for men. Physical activity (PA) has been shown to be a useful ‘hook’ to assist with such engagement. ‘Men on the Move’ (MOM) is a 12 week, community-based, gender-sensitised, PA programme established as a pragmatic controlled trial and aimed at improving the health and well-being of inactive men. The programme was co-created with Local Sports Partnerships (LSP), delivered by experienced PA Coordinators (PACs), and often supported by local community champions.
This paper reports on the process evaluation of the MOM programme using data collected from focus groups with the LSP’s and those involved in delivering MOM from all eight counties that took part. Findings highlight the importance of negotiated partnerships at and between national and local levels in terms of providing support, consistent guidance and appropriately branded materials to the LSP’s. The underpinning inclusive ethos of MOM, embodied by the PAC’s, led to the creation of a fun, inclusive and comfortable atmosphere that helped sustain men’s involvement. This was aided by the use of male familiar settings through which to deliver the programme. While PA focused, findings here suggest a much wider impact on mental well-being and social connection and that this was achieved in a very cost-effective way. Importantly, men’s health training (ENGAGE) was a key factor in programme design and implementation assisting in building capacity among service providers to work with men. Joined up service provision and drawing on existing, trusted, local community networks were vital to recruiting men into the programme. Finally, the potential for MOM to signpost and offer an aftercare plan to community support for the men beyond the 12-week programme was noted as important particularly where there is increased need of these among more marginalised groups of men.
This process evaluation provides a good example of how health promotion interventions need to recognise and exploit the fact that health and well-being are integrally linked to the communities where people live out and experience their daily lives. Ensuring that MOM was embedded within existing community structures, and supported by community champions with the requisite skills and local knowledge, underpinned programme success and sustainability
On the Verdict of the German Physical Society Against the Karlsruhe Physics Course – a Chronicle of Events
No full textThe Karlsruhe Physics Course (KPC) is a novel approach to the teaching of physics at the secondary school. It was developed more than 30 years ago. The KPC textbooks have since been used in a certain, slightly increasing number of German schools. Simultaneously, ideas of the KPC have found their way into the mainstream textbooks. Only recently, the German Physical Society (DPG) got aware of the course. In their opinion the KPC represents a danger to the teaching of physic. Therefore, the DPG nominated an expert panel with the assignment of finding scientific errors in the KPC. The panel believed to have found such errors. Thereupon the DPG has initiated a campaign with the objective of eliminating not only the KPC textbooks from the market but to eradicate any other manifestation of ideas that might have originated in the KPC work. The DPG did so not only in Germany but worldwide. Among other things, the DPG alerted the European Physical Society and the Chinese Physical Society. As a result of these measures, a discussion of unusual fierceness arose, first in Germany, but then spreading to other countries. Thereby the physics community got more and more polarized. A chronicle of an eventful year and a brief evaluation will be given from the perspective of the author of the course and of a teacher who uses the KPC in his classes
Effect of Sustained Hand Grip Isometric Exercise on the Response of Erythrocyte 2,3-diphosphoglycerate in Untrained Men
No full textAuthor Institution: Department of Biology, University of DaytonExperiments were designed to examine the role of erythrocyte 2,3-diphosphoglycerate (2,3-DPG) in a purely isometric exercise (hand-grip dynamometer) using the human arm as an in vivo model, since the literature contains very little information concerning the contribution of this phosphate in such exercise. 2,3-DPG provides a compensatory adjustment to facilitate oxygen delivery during hypoxic conditions. Its breakdown occurs under acidosis. Twelve untrained males, age ranging from 19 to 22 years, exercised using a hand-grip dynamometer at a sustained contraction of load greater than 50% of their individual maximal voluntary contractions (MVC) until exhaustion occurred between 1.8-3.2 min. There were no significant post-exercise changes in the mean levels of 2,3-DPG when measured as either |imolml * red blood cell (RBC) or mol-mol1 hemoglobin (Hb) immediately after exercise and 50 min after exercise even though immediate post-exercise increase in mean lactate levels and decrease in mean pH levels were significant (P <0.001). It is concluded that the duration of exercise in the present study was too brief for acidosis to affect 2,3-DPG metabolism
Effects of yoga practice on body image and interoceptive awareness in young women: a randomized controlled trial with self-report and psychophysiological measures
No full textopenLa letteratura ha dimostrato che il coinvolgimento in attività embodying, ovvero che incoraggiano la connessione della mente con il corpo, è associato allo sviluppo di immagine corporea positiva e all’aumento della consapevolezza enterocettiva (Menzel & Levine, 2011; Fredrickson & Roberts, 1997; Arora & Bhattacharjee, 2008), entrambi considerabili fattori protettivi rispetto allo sviluppo di psicopatologia legata all’immagine corporea, come i disturbi dell’alimentazione (Cash & Deagle, 1997; Fairburn & Harrison, 2003), e predittivi di benessere psico-fisico (Franzoi, 1995). Il presente elaborato si propone di indagare, tramite misurazioni self-report e rilevazioni psicofisiologiche, l’efficacia di un intervento randomizzato controllato basato sulla pratica di yoga nei due costrutti di interesse (i.e. immagine corporea e consapevolezza enterocettiva), in confronto alla pratica di attività fisica di tipo non-embodying (i.e. ginnastica total body). I risultati consentiranno di comprendere in modo approfondito l’effetto della pratica di yoga sull’immagine corporea e la consapevolezza enterocettiva delle giovani donne.The literature hows that engaging in embodying activities, which encourage connection mind-to-body, is useful to enhance positive body image and interoceptive awareness (Menzel & Levine, 2011; Fredrickson & Roberts, 1997; Arora & Bhattacharjee, 2008). Both of these constructs are considered protective factors against the development of body image-related psychopathologies, such as eating disorders (Cash & Deagle, 1997; Fairburn & Harrison, 2003), and are predictive of overall physical and psychological well-being (Franzoi, 1995). The present study aims to investigate, through self-report measures and psychophysiological assessments, the effectiveness of a randomized controlled intervention based on yoga practice on the two constructs of interest (i.e., body image and interoceptive awareness), compared to the practice of a non-embodying physical activity (i.e., total body workout). The results will provide a deeper understanding of the impact of yoga practice on body image and interoceptive awareness in young women
