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Products 238

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A guide for standardized interpretation of lumbar multifidus ultrasonography; an observational study

Background Inconsistent descriptions of Lumbar multifidus (LM) morphology were previously identified, especially in research applying ultrasonography (US), hampering its clinical applicability with regard to diagnosis and therapy. The aim of this study is to determine the LM-sonoanatomy by comparing high-resolution reconstructions from a 3-D digital spine compared to standard LM-ultrasonography. Methods An observational study was carried out. From three deeply frozen human tissue blocks of the lumbosacral spine, a large series of consecutive photographs at 78 µm interval were acquired and reformatted into 3-D blocks. This enabled the reconstruction of (semi-)oblique cross-sections that could match US-images obtained from a healthy volunteer. Transverse and oblique short-axis views were compared from the most caudal insertion of LM to L1. Results Based on the anatomical reconstructions, we could distinguish the LM from the adjacent erector spinae (ES) in the standard US imaging of the lower spine. At the lumbosacral junction, LM is the only dorsal muscle facing the surface. From L5 upwards, the ES progresses from lateral to medial. A clear distinction between deep and superficial LM could not be discerned. We were only able to identify five separate bands between every lumbar spinous processes and the dorsal part of the sacrum in the caudal anatomical cross-sections, but not in the standard US images. Conclusion The detailed cross-sectional LM-sonoanatomy and reconstructions facilitate the interpretations of standard LM US-imaging, the position of the separate LM-bands, the details of deep interspinal muscles, and demarcation of the LM versus the ES. Guidelines for electrode positioning in EMG studies should be refined to establish reliable and verifiable findings. For clinical practice, this study can serve as a guide for a better characterisation of LM compared to ES and for a more reliable placement of US-probe in biofeedback.

MULTIFILE

06/30/2022
A guide for standardized interpretation of lumbar multifidus ultrasonography; an observational study
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Predictors of mid-term event-free survival in adults with corrected tetralogy of Fallot

Objectives Patients who underwent corrective surgery for tetralogy of Fallot (TOF) have increased long-term risk of cardiovascular morbidity and mortality. Yet, limited information is available on how to evaluate the risk in this population. Therefore, the aim of this study was to investigate the prognostic value of aerobic exercise capacity, along with other related parameters, at medium-term follow-up in adult patients with tetralogy of Fallot. Methods and results Between 2000 and 2003, 92 adults (age 26.2 ± 7.8 years; 63 male) with corrected TOF or TOF-type morphology underwent a cardiopulmonary exercise test (CPET) until exhaustion and echocardiography. During a mean follow-up of 7.3 ± 1.2 years (range 0.9 to 9.3 years), 2 patients died and 26 patients required at least 1 cardiac-related intervention at a mean age of 28.9 ± 7.9 years. Event-free survival tended to be higher in patients with the classical type of TOF (P = 0.061). At multivariate Cox analysis, age at CPET [hazard ratio (HR): 1.13, P = 0.006], age at correction (HR: 0.82, P = 0.037), right ventricular (RV) function (HR: 4.94, P = 0.001), QRS duration (HR: 1.02, P = 0.007), percentage of predicted peak oxygen uptake (peak VO2%) (HR: 0.96, P = 0.029) and ventilatory effi ciency slope (VE/VCO2 slope) (HR: 1.13, P = 0.021) were signifi cantly related to the incidence of death/cardiac-related intervention during medium follow-up. Conclusions Early corrective surgery and a well-preserved RV are associated with a better outcome in adults with corrected TOF. Furthermore, CPET provides important prognostic information; peak VO2% and VE/VCO2 slope are independent predictors for event-free survival in patients with corrected TOF.

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12/31/2011
Predictors of mid-term event-free survival in adults with corrected tetralogy of Fallot
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'Hakken en plakken'

Orthography is considered to be a major problem in Dutch education, since many pupils don’t seem to be able to master orthographic rules, even after years of education. In educational literature it is argued that the problems related to spelling are caused by approaches that focus more on rules of thumb than on linguistic insights. This is somewhat remarkable, since a good understanding of the Dutch orthographic system requires a fair amount of morphological knowledge. In order to effectively implement this knowledge, the development of a morphological awareness (MA) seems to be required. Therefore, a short intervention was designed for the upper levels of secondary schools (4 havo) which aimed to foster MA and, subsequently, improve orthographic skills. Results of this quasi-experimental study indicate that a short intervention can significantly boost MA, but that students don’t seem to be able to use MA effectively to enhance spelling performance.

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10/23/2019
'Hakken en plakken'

Projects 2

project

Biobased leer op basis van mycelium

Dit project richt zich op de ontwikkeling van de biotechnologische en chemische procesvoering om op basis van mycelium een alternatief voor leer te produceren. In vergelijking met leer is het voordeel van mycelium dat geen runderen nodig zijn, de productie kan plaatsvinden onder industriële condities en met gebruik van reststromen, de CO2 uitstoot alsook hoeveelheid afval verlaagd wordt, en het gebruik van toxische stoffen zoals chroom wordt vervangen door biobased alternatieven. In het project zullen de procescondities worden bepaald die leiden tot de vorming van optimaal mycelium. Daartoe zullen twee verschillende schimmels worden gekweekt in bioreactoren bij de Hogeschool Arnhem Nijmegen (HAN), waarbij specifiek de effecten van de procescondities (temperatuur, pH, shear, beluchting) en de samenstelling van het kweekmedium op groei van het mycelium en materiaal eigenschappen zullen worden onderzocht. De meest optimale condities zullen vervolgens worden opgeschaald. Op het op deze wijze verkregen materiaal zal Mylium BV een aantal nabehandelingsstappen uitvoeren om de sterkte, elasticiteit, en duurzaamheid van het product te vergroten. Daartoe worden biobased plasticizers, cross-linkers en/of flexibility agents gebruikt. Het resulterende eindproduct zal middels specifiek fysieke testen vergeleken worden met leer alsook worden voorgelegd aan mogelijke klanten. Indien beide resultaten positief zijn kan het betreffende proces na het project verder worden opgeschaald voor toepassing naar de markt.

Finished
project

MICROL: Production of microparticle-based long-acting injectable protein formulations by supercritical microfluidic (SCMF) technology delivery systems

Biotherapeutic medicines such as peptides, recombinant proteins, and monoclonal antibodies have successfully entered the market for treating or providing protection against chronic and life-threatening diseases. The number of relevant commercial products is rapidly increasing. Due to degradation in the gastro-intestinal tract, protein-based drugs cannot be taken orally but need to be administered via alternative routes. The parenteral injection is still the most widely applied administration route but therapy compliance of injection-based pharmacotherapies is a concern. Long-acting injectable (LAI) sustained release dosage forms such as microparticles allow less frequent injection to maintain plasma levels within their therapeutic window. Spider Silk Protein and Poly Lactic-co-Glycolic Acid (PLGA) have been attractive candidates to fabricate devices for drug delivery applications. However, conventional microencapsulation processes to manufacture microparticles encounter drawbacks such as protein activity loss, unacceptable residual organic solvents, complex processing, and difficult scale-up. Supercritical fluids (SCF), such as supercritical carbon dioxide (scCO2), have been used to produce protein-loaded microparticles and is advantageous over conventional methods regarding adjustable fluid properties, mild operating conditions, interfacial tensionless, cheap, non-toxicity, easy downstream processing and environment-friendly. Supercritical microfluidics (SCMF) depict the idea to combine strengths of process scale reduction with unique properties of SCF. Concerning the development of long-acting microparticles for biological therapeutics, SCMF processing offers several benefits over conventionally larger-scale systems such as enhanced control on fluid flow and other critical processing parameters such as pressure and temperature, easy modulation of product properties (such as particle size, morphology, and composition), cheaper equipment build-up, and convenient parallelization for high-throughput production. The objective of this project is to develop a mild microfluidic scCO2 based process for the production of long-acting injectable protein-loaded microparticles with, for example, Spider Silk Protein or PLGA as the encapsulating materials, and to evaluate the techno-economic potential of such SCMF technology for practical & industrial production.

Ongoing