152 research outputs found
In vivo biodistribution of stem cells using molecular nuclear medicine imaging
No full textStudies on stem cell are rapidly developing since these cells have great therapeutic potential for numerous diseases and has generated much promise as well as confusion due to contradictory results. Major questions in this research field have been raised as to how and in which numbers stem cells home to target tissues after administration, whether the cells engraft and differentiate, and what their long-term fate is. To answer these questions, reliable in vivo tracking techniques are essential. In vivo molecular imaging techniques using magnetic resonance imaging, bioluminescence, and scintigraphy have been applied for this purpose in experimental studies. The aim of this review is to discuss various radiolabeling techniques for early stem cell tracking, the need for validation of viability and performance of the cells after labeling, and the routes of administration in experimental animal models. In addition, we evaluate current problems and directions related to stem cell tracking using radiolabels, including a possible role for their clinical implementation. © 2010 Wiley-Liss, Inc
Current Opportunities and Challenges of Next Generation Sequencing (NGS) of DNA; Determining Health and Diseases
No full textMany publications have demonstrated the huge potential of NGS methods in terms of new species discovery, environment monitoring, ecological studies, etc. [24,35,92,97,103]. Undoubtedly, NGS will become one the major tools for species identification and for routine diagnostic use. While read lengths are still quite short for most existing systems ranging between 50 bp and 800 bp, they are likely to improve soon. This will enable easier, faster, and more reliable contig assembly and subsequent matching against reference databases. When data generation is no longer a bottleneck, the storage, speed of analysis, and interpretation of DNA sequence data are becoming the major challenges. Also, the integration or the use of data originating from diverse datasets and a variety of data providers are serious issues that need to be addressed. Poor sequence record annotations and species name assignments are known problems that should be instantly addressed and would allow the creation of reference databases used for routine diagnostics based on NGS. Samples with huge amounts of short DNA fragments need to be analyzed and compared against reference databases in an efficient and fast way. Although a number of solutions have been proposed by Industry; offering commercial software, there still remain hurdles to take. One of the challenges that we need to address is data upload from client’s computers to central or distributed data storage and analysis services. Another one is the efficient parallelization of analyses using cloud or grid solutions. The reliability and up-time of storage and analyses facilities is another important problem that need to be addressed if one wants to use it for routine diagnostics. Finally, the management, reporting and visualization of the analyses results are among the last issues, but not the least challenging ones. Considering the constant growth of computational power and storage capacity needed by different bioinformatics applications, working with single or a limited number of servers is no longer realistic. Using a cloud environment and grid computing is becoming a must. Even single cloud service provider can be restrictive for bioinformatics applications and working with more than one cloud can make the workflow more robust in the face of failures and always growing capacity needs. In this white paper we review the current state of the art in this field. We discuss the main limitations and challenges that we need to address such as; data upload from client’s computers to central or distributed data storage and analysis services; efficient parallelization of analyses using grid solutions; reliability and up-time of storage and analyses facilities for routine diagnostics; management, retrieving and visualization of the analyses results
Combinatory Use of hLF(1-11), a Synthetic Peptide Derived from Human Lactoferrin, and Fluconazole/Amphotericin B against Malassezia furfur Reveals a Synergistic/Additive Antifungal Effect
No full textObjective: The increasing resistance of Malassezia yeasts against commonly used antifungal drugs dictates the need for novel antifungal compounds. Human actoferrin-based peptides show a broad spectrum of antimicrobial activities. Various assays were performed to find the optimal growth conditions of the yeasts and to assess cell viability, using media with low lipid content to avoid peptide binding to medium components. Methods: In the current study, we tested the antimicrobial susceptibility of 30 strains of M. furfur that cover the known IGS1 genotypic variation. Results: hLF(1-11) inhibited the growth of all species tested, resulting in minimum inhibitory concentrations (MIC) values ranging from 12.5 to 100 μg/mL. In the combinatory tests, the majority of fractional inhibitory concentration indexes (FIC) for the tested strains of M. furfur were up to 1.0, showing that there is a synergistic or additive effect on the efficacy of the antifungal drugs when used in combination with hLF(1-11). Conclusion: Results showed that hLF(1-11) could be combined with fluconazole or amphotericin for the antimicrobial treatment of resistant strains, enhancing the potency of these antifungal drugs, resulting in an improved outcome for the patient
Paradise lost. [electronic resource] : A poem, in twelve books. The author John Milton.
No full textWith two final advertisement leaves.frontis = ill. - These sheets were reissued in 1719 with a different titlepage bearing the imprint: printed for M. Welling. Pp.78,79,93,159,273 misnumbered 76,78,39,156,293 respectivelyElectronic reproduction.English Short Title Catalog,Reproduction of original from British Library
Dasycladus vermicularis Krasser 1898
No full text<i>2.1. Sulfated metabolites of D. vermicularis</i> <p> <b>⇑</b> Corresponding author. <i>E-mail address:</i> [email protected] (G. Pohnert).</p> <p> Three candidate molecules for which sulfatation was indicated by the presence of a fragment of [M–H–80] – in the mass spectrum were detected by UPLC–MS/MS measurements in extracts of <i>D. vermicularis</i>. The metabolite with a mass of 273 [M–H] – and a fragment with <i>m</i> / <i>z</i> = 193 could readily be assigned to dihydroxycoumarin sulfate (Fig. 1) based on previous results and co-injection with a synthetic standard (Welling et al., 2009). For identification of the two unknown potentially sulfated metabolites (<i>m</i> / <i>z</i> = 217 [M–H] – and 231 [M–H] –, respectively) synthetic standards were prepared. Based on mass spectra and polarity in UPLC–MS (Fig. 2A, D and F) we selected 4-(sulfooxy)benzoic acid (SBA) and 4-(sulfooxy)phenylacetic acid (SPA) as likely candidates. After estimation of the content of the metabolites in the algal extract, co-injection experiments with algal extract and the synthetic standards were performed (Fig. 2C and E). Peak symmetry was important since the short retention times and strong solvent effects of the samples required a rigorous quality control of co-eluting peaks. SBA showed the same retention time and mass spectrum to the first sulfated metabolite in the <i>D. vermicularis</i> extract. When added in co-injection experiments, an increase of intensity of the first signal was observed (Fig. 2C). The mass spectrum remained unaffected by the co-injection. The <i>ortho</i> - and <i>meta</i> -isomers of (sulfooxy)benzoic acid eluted at different retention times (data not shown). The same procedure was applied for co-injection of SPA (Fig. 2E). No significant change in peak symmetry was observed upon addition of SBA or SPA, which unambiguously confirms the identity of the natural and synthetic products. Besides the occurrence as catabolic products in mouse urine, these metabolites have to our knowledge not been reported as natural products before (Manna et al., 2011; van der Hooft et al., 2012).</p>Published as part of <i>Kurth, Caroline, Welling, Matthew & Pohnert, Georg, 2015, Sulfated phenolic acids from Dasycladales siphonous green algae, pp. 417-423 in Phytochemistry 117</i> on page 417, DOI: 10.1016/j.phytochem.2015.07.010, <a href="http://zenodo.org/record/10486436">http://zenodo.org/record/10486436</a>
Developing a tested vision for the design of a child participation toolkit for the SWKGroep
No full textThis report describes my graduation report for the Master Design for Interaction, part of Industrial Design Engineering at the technical University Delft. The project is in collaboration with both the Play Well Lab and the SWKGroep. The SWKGroep asked for a child participation toolkit which would help them discover the latent knowledge of the children. In order to be able to go into depth while designing this toolkit, the project is split up into two individual graduation projects. This report describes the first project.“My design goal is to develop a substantiated and partly tested vision for the development of a child participation Toolkit, which is suitable within the context of the SWKGroep facilities and based on the expectations, wishes, needs and capacity of both the staff members as well as the children.”The first chapter will introduce the different stakeholders involved in the project. These are the SWKGroep and the Play Well Lab. The chapter will conclude with the relevance of this project for both stakeholders. The second chapter will describe the research phase, including different interviews, a generative session and an analysis of the results. The chapter will conclude with the discovered problem area and my design focus within this project. Within the third chapter, an approach for this defined problem area will be defined. The chosen approach will be explained and the chapter concludes with an explanation on why this approach would fit the defined problem area. After describing this approach, the approach will be elaborated into ideas. This is done in chapter 4, which includes the ideation phase. This chapter will end with a set of 23 ideas/tools which could be used for child participation at the BSO. The next step, described in chapter 5, is validation of the approach. This is done by testing a selection of the ideas at the BSO to see what the obstacles and enablers are when doing child participation at the BSO. The insights from the user-tests are discussed and this chapter will conclude with a validation of the approach including conditions to be met and an overview of opportunities which were found during the tests. Chapter 6 will conclude this report with recommendations for the follow-up project and a reflection on this project.Design for Interactio
Effects of physical exercise and body weight on disease-specific outcomes of people with rheumatic and musculoskeletal diseases (rmds): systematic reviews and meta-analyses informing the 2021 eular recommendations for lifestyle improvements in people with
No full textThis work was funded by the European League Against Rheumatism.
SMMV and JMG are supported by Versus Arthritis (grant number 21755) and the
NIHR Manchester Biomedical Research Centre. The views expressed are those of
the author(s) and not necessarily those of the NHS, the NIHR or the Department of
Health.Gwinnutt J.M., Wieczorek M., Cavalli G., Balanescu A., Bischoff-Ferrari H.A., Boonen A., De Souza S., De Thurah A., Dorner T.E., Moe R.H., Putrik P., Rodríguez-Carrio J., Silva-Fernández L., Stamm T., Walker-Bone K., Welling J., Zlatković-Švenda M.I., Guillemin F., Verstappen S.M.M
Extensional viscosity aspects of HPAM in porous flow: An experimental and numerical study
No full textPolymer flooding is the most widely used chemical EOR method. Despite being widely used, the apparent shear-thickening behaviour of the polymer solutions in porous flow at high flow rates is poorly understood. One of the supposed mechanisms is the strain-thickening behaviour of polymer solutions. This fluid property will alter the flow dynamics during porous flow compared to Newtonian and purely shear-thinning flow. In this research, the objective is to improve our understanding of polymer flow through a simple single slit geometry (e-VROC) and more complex geometries (porous flow characterised by pore network models) in order to allow oil recovery optimisation for polymer flooding. The intrinsic viscosity of HPAM3630S is investigated experimentally using the Extensional Viscometer/ Rheometer On a Chip (e-VROC). The e-VROC has a microfluidic hyperbolically-shaped contraction-expansion geometry. The water salinity is used as a control parameter to reduce the fluid viscosity. Initial calibration of the device with Newtonian fluids and analytical analysis of the e-VROC geometry indicate that the shear component of the flow is large in the converging section – contrary to the claimed advantages of the hyperbolic geometry. Newtonian flow can therefore not be regarded as extension dominated. Consequently, the provided analysis of the e-VROC pressure data is currently unable to determine the true extensional viscosity of a Newtonian fluid. Therefore the analysis should be regarded as an extensional viscosity indexer in comparing different fluids. For polymer flowthe pressure gradient over the contraction-expansion area increases more than linearlywith increasing flow rate. This indicates strain-thickening behaviour. The salinity highly impacts the amount of strain-thickening; the higher the brine salinity the lower the pressure gradient over the contraction-expansion area. Furthermore, a high noise content in the time-pressure signal is observed together with reproducibility problems regarding polymer flow. Differences upto 30% in pressure gradients between measurements are reported for the same fluid. Both can probably be attributed to elasticity due to the short residence time of the polymer solutions in the contraction-expansion geometry compared to their relaxation times. The fluid flow process is modelled using finite element modelling (GeoDict&COMSOL) and pore network modelling using MATLAB to study the (changed) fluid flow behaviour. It was shown that Newtonian flow through the e-VROC can be modelled using both COMSOL and GeoDict. Furthermore, it was shown that the pressure drop due to pure shear losses in the e-VROC can be significant during polymer flow. The developed Matlab code enables modelling the steady state response of pore network systems. The systems contains more than 10000 non-linear throat equations. This captures both extension-thickening and shear-thinning pressure losses. This successfully demonstrates proof of concept set out at the beginning of this study. Using the pore network model, it is studied how a macroscopic pressure over a rock sample is redistributed in microscopic pressure drops between individual pores. It is shown that the microscopic pressure drop distribution forNewtonian flowpredicted by the pore network model is in good agreementwith the microscopic pressure drop distribution inside the porous medium predicted by GeoDict. However, the corresponding permeability predicted by the pore network modelling is one order of magnitude too low. From this it can be concluded that the resistance to flow between the pores is overestimated by the used transport equations. Nevertheless, a qualitative interpretation of the (changed) microscopic redistribution of pressure for non-Newtonian flow can still be made. Secondly, the microscopic pressure drop distribution within the sample for purely shear-thinning flow is compared to Newtonian flow. The variance and kurtosis of the distribution decrease compared to Newtonian flow. This implies better conformance control during using purely shear-thinning flow. Above a critical flow rate, strain-thickening behaviour reverses this process. The variance and kurtosis of the pressure drop distribution increase. This has a negative impact on conformance control.Petroleum EngineeringGeoscience & EngineeringCivil Engineering and Geoscience
- …
