Ultra-thin Metal Coating to Reduce RF-Reflection Loss of CFRP Reflectors

Een carbon-fiber versterkt plastic reflector heeft bij hogere frequentie een verlies bij reflectie. Zo tot 10 GHz is dit nog niet zo veel. (De James Webb Space Telescoop heeft een antenne voor de data downlink zonder metallisatie voor de 8.4 GHz link). Boven Ku-band neemt het verlies bij reflectie langzaam toe. Boven de 100 GHz is het al zo'n 5% en daarom wordt er metalliseren toegepast. Een andere methode is om een dunne film met metaal laag te gebruiken. Dat is iets minder goed, afhankelijk ook van de dikte. Dit wordt besproken samen met de manier om dat te berekenen

Kosten weiderantsoen Dynamisch Beweiden mei, juni en juli 2013

Op basis van de melkproductie en de bijvoeding is terug gerekend hoeveel weidegras de koeien hebben opgenomen. Voor de overige producten is uitgegaan van de hoeveelheid die door de melkveehouders is opgegeven. Voor weidegras is met een kostprijs van 7 eurocent per kg droge stof gerekend. Voor kuilgras en maïskuil is gerekend met een kostprijs van respectievelijk 17 eurocent en 15 eurocent. De overige voedermiddelen zijn ingerekend op basis van een kostprijs zoals die door de melkveehouders is opgegeven

Temporary Right Middle Lobe Occlusion with a Blocking Device to Enable Collateral Ventilation Measurement of the Right Major Fissure

BACKGROUND: Absence of interlobar collateral ventilation is essential to achieve lobar volume reduction after endobronchial valve (EBV) treatment and can be assessed using the Chartis measurement. However, especially in lower lobe measurements, Chartis can be complicated by the "no-flow phenomenon", during which a sudden cessation of flow is observed, leading to an unreliable measurement. If this phenomenon occurs in the right lower lobe, when measuring collateral flow over the right major fissure, the entrance to the right middle lobe should be occluded, and the Chartis balloon should be placed in the right upper lobe. Both Watanabe spigots and balloon catheters can be used to achieve occlusion. OBJECTIVE: Our aim was to demonstrate that right middle lobe occlusion with a blocking device is helpful in obtaining a reliable Chartis outcome in case of the no-flow phenomenon in the right lower lobe. METHODS: We performed a retrospective analysis of patients scheduled for EBV treatment in an EBV registry between September 2016 and September 2019. RESULTS: We included 15 patients with severe emphysema (median age 63 years [range 47-73], 73% female, and FEV1 24% [range 19-36] of predicted), who required temporary middle lobe occlusion (12 Watanabe spigot, 3 balloon catheter). After occlusion, a reliable Chartis outcome was obtained in all patients. CONCLUSION: Temporary middle lobe occlusion using a blocking device is helpful in obtaining a reliable Chartis outcome in case of a right lower lobe no-flow phenomenon

Gastrointestinal adverse drug reaction profile of etanercept:Real world data from patients and healthcare professionals

Objective. We aimed to describe the nature and frequency of gastrointestinal adverse drug reactions (GI-ADRs) of etanercept (ETN) using patient-reported and healthcare professional (HCP)-registered data and compared this frequency with the GI-ADR frequency of the widely used tumor necrosis factor-α inhibitor adalimumab (ADA). Methods. Reported GI-ADRs of ETN for rheumatic diseases were collected from the Dutch Biologic Monitor and DREAM registries. We described the clinical course of GI-ADRs and compared the frequency with ADA in both data sources using Fisher exact test. Results. Out of 416 patients using ETN for inflammatory rheumatic diseases in the Dutch Biologic Monitor, 25 (6%) patients reported 36 GI-ADRs. In the DREAM registries 11 GI-ADRs were registered for 9 patients (2.3%), out of 399 patients using ETN, with an incidence of 7.1 per 1000 patient-years. Most GI-ADRs consisted of diarrhea, nausea, and abdominal pain. GI-ADRs led to ETN discontinuation in 1 patient (4%) and dose adjustment in 4 (16%) in the Dutch Biologic Monitor. Eight GI-ADRs (73%) led to ETN discontinuation in the DREAM registries. The frequency of GI-ADRs of ETN did not significantly differ from GI-ADRs of ADA in both data sources (Dutch Biologic Monitor: ETN 8.7% vs ADA 5.3%, P = 0.07; DREAM: ETN 2.8% vs ADA 4.7%, P = 0.16). Conclusion. Most GI-ADRs associated with ETN concerned gastrointestinal symptoms. These ADRs may lead to dose adjustment or ETN discontinuation. The frequency of ETN-associated GI-ADRs was comparable to the frequency of ADA-associated GI-ADRs. Knowledge about these previously unknown ADRs can facilitate early recognition and improve patient communication

Chartis Measurement of Collateral Ventilation:Conscious Sedation versus General Anesthesia

BACKGROUND: Absence of interlobar collateral ventilation using the Chartis measurement is the key predictor for successful endobronchial valve treatment in severe emphysema. Chartis was originally validated in spontaneous breathing patients under conscious sedation (CS); however, this can be challenging due to cough, mucus secretion, mucosal swelling, and bronchoconstriction. Performing Chartis under general anesthesia (GA) avoids these problems and may result in an easier procedure with a higher success rate. However, using Chartis under GA with positive pressure ventilation has not been validated. OBJECTIVES: In this study we investigated the impact of anesthesia technique, CS versus GA, on the feasibility and outcomes of Chartis measurement. METHODS: We retrospectively analyzed all Chartis measurements performed at our hospital from October 2010 until December 2017. RESULTS: We analyzed 250 emphysema patients (median forced expiratory volume in 1 s 26%, range 12-52% predicted). In 121 patients (48%) the measurement was performed using CS, in 124 (50%) using GA, and in 5 (2%) both anesthesia techniques were used. In total, 746 Chartis readings were analyzed (432 CS, 277 GA, and 37 combination). Testing under CS took significantly longer than GA (median 19 min [range 5-65] vs. 11 min [3-35], p < 0.001) and required more measurements (3 [1-13] vs. 2 [1-6], p < 0.001). There was no significant difference in target lobe volume reduction after treatment (-1,123 mL [-3,604 to 332] in CS vs. -1,251 mL [-3,333 to -1] in GA, p = 0.35). CONCLUSIONS: In conclusion, Chartis measurement under CS took significantly longer and required more measurements than under GA, without a difference in treatment outcome. We recommend a prospective trial comparing both techniques within the same patients to validate this approach

A New Oxygen Uptake Measurement Supporting Target Selection for Endobronchial Valve Treatment

BACKGROUND: Adequate target lobe selection for endobronchial valve (EBV) treatment in patients with severe emphysema is essential for treatment success and can be based on emphysema destruction, lobar perfusion, lobar volume, and collateral ventilation. As some patients have >1 target lobe for EBV treatment, we were interested whether we could identify the least functional lobe. OBJECTIVES: The objective of this study was to investigate the relationship between endoscopic lobar measurement of oxygen uptake, lobar destruction, and vascular volume, and whether this could help in identifying the least functional lobe and thus optimal target for EBV treatment. METHOD: We prospectively included patients who were scheduled for EBV treatment in our hospital. A customized gas analysis setup was used to measure lobar O2 uptake after lobar balloon occlusion. Quantitative CT analysis was performed to assess the degree of emphysematous destruction and lobar arterial and venous volumes. RESULTS: Twenty-one (5 male/16 female) patients with emphysema (median age 63 years, FEV1 25% of predicted, residual volume 234% of predicted) were included, and 49 endoscopic lobar measurements were performed. A lower O2 uptake significantly correlated with a higher degree of emphysematous lobar destruction (Spearman's ρ: 0.39, p < 0.01), and lower arterial and venous vascular volumes of the lobes (-0.46 and -0.47, respectively; both p < 0.001). CONCLUSIONS: Endoscopic measurement of lobar O2 uptake is feasible in patients with emphysema. Measurement of lobar O2 uptake helped to identify the least functional lobe and can be used as additional tool for EBV target lobe selection

Using a satellite swarm for building a space-based radio telescope for low frequencies

In radio astronomy, as in astronomy in general, a wide range of frequencies is observed as each spectral band o_ers a unique window to study astrophysical phenomena. In the recent years, new observatories have been designed and built at the extreme limits of the radio spectrum. For the low frequencies several Earth-based radio telescopes are constructed at this moment. In the Netherlands, the Low Frequency Array (LOFAR) is being constructed at this moment and will be operational later this year. LOFAR observes the sky between 30 and 240 MHz. Observing at even lower frequencies is very interesting, but, due to the inuence of the Earth's ionosphere this is not possible from Earth. Thus, the only option to observe low frequencies is a telescope in spac

OLFAR - orbiting low frequency array; using a satellite swarm for building a space-based radio telescope for low frequencies

In radio astronomy, as in astronomy in general, a wide range of frequencies is observed as each spectral band offers a unique window to study astrophysical phenomena. In the recent years, new observatories have been designed and built at the extreme limits of the radio spectrum. For the low frequencies several Earth-based radio telescopes are constructed at this moment. In the Netherlands, the Low Frequency Array (LOFAR) is being constructed at this moment and will be operational later this year. LOFAR observes the sky between 30 and 240 MHz. Observing at even lower frequencies is very interesting, but, due to the influence of the Earth’s ionosphere this is not possible from Earth. Thus, the only option to observe low frequencies is a telescope in space