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Author (up) de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title General conclusions and future perspectives Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 243-253  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract This chapter provides an overview of statistical and quantitative methodologies that have pushed (scanning) transmission electron microscopy ((S)TEM) toward accurate and precise measurements of unknown structure parameters for understanding the relation between the structure of a material and its properties. Hereby, statistical parameter estimation theory has extensively been used which enabled not only measuring atomic column positions, but also quantifying the number of atoms, and detecting atomic columns as accurately and precisely as possible from experimental images. As a general conclusion, it can be stated that advanced statistical techniques are ideal tools to perform quantitative electron microscopy at the atomic scale. In the future, statistical methods will continue to be developed and novel quantification procedures will open up new possibilities for studying material structures at the atomic scale.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177533 Serial 6781  
Permanent link to this record
 

 
Author (up) de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Introduction Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 1-28  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177525 Serial 6784  
Permanent link to this record
 

 
Author (up) de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Optimal experiment design for nanoparticle atom counting from ADF STEM images Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 145-175  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this chapter, the principles of detection theory are used to quantify the probability of error for atom counting from high-resolution scanning transmission electron microscopy (HRSTEM) images. Binary and multiple hypothesis testing have been investigated in order to determine the limits to the precision with which the number of atoms in a projected atomic column can be estimated. The probability of error has been calculated when using STEM images, scattering cross-sections or peak intensities as a criterion to count atoms. Based on this analysis, we conclude that scattering cross-sections perform almost equally well as images and perform better than peak intensities. Furthermore, the optimal STEM detector design can be derived for atom counting using the expression of the probability of error. We show that for very thin objects the low-angle annular dark-field (LAADF) regime is optimal and that for thicker objects the optimal inner detector angle increases.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177530 Serial 6785  
Permanent link to this record
 

 
Author (up) de Backer, A.; Fatermans, J.; den Dekker, A.J.; Van Aert, S. pdf  doi
isbn  openurl
  Title Statistical parameter estimation theory : principles and simulation studies Type H2 Book chapter
  Year 2021 Publication Advances in imaging and electron physics T2 – Advances in imaging and electron physics Abbreviated Journal  
  Volume Issue Pages 29-72  
  Keywords H2 Book chapter; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this chapter, the principles of statistical parameter estimation theory for a quantitative analysis of atomic-resolution electron microscopy images are introduced. Within this framework, electron microscopy images are described by a parametric statistical model. Here, parametric models are introduced for different types of electron microscopy images: reconstructed exit waves, annular dark-field (ADF) scanning transmission electron microscopy (STEM) images, and simultaneously acquired ADF and annular bright-field (ABF) STEM images. Furthermore, the Cramér-Rao lower bound (CRLB) is introduced, i.e. a theoretical lower bound on the variance of any unbiased estimator. This CRLB is used to quantify the precision of the structure parameters of interest, such as the atomic column positions and the integrated atomic column intensities.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2021-03-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume 217 Series Issue Edition  
  ISSN ISBN 978-0-12-824607-8; 1076-5670 Additional Links UA library record  
  Impact Factor Times cited Open Access Not_Open_Access  
  Notes ERC Consolidator project funded by the European Union grant #770887 Picometrics Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:177527 Serial 6788  
Permanent link to this record
 

 
Author (up) De Backer, A.; Jones, L.; Lobato, I.; Altantzis, T.; Goris, B.; Nellist, P.D.; Bals, S.; Van Aert, S. url  doi
openurl 
  Title Three-dimensional atomic models from a single projection using Z-contrast imaging: verification by electron tomography and opportunities Type A1 Journal article
  Year 2017 Publication Nanoscale Abbreviated Journal Nanoscale  
  Volume 9 Issue 9 Pages 8791-8798  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In order to fully exploit structure–property relations of nanomaterials, three-dimensional (3D) characterization at the atomic scale is often required. In recent years, the resolution of electron tomography has reached the atomic scale. However, such tomography typically requires several projection images demanding substantial electron dose. A newly developed alternative circumvents this by counting the number of atoms across a single projection. These atom counts can be used to create an initial atomic model with which an energy minimization can be applied to obtain a relaxed 3D reconstruction of the nanoparticle. Here, we compare, at the atomic scale, this single projection reconstruction approach with tomography and find an excellent agreement. This new approach allows for the characterization of beam-sensitive materials or where the acquisition of a tilt series is impossible. As an example, the utility is illustrated by the 3D atomic scale characterization of a nanodumbbell on an in situ heating holder of limited tilt range.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000404614700031 Publication Date 2017-06-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.367 Times cited 33 Open Access OpenAccess  
  Notes The authors gratefully acknowledge funding from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0374.13N, G.0369.15N, G.0368.15N, and WO.010.16N) and postdoctoral grants to T. Altantzis, A. De Backer, and B. Goris. S. Bals acknowledges financial support from the European Research Council (Starting Grant No. COLOURATOM 335078). Funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiatieve-I3) is acknowledged. The authors would also like to thank Luis Liz-Marzán, Marek Grzelczak, and Ana Sánchez-Iglesias for sample provision. (ROMEO:yellow; preprint:; postprint:restricted ; pdfversion:cannot); saraecas; ECAS_Sara; Approved Most recent IF: 7.367  
  Call Number EMAT @ emat @ c:irua:144436UA @ admin @ c:irua:144436 Serial 4617  
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Author (up) de Backer, A.; Martinez, G.T.; MacArthur, K.E.; Jones, L.; Béché, A.; Nellist, P.D.; Van Aert, S. pdf  url
doi  openurl
  Title Dose limited reliability of quantitative annular dark field scanning transmission electron microscopy for nano-particle atom-counting Type A1 Journal article
  Year 2015 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 151 Issue 151 Pages 56-61  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Quantitative annular dark field scanning transmission electron microscopy (ADF STEM) has become a powerful technique to characterise nano-particles on an atomic scale. Because of their limited size and beam sensitivity, the atomic structure of such particles may become extremely challenging to determine. Therefore keeping the incoming electron dose to a minimum is important. However, this may reduce the reliability of quantitative ADF STEM which will here be demonstrated for nano-particle atom-counting. Based on experimental ADF STEM images of a real industrial catalyst, we discuss the limits for counting the number of atoms in a projected atomic column with single atom sensitivity. We diagnose these limits by combining a thorough statistical method and detailed image simulations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000351237800008 Publication Date 2014-12-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 29 Open Access  
  Notes 312483 Esteem2; 278510 Vortex; Fwo G039311; G006410; G037413; esteem2ta; ECASJO; Approved Most recent IF: 2.843; 2015 IF: 2.436  
  Call Number c:irua:123927 c:irua:123927 Serial 753  
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Author (up) de Backer, A.; Martinez, G.T.; Rosenauer, A.; Van Aert, S. pdf  url
doi  openurl
  Title Atom counting in HAADF STEM using a statistical model-based approach : methodology, possibilities, and inherent limitations Type A1 Journal article
  Year 2013 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 134 Issue Pages 23-33  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract In the present paper, a statistical model-based method to count the number of atoms of monotype crystalline nanostructures from high resolution high-angle annular dark-field (HAADF) scanning transmission electron microscopy (STEM) images is discussed in detail together with a thorough study on the possibilities and inherent limitations. In order to count the number of atoms, it is assumed that the total scattered intensity scales with the number of atoms per atom column. These intensities are quantitatively determined using model-based statistical parameter estimation theory. The distribution describing the probability that intensity values are generated by atomic columns containing a specific number of atoms is inferred on the basis of the experimental scattered intensities. Finally, the number of atoms per atom column is quantified using this estimated probability distribution. The number of atom columns available in the observed STEM image, the number of components in the estimated probability distribution, the width of the components of the probability distribution, and the typical shape of a criterion to assess the number of components in the probability distribution directly affect the accuracy and precision with which the number of atoms in a particular atom column can be estimated. It is shown that single atom sensitivity is feasible taking the latter aspects into consideration.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000324474900005 Publication Date 2013-05-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 48 Open Access  
  Notes FWO; Esteem2; FP 2007-2013; esteem2_jra2 Approved Most recent IF: 2.843; 2013 IF: 2.745  
  Call Number UA @ lucian @ c:irua:109916 Serial 162  
Permanent link to this record
 

 
Author (up) De Backer, A.; Van Aert, S.; Faes, C.; Arslan Irmak, E.; Nellist, P.D.; Jones, L. url  doi
openurl 
  Title Experimental reconstructions of 3D atomic structures from electron microscopy images using a Bayesian genetic algorithm Type A1 Journal article
  Year 2022 Publication N P J Computational Materials Abbreviated Journal npj Comput Mater  
  Volume 8 Issue 1 Pages 216  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract We introduce a Bayesian genetic algorithm for reconstructing atomic models of monotype crystalline nanoparticles from a single projection using Z-contrast imaging. The number of atoms in a projected atomic column obtained from annular dark field scanning transmission electron microscopy images serves as an input for the initial three-dimensional model. The algorithm minimizes the energy of the structure while utilizing a priori information about the finite precision of the atom-counting results and neighbor-mass relations. The results show promising prospects for obtaining reliable reconstructions of beam-sensitive nanoparticles during dynamical processes from images acquired with sufficiently low incident electron doses.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000866500900001 Publication Date 2022-10-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2057-3960 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A. and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B. L.J. acknowledges Science Foundation Ireland (SFI – grant number URF/RI/191637), the Royal Society, and the AMBER Centre. The authors acknowledge Aakash Varambhia for his assistance and expertise with the experimental recording and use of characterization facilities within the David Cockayne Centre for Electron Microscopy, Department of Materials, University of Oxford, and in particular the EPSRC (EP/K040375/1 South of England Analytical Electron Microscope).; esteem3reported; esteem3JRA Approved Most recent IF: NA  
  Call Number EMAT @ emat @c:irua:191398 Serial 7114  
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Author (up) de Backer, A.; Van Aert, S.; van Dyck, D. pdf  url
doi  openurl
  Title High precision measurements of atom column positions using model-based exit wave reconstruction Type A1 Journal article
  Year 2011 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 111 Issue 9/10 Pages 1475-1482  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract In this paper, it has been investigated how to measure atom column positions as accurately and precisely as possible using a focal series of images. In theory, it is expected that the precision would considerably improve using a maximum likelihood estimator based on the full series of focal images. As such, the theoretical lower bound on the variances of the unknown atom column positions can be attained. However, this approach is numerically demanding. Therefore, maximum likelihood estimation has been compared with the results obtained by fitting a model to a reconstructed exit wave rather than to the full series of focal images. Hence, a real space model-based exit wave reconstruction technique based on the channelling theory is introduced. Simulations show that the reconstructed complex exit wave contains the same amount of information concerning the atom column positions as the full series of focal images. Only for thin samples, which act as weak phase objects, this information can be retrieved from the phase of the reconstructed complex exit wave.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000300461200004 Publication Date 2011-07-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 8 Open Access  
  Notes Fwo Approved Most recent IF: 2.843; 2011 IF: 2.471  
  Call Number UA @ lucian @ c:irua:91879 Serial 1438  
Permanent link to this record
 

 
Author (up) De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. pdf  url
doi  openurl
  Title StatSTEM: An efficient approach for accurate and precise model-based quantification of atomic resolution electron microscopy images Type A1 Journal article
  Year 2016 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 171 Issue 171 Pages 104-116  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract An efficient model-based estimation algorithm is introduced to quantify the atomic column positions and intensities from atomic resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for overlap between neighbouring columns, enabling the analysis of a large field of view. For this algorithm, the accuracy and precision with which measurements for the atomic column positions and scattering cross-sections from annular dark field (ADF) STEM images can be estimated, has been investigated. The highest attainable precision is reached even for low dose images. Furthermore, the advantages of the model-based approach taking into account overlap between neighbouring columns are highlighted. This is done for the estimation of the distance between two neighbouring columns as a function of their distance and for the estimation of the scattering cross-section which is compared to the integrated intensity from a Voronoi cell. To provide end-users this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000389106200014 Publication Date 2016-09-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 43 Open Access  
  Notes The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0393.11, G.0064.10 and G.0374.13), a Ph.D. research grant to K.H.W. van den Bos, and a postdoctoral research grant to A. De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). A. Rosenauer is acknowledged for providing the STEMsim program.; esteem2_jra2 Approved Most recent IF: 2.843  
  Call Number EMAT @ emat @ c:irua:135516 Serial 4280  
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Author (up) De Backer, A.; van den Bos, K.H.W.; Van den Broek, W.; Sijbers, J.; Van Aert, S. pdf  url
doi  openurl
  Title StatSTEM: An efficient program for accurate and precise model-based quantification of atomic resolution electron microscopy images Type P1 Proceeding
  Year 2017 Publication Journal of physics : conference series T2 – Electron Microscopy and Analysis Group Conference 2017 (EMAG2017), 3-6 July 2017, Manchester, UK Abbreviated Journal J. Phys.: Conf. Ser.  
  Volume 902 Issue Pages 012013  
  Keywords P1 Proceeding; Electron microscopy for materials research (EMAT); Vision lab  
  Abstract An efficient model-based estimation algorithm is introduced in order to quantify the atomic column positions and intensities from atomic resolution (scanning) transmission electron microscopy ((S)TEM) images. This algorithm uses the least squares estimator on image segments containing individual columns fully accounting for the overlap between neighbouring columns, enabling the analysis of a large field of view. For this algorithm, the accuracy and precision with which measurements for the atomic column positions and scattering cross-sections from annular dark field (ADF) STEM images can be estimated, is investigated. The highest attainable precision is reached even for low dose images. Furthermore, advantages of the model- based approach taking into account overlap between neighbouring columns are highlighted. To provide end-users this well-established quantification method, a user friendly program, StatSTEM, is developed which is freely available under a GNU public license.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000416370700013 Publication Date 2017-10-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1742-6588 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 1 Open Access OpenAccess  
  Notes The authors acknowledge nancial support from the Research Foundation Flanders (FWO, Belgium) through project funding (G.0374.13N, G.0368.15N, G.0369.15N, WO.010.16N) and a PhD research grant to K H W van den Bos, and a postdoctoral research grant to A De Backer. The research leading to these results has received funding from the European Union Seventh Framework Programme under Grant Agreement 312483 – ESTEEM2 (Integrated Infrastructure Initiative-I3). A Rosenauer is acknowledged for providing the STEMsim program. Approved Most recent IF: NA  
  Call Number EMAT @ emat @c:irua:147188 Serial 4764  
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Author (up) De Backer, A.; Zhang, Z.; van den Bos, K.H.W.; Bladt, E.; Sánchez‐Iglesias, A.; Liz‐Marzán, L.M.; Nellist, P.D.; Bals, S.; Van Aert, S. url  doi
openurl 
  Title Element Specific Atom Counting at the Atomic Scale by Combining High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X‐ray Spectroscopy Type A1 Journal article
  Year 2022 Publication Small methods Abbreviated Journal Small Methods  
  Volume Issue Pages 2200875  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract A new methodology is presented to count the number of atoms in multimetallic nanocrystals by combining energy dispersive X-ray spectroscopy (EDX) and high angle annular dark field scanning transmission electron microscopy (HAADF STEM). For this purpose, the existence of a linear relationship between the incoherent HAADF STEM and EDX images is exploited. Next to the number of atoms for each element in the atomic columns, the method also allows quantification of the error in the obtained number of atoms, which is of importance given the noisy nature of the acquired EDX signals. Using experimental images of an Au@Ag core–shell nanorod, it is demonstrated that 3D structural information can be extracted at the atomic scale. Furthermore, simulated data of an Au@Pt core–shell nanorod show the prospect to characterize heterogeneous nanostructures with adjacent atomic numbers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000862072700001 Publication Date 2022-09-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2366-9608 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 12.4 Times cited 5 Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S.V.A., Grant 815128 REALNANO to S.B., and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0267.18N, G.0502.18N, G.0346.21N) and a postdoctoral grant to A.D.B.; esteem3reported; esteem3JRA Approved Most recent IF: 12.4  
  Call Number EMAT @ emat @c:irua:191570 Serial 7109  
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Author (up) De Backer, J. url  openurl
  Title The versatile nature of cytoglobin, the Swiss army knife among globins, with a preference for oxidative stress Type Doctoral thesis
  Year 2023 Publication Abbreviated Journal  
  Volume Issue Pages XVIII, 232 p.  
  Keywords Doctoral thesis; Pharmacology. Therapy; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Proteinscience, proteomics and epigenetic signaling (PPES)  
  Abstract Since its discovery 20 years ago, many studies have been performed to gain insight into the functional role of cytoglobin (Cygb). However, Cygb has been proven to be a promiscuous protein. Yet, there is a consensus that Cygb is a cytoprotective protein involved in redox homeostasis. CYGB is a ubiquitously expressed hexacoordinated globin that is highly expressed in melanocytes and is often found to be downregulated during melanocyte-to-melanoma transition. In Chapter III, we investigated the molecular mechanism through which CYGB could be involved in redox regulation. Here, we showed that CYGB contains two redox-sensitive cysteine residues and that the formation of an intramolecular disulfide bridge resulted in the heme group becoming more accessible to external ligands. This supports the hypothesis that Cys38 and Cys83 serve as sensitive redox sensors. In Chapter IV we showed that CYGB mRNA and protein levels were elevated upon exposure to hypoxia. Interestingly, this upregulation was most likely HIF-2α-dependent. We propose that in melanoma, HIF-2α, rather than HIF-1α, positively regulates CYGB under hypoxic conditions in a cell type specific way. In Chapter V, the cytotoxic effect of indirect NTP treatment in two melanoma cell lines with divergent endogenous CYGB expression levels was investigated. We confirmed that NTP endows cytotoxicity that induces cell death through apoptosis and that this was mediated through the production of ROS. Moreover, we showed that CYGB protects melanoma cells from ROS-induced apoptosis by the scavenging of ROS. Interestingly, CYGB expression influenced the expression of NRF2 and HO-1. We identified the lncRNA MEG3 as a possible mechanism through which NRF2 expression and its downstream target HO-1 can be regulated by CYGB. In chapter VI, increased basal ROS levels and higher degree of lipid peroxidation upon RSL3 treatment contributed to the increased sensitivity of CYGB knockdown G361 cells to ferroptosis. Furthermore, transcriptome analysis demonstrates the enrichment of multiple cancer malignancy pathways upon CYGB knockdown, supporting a tumor-suppressive role for CYGB. Remarkably, CYGB expression regulation was identified as a critical determinant of the ferroptosis–pyroptosis therapy response. This suggests that CYGB is involved in the regulation of multiple modes of programmed cell death. FInally, we sought to delineate the RONS that are responsible for plasma-induced ICD. Our results highlight the importance of the short-lived species. Furthermore, we are first to demonstrate that NTP-created vaccine is safely prepared and offers complete protection. Moreover, we provide conclusive evidence that direct application of NTP induces ICD in melanoma.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:193568 Serial 7277  
Permanent link to this record
 

 
Author (up) De Backer, J.; Lin, A.; Berghe, W.V.; Bogaerts, A.; Hoogewijs, D. url  doi
openurl 
  Title Cytoglobin inhibits non-thermal plasma-induced apoptosis in melanoma cells through regulation of the NRF2-mediated antioxidant response Type A1 Journal article
  Year 2022 Publication Redox Biology Abbreviated Journal Redox Biol  
  Volume 55 Issue Pages 102399  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Proteinscience, proteomics and epigenetic signaling (PPES)  
  Abstract Melanoma arises from pigment-producing cells called melanocytes located in the basal layers of the epidermis of the skin. Cytoglobin (CYGB) is a ubiquitously expressed hexacoordinated globin that is highly enriched in me­lanocytes and frequently downregulated during melanomagenesis. Previously, we showed that non-thermal plasma (NTP)-produced reactive oxygen and nitrogen species (RONS) lead to the formation of an intra­ molecular disulfide bridge that would allow CYGB to function as a redox-sensitive protein. Here, we investigate the cytotoxic effect of indirect NTP treatment in two melanoma cell lines with divergent endogenous CYGB expression levels, and we explore the role of CYGB in determining treatment outcome. Our findings are consistent with previous studies supporting that NTP cytotoxicity is mediated through the production of RONS and leads to apoptotic cell death in melanoma cells. Furthermore, we show that NTP-treated solutions elicit an antioxidant response through the activation of nuclear factor erythroid 2–related factor 2 (NRF2). The knock­ down and overexpression of CYGB respectively sensitizes and protects melanoma cells from RONS-induced apoptotic cell death. The presence of CYGB enhances heme-oxygenase 1 (HO-1) and NRF2 protein expression levels, whereas the absence impairs their expression. Moreover, analysis of the CYGB-dependent transcriptome demonstrates the tumor suppressor long non-coding RNA maternally expressed 3 (MEG3) as a hitherto unde­ scribed link between CYGB and NRF2. Thus, the presence of CYGB, at least in melanoma cells, seems to play a central role in determining the therapeutic outcome of RONS-inducing anticancer therapies, like NTP-treated solutions, possessing both tumor-suppressive and oncogenic features. Hence, CYGB expression could be of in­ terest either as a biomarker or as a candidate for future targeted therapies in melanoma.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000844595100002 Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2213-2317 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 11.4 Times cited Open Access OpenAccess  
  Notes This work was funded in part by the Research Foundation – Flanders (FWO) and the Flemish Government. The FWO fellowships and grants that funded this work include: 12S9221 N (Abraham Lin) and G044420 N (Abraham Lin and Annemie Bogaerts). Joey De Backer acknowledges a visiting fellowship from the University of Fribourg. David Hoogewijs acknowledges support by the Swiss National Science Foundation (grants 31003A173000 and 310030207460). Approved Most recent IF: 11.4  
  Call Number PLASMANT @ plasmant @c:irua:190635 Serial 7101  
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Author (up) De Backer, J.; Maric, D.; Zuhra, K.; Bogaerts, A.; Szabo, C.; Vanden Berghe, W.; Hoogewijs, D. url  doi
openurl 
  Title Cytoglobin Silencing Promotes Melanoma Malignancy but Sensitizes for Ferroptosis and Pyroptosis Therapy Response Type A1 Journal article
  Year 2022 Publication Antioxidants Abbreviated Journal Antioxidants  
  Volume 11 Issue 8 Pages 1548  
  Keywords A1 Journal article; Pharmacology. Therapy; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Proteinscience, proteomics and epigenetic signaling (PPES)  
  Abstract Despite recent advances in melanoma treatment, there are still patients that either do not respond or develop resistance. This unresponsiveness and/or acquired resistance to therapy could be explained by the fact that some melanoma cells reside in a dedifferentiated state. Interestingly, this dedifferentiated state is associated with greater sensitivity to ferroptosis, a lipid peroxidation-reliant, iron-dependent form of cell death. Cytoglobin (CYGB) is an iron hexacoordinated globin that is highly enriched in melanocytes and frequently downregulated during melanomagenesis. In this study, we investigated the potential effect of CYGB on the cellular sensitivity towards (1S, 3R)-RAS-selective lethal small molecule (RSL3)-mediated ferroptosis in the G361 melanoma cells with abundant endogenous expression. Our findings show that an increased basal ROS level and higher degree of lipid peroxidation upon RSL3 treatment contribute to the increased sensitivity of CYGB knockdown G361 cells to ferroptosis. Furthermore, transcriptome analysis demonstrates the enrichment of multiple cancer malignancy pathways upon CYGB knockdown, supporting a tumor-suppressive role for CYGB. Remarkably, CYGB knockdown also triggers activation of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome and subsequent induction of pyroptosis target genes. Altogether, we show that silencing of CYGB expression modulates cancer therapy sensitivity via regulation of ferroptosis and pyroptosis cell death signaling pathways.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000846411000001 Publication Date 2022-08-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2076-3921 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 7  
  Call Number PLASMANT @ plasmant @c:irua:190686 Serial 7102  
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Author (up) De Backer, J.; Razzokov, J.; Hammerschmid, D.; Mensch, C.; Hafideddine, Z.; Kumar, N.; van Raemdonck, G.; Yusupov, M.; Van Doorslaer, S.; Johannessen, C.; Sobott, F.; Bogaerts, A.; Dewilde, S. pdf  url
doi  openurl
  Title The effect of reactive oxygen and nitrogen species on the structure of cytoglobin: A potential tumor suppressor Type A1 Journal article
  Year 2018 Publication Redox Biology Abbreviated Journal Redox Biol  
  Volume 19 Issue Pages 1-10  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Molecular Spectroscopy (MolSpec)  
  Abstract Many current anti-cancer therapies rely on increasing the intracellular reactive oxygen and nitrogen species (RONS) contents with the aim to induce irreparable damage, which subsequently results in tumor cell death. A novel tool in cancer therapy is the use of cold atmospheric plasma (CAP), which has been found to be very effective in the treatment of many different cancer cell types in vitro as well as in vivo, mainly through the vast generation of RONS. One of the key determinants of the cell's fate will be the interaction of RONS, generated by CAP, with important proteins, i.e. redox-regulatory proteins. One such protein is cytoglobin (CYGB), a recently discovered globin proposed to be involved in the protection of the cell against oxidative stress. In this study, the effect of plasma-produced RONS on CYGB was investigated through the treatment of CYGB with CAP for different treatment times. Spectroscopic analysis of CYGB showed that although chemical modifications occur, its secondary structure remains intact. Mass spectrometry experiments identified these modifications as oxidations of mainly sulfur-containing and aromatic amino acids. With longer treatment time, the treatment was also found to induce nitration of the heme. Furthermore, the two surface-exposed cysteine residues of CYGB were oxidized upon treatment, leading to the formation of intermolecular disulfide bridges, and potentially also intramolecular disulfide bridges. In addition, molecular dynamics and docking simulations confirmed, and further show, that the formation of an intramolecular disulfide bond, due to oxidative conditions, affects the CYGB 3D structure, thereby opening the access to the heme group, through gate functioning of His117. Altogether, the results obtained in this study (1) show that plasma-produced RONS can extensively oxidize proteins and (2) that the oxidation status of two redox-active cysteines lead to different conformations of CYGB.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000449722100002 Publication Date 2018-07-24  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2213-2317 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.337 Times cited Open Access OpenAccess  
  Notes M.Y. and N.K. gratefully acknowledge financial support from the Research Foundation – Flanders (FWO), Grant nos. 1200216N and 12J5617N. The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI). C.M acknowledges the financial support provided by the Flemish Community and the University of Antwerp (BOF-NOI) for the pre-doctoral scholarship is under grant number/project ID: 28465. S.V.D., S. D. and Z.H. acknowledge the FWO (Grant G.0687.13) and the GOA-BOF UA 2013–2016 (project-ID 28312) for funding. The computational resources and services used in this work were provided by the HPC core facility CalcUA of the Universiteit Antwerpen, and VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government – department EWI. Approved Most recent IF: 6.337  
  Call Number PLASMANT @ plasmant @c:irua:152818 Serial 5006  
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Author (up) de Backer, J.; Vanderveken, O.; Vos, W.; Devolder, A.; Verhulst, S.; Verbraecken, J. openurl 
  Title Functional imaging to predict treatment success of mandibular advancement devices in sleep-disordered breathing Type H3 Book chapter
  Year 2008 Publication Abbreviated Journal  
  Volume Issue Pages 141-155  
  Keywords H3 Book chapter; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Antwerpen Editor  
  Language Wos Publication Date 0000-00-00  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:72885 Serial 1298  
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Author (up) de Backer, J.; Vos, W.; Van Holsbeke, C.; Vinchurkar, S.; Claes, R.; Parizel, P.M.; de Backer, W. url  doi
openurl 
  Title Effect of high-dose N-acetylcysteine on airway geometry, inflammation, and oxidative stress in COPD patients Type A1 Journal article
  Year 2013 Publication International Journal Of Chronic Obstructive Pulmonary Disease Abbreviated Journal Int J Chronic Obstr  
  Volume 8 Issue Pages 569-579  
  Keywords A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Background: Previous studies have demonstrated the potential beneficial effect of N-acetylcysteine (NAC) in chronic obstructive pulmonary disease (COPD). However, the required dose and responder phenotype remain unclear. The current study investigated the effect of high-dose NAC on airway geometry, inflammation, and oxidative stress in COPD patients. Novel functional respiratory imaging methods combining multislice computed tomography images and computer-based flow simulations were used with high sensitivity for detecting changes induced by the therapy. Methods: Twelve patients with Global Initiative for Chronic Obstructive Lung Disease stage II COPD were randomized to receive NAC 1800 mg or placebo daily for 3 months and were then crossed over to the alternative treatment for a further 3 months. Results: Significant correlations were found between image-based resistance values and glutathione levels after treatment with NAC (P = 0.011) and glutathione peroxidase at baseline (P = 0.036). Image-based resistance values appeared to be a good predictor for glutathione peroxidase levels after NAC (P = 0.02), changes in glutathione peroxidase levels (P = 0.035), and reduction in lobar functional residual capacity levels (P = 0.00084). In the limited set of responders to NAC therapy, the changes in airway resistance were in the same order as changes induced by budesonide/formoterol. Conclusion: A combination of glutathione, glutathione peroxidase, and imaging parameters could potentially be used to phenotype COPD patients who would benefit from addition of NAC to their current therapy. The findings of this small pilot study need to be confirmed in a larger pivotal trial.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000327537300001 Publication Date 2013-11-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1178-2005; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.157 Times cited 21 Open Access  
  Notes ; JDB is a founder/shareholder of FluidDA NV, Kontich, Belgium. WV, SV, and CVH are employed by FluidDA NV, and WDB is the director of FluidDA NV. PMP and RC have no conflicts of interest to report. The study was supported by Zambon SpA, Bresso, Italy. ; Approved Most recent IF: 3.157; 2013 IF: NA  
  Call Number UA @ lucian @ c:irua:112799 Serial 813  
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Author (up) de Backer, J.W.; Vanderveken, O.M.; Vos, W.G.; Devolder, A.; Verhulst, S.L.; Verbraecken, J.A.; Parizel, P.M.; Braem, M.J.; van de Heyning, P.H.; de Backer, W.A. doi  openurl
  Title Functional imaging using computational fluid dynamics to predict treatment success of mandibular advancement devices in sleep-disordered breathing Type A1 Journal article
  Year 2007 Publication Journal of biomechanics Abbreviated Journal J Biomech  
  Volume 40 Issue 16 Pages 3708-3714  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP); Translational Neurosciences (TNW)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000251845100020 Publication Date 2007-08-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9290; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.664 Times cited 66 Open Access  
  Notes Approved Most recent IF: 2.664; 2007 IF: 2.897  
  Call Number UA @ lucian @ c:irua:64860 Serial 1299  
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Author (up) de Backer, J.W.; Vos, W.G.; Burnell, P.; Verhulst, S.L.; Salmon, P.; de Clerck, N.; de Backer, W. doi  openurl
  Title Study of the variability in upper and lower airway morphology in Sprague-Dawley rats using modern micro-CT scan-based segmentation techniques Type A1 Journal article
  Year 2009 Publication The anatomical record: advances in integrative anatomy and evolutionary biology Abbreviated Journal Anat Rec  
  Volume 292 Issue 5 Pages 720-727  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Animal models are being used extensively in pre-clinical and safety assessment studies to assess the effectiveness and safety of new chemical entities and delivery systems. Although never entirely replacing the need for animal testing, the use of computer simulations could eventually reduce the amount of animals needed for research purposes and refine the data acquired from the animal studies. Computational fluid dynamics is a powerful tool that makes it possible to simulate flow and particle behavior in animal or patient-specific respiratory models, for purposes of inhaled delivery. This tool requires an accurate representation of the respiratory system, respiration and dose delivery attributes. The aim of this study is to develop a representative airway model of the Sprague-Dawley rat using static and dynamic micro-CT scans. The entire respiratory tract was modeled, from the snout and nares down to the central airways at the point where no distinction could be made between intraluminal air and the surrounding tissue. For the selection of the representative model, variables such as upper airway movement, segmentation length, airway volume and size are taken into account. Dynamic scans of the nostril region were used to illustrate the characteristic morphology of this region in anaesthetized animals. It could be concluded from this study that it was possible to construct a highly detailed representative model of a Sprague-Dawley rat based on imaging modalities such as micro-CT scans  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000265766000010 Publication Date 2009-03-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1932-8486;1932-8494; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.431 Times cited 16 Open Access  
  Notes Approved Most recent IF: 1.431; 2009 IF: 1.490  
  Call Number UA @ lucian @ c:irua:76455 Serial 3342  
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Author (up) de Backer, J.W.; Vos, W.G.; Devolder, A.; Verhulst, S.L.; Germonpré, P.; Wuyts, F.L.; Parizel, P.M.; de Backer, W. doi  openurl
  Title Computational fluid dynamics can detect changes in airway resistance in asthmatics after acute bronchodilation Type A1 Journal article
  Year 2008 Publication Journal of biomechanics Abbreviated Journal J Biomech  
  Volume 41 Issue 1 Pages 106-113  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000253062100014 Publication Date 2007-08-15  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-9290; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.664 Times cited 53 Open Access  
  Notes Approved Most recent IF: 2.664; 2008 IF: 2.784  
  Call Number UA @ lucian @ c:irua:64859 Serial 456  
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Author (up) de Backer, J.W.; Vos, W.G.; Germonpré, P.; Salgado, R.; Parizel, P.M.; de Backer, W. doi  openurl
  Title Clinical applications of image-based airway computational fluid dynamics: assessment of inhalation medication and endobronchial devices Type A3 Journal article
  Year 2009 Publication Proceedings of the Society of Photo-optical Instrumentation Engineers Abbreviated Journal  
  Volume 7262 Issue Pages 72621p,1-72621p,9  
  Keywords A3 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Computational fluid dynamics (CFD) is a technique that is used increasingly in the biomedical field. Solving the flow equations numerically provides a convenient way to assess the efficiency of therapies and devices, ranging from cardiovascular stents and heart valves to hemodialysis workflows. Also in the respiratory field CFD has gained increasing interest, especially through the combination of three dimensional image reconstruction which results in highend patient-specific models. This paper provides an overview of clinical applications of CFD through image based modeling, resulting from recent studies performed in our center. We focused on two applications: assessment of the efficiency of inhalation medication and analysis of endobronchial valve placement. In the first application we assessed the mode of action of a novel bronchodilator in 10 treated patients and 4 controls. We assessed the local volume increase and resistance change based on the combination of imaging and CFD. We found a good correlation between the changes in volume and resistance coming from the CFD results and the clinical tests. In the second application we assessed the placement and effect of one way endobronchial valves on respiratory function in 6 patients. We found a strong patientspecific result of the therapy where in some patients the therapy resulted in complete atelectasis of the target lobe while in others the lobe remained inflated. We concluded from these applications that CFD can provide a better insight into clinically relevant therapies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2009-02-27  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Additional Links UA library record  
  Impact Factor Times cited Open Access  
  Notes Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:79497 Serial 374  
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Author (up) de Backer, J.W.; Vos, W.G.; Gorlé, C.D.; Germonpré, P.; Partoens, B.; Wuyts, F.L.; Parizel, P.M.; de Backer, W. doi  openurl
  Title Flow analyses in the lower airways: patient-specific model and boundary conditions Type A1 Journal article
  Year 2008 Publication Medical engineering and physics Abbreviated Journal Med Eng Phys  
  Volume 30 Issue 7 Pages 872-879  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Computational fluid dynamics (CFD) is increasingly applied in the respiratory domain. The ability to simulate the flow through a bifurcating tubular system has increased the insight into the internal flow dynamics and the particular characteristics of respiratory flows such as secondary motions and inertial effects. The next step in the evolution is to apply the technique to patient-specific cases, in order to provide more information about pathological airways. This study presents a patient-specific approach where both the geometry and the boundary conditions (BC) are based on individual imaging methods using computed tomography (CT). The internal flow distribution of a 73-year-old female suffering from chronic obstructive pulmonary disease (COPD) is assessed. The validation is performed through the comparison of lung ventilation with gamma scintigraphy. The results show that in order to obtain agreement within the accuracy limits of the gamma scintigraphy scan, both the patient-specific geometry and the BC (driving pressure) play a crucial role. A minimal invasive test (CT scan) supplied enough information to perform an accurate CFD analysis. In the end it was possible to capture the pathological features of the respiratory system using the imaging and computational fluid dynamics techniques. This brings the introduction of this new technique in the clinical practice one step closer.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000259768300009 Publication Date 2007-12-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1350-4533; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.819 Times cited 82 Open Access  
  Notes Approved Most recent IF: 1.819; 2008 IF: 2.216  
  Call Number UA @ lucian @ c:irua:71693 Serial 1224  
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Author (up) de Backer, J.W.; Vos, W.G.; Verhulst, S.L.; de Backer, W. doi  openurl
  Title Novel imaging techniques using computer methods for the evaluation of the upper airway in patients with sleep-disordered breathing: a comprehensive review Type A1 Journal article
  Year 2008 Publication Sleep medicine reviews Abbreviated Journal Sleep Med Rev  
  Volume 12 Issue 6 Pages 437-447  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Patients with sleep related breathing disorders (SRBD) can be treated with nasal continuous positive airway pressure (nCPAP) or with several upper airway (UA) interventions. While nCPAP is almost always effective when clinically well tolerated, the therapeutic outcome of UA surgery and UA devices is difficult to predict. The improvement of our capability to perform the latter predictions more accurately is of great clinical importance since it will prevent patients to be treated with ineffective, sometimes irreversible, techniques. In this review we describe the importance of new imaging methods in this respect. We first refer to the most important pathophysiological mechanisms known so far to play a role in SRBD, indicating that functional imaging could elucidate these mechanisms in a patient specific manner. Then we describe the new technologies that make UA imaging more functional referring to the data as they are presently available. Finally we summarise the studies that do indicate that the use of functional imaging of the UA in SRBD patients may significantly help to predict the clinical outcome after UA interventions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York Editor  
  Language Wos 000261904500003 Publication Date 2008-10-16  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1087-0792; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.958 Times cited 33 Open Access  
  Notes Approved Most recent IF: 8.958; 2008 IF: 6.143  
  Call Number UA @ lucian @ c:irua:71640 Serial 2378  
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Author (up) de Backer, J.W.; Vos, W.G.; Vinchurkar, S.C.; Claes, R.; Drollmann, A.; Wulfrank, D.; Parizel, P.M.; Germonpré, P.; de Backer, W. pdf  doi
openurl 
  Title Validation of computational fluid dynamics in CT-based airway models with SPECT/CT1 Type A1 Journal article
  Year 2010 Publication Radiology Abbreviated Journal Radiology  
  Volume 257 Issue 3 Pages 854-862  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Purpose: To compare the results obtained by using numerical flow simulations with the results of combined single photon emission computed tomography (SPECT) and computed tomography (CT) and to demonstrate the importance of correct boundary conditions for the numerical methods to account for the large amount of interpatient variability in airway geometry. Materials and Methods: This study was approved by all relevant institutional review boards. All patients gave their signed informed consent. In this study, six patients with mild asthma (three men; three women; overall mean age, 46 years ± 17 [standard deviation]) underwent CT at functional residual capacity and total lung capacity, as well as SPECT/CT. CT data were used for segmentation and computational fluid dynamics (CFD) simulations. A comparison was made between airflow distribution, as derived with (a) SPECT/CT through tracer concentration analysis, (b) CT through lobar expansion measurement, and (c) CFD through flow computer simulation. Also, the heterogeneity of the ventilation was examined. Results: Good agreement was found between SPECT/CT, CT, and CFD in terms of airflow distribution and hot spot detection. The average difference for the internal airflow distribution was less than 3% for CFD and CT versus SPECT/CT. Heterogeneity in ventilation patterns could be detected with SPECT/CT and CFD. Conclusion: This results of this study show that patient-specific computer simulations with appropriate boundary conditions yield information that is similar to that obtained with functional imaging tools, such as SPECT/CT.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000284469300031 Publication Date 2010-11-17  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0033-8419;1527-1315; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.296 Times cited 100 Open Access  
  Notes ; Supported by Novartis. ; Approved Most recent IF: 7.296; 2010 IF: 6.069  
  Call Number UA @ lucian @ c:irua:85379 Serial 3831  
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Author (up) De Backer, L.; Vos, W.; Dieriks, B.; Daems, D.; Verhulst, S.; Vinchurkar, S.; Ides, K.; de Backer, J.; Germonpré, P.; de Backer, W. url  doi
openurl 
  Title The effects of long-term noninvasive ventilation in hypercapnic COPD patients : a randomized controlled pilot study Type A1 Journal article
  Year 2011 Publication International journal of chronic obstructive pulmonary disease Abbreviated Journal Int J Chronic Obstr  
  Volume 6 Issue Pages 615-624  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Introduction: Noninvasive ventilation (NIV) is a well-established treatment for acute-on-chronic respiratory failure in hypercapnic COPD patients. Less is known about the effects of a long-term treatment with NIV in hypercapnic COPD patients and about the factors that may predict response in terms of improved oxygenation and lowered CO2 retention.Methods: In this study, we randomized 15 patients to a routine pharmacological treatment (n = 5, age 66 [standard deviation ± 6] years, FEV1 30.5 [±5.1] %pred, PaO2 65 [±6] mmHg, PaCO2 52.4 [±6.0] mmHg) or to a routine treatment and NIV (using the Synchrony BiPAP device [Respironics, Inc, Murrsville, PA]) (n = 10, age 65 [±7] years, FEV1 29.5 [±9.0] %pred, PaO2 59 [±13] mmHg, PaCO2 55.4 [±7.7] mmHg) for 6 months. We looked at arterial blood gasses, lung function parameters and performed a low-dose computed tomography of the thorax, which was later used for segmentation (providing lobe and airway volumes, iVlobe and iVaw) and post-processing with computer methods (providing airway resistance, iRaw) giving overall a functional image of the separate airways and lobes.Results: In both groups there was a nonsignificant change in FEV1 (NIV group 29.5 [9.0] to 38.5 [14.6] %pred, control group 30.5 [5.1] to 36.8 [8.7] mmHg). PaCO2 dropped significantly only in the NIV group (NIV: 55.4 [7.7] → 44.5 [4.70], P = 0.0076; control: 52.4 [6.0] → 47.6 [8.2], NS). Patients actively treated with NIV developed a more inhomogeneous redistribution of mass flow than control patients. Subsequent analysis indicated that in NIV-treated patients that improve their blood gases, mass flow was also redistributed towards areas with higher vessel density and less emphysema, indicating that flow was redistributed towards areas with better perfusion. There was a highly significant correlation between the % increase in mass flow towards lobes with a blood vessel density of >9% and the increase in PaO2. Improved ventilation–perfusion match and recruitment of previously occluded small airways can explain the improvement in blood gases.Conclusion: We can conclude that in hypercapnic COPD patients treated with long-term NIV over 6 months, a mass flow redistribution occurs, providing a better ventilation–perfusion match and hence better blood gases and lung function. Control patients improve homogeneously in iVaw and iRaw, without improvement in gas exchange since there is no improved ventilation/perfusion ratio or increased alveolar ventilation. These differences in response can be detected through functional imaging, which gives a more detailed report on regional lung volumes and resistances than classical lung function tests do. Possibly only patients with localized small airway disease are good candidates for long-term NIV treatment. To confirm this and to see if better arterial blood gases also lead to better health related quality of life and longer survival, we have to study a larger population.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000208709800066 Publication Date 2011-11-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1178-2005; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.157 Times cited 28 Open Access  
  Notes ; ; Approved Most recent IF: 3.157; 2011 IF: NA  
  Call Number UA @ lucian @ c:irua:93164 Serial 866  
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Author (up) De Backer, L.A.; Vos, W.; de Backer, J.; Van Holsbeke, C.; Vinchurkar, S.; de Backer, W. pdf  doi
openurl 
  Title The acute effect of budesonide/formoterol in COPD : a multi-slice computed tomography and lung function study Type A1 Journal article
  Year 2012 Publication European Respiratory Journal Abbreviated Journal Eur Respir J  
  Volume 40 Issue 2 Pages 298-305  
  Keywords A1 Journal article; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract The Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification of chronic obstructive pulmonary disease (COPD) does not always match with other clinical disease descriptors such as exacerbation frequency and quality of life, indicating that forced expiratory volume in 1 s (FEV1) is not a perfect descriptor of the disease. The aim of this study was to find out whether changes in airway geometry after inhalation of the most commonly used inhalation therapy in severe COPD can more adequately be described with an image-based approach than with spirometry. 10 COPD GOLD stage III patients were assessed in a double-blind crossover study. Airway volumes were analysed using segmentation of multi-slice computed tomography (MSCT) images; airway resistance was determined using computational fluid dynamics (CFD). Distal airway volume significantly increased (p=0.011) in patients 4 h after receiving a budesonide/formoterol combination from 9.6+/-4.67 cm(3) to 10.14+/-4.81 cm(3). Also CFD-determined airway resistance significantly decreased (p=0.047) from 0.051+/-0.021 kPa.s.L-1 to 0.043+/- 0.019 kPa.s.L-1. None of the lung function parameters showed a significant change. Only functional residual capacity (FRC) showed a trend to decline (p=0.056). Only the image-based parameters were able to predict the visit at which the combination product was administered. This study showed that imaging is a sensitive, complementary tool to describe changes in airway structure.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Copenhagen Editor  
  Language Wos 000307291700006 Publication Date 2011-12-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0903-1936;1399-3003; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 10.569 Times cited 37 Open Access  
  Notes ; ; Approved Most recent IF: 10.569; 2012 IF: 6.355  
  Call Number UA @ lucian @ c:irua:101113 Serial 3568  
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Author (up) De Backer, L.A.; Vos, W.G.; Salgado, R.; de Backer, J.W.; Devolder, A.; Verhulst, S.L.; Claes, R.; Germonpré, P.R.; de Backer, W.A. url  doi
openurl 
  Title Functional imaging using computer methods to compare the effect of salbutamol and ipratropium bromide in patient-specific airway models of COPD Type A1 Journal article
  Year 2011 Publication International journal of chronic obstructive pulmonary disease Abbreviated Journal Int J Chronic Obstr  
  Volume 6 Issue Pages 637-646  
  Keywords A1 Journal article; Condensed Matter Theory (CMT); Vision lab; Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Background: Salbutamol and ipratropium bromide improve lung function in patients with chronic obstructive pulmonary disease (COPD). However, their bronchodilating effect has not yet been compared in the central and distal airways. Functional imaging using computational fluid dynamics offers the possibility of making such a comparison. The objective of this study was to assess the effects of salbutamol and ipratropium bromide on the geometry and computational fluid dynamics-based resistance of the central and distal airways.Methods: Five patients with Global Initiative for Chronic Obstructive Lung Disease Stage III COPD were randomized to a single dose of salbutamol or ipratropium bromide in a crossover manner with a 1-week interval between treatments. Patients underwent lung function testing and a multislice computed tomography scan of the thorax that was used for functional imaging. Two hours after dosing, the patients again underwent lung function tests and repeat computed tomography.Results: Lung function parameters, including forced expiratory volume in 1 second, vital capacity, overall airway resistance, and specific airway resistance, changed significantly after administration of each product. On functional imaging, the bronchodilating effect was greater in the distal airways, with a corresponding drop in airway resistance, compared with the central airways. Salbutamol and ipratropium bromide were equally effective at first glance when looking at lung function tests, but when viewed in more detail with functional imaging, hyporesponsiveness could be shown for salbutamol in one patient. Salbutamol was more effective in the other patients.Conclusion: This pilot study gives an innovative insight into the modes of action of salbutamol and ipratropium bromide in patients with COPD, using the new techniques of functional imaging and computational fluid dynamics.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000208709800068 Publication Date 2011-11-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1178-2005; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.157 Times cited 25 Open Access  
  Notes ; ; Approved Most recent IF: 3.157; 2011 IF: NA  
  Call Number UA @ lucian @ c:irua:93165 Serial 1300  
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Author (up) de Backer, W.; Vos, W.; Van Holsbeke, C.; Vinchurkar, S.; Claes, R.; Hufkens, A.; Parizel, P.M.; Bedert, L.; de Backer, J. pdf  doi
openurl 
  Title The effect of roflumilast in addition to LABA/LAMA/ICS treatment in COPD patients Type L1 Letter to the editor
  Year 2014 Publication European Respiratory Journal Abbreviated Journal Eur Respir J  
  Volume 44 Issue 2 Pages 527-529  
  Keywords L1 Letter to the editor; Biophysics and Biomedical Physics; Condensed Matter Theory (CMT); Antwerp Surgical Training, Anatomy and Research Centre (ASTARC); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Copenhagen Editor  
  Language Wos 000340017300029 Publication Date 2014-05-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0903-1936;1399-3003; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 10.569 Times cited 26 Open Access  
  Notes ; ; Approved Most recent IF: 10.569; 2014 IF: 7.636  
  Call Number UA @ lucian @ c:irua:117335 Serial 832  
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Author (up) de Baerdemaeker, T.; Lemmens, B.; Dotremont, C.; Fret, J.; Roef, L.; Goiris, K.; Diels, L. pdf  doi
openurl 
  Title Benchmark study on algae harvesting with backwashable submerged flat panel membranes Type A1 Journal article
  Year 2013 Publication Bioresource technology Abbreviated Journal  
  Volume 129 Issue Pages 582-591  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)  
  Abstract The feasibility of algae harvesting with submerged flat panel membranes was investigated as pre-concentration step prior to centrifugation. Polishing of the supernatant coming from the centrifuge was evaluated as well. The effect of membrane polymer (polyvinyl chloride [PVC], polyethersulfone polyvinyl-pyrollidone [PES-PVP], poly vinylidene fluoride [PVDF]), pore size (microfiltration [MF], ultrafiltration [UF]), algae cell concentrations and species were investigated at lab-scale. In addition, backwashing as fouling control was compared to standard relaxation. PVDF was the superior polymer, and UF showed better fouling resistance. Backwashing outperformed relaxation in fouling control. The backwashable membranes allowed up to 300% higher fluxes compared to commercial flat panel benchmark (PVC) membranes. Estimations on energy consumption for membrane filtration followed by centrifugation revealed relatively low values of 0.169 kW h/kg of dry weight of algae compared to 0.5 kW h/kg for algae harvesting via classical centrifuge alone. (C) 2012 Elsevier Ltd. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000324566000079 Publication Date 2012-11-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0960-8524 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:111203 Serial 7554  
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