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Author De wael, A.; De Backer, A.; Yu, C.-P.; Sentürk, D.G.; Lobato, I.; Faes, C.; Van Aert, S. pdf  url
doi  openurl
  Title Three Approaches for Representing the Statistical Uncertainty on Atom-Counting Results in Quantitative ADF STEM Type A1 Journal article
  Year 2022 Publication Microscopy and microanalysis Abbreviated Journal Microsc Microanal  
  Volume Issue Pages 1-9  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract A decade ago, a statistics-based method was introduced to count the number of atoms from annular dark-field scanning transmission electron microscopy (ADF STEM) images. In the past years, this method was successfully applied to nanocrystals of arbitrary shape, size, and composition (and its high accuracy and precision has been demonstrated). However, the counting results obtained from this statistical framework are so far presented without a visualization of the actual uncertainty about this estimate. In this paper, we present three approaches that can be used to represent counting results together with their statistical error, and discuss which approach is most suited for further use based on simulations and an experimental ADF STEM image.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000854930500001 Publication Date 2022-09-19  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1431-9276 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 2.8 Times cited Open Access OpenAccess  
  Notes This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (Grant Agreement No. 770887 and No. 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through grants to A.D.w. and A.D.B. and projects G.0502.18N, G.0267.18N, and EOS 30489208. S.V.A. acknowledges TOP BOF funding from the University of Antwerp. The authors are grateful to L.M. Liz-Marzán (CIC biomaGUNE and Ikerbasque) for providing the samples. esteem3reported; esteem3jra Approved Most recent IF: 2.8  
  Call Number EMAT @ emat @c:irua:190585 Serial 7119  
Permanent link to this record
 

 
Author Sentürk, D.G.; De Backer, A.; Friedrich, T.; Van Aert, S. pdf  url
doi  openurl
  Title Optimal experiment design for element specific atom counting using multiple annular dark field scanning transmission electron microscopy detectors Type A1 Journal article
  Year 2022 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 242 Issue Pages 113626  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract This paper investigates the possible benefits for counting atoms of different chemical nature when analysing multiple 2D scanning transmission electron microscopy (STEM) images resulting from independent annular dark field (ADF) detector regimes. To reach this goal, the principles of statistical detection theory are used to quantify the probability of error when determining the number of atoms in atomic columns consisting of multiple types of elements. In order to apply this theory, atom-counting is formulated as a statistical hypothesis test, where each hypothesis corresponds to a specific number of atoms of each atom type in an atomic column. The probability of error, which is limited by the unavoidable presence of electron counting noise, can then be computed from scattering-cross sections extracted from multiple ADF STEM images. Minimisation of the probability of error as a function of the inner and outer angles of a specified number of independent ADF collection regimes results in optimal experimental designs. Based on simulations of spherical Au@Ag and Au@Pt core–shell nanoparticles, we investigate how the combination of two non-overlapping detector regimes helps to improve the probability of error when unscrambling two types of atoms. In particular, the combination of a narrow low angle ADF detector with a detector formed by the remaining annular collection regime is found to be optimal. The benefit is more significant if the atomic number Z difference becomes larger. In

addition, we show the benefit of subdividing the detector regime into three collection areas for heterogeneous nanostructures based on a structure consisting of three types of elements, e.g., a mixture of Au, Ag and Al atoms. Finally, these results are compared with the probability of error resulting when one would ultimately use a pixelated 4D STEM detector and how this could help to further reduce the incident electron dose.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000873778100001 Publication Date 0000-00-00  
  Series Editor (up) 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 2.2 Times cited Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert and Grant 823717 ESTEEM3). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N and EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF).; esteem3reported; esteem3jra Approved Most recent IF: 2.2  
  Call Number EMAT @ emat @c:irua:190925 Serial 7118  
Permanent link to this record
 

 
Author De Backer, A.; Bals, S.; Van Aert, S. pdf  url
doi  openurl
  Title A decade of atom-counting in STEM: From the first results toward reliable 3D atomic models from a single projection Type A1 Journal article
  Year 2023 Publication Ultramicroscopy Abbreviated Journal  
  Volume Issue Pages 113702  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Quantitative structure determination is needed in order to study and understand nanomaterials at the atomic scale. Materials characterisation resulting in precise structural information is a crucial point to understand the structure–property relation of materials. Counting the number of atoms and retrieving the 3D atomic structure of nanoparticles plays an important role here. In this paper, an overview will be given of the atom-counting methodology and its applications over the past decade. The procedure to count the number of atoms will be discussed in detail and it will be shown how the performance of the method can be further improved. Furthermore, advances toward mixed element nanostructures, 3D atomic modelling based on the atom-counting results, and quantifying the nanoparticle dynamics will be highlighted.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000953765800001 Publication Date 2023-02-10  
  Series Editor (up) 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 2.2 Times cited 3 Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert, Grant 815128 REALNANO to S. Bals, 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 EOS 30489208) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF) . The authors also thank the colleagues who have contributed to this work over the years, including T. Altantzis, E. Arslan Irmak, K.J. Batenburg, E. Bladt, A. De wael, R. Erni, C. Faes, B. Goris, L. Jones, L.M. Liz-Marzán, I. Lobato, G.T. Martinez, P.D. Nellist, M.D. Rosell, A. Rosenauer, K.H.W. van den Bos, A. Varambhia, and Z. Zhang.; esteem3reported; esteem3JRA Approved Most recent IF: 2.2; 2023 IF: 2.843  
  Call Number EMAT @ emat @c:irua:195896 Serial 7236  
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Author Lin, A.; Sahun, M.; Biscop, E.; Verswyvel, H.; De Waele, J.; De Backer, J.; Theys, C.; Cuypers, B.; Laukens, K.; Berghe, W.V.; Smits, E.; Bogaerts, A. pdf  url
doi  openurl
  Title Acquired non-thermal plasma resistance mediates a shift towards aerobic glycolysis and ferroptotic cell death in melanoma Type A1 Journal article
  Year 2023 Publication Drug resistance updates Abbreviated Journal  
  Volume 67 Issue Pages 100914  
  Keywords A1 Journal article; Pharmacology. Therapy; ADReM Data Lab (ADReM); Center for Oncological Research (CORE); Proteinscience, proteomics and epigenetic signaling (PPES); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract To gain insights into the underlying mechanisms of NTP therapy sensitivity and resistance, using the firstever

NTP-resistant cell line derived from sensitive melanoma cells (A375).

Methods: Melanoma cells were exposed to NTP and re-cultured for 12 consecutive weeks before evaluation

against the parental control cells. Whole transcriptome sequencing analysis was performed to identify differentially

expressed genes and enriched molecular pathways. Glucose uptake, extracellular lactate, media acidification,

and mitochondrial respiration was analyzed to determine metabolic changes. Cell death inhibitors were

used to assess the NTP-induced cell death mechanisms, and apoptosis and ferroptosis was further validated via

Annexin V, Caspase 3/7, and lipid peroxidation analysis.

Results: Cells continuously exposed to NTP became 10 times more resistant to NTP compared to the parental cell

line of the same passage, based on their half-maximal inhibitory concentration (IC50). Sequencing and metabolic

analysis indicated that NTP-resistant cells had a preference towards aerobic glycolysis, while cell death analysis

revealed that NTP-resistant cells exhibited less apoptosis but were more vulnerable to lipid peroxidation and

ferroptosis.

Conclusions: A preference towards aerobic glycolysis and ferroptotic cell death are key physiological changes in

NTP-resistance cells, which opens new avenues for further, in-depth research into other cancer types.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000925156500001 Publication Date 2022-12-29  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1368-7646 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 24.3 Times cited Open Access OpenAccess  
  Notes The authors would like to thank Dr. Christophe Deben and Ms. Hannah Zaryouh (Center for Oncological Research, University of Antwerp) for the use and their help with the D300e Digital Dispenser and Spark® Cyto, as well as Ms. Rapha¨elle Corremans (Laboratory Pathophysiology, University of Antwerp) for the use of their lactate meter. The authors would also like to acknowledge the help from Ms. Tias Verhezen and Mr. Cyrus Akbari, who was involved at the start of the project but could not continue due to the COVID-19 pandemic. The authors also acknowledge the resources and services provided by the VSC (Flemish Supercomputer Center). 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 also include: 12S9221N (Abraham Lin), G044420N (Abraham Lin, Annemie Bogaerts), and 1S67621N (Hanne Verswyvel). We would also like to thank several patrons, as part of this research was funded by donations from different donors, including Dedert Schilde vzw, Mr. Willy Floren, and the Vereycken family. We would also like to acknowledge the support from the European Cooperation in Science & Technology (COST) Action on Therapeutical applications of Cold Plasmas (CA20114; PlasTHER). Approved Most recent IF: 24.3; 2023 IF: 10.906  
  Call Number PLASMANT @ plasmant @c:irua:193167 Serial 7240  
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Author Zhang, Z.; Lobato, I.; De Backer, A.; Van Aert, S.; Nellist, P. pdf  url
doi  openurl
  Title Fast generation of calculated ADF-EDX scattering cross-sections under channelling conditions Type A1 Journal article
  Year 2023 Publication Ultramicroscopy Abbreviated Journal  
  Volume 246 Issue Pages 113671  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Advanced materials often consist of multiple elements which are arranged in a complicated structure. Quantitative scanning transmission electron microscopy is useful to determine the composition and thickness of nanostructures at the atomic scale. However, significant difficulties remain to quantify mixed columns by comparing the resulting atomic resolution images and spectroscopy data with multislice simulations where dynamic scattering needs to be taken into account. The combination of the computationally intensive nature of these simulations and the enormous amount of possible mixed column configurations for a given composition indeed severely hamper the quantification process. To overcome these challenges, we here report the development of an incoherent non-linear method for the fast prediction of ADF-EDX scattering cross-sections of mixed columns under channelling conditions. We first explain the origin of the ADF and EDX incoherence from scattering physics suggesting a linear dependence between those two signals in the case of a high-angle ADF detector. Taking EDX as a perfect incoherent reference mode, we quantitatively examine the ADF longitudinal incoherence under different microscope conditions using multislice simulations. Based on incoherent imaging, the atomic lensing model previously developed for ADF is now expanded to EDX, which yields ADF-EDX scattering cross-section predictions in good agreement with multislice simulations for mixed columns in a core–shell nanoparticle and a high entropy alloy. The fast and accurate prediction of ADF-EDX scattering cross-sections opens up new opportunities to explore the wide range of ordering possibilities of heterogeneous materials with multiple elements.  
  Address  
  Corporate Author Zezhong Zhang Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000995063900001 Publication Date 2022-12-28  
  Series Editor (up) 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 2.2 Times cited Open Access OpenAccess  
  Notes European Research Council 770887 PICOMETRICS; Fonds Wetenschappelijk Onderzoek No.G.0502.18N; Horizon 2020, 770887 ; Horizon 2020 Framework Programme; European Research Council, 823717 ESTEEM3 ; esteem3reported; esteem3JRa Approved Most recent IF: 2.2; 2023 IF: 2.843  
  Call Number EMAT @ emat @c:irua:195890 Serial 7251  
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Author Arteaga Cardona, F.; Jain, N.; Popescu, R.; Busko, D.; Madirov, E.; Arús, B.A.; Gerthsen, D.; De Backer, A.; Bals, S.; Bruns, O.T.; Chmyrov, A.; Van Aert, S.; Richards, B.S.; Hudry, D. pdf  url
doi  openurl
  Title Preventing cation intermixing enables 50% quantum yield in sub-15 nm short-wave infrared-emitting rare-earth based core-shell nanocrystals Type A1 Journal article
  Year 2023 Publication Nature communications Abbreviated Journal Nat Commun  
  Volume 14 Issue 1 Pages 4462  
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)  
  Abstract Short-wave infrared (SWIR) fluorescence could become the new gold standard in optical imaging for biomedical applications due to important advantages such as lack of autofluorescence, weak photon absorption by blood and tissues, and reduced photon scattering coefficient. Therefore, contrary to the visible and NIR regions, tissues become translucent in the SWIR region. Nevertheless, the lack of bright and biocompatible probes is a key challenge that must be overcome to unlock the full potential of SWIR fluorescence. Although rare-earth-based core-shell nanocrystals appeared as promising SWIR probes, they suffer from limited photoluminescence quantum yield (PLQY). The lack of control over the atomic scale organization of such complex materials is one of the main barriers limiting their optical performance. Here, the growth of either homogeneous (α-NaYF<sub>4</sub>) or heterogeneous (CaF<sub>2</sub>) shell domains on optically-active α-NaYF<sub>4</sub>:Yb:Er (with and without Ce<sup>3+</sup>co-doping) core nanocrystals is reported. The atomic scale organization can be controlled by preventing cation intermixing only in heterogeneous core-shell nanocrystals with a dramatic impact on the PLQY. The latter reached 50% at 60 mW/cm<sup>2</sup>; one of the highest reported PLQY values for sub-15 nm nanocrystals. The most efficient nanocrystals were utilized for in vivo imaging above 1450 nm.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001037058500022 Publication Date 2023-07-25  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2041-1723 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 16.6 Times cited 1 Open Access OpenAccess  
  Notes D.H. would like to thank Dominique Ectors (Bruker AXS GmbH, Karlsruhe, Germany) for assistance and discussion on the PXRD data and TOPAS evaluations. The authors would like to acknowledge the financial support provided by the Helmholtz Association via: i) the Professorial Recruitment Initiative Funding (B.S.R.); ii) the Research Field Energy – Program Materials and Technologies for the Energy Transition – Topic 1 Photovoltaics (F.A.C., D.B., E.M., B.S.R., D.H.). This project received funding from the European Union’s Horizon 2020 innovation programme under grant agreement 823717. This work was supported by the European Research Council (grant 770887-PICOMETRICS to S.V.A. and Grant 815128-REALNANO to S.B.). The authors acknowledge financial support from the ResearchFoundation Flanders (FWO, Belgium) through project fundings (G.0346.21 N to S.V.A. and S.B.) and a postdoctoral grant (A.D.B.). The authors (B.A.A., O.T.B. and A.C.) acknowledge funding from the Helmholtz Zentrum München, the DFG-Emmy Noether program (BR 5355/2-1) and from the CZI Deep Tissue Imaging (DTI-0000000248). The authors (O.T.B. and D.H.) would like to thank the Helmholtz Imaging (ZT-I-PF-4-038-BENIGN). Approved Most recent IF: 16.6; 2023 IF: 12.124  
  Call Number EMAT @ emat @c:irua:198158 Serial 8808  
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Author Lobato, I.; De Backer, A.; Van Aert, S. pdf  url
doi  openurl
  Title Real-time simulations of ADF STEM probe position-integrated scattering cross-sections for single element fcc crystals in zone axis orientation using a densely connected neural network Type A1 Journal article
  Year 2023 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 251 Issue Pages 113769  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract Quantification of annular dark field (ADF) scanning transmission electron microscopy (STEM) images in terms

of composition or thickness often relies on probe-position integrated scattering cross sections (PPISCS). In

order to compare experimental PPISCS with theoretically predicted ones, expensive simulations are needed for

a given specimen, zone axis orientation, and a variety of microscope settings. The computation time of such

simulations can be in the order of hours using a single GPU card. ADF STEM simulations can be efficiently

parallelized using multiple GPUs, as the calculation of each pixel is independent of other pixels. However, most

research groups do not have the necessary hardware, and, in the best-case scenario, the simulation time will

only be reduced proportionally to the number of GPUs used. In this manuscript, we use a learning approach and

present a densely connected neural network that is able to perform real-time ADF STEM PPISCS predictions as

a function of atomic column thickness for most common face-centered cubic (fcc) crystals (i.e., Al, Cu, Pd, Ag,

Pt, Au and Pb) along [100] and [111] zone axis orientations, root-mean-square displacements, and microscope

parameters. The proposed architecture is parameter efficient and yields accurate predictions for the PPISCS

values for a wide range of input parameters that are commonly used for aberration-corrected transmission

electron microscopes.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001011617200001 Publication Date 2023-06-01  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 2.2 Times cited Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N and G0A7723N) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF), Belgium. Approved Most recent IF: 2.2; 2023 IF: 2.843  
  Call Number EMAT @ emat @c:irua:197275 Serial 8812  
Permanent link to this record
 

 
Author Şentürk, DG.; Yu, CP.; De Backer, A.; Van Aert, S. pdf  url
doi  openurl
  Title Atom counting from a combination of two ADF STEM images Type A1 Journal article
  Year 2024 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 255 Issue Pages 113859  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)  
  Abstract To understand the structure–property relationship of nanostructures, reliably quantifying parameters, such as the number of atoms along the projection direction, is important. Advanced statistical methodologies have made it possible to count the number of atoms for monotype crystalline nanoparticles from a single ADF STEM image. Recent developments enable one to simultaneously acquire multiple ADF STEM images. Here, we present an extended statistics-based method for atom counting from a combination of multiple statistically independent ADF STEM images reconstructed from non-overlapping annular detector collection regions which improves the accuracy and allows one to retrieve precise atom-counts, especially for images acquired with low electron doses and multiple element structures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001089064200001 Publication Date 2023-09-23  
  Series Editor (up) 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 2.2 Times cited Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G034621N, G0A7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). Approved Most recent IF: 2.2; 2024 IF: 2.843  
  Call Number EMAT @ emat @c:irua:201008 Serial 8964  
Permanent link to this record
 

 
Author Şentürk, D.G.; De Backer, A.; Van Aert, S. pdf  url
doi  openurl
  Title Element specific atom counting for heterogeneous nanostructures: Combining multiple ADF STEM images for simultaneous thickness and composition determination Type A1 Journal Article
  Year 2024 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 259 Issue Pages 113941  
  Keywords A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;  
  Abstract In this paper, a methodology is presented to count the number of atoms in heterogeneous nanoparticles based on the combination of multiple annular dark field scanning transmission electron microscopy (ADF STEM) images. The different non-overlapping annular detector collection regions are selected based on the principles of optimal statistical experiment design for the atom-counting problem. To count the number of atoms, the total intensities of scattered electrons for each atomic column, the so-called scattering cross-sections, are simultaneously compared with simulated library values for the different detector regions by minimising the squared differences. The performance of the method is evaluated for simulated Ni@Pt and Au@Ag core-shell nanoparticles. Our approach turns out to be a dose efficient alternative for the investigation of beam-sensitive heterogeneous materials as compared to the combination of ADF STEM and energy dispersive X-ray spectroscopy.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2024-02-19  
  Series Editor (up) Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record  
  Impact Factor 2.2 Times cited Open Access OpenAccess  
  Notes This work was supported by the European Research Council (Grant 770887 PICOMETRICS to S. Van Aert). The authors acknowledge financial support from the Research Foundation Flanders (FWO, Belgium) through project fundings (G.0346.21N, GOA7723N, and EOS 40007495) and a postdoctoral grant to A. De Backer. S. Van Aert acknowledges funding from the University of Antwerp Research fund (BOF). Approved Most recent IF: 2.2; 2024 IF: 2.843  
  Call Number EMAT @ emat @c:irua:204353 Serial 8996  
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