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4. Severity of COVID-19 among Hospitalized Patients: Omicron Remains a Severe Threat for Immunocompromised Hosts

Author

Nevejan, Louis, primary, Ombelet, Sien, additional, Laenen, Lies, additional, Keyaerts, Els, additional, Demuyser, Thomas, additional, Seyler, Lucie, additional, Soetens, Oriane, additional, Van Nedervelde, Els, additional, Naesens, Reinout, additional, Geysels, Dieter, additional, Verstrepen, Walter, additional, Cattoir, Lien, additional, Martens, Steven, additional, Michel, Charlotte, additional, Mathieu, Elise, additional, Reynders, Marijke, additional, Evenepoel, Anton, additional, Hellemans, Jorn, additional, Vanhee, Merijn, additional, Magerman, Koen, additional, Maes, Justine, additional, Matheeussen, Veerle, additional, Boogaerts, Hélène, additional, Lagrou, Katrien, additional, Cuypers, Lize, additional, and André, Emmanuel, additional

Published
2022
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6. Nationwide Harmonization Effort for Semi-Quantitative Reporting of SARS-CoV-2 PCR Test Results in Belgium

Author

Cuypers, Lize, primary, Bode, Jannes, additional, Beuselinck, Kurt, additional, Laenen, Lies, additional, Dewaele, Klaas, additional, Janssen, Reile, additional, Capron, Arnaud, additional, Lafort, Yves, additional, Paridaens, Henry, additional, Bearzatto, Bertrand, additional, Cauchie, Mathieu, additional, Huwart, Aline, additional, Degosserie, Jonathan, additional, Fagnart, Olivier, additional, Overmeire, Yarah, additional, Rouffiange, Arlette, additional, Vandecandelaere, Ilse, additional, Deffontaine, Marine, additional, Pilate, Thomas, additional, Yin, Nicolas, additional, Micalessi, Isabel, additional, Roisin, Sandrine, additional, Moons, Veronique, additional, Reynders, Marijke, additional, Steyaert, Sophia, additional, Henin, Coralie, additional, Lazarova, Elena, additional, Obbels, Dagmar, additional, Dufrasne, François E., additional, Pirenne, Hendri, additional, Schepers, Raf, additional, Collin, Anaëlle, additional, Verhasselt, Bruno, additional, Gillet, Laurent, additional, Jonckheere, Stijn, additional, Van Lint, Philippe, additional, Van den Poel, Bea, additional, Van der Beken, Yolien, additional, Stojkovic, Violeta, additional, Garrino, Maria-Grazia, additional, Segers, Hannah, additional, Vos, Kevin, additional, Godefroid, Maaike, additional, Pede, Valerie, additional, Nollet, Friedel, additional, Claes, Vincent, additional, Verschraegen, Inge, additional, Bogaerts, Pierre, additional, Van Gysel, Marjan, additional, Leurs, Judith, additional, Saegeman, Veroniek, additional, Soetens, Oriane, additional, Vanhee, Merijn, additional, Schiettekatte, Gilberte, additional, Huyghe, Evelyne, additional, Martens, Steven, additional, Lemmens, Ann, additional, Nailis, Heleen, additional, Laffineur, Kim, additional, Steensels, Deborah, additional, Vanlaere, Elke, additional, Gras, Jérémie, additional, Roussel, Gatien, additional, Gijbels, Koenraad, additional, Boudewijns, Michael, additional, Sion, Catherine, additional, Achtergael, Wim, additional, Maurissen, Wim, additional, Iliano, Luc, additional, Chantrenne, Marianne, additional, Vanheule, Geert, additional, Flies, Reinoud, additional, Hougardy, Nicolas, additional, Berth, Mario, additional, Verbeke, Vanessa, additional, Morent, Robin, additional, Vankeerberghen, Anne, additional, Bontems, Sébastien, additional, Kehoe, Kaat, additional, Schallier, Anneleen, additional, Ho, Giang, additional, Bafort, Kristof, additional, Raymaekers, Marijke, additional, Pypen, Yolande, additional, Heinrichs, Amelie, additional, Schuermans, Wim, additional, Cuigniez, Dominique, additional, Lali, Salah Eddine, additional, Drieghe, Stefanie, additional, Ory, Dieter, additional, Le Mercier, Marie, additional, Van Laethem, Kristel, additional, Thoelen, Inge, additional, Vandamme, Sarah, additional, Mansoor, Iqbal, additional, Vael, Carl, additional, De Sloovere, Maxime, additional, Declerck, Katrien, additional, Dequeker, Elisabeth, additional, Desmet, Stefanie, additional, Maes, Piet, additional, Lagrou, Katrien, additional, and André, Emmanuel, additional

Published
2022
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7. Nationwide Harmonization Effort for Semi-Quantitative Reporting of SARS-CoV-2 PCR Test Results in Belgium.

Author

UCL - (MGD) Laboratoire de biologie clinique, UCL - SSS/IREC/MONT - Pôle Mont Godinne, Cuypers, Lize, Bode, Jannes, Beuselinck, Kurt, Laenen, Lies, Dewaele, Klaas, Janssen, Reile, Capron, Arnaud, Lafort, Yves, Paridaens, Henry, Bearzatto, Bertrand, Cauchie, Mathieu, Huwart, Aline, Degosserie, Jonathan, Fagnart, Olivier, Overmeire, Yarah, Rouffiange, Arlette, Vandecandelaere, Ilse, Deffontaine, Marine, Pilate, Thomas, Yin, Nicolas, Micalessi, Isabel, Roisin, Sandrine, Moons, Veronique, Reynders, Marijke, Steyaert, Sophia, Henin, Coralie, Lazarova, Elena, Obbels, Dagmar, Dufrasne, François E, Pirenne, Hendri, Schepers, Raf, Collin, Anaëlle, Verhasselt, Bruno, Gillet, Laurent, Jonckheere, Stijn, Van Lint, Philippe, Van den Poel, Bea, Van der Beken, Yolien, Stojkovic, Violeta, Garrino, Maria-Grazia, Segers, Hannah, Vos, Kevin, Godefroid, Maaike, Pede, Valerie, Nollet, Friedel, Claes, Vincent, Verschraegen, Inge, Bogaerts, Pierre, Van Gysel, Marjan, Leurs, Judith, Saegeman, Veroniek, Soetens, Oriane, Vanhee, Merijn, Schiettekatte, Gilberte, Huyghe, Evelyne, Martens, Steven, Lemmens, Ann, Nailis, Heleen, Laffineur, Kim, Steensels, Deborah, Vanlaere, Elke, Gras, Jérémie, Roussel, Gatien, Gijbels, Koenraad, Boudewijns, Michael, Sion, Catherine, Achtergael, Wim, Maurissen, Wim, Iliano, Luc, Chantrenne, Marianne, Vanheule, Geert, Flies, Reinoud, Hougardy, Nicolas, Berth, Mario, Verbeke, Vanessa, Morent, Robin, Vankeerberghen, Anne, Bontems, Sébastien, Kehoe, Kaat, Schallier, Anneleen, Ho, Giang, Bafort, Kristof, Raymaekers, Marijke, Pypen, Yolande, Heinrichs, Amelie, Schuermans, Wim, Cuigniez, Dominique, Lali, Salah Eddine, Drieghe, Stefanie, Ory, Dieter, Le Mercier, Marie, Van Laethem, Kristel, Thoelen, Inge, Vandamme, Sarah, Mansoor, Iqbal, Vael, Carl, De Sloovere, Maxime, Declerck, Katrien, Dequeker, Elisabeth, Desmet, Stefanie, Maes, Piet, Lagrou, Katrien, André, Emmanuel, UCL - (MGD) Laboratoire de biologie clinique, UCL - SSS/IREC/MONT - Pôle Mont Godinne, Cuypers, Lize, Bode, Jannes, Beuselinck, Kurt, Laenen, Lies, Dewaele, Klaas, Janssen, Reile, Capron, Arnaud, Lafort, Yves, Paridaens, Henry, Bearzatto, Bertrand, Cauchie, Mathieu, Huwart, Aline, Degosserie, Jonathan, Fagnart, Olivier, Overmeire, Yarah, Rouffiange, Arlette, Vandecandelaere, Ilse, Deffontaine, Marine, Pilate, Thomas, Yin, Nicolas, Micalessi, Isabel, Roisin, Sandrine, Moons, Veronique, Reynders, Marijke, Steyaert, Sophia, Henin, Coralie, Lazarova, Elena, Obbels, Dagmar, Dufrasne, François E, Pirenne, Hendri, Schepers, Raf, Collin, Anaëlle, Verhasselt, Bruno, Gillet, Laurent, Jonckheere, Stijn, Van Lint, Philippe, Van den Poel, Bea, Van der Beken, Yolien, Stojkovic, Violeta, Garrino, Maria-Grazia, Segers, Hannah, Vos, Kevin, Godefroid, Maaike, Pede, Valerie, Nollet, Friedel, Claes, Vincent, Verschraegen, Inge, Bogaerts, Pierre, Van Gysel, Marjan, Leurs, Judith, Saegeman, Veroniek, Soetens, Oriane, Vanhee, Merijn, Schiettekatte, Gilberte, Huyghe, Evelyne, Martens, Steven, Lemmens, Ann, Nailis, Heleen, Laffineur, Kim, Steensels, Deborah, Vanlaere, Elke, Gras, Jérémie, Roussel, Gatien, Gijbels, Koenraad, Boudewijns, Michael, Sion, Catherine, Achtergael, Wim, Maurissen, Wim, Iliano, Luc, Chantrenne, Marianne, Vanheule, Geert, Flies, Reinoud, Hougardy, Nicolas, Berth, Mario, Verbeke, Vanessa, Morent, Robin, Vankeerberghen, Anne, Bontems, Sébastien, Kehoe, Kaat, Schallier, Anneleen, Ho, Giang, Bafort, Kristof, Raymaekers, Marijke, Pypen, Yolande, Heinrichs, Amelie, Schuermans, Wim, Cuigniez, Dominique, Lali, Salah Eddine, Drieghe, Stefanie, Ory, Dieter, Le Mercier, Marie, Van Laethem, Kristel, Thoelen, Inge, Vandamme, Sarah, Mansoor, Iqbal, Vael, Carl, De Sloovere, Maxime, Declerck, Katrien, Dequeker, Elisabeth, Desmet, Stefanie, Maes, Piet, Lagrou, Katrien, and André, Emmanuel

Abstract

From early 2020, a high demand for SARS-CoV-2 tests was driven by several testing indications, including asymptomatic cases, resulting in the massive roll-out of PCR assays to combat the pandemic. Considering the dynamic of viral shedding during the course of infection, the demand to report cycle threshold (Ct) values rapidly emerged. As Ct values can be affected by a number of factors, we considered that harmonization of semi-quantitative PCR results across laboratories would avoid potential divergent interpretations, particularly in the absence of clinical or serological information. A proposal to harmonize reporting of test results was drafted by the National Reference Centre (NRC) UZ/KU Leuven, distinguishing four categories of positivity based on RNA copies/mL. Pre-quantified control material was shipped to 124 laboratories with instructions to setup a standard curve to define thresholds per assay. For each assay, the mean Ct value and corresponding standard deviation was calculated per target gene, for the three concentrations (10, 10 and 10 copies/mL) that determine the classification. The results of 17 assays are summarized. This harmonization effort allowed to ensure that all Belgian laboratories would report positive PCR results in the same semi-quantitative manner to clinicians and to the national database which feeds contact tracing interventions.

Published
2022

8. Laboratory information system requirements to manage the COVID-19 pandemic: A report from the Belgian national reference testing center

Author

Weemaes, Matthias, primary, Martens, Steven, additional, Cuypers, Lize, additional, Van Elslande, Jan, additional, Hoet, Katrien, additional, Welkenhuysen, Joris, additional, Goossens, Ria, additional, Wouters, Stijn, additional, Houben, Els, additional, Jeuris, Kirsten, additional, Laenen, Lies, additional, Bruyninckx, Katrien, additional, Beuselinck, Kurt, additional, André, Emmanuel, additional, Depypere, Melissa, additional, Desmet, Stefanie, additional, Lagrou, Katrien, additional, Van Ranst, Marc, additional, Verdonck, Ann K L C, additional, and Goveia, Jermaine, additional

Published
2020
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9. Duplex tab exhaust nozzle

Author

Gutmark, Ephraim Jeff and Martens, Steven (nmn)

Subjects
Fluid Mechanics And Thermodynamics
Abstract

An exhaust nozzle includes a conical duct terminating in an annular outlet. A row of vortex generating duplex tabs are mounted in the outlet. The tabs have compound radial and circumferential aft inclination inside the outlet for generating streamwise vortices for attenuating exhaust noise while reducing performance loss.

Published
2012

11. Structure of coherent instabilities in a supersonic shear layer

Author

Martens, Steven, Kinzie, Kevin W., and McLaughlin, Dennis K.

Subjects
Aerodynamics, Supersonic -- Research, Shear flow -- Observations, Flow visualization -- Observations, Aerospace and defense industries, Business
Abstract

The measurements of Mach number profiles for two stream conditions provide insights into the instabilities present in supersonic shear layers. An artificial excitation for two-dimensional (2-D) waves produces 2-D instabilities in both the cases. The excited three-dimensional waves create oblique instability waves for different excitation angles. The growth rate of waves for low Mach number conditions remain unaffected by excitation, whereas enhanced mixing is observed for the higher Mach number profiles.

Published
1996

12. Measurements of Kelvin-Helmholtz instabilities in a supersonic shear layer

Author

Martens, Steven, Kinzie, Kevin W., and McLaughlin, Dennis K.

Subjects
Aerodynamics, Supersonic -- Analysis, Shear (Mechanics) -- Analysis, Stability -- Analysis, Aerospace and defense industries, Business
Abstract

Examination of mass velocity fluctuations in a new supersonic shear layer in natural and excited conditions reveal that glow discharge excitation affects the shear layer with respect to growth rate and spectral content of the fluctuations. Glow excitation enables the evaluation of oblique instability waves/turbulence structures, seen at high Mach numbers in the shear layer. The distinct features of this technique help study the supersonic mixing problem.

Published
1994

15. Polyimide based amorphous silicon solar modules

Author

Jeffrey, Frank R, Grimmer, Derrick P, Martens, Steven A, Abudagga, Khaled, Thomas, Michael L, and Noak, Max

Subjects
Spacecraft Propulsion And Power
Abstract

Requirements for space power are increasingly emphasizing lower costs and higher specific powers. This results from new fiscal constraints, higher power requirements for larger applications, and the evolution toward longer distance missions such as a Lunar or Mars base. The polyimide based a-Si modules described are being developed to meet these needs. The modules consist of tandem a-Si solar cell material deposited directly on a roll of polyimide. A laser scribing/printing process subdivides the deposition into discrete cell strips which are series connected to produce the required voltage without cutting the polymer backing. The result is a large, monolithic, blanket type module approximately 30 cm wide and variable in length depending on demand. Current production modules have a specific power slightly over 500 W/Kg with room for significant improvement. Costs for the full blanket modules range from $30/Watt to $150/Watt depending on quantity and engineering requirements. Work to date focused on the modules themselves and adjusting them for the AMO spectrum. Work is needed yet to insure that the modules are suitable for the space environment.

Published
1993

23. Click and Click-Inspired Chemistry for the Design of Sequence-Controlled Polymers.

Author

Martens, Steven, Holloway, Joshua O., and Du Prez, Filip. E.

Subjects
*BIOPOLYMERS, *CLICK chemistry, *CHEMICAL reactions, *POLYMER structure, *DIELS-Alder reaction
Abstract

During the previous decade, many popular chemical reactions used in the area of 'click' chemistry and similarly efficient 'click-inspired' reactions have been applied for the design of sequence-defined and, more generally, sequence-controlled structures. This combination of topics has already made quite a significant impact on scientific research to date and has enabled the synthesis of highly functionalized and complex oligomeric and polymeric structures, which offer the prospect of many exciting further developments and applications in the near future. This minireview highlights the fruitful combination of these two topics for the preparation of sequence-controlled oligomeric and macromolecular structures and showcases the vast number of publications in this field within a relatively short span of time. It is divided into three sections according to the click-(inspired) reaction that has been applied: copper-catalyzed azide-alkyne cycloaddition, thiol-X, and related thiolactone-based reactions, and finally Diels-Alder-chemistry-based routes are outlined, respectively. [ABSTRACT FROM AUTHOR]

Published
2017
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24. Responsive Thiolactone-Derived N-Substituted Poly(Urethane-Amide)s.

Author

Espeel, Pieter, Celasun, Sensu, Omurtag, Pinar Sinem, Martens, Steven, and Du Prez, Filip E.

Subjects
POLYMERS, MONOMERS, VINYL ethers, CRITICAL solution point, SUBSTITUENTS (Chemistry)
Abstract

AB′ type monomers containing a thiolactone unit and vinyl ether moiety have been prepared with high yields. Aminolysis of the thiolactone moiety generates the corresponding thiol in situ, and upon UV-irradiation, radical polyaddition occurs in the same medium, yielding linear poly(amide-urethane)s with different side chain residues and (Poly(Ethylene Oxide)) PEO-like backbone. Moreover, these unique polymers feature lower critical solution temperature behavior in water. Systematic modification of the responsive polymers reveals the influence of the variation of the side chains and the backbone structure on the corresponding solubility properties. In selected cases, multiresponsive polymers have been developed, which also respond to pH and metal concentration. [ABSTRACT FROM AUTHOR]

Published
2017
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26. Mechanical Chevrons and Fluidics for Advanced Military Aircraft Noise Reduction

Author

NAVAL RESEARCH LAB WASHINGTON DC, Kailasanath, K, Gutmark, Ephraim, Martens, Steven, NAVAL RESEARCH LAB WASHINGTON DC, Kailasanath, K, Gutmark, Ephraim, and Martens, Steven

Abstract

There is a growing need to reduce significantly the noise generated by high-performance, supersonic military aircraft. The noise generated during takeoff and landing on aircraft carriers has direct impact on shipboard health and safety issues. Noise complaints are increasing as communities move closer to military bases or when there are changes due to base closures and realignment. Furthermore, U.S. and international noise regulations and policies will have an impact on military operations and training unless we take effective steps to reduce the noise. In response to a statement of need (WPSON-07-04) identified by SERDP, the Naval Research laboratory (NRL) in collaboration with the University of Cincinnati (UC) and GE Aircraft Engines, proposed a three-year research program investigating the use of mechanical chevrons and fluidics for reducing the noise from supersonic military jet aircraft. The technical approach adopted was a combined experimental and computational study. This final technical report provides details of the studies conducted and the results obtained. First, we show that the numerical simulations can accurately predict the details of the flow field and noise generated by supersonic jets from nozzles that are representative of military jet aircraft engine nozzles. Then, we use the numerical simulations and complementary experiments to derive further information on the source of noise from supersonic jets under a variety of operating conditions. With the benefit of this knowledge, we investigate and report on the potential of mechanical chevrons and three fluidics-based techniques to reduce the noise. We find that each of the techniques investigated are capable of providing significant noise reduction but further studies are needed to optimize these techniques and assess a tradeoff between various factors such as cost of implementation, potential impact on performance and benefits derived., The original document contains color images. Sponsored in part b y Strategic Environmental Research and Development Program.

Published
2011

27. Computational Aeroacoustics of a Separate Flow Exhaust System with Eccentric Inner Nozzle

Author

Mihaescu, Mihai, Gutmark, Ephraim, Szasz, Robert, Fuchs, Laszlo, Martens, Steven, Mihaescu, Mihai, Gutmark, Ephraim, Szasz, Robert, Fuchs, Laszlo, and Martens, Steven

Abstract

A major issue related to our modern way of life is the noise caused by jet engine powered airliners. Methods to reduce the jet noise were proposed in the last decades starting with the introduction of high bypass turbofan engines. A numerical investigation of flow and acoustics of a separate flow exhaust system is performed in the present paper. The goal is to investigate how the noise generated by a separate flow jet engine exhaust is influenced if the symmetry of the jet exhaust geometry is broken by having the inner nozzle and the center body off the center line axis of the fan nozzle. A decomposition of flow variables is used that allows separation of flow and acoustic computations. Large Eddy Simulation approach is employed to compute the flow field and the acoustic sources. The inhomogeneous wave equation is used to compute the acoustic near- and far-fields. Using this method, previous numerical studies of the symmetric (baseline) configuration showed good agreement between the computed data and the experimental results. Comparisons between the near- and far-field baseline concentric case and the computations obtained using the eccentric configuration are performed showing an acoustic benefit for the offset case., QC 20111117. AIAA 2007-13

Published
2007

48. Being a team captain.

Author

Martens, Steven

Abstract

Davis cup and Fed cup are no doubt the most renowned team competitions in tennis and go back a long way in tennis history. Other team events at international level include Junior Davis and Fed cup, national club matches. This article is a personal account of what was required as a team captain within the ITF team competition setting. I summaries key roles and how the role has changed throughout the years. [ABSTRACT FROM AUTHOR]

Published
2010

49. The Use of Low compression Balls in the Development of High Performance Players.

Author

Martens, Steven and De Vylder, Max

Abstract

The article presents the authors' views on various techniques used in tennis. According to them, the use of slower red and green balls in smaller courts helps in enhancing the talent of the young tennis players. In their view the use of different kind of balls, that have different bouncing rates, by the young players helps them to develop a wider range of strokes and appropriate tactical decision-making approach.

Published
2007

50. Ser capitán de un equipo.

Author

Martens, Steven

Abstract

Copyright of Coaching & Sport Science Review (Spanish Version) is the property of International Tennis Federation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2010

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