73 research outputs found
Interactive tailor system
Interactive Tailor System is an online system designed for tailors. A system that enables tailors to keep the data of their customers. A profile of each customer will be created by the tailor. All necessary details of the clients are stored in the system and retrieved. The measurements of customers will be recorded and found easily when needed. The tailors will use a picture see the measurements of the customers. The tailor will need to click the leg in order to see how much it measures. Before using the system users need to register then they must login with their username and password in order to enter the system. The system is constituted of different components such login function, insertion of data in the database, extraction of data from the database, search facility, mail sending. The methodology chosen to develop this system is waterfall model approach. This method is simple to implement, the amount of resources needed are minimal and after each phase the output is obtained, therefore it has clear visibility
Interactive tailor system
Interactive Tailor System is an online system designed for tailors. A system that enables tailors to keep the data of their customers. A profile of each customer will be created by the tailor. All necessary details of the clients are stored in the system and retrieved. The measurements of customers will be recorded and found easily when needed. The tailors will use a picture see the measurements of the customers. The tailor will need to click the leg in order to see how much it measures. Before using the system users need to register then they must login with their username and password in order to enter the system. The system is constituted of different components such login function, insertion of data in the database, extraction of data from the database, search facility, mail sending. The methodology chosen to develop this system is waterfall model approach. This method is simple to implement, the amount of resources needed are minimal and after each phase the output is obtained, therefore it has clear visibility
Impact modifiers als high-tech toepassing van RAFT polymerisatie : van experiment tot modelgebaseerd ontwerp
Prenatal stress exposure is associated with increased dyspnoea perception in adulthood
Prenatal exposure to maternal stress is associated with increased perception of dyspnea in adulthood 28 years later
Groene kunstmeststoffen
In Vlaanderen wordt er jaarlijks 66 miljoen kg N en 4,5 miljoen kg P2O5 als kunstmest gebruikt in de landbouw. Nochtans vergt de aanmaak van kunstmest-N m.b.v. fossiele grondstoffen zeer veel energie (37 GJ/ton NH4 of 2 L olie per ton N). Daarnaast heerst wereldwijd de discussie over een dreigend fosfaattekort. Fosfaat is immers een eindige grondstof, in die zin dat rijke fosfaatertsen opraken en de stof na gebruik in de landbouw uiteindelijk met de huidige technologie niet meer beschikbaar is. Tegen het einde van deze eeuw zullen de beschikbare natuurlijke bronnen dan ook grotendeels zijn opgebruikt. Een gelijkaardig probleem stelt zich voor essentiële micronutriënten. Het wordt dan ook meer en meer duidelijk dat we in de overgang van fossiele naar hernieuwbare economie ook meer aandacht zullen moeten besteden aan recuperatie en hergebruik van macro- en micronutriënten, bv. uit mest- en digestaatverwerking
Impact modifiers als high-tech toepassing van RAFT polymerisatie
Schokweerstand is één van de belangrijkste eigenschappen van een kunststof voor succesvol gebruik in allerlei toepassingen. Om de schokweerstand te boosten, kan een impact modifier (zie Figuur 1) in de vorm van core-shell nanodeeltjes toegevoegd worden aan kunststoffen. De productie van deze core-shell nanodeeltjes is echter niet vanzelfsprekend en vergt het gebruik van een gecontroleerde polymerisatietechniek, namelijk reversibele additie-fragmentatie ketentransfer (RAFT) polymerisatie, in emulsie. Als RAFT-specifiek reagens worden xanthaten aangewend. Ondanks een verminderde controle over de ketengroei, hebben xanthaten als specifiek voordeel dat ze oppervlakteactief zijn en daarom kunnen gebruikt worden voor de productie van core-shell nanodeeltjes
Zilucoplan in patients with acute hypoxic respiratory failure due to COVID-19 (ZILU-COV) : a structured summary of a study protocol for a randomised controlled trial
Objectives: Zilucoplan (complement C5 inhibitor) has profound effects on inhibiting acute lung injury post COVID-19, and can promote lung repair mechanisms that lead to improvement in lung oxygenation parameters. The purpose of this study is to investigate the efficacy and safety of Zilucoplan in improving oxygenation and short- and long-term outcome of COVID-19 patients with acute hypoxic respiratory failure.
Trial design: This is a phase 2 academic, prospective, 2:1 randomized, open-label, multi-center interventional study.
Participants: Adult patients (>= 18y old) will be recruited at specialized COVID-19 units and ICUs at 9 Belgian hospitals.
The main eligibility criteria are as follows:
1) Inclusion criteria:
a. Recent (>= 6 days and <= 16 days) SARS-CoV-2 infection.
b. Chest CT scan showing bilateral infiltrates within the last 2 days prior to randomisation.
c. Acute hypoxia (defined as PaO2/FiO(2) below 350 mmHg or SpO2 below 93% on minimal 2 L/min supplemental oxygen).
d. Signs of cytokine release syndrome characterized by either high serum ferritin, or high D-dimers, or high LDH or deep lymphopenia or a combination of those.
2) Exclusion criteria:
e. Mechanical ventilation for more than 24 hours prior to randomisation.
f. Active bacterial or fungal infection.
g. History of meningococcal disease (due to the known high predisposition to invasive, often recurrent meningococcal infections of individuals deficient in components of the alternative and terminal complement pathways).
Intervention and comparator: Patients in the experimental arm will receive daily 32,4 mg Zilucoplan subcutaneously and a daily IV infusion of 2g of the antibiotic ceftriaxone for 14 days (or until hospital discharge, whichever comes first) in addition to standard of care. These patients will receive additional prophylactic antibiotics until 14 days after the last Zilucoplan dose: hospitalized patients will receive a daily IV infusion of 2g of ceftriaxone, discharged patients will switch to daily 500 mg of oral ciprofloxacin.The control group will receive standard of care and a daily IV infusion of 2g of ceftriaxone for 1 week (or until hospital discharge, whichever comes first), to control for the effects of antibiotics on the clinical course of COVID-19.
Main outcomes: The primary endpoint is the improvement of oxygenation as measured by mean and/or median change from pre-treatment (day 1) to post-treatment (day 6 and 15 or at discharge, whichever comes first) in PaO2/FiO(2) ratio, P(A-a)O-2 gradient and a/A PO2 ratio.(PAO(2)= Partial alveolar pressure of oxygen, PaO2=partial arterial pressure of oxygen, FiO(2)=Fraction of inspired oxygen).
Randomisation: Patients will be randomized in a 2:1 ratio (Zilucoplan: control). Randomization will be done using an Interactive Web Response System (REDCap).
Blinding (masking): In this open-label trial neither participants, caregivers, nor those assessing the outcomes will be blinded to group assignment.
Numbers to be randomised (sample size): A total of 81 patients will be enrolled: 54 patients will be randomized to the experimental arm and 27 patients to the control arm.
Trial Status: ZILU-COV protocol Version 4.0 (June 10 2020). Participant recruitment started on June 23 2020 and is ongoing. Given the uncertainty of the pandemic, it is difficult to predict the anticipated end date.
Trial registration: The trial was registered on Clinical Trials.gov on May 11(th), 2020 (ClinicalTrials.gov Identifier: NCT04382755) and on EudraCT (Identifier: 2020-002130-33).
Full protocol: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol
Temporal changes in the epidemiology, management, and outcome from acute respiratory distress syndrome in European intensive care units: a comparison of two large cohorts
Background: Mortality rates for patients with ARDS remain high. We assessed temporal changes in the epidemiology and management of ARDS patients requiring invasive mechanical ventilation in European ICUs. We also investigated the association between ventilatory settings and outcome in these patients. Methods: This was a post hoc analysis of two cohorts of adult ICU patients admitted between May 1–15, 2002 (SOAP study, n = 3147), and May 8–18, 2012 (ICON audit, n = 4601 admitted to ICUs in the same 24 countries as the SOAP study). ARDS was defined retrospectively using the Berlin definitions. Values of tidal volume, PEEP, plateau pressure, and FiO2 corresponding to the most abnormal value of arterial PO2 were recorded prospectively every 24 h. In both studies, patients were followed for outcome until death, hospital discharge or for 60 days. Results: The frequency of ARDS requiring mechanical ventilation during the ICU stay was similar in SOAP and ICON (327[10.4%] vs. 494[10.7%], p = 0.793). The diagnosis of ARDS was established at a median of 3 (IQ: 1–7) days after admission in SOAP and 2 (1–6) days in ICON. Within 24 h of diagnosis, ARDS was mild in 244 (29.7%), moderate in 388 (47.3%), and severe in 189 (23.0%) patients. In patients with ARDS, tidal volumes were lower in the later (ICON) than in the earlier (SOAP) cohort. Plateau and driving pressures were also lower in ICON than in SOAP. ICU (134[41.1%] vs 179[36.9%]) and hospital (151[46.2%] vs 212[44.4%]) mortality rates in patients with ARDS were similar in SOAP and ICON. High plateau pressure (> 29 cmH2O) and driving pressure (> 14 cmH2O) on the first day of mechanical ventilation but not tidal volume (> 8 ml/kg predicted body weight [PBW]) were independently associated with a higher risk of in-hospital death. Conclusion: The frequency of and outcome from ARDS remained relatively stable between 2002 and 2012. Plateau pressure > 29 cmH2O and driving pressure > 14 cmH2O on the first day of mechanical ventilation but not tidal volume > 8 ml/kg PBW were independently associated with a higher risk of death. These data highlight the continued burden of ARDS and provide hypothesis-generating data for the design of future studies
The clinical relevance of oliguria in the critically ill patient : Analysis of a large observational database
Funding Information: Marc Leone reports receiving consulting fees from Amomed and Aguettant; lecture fees from MSD, Pfizer, Octapharma, 3 M, Aspen, Orion; travel support from LFB; and grant support from PHRC IR and his institution. JLV is the Editor-in-Chief of Critical Care. The other authors declare that they have no relevant financial interests. Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Urine output is widely used as one of the criteria for the diagnosis and staging of acute renal failure, but few studies have specifically assessed the role of oliguria as a marker of acute renal failure or outcomes in general intensive care unit (ICU) patients. Using a large multinational database, we therefore evaluated the occurrence of oliguria (defined as a urine output 16 years) patients in the ICON audit who had a urine output measurement on the day of admission were included. To investigate the association between oliguria and mortality, we used a multilevel analysis. Results: Of the 8292 patients included, 2050 (24.7%) were oliguric during the first 24 h of admission. Patients with oliguria on admission who had at least one additional 24-h urine output recorded during their ICU stay (n = 1349) were divided into three groups: transient - oliguria resolved within 48 h after the admission day (n = 390 [28.9%]), prolonged - oliguria resolved > 48 h after the admission day (n = 141 [10.5%]), and permanent - oliguria persisting for the whole ICU stay or again present at the end of the ICU stay (n = 818 [60.6%]). ICU and hospital mortality rates were higher in patients with oliguria than in those without, except for patients with transient oliguria who had significantly lower mortality rates than non-oliguric patients. In multilevel analysis, the need for RRT was associated with a significantly higher risk of death (OR = 1.51 [95% CI 1.19-1.91], p = 0.001), but the presence of oliguria on admission was not (OR = 1.14 [95% CI 0.97-1.34], p = 0.103). Conclusions: Oliguria is common in ICU patients and may have a relatively benign nature if only transient. The duration of oliguria and need for RRT are associated with worse outcome.publishersversionPeer reviewe
Gecombineerde analyse van Myelin Water Imaging en geavanceerde Diffusie MRI in ziekte en gezondheid
The ability to visualize the brain in vivo using magnetic resonance imaging (MRI) has been of great importance both in clinical practice and research. Yet imaging is often limited to describing the macrostructure, at spatial resolutions of 1 mm. To unravel the anatomy at a sub-voxel level we are bound to inferring information in an indirect manner.
Diffusion MRI (dMRI) quantifies the random motion of water molecules, which contains information on the integrity of cell membranes and axonal organization.
In recent years, the link between the diffusion signal and underlying tissue (in particular white matter) has been made by a variety of novel dMRI models. However, through the fractional anisotropy (FA) the basic model diffusion tensor imaging (DTI) only yields very general information on 'tissue integrity'. Furthermore, no diffusion model is able to specifically quantify the myelin content, because diffusion times of water near myelin are simply too short. A different family of MRI modalities, called Myelin Water Imaging (MWI), allows to quantify the amount of water residing in between the myelin bilayers, based on the distinctive short T2 times it exhibits. The myelin water fraction (MWF) obtained through multi-exponential T2 relaxation (MET2) currently is the gold standard for in vivo quantification of myelin content. By combined analysis of MWI and dMRI data, results from both modalities can be better interpreted.
The original contribution and main goal of this doctoral research project was to determine if combining MWI and advanced multi-shell dMRI models for use in basic and clinical research was feasible and had added-value.
Because MWI was previously not used at KU/UZ Leuven, the first part of this thesis investigates practicalities on the implementation of MWI. Through simulations it was made clear that MWI data requires adequate compensation for stimulated echoes. It was furthermore shown that MWF is underestimated due to necessary regularization of the fitting procedure and that its precision is limited due to noise. Reproducibility and biological variability were assessed and resulted in minimal sample size estimations that meet current ongoing research projects.
In the second part of this thesis, we assessed the potential added value of combining MWI and dMRI in health and pathology.
Across the lifespan, the white matter undergoes normal changes. By analyzing MWI and dMRI data from 59 healthy volunteers between 17 and 70 years of age, we could confirm that with advancing age diffusion increasingly occurs in an isotropic way. Estimates of MWF, axonal-like diffusion (NDI) and mean kurtosis (MK, 'restrictedness of diffusion') reached an optimum around the age of 50. The theory of retrogenesis, postulating that late-developing white matter degenerates first, was partly confirmed, yet we showed that the early FA decrease in aging could be related to axonal dispersion rather than demyelination. Furthermore, associations between MWI and advanced dMRI metrics were made, clarifying that throughout white matter MWI has more common ground with advanced models such as DKI and NODDI than with basic models such as DTI.
To test whether MWI and/or advanced dMRI allow a better characterization of pathological white matter, we applied both modalities in a spectrum of presumed white matter pathologies given different degrees of myelin change: demyelinating lesions, dysmyelinating lesions and suspected white matter damage.
With aging, white matter hyperintensities (WMH) are occasionally detected on T2 weighted MRI scans without initial cognitive complaints. This is called leukoaraiosis. As progression of these lesions carries an increased risk of stroke, dementia and depression, follow-up may become clinically important. Using clinical MRI the tissue microstructure of WMH seems uniform, although from histology it is known that periventricular lesions (PVWMH) and deep WM (DWMH) are differently impacted. From scans of 25 older adults aged between 65 - 87 years, we found similar appearance of PVWMH and DWMH in terms of DTI metrics, while MWF detected demyelination in PVWMH and not in DWMH compared to normal appearing white matter (NAWM). This demonstrates that even though DTI metrics are known to be very sensitive for white matter microstructural changes, they are unable to distinguish subtypes that differ on myelination and use of MWF bears a clear added value in assessment of demyelinating lesions. This study also confirmed the decreasing trend of MWF in aging NAWM.
Neurofibromatosis type 1 (NF1) is a genetic disorder in which children often present T2 weighted hyperintensities frequently called "unidentified bright objects" (UBOs). Their presence correlates with cognitive dysfunction. Although little evidence from human histology is available, the pathologic substrate of UBOs is believed to be dysmyelination, more specifically intramyelinic edema in absence of demyelination. We compared 30 UBOs and contralateral NAWM (cNAWM) of 17 children. Advanced dMRI showed reduced neurite-like diffusion in UBOs which is possible under conditions of edema, yet also leaves the option for axonal loss. However because water fractions from MWI were not different, demyelination and therefore axonal loss could be considered unlikely, leaving edema as possible hypothesis. Because the amount of isotropic diffusion was similar in UBOs and cNAWM, regular vasogenic edema would however be unlikely, suggesting intramyelinic edema is a plausible hypothesis. This study demonstrated that through combined interpretation of MWI and dMRI metrics, also the in vivo characterization of dysmyelinating lesions can be improved.
In a previous study, chemotherapy treated breast cancer patients (C+) presented longitudinal changes in DTI metrics compared to healthy controls (HC) and non-chemotherapy treated patients (C-), suggesting white matter damage. Three to four years later we investigated these same groups using advanced dMRI and MWI in order to elucidate on the type of damage. Both in a voxel-based analysis (VBA) and in previously defined ROI, metric values were compared between 25 C+, 14 C- and 13 HC. No differences were detected in DTI metrics, confirmed by longitudinal normalization. Because of this apparent recovery, it was not possible to use MWI and advanced dMRI for defining the type of WM injury related to chemotherapy treatment. Further longitudinal assessment using VBA before and after chemotherapy treatment is necessary to determine whether MWI and/or advanced dMRI can elucidate on this.
This doctoral research project has demonstrated that MWI metrics are most useful in cases where other, more sensitive, metrics have identified white matter changes. In those cases (e.g. demyelination or dysmyelination), combining MWI and dMRI allows hypothesis testing not possible using standard DTI alone. More research is necessary to assess the added value in pathologies involving presumed white matter changes.status: publishe
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