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Affiliation(s)
- Georgios Louloudis
- George Louloudis is a master's student at University College Cork. Do you have a career story to share? Send it to
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Ni R, Straumann N, Fazio S, Dean-Ben XL, Louloudis G, Keller C, Razansky D, Ametamey S, Mu L, Nombela-Arrieta C, Klohs J. Imaging increased metabolism in the spinal cord in mice after middle cerebral artery occlusion. Photoacoustics 2023; 32:100532. [PMID: 37645255 PMCID: PMC10461215 DOI: 10.1016/j.pacs.2023.100532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 07/13/2023] [Accepted: 07/13/2023] [Indexed: 08/31/2023]
Abstract
Emerging evidence indicates crosstalk between the brain and hematopoietic system following cerebral ischemia. Here, we investigated metabolism and oxygenation in the spleen and spinal cord in a transient middle cerebral artery occlusion (tMCAO) model. Sham-operated and tMCAO mice underwent [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) to assess glucose metabolism. Naïve, sham-operated and tMCAO mice underwent multispectral optoacoustic tomography (MSOT) assisted by quantitative model-based reconstruction and unmixing algorithms for accurate mapping of oxygenation patterns in peripheral tissues at 24 h after reperfusion. We found increased [18F]FDG uptake and reduced MSOT oxygen saturation, indicating hypoxia in the thoracic spinal cord of tMCAO mice compared with sham-operated mice but not in the spleen. Reduced spleen size was observed in tMCAO mice compared with sham-operated mice ex vivo. tMCAO led to an increase in the numbers of mature T cells in femoral bone marrow tissues, concomitant with a stark reduction in these cell subsets in the spleen and peripheral blood. The combination of quantitative PET and MSOT thus enabled observation of hypoxia and increased metabolic activity in the spinal cord of tMCAO mice at 24 h after occlusion compared to sham-operated mice.
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Affiliation(s)
- Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
- Zentrum für Neurowissenschaften Zurich, Zurich, Switzerland
| | - Nadja Straumann
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
| | - Serana Fazio
- Department of Medical Oncology and Hematology, University and University Hospital Zurich, Zurich, Switzerland
| | - Xose Luis Dean-Ben
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
| | - Georgios Louloudis
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
| | - Claudia Keller
- Center for Radiopharmaceutical Sciences ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Daniel Razansky
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
- Zentrum für Neurowissenschaften Zurich, Zurich, Switzerland
| | - Simon Ametamey
- Center for Radiopharmaceutical Sciences ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Linjing Mu
- Center for Radiopharmaceutical Sciences ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - César Nombela-Arrieta
- Department of Medical Oncology and Hematology, University and University Hospital Zurich, Zurich, Switzerland
| | - Jan Klohs
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
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Krassakis P, Karavias A, Zygouri E, Roumpos C, Louloudis G, Pyrgaki K, Koukouzas N, Kempka T, Karapanos D. GIS-Based Assessment of Hybrid Pumped Hydro Storage as a Potential Solution for the Clean Energy Transition: The Case of the Kardia Lignite Mine, Western Greece. Sensors (Basel) 2023; 23:593. [PMID: 36679390 PMCID: PMC9864897 DOI: 10.3390/s23020593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/15/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Planned decommissioning of coal-fired plants in Europe requires innovative technical and economic strategies to support coal regions on their path towards a climate-resilient future. The repurposing of open pit mines into hybrid pumped hydro power storage (HPHS) of excess energy from the electric grid, and renewable sources will contribute to the EU Green Deal, increase the economic value, stabilize the regional job market and contribute to the EU energy supply security. This study aims to present a preliminary phase of a geospatial workflow used to evaluate land suitability by implementing a multi-criteria decision making (MCDM) technique with an advanced geographic information system (GIS) in the context of an interdisciplinary feasibility study on HPHS in the Kardia lignite open pit mine (Western Macedonia, Greece). The introduced geospatial analysis is based on the utilization of the constraints and ranking criteria within the boundaries of the abandoned mine regarding specific topographic and proximity criteria. The applied criteria were selected from the literature, while for their weights, the experts' judgement was introduced by implementing the analytic hierarchy process (AHP), in the framework of the ATLANTIS research program. According to the results, seven regions were recognized as suitable, with a potential energy storage capacity from 1.09 to 5.16 GWh. Particularly, the present study's results reveal that 9.27% (212,884 m2) of the area had a very low suitability, 15.83% (363,599 m2) had a low suitability, 23.99% (550,998 m2) had a moderate suitability, 24.99% (573,813 m2) had a high suitability, and 25.92% (595,125 m2) had a very high suitability for the construction of the upper reservoir. The proposed semi-automatic geospatial workflow introduces an innovative tool that can be applied to open pit mines globally to identify the optimum design for an HPHS system depending on the existing lower reservoir.
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Affiliation(s)
- Pavlos Krassakis
- Centre for Research and Technology, Hellas (CERTH), 52 Egialias St., 151 25 Maroussi, Greece
| | - Andreas Karavias
- Centre for Research and Technology, Hellas (CERTH), 52 Egialias St., 151 25 Maroussi, Greece
| | - Evangelia Zygouri
- Centre for Research and Technology, Hellas (CERTH), 52 Egialias St., 151 25 Maroussi, Greece
| | - Christos Roumpos
- Public Power Corporation of Greece (PPC), Department of Mining Engineering and Closure Planning, 104 32 Athens, Greece
| | - Georgios Louloudis
- Public Power Corporation of Greece (PPC), Department of Mining Engineering and Closure Planning, 104 32 Athens, Greece
| | - Konstantina Pyrgaki
- Centre for Research and Technology, Hellas (CERTH), 52 Egialias St., 151 25 Maroussi, Greece
| | - Nikolaos Koukouzas
- Centre for Research and Technology, Hellas (CERTH), 52 Egialias St., 151 25 Maroussi, Greece
| | - Thomas Kempka
- GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany
- Institute of Geosciences, University of Potsdam, Karl-Liebknecht-St. 24–25, 14476 Potsdam, Germany
| | - Dimitris Karapanos
- Centre for Research and Technology, Hellas (CERTH), 52 Egialias St., 151 25 Maroussi, Greece
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Ni R, Müller Herde A, Haider A, Keller C, Louloudis G, Vaas M, Schibli R, Ametamey SM, Klohs J, Mu L. In vivo Imaging of Cannabinoid Type 2 Receptors: Functional and Structural Alterations in Mouse Model of Cerebral Ischemia by PET and MRI. Mol Imaging Biol 2022; 24:700-709. [PMID: 34642898 PMCID: PMC9581861 DOI: 10.1007/s11307-021-01655-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 09/09/2021] [Accepted: 09/14/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE Stroke is one of the most prevalent vascular diseases. Non-invasive molecular imaging methods have the potential to provide critical insights into the temporal dynamics and follow alterations of receptor expression and metabolism in ischemic stroke. The aim of this study was to assess the cannabinoid type 2 receptor (CB2R) levels in transient middle cerebral artery occlusion (tMCAO) mouse models at subacute stage using positron emission tomography (PET) with our novel tracer [18F]RoSMA-18-d6 and structural imaging by magnetic resonance imaging (MRI). PROCEDURES Our recently developed CB2R PET tracer [18F]RoSMA-18-d6 was used for imaging neuroinflammation at 24 h after reperfusion in tMCAO mice. The RNA expression levels of CB2R and other inflammatory markers were analyzed by quantitative real-time polymerase chain reaction using brain tissues from tMCAO (1 h occlusion) and sham-operated mice. [18F]fluorodeoxyglucose (FDG) was included for evaluation of the cerebral metabolic rate of glucose (CMRglc). In addition, diffusion-weighted imaging and T2-weighted imaging were performed for anatomical reference and delineating the lesion in tMCAO mice. RESULTS mRNA expressions of inflammatory markers TNF-α, Iba1, MMP9 and GFAP, CNR2 were increased to 1.3-2.5 fold at 24 h after reperfusion in the ipsilateral compared to contralateral hemisphere of tMCAO mice, while mRNA expression of the neuronal marker MAP-2 was markedly reduced to ca. 50 %. Reduced [18F]FDG uptake was observed in the ischemic striatum of tMCAO mouse brain at 24 h after reperfusion. Although higher activity of [18F]RoSMA-18-d6 in ex vivo biodistribution studies and higher standard uptake value ratio (SUVR) were detected in the ischemic ipsilateral compared to contralateral striatum in tMCAO mice, the in vivo specificity of [18F]RoSMA-18-d6 was confirmed only in the CB2R-rich spleen. CONCLUSIONS This study revealed an increased [18F]RoSMA-18-d6 measure of CB2R and a reduced [18F]FDG measure of CMRglc in the ischemic striatum of tMCAO mice at subacute stage. [18F]RoSMA-18-d6 might be a promising PET tracer for detecting CB2R alterations in animal models of neuroinflammation without neuronal loss.
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Affiliation(s)
- Ruiqing Ni
- Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
| | - Adrienne Müller Herde
- Department of Chemistry and Applied Biosciences, ETH Zurich, HCI H427 Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Ahmed Haider
- Department of Chemistry and Applied Biosciences, ETH Zurich, HCI H427 Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Claudia Keller
- Department of Chemistry and Applied Biosciences, ETH Zurich, HCI H427 Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Georgios Louloudis
- Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
| | - Markus Vaas
- Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
| | - Roger Schibli
- Department of Chemistry and Applied Biosciences, ETH Zurich, HCI H427 Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Simon M Ametamey
- Department of Chemistry and Applied Biosciences, ETH Zurich, HCI H427 Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland
| | - Jan Klohs
- Institute for Biomedical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
| | - Linjing Mu
- Department of Chemistry and Applied Biosciences, ETH Zurich, HCI H427 Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland.
- Department of Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland.
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Louloudis G, Ambrosini S, Paneni F, Camici GG, Benke D, Klohs J. Corrigendum: Adeno-Associated Virus-Mediated Gain-of-Function mPCSK9 Expression in the Mouse Induces Hypercholesterolemia, Monocytosis, Neutrophilia, and a Hypercoagulative State. Front Cardiovasc Med 2022; 8:820282. [PMID: 35097032 PMCID: PMC8790749 DOI: 10.3389/fcvm.2021.820282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/20/2021] [Indexed: 12/02/2022] Open
Affiliation(s)
- Georgios Louloudis
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
- Zurich Neuroscience Center (ZNZ), Zurich, Switzerland
| | - Samuele Ambrosini
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Francesco Paneni
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
- University Heart Center, Cardiology, University Hospital Zurich, Zurich, Switzerland
- Department of Research and Education, University Hospital Zurich, Zurich, Switzerland
| | - Giovanni G. Camici
- Zurich Neuroscience Center (ZNZ), Zurich, Switzerland
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Dietmar Benke
- Zurich Neuroscience Center (ZNZ), Zurich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Jan Klohs
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland
- Zurich Neuroscience Center (ZNZ), Zurich, Switzerland
- *Correspondence: Jan Klohs ; orcid.org/0000-0003-4065-2807
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Louloudis G, Ambrosini S, Paneni F, Camici GG, Benke D, Klohs J. Adeno-Associated Virus-Mediated Gain-of-Function mPCSK9 Expression in the Mouse Induces Hypercholesterolemia, Monocytosis, Neutrophilia, and a Hypercoagulative State. Front Cardiovasc Med 2021; 8:718741. [PMID: 34631822 PMCID: PMC8492965 DOI: 10.3389/fcvm.2021.718741] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/20/2021] [Indexed: 01/20/2023] Open
Abstract
Hypercholesterolemia has previously been induced in the mouse by a single intravenous injection of adeno-associated virus (AAV)-based vector harboring gain-of-function pro-protein convertase subtilisin/kexin type 9. Despite the recent emergence of the PCSK9-AAV model, the profile of hematological and coagulation parameters associated with it has yet to be characterized. We injected 1.0 × 1011 viral particles of mPCSK9-AAV or control AAV into juvenile male C57BL/6N mice and fed them with either a Western-type high-fat diet (HFD) or standard diet over the course of 3 weeks. mPCSK9-AAV mice on HFD exhibited greater plasma PCSK9 concentration and lower low-density lipoprotein levels, concomitant with increased total cholesterol and non-high-density lipoprotein (non-HDL)-cholesterol concentrations, and lower HDL-cholesterol concentrations than control mice. Furthermore, mPCSK9-AAV-injected mice on HFD exhibited no signs of atherosclerosis at 3 weeks after the AAV injection. Hypercholesterolemia was associated with a thromboinflammatory phenotype, as neutrophil levels, monocyte levels, and neutrophil-to-lymphocyte ratios were higher and activated partial thromboplastin times (aPTTs) was lower in HFD-fed mPCSK9-AAV mice. Therefore, the mPCSK9-AAV is a suitable model of hypercholesterolemia to examine the role of thromboinflammatory processes in the pathogenesis of cardiovascular and cerebrovascular diseases.
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Affiliation(s)
- Georgios Louloudis
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Neuroscience Center (ZNZ), Zurich, Switzerland
| | - Samuele Ambrosini
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Francesco Paneni
- Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland.,University Heart Center, Cardiology, University Hospital Zurich, Zurich, Switzerland.,Department of Research and Education, University Hospital Zurich, Zurich, Switzerland
| | - Giovanni G Camici
- Zurich Neuroscience Center (ZNZ), Zurich, Switzerland.,Center for Molecular Cardiology, University of Zurich, Zurich, Switzerland
| | - Dietmar Benke
- Zurich Neuroscience Center (ZNZ), Zurich, Switzerland.,Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Jan Klohs
- Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.,Zurich Neuroscience Center (ZNZ), Zurich, Switzerland
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Muehlberger G, Seaward L, Terras M, Ares Oliveira S, Bosch V, Bryan M, Colutto S, Déjean H, Diem M, Fiel S, Gatos B, Greinoecker A, Grüning T, Hackl G, Haukkovaara V, Heyer G, Hirvonen L, Hodel T, Jokinen M, Kahle P, Kallio M, Kaplan F, Kleber F, Labahn R, Lang EM, Laube S, Leifert G, Louloudis G, McNicholl R, Meunier JL, Michael J, Mühlbauer E, Philipp N, Pratikakis I, Puigcerver Pérez J, Putz H, Retsinas G, Romero V, Sablatnig R, Sánchez JA, Schofield P, Sfikas G, Sieber C, Stamatopoulos N, Strauß T, Terbul T, Toselli AH, Ulreich B, Villegas M, Vidal E, Walcher J, Weidemann M, Wurster H, Zagoris K. Transforming scholarship in the archives through handwritten text recognition. JD 2019. [DOI: 10.1108/jd-07-2018-0114] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose
An overview of the current use of handwritten text recognition (HTR) on archival manuscript material, as provided by the EU H2020 funded Transkribus platform. It explains HTR, demonstrates Transkribus, gives examples of use cases, highlights the affect HTR may have on scholarship, and evidences this turning point of the advanced use of digitised heritage content. The paper aims to discuss these issues.
Design/methodology/approach
This paper adopts a case study approach, using the development and delivery of the one openly available HTR platform for manuscript material.
Findings
Transkribus has demonstrated that HTR is now a useable technology that can be employed in conjunction with mass digitisation to generate accurate transcripts of archival material. Use cases are demonstrated, and a cooperative model is suggested as a way to ensure sustainability and scaling of the platform. However, funding and resourcing issues are identified.
Research limitations/implications
The paper presents results from projects: further user studies could be undertaken involving interviews, surveys, etc.
Practical implications
Only HTR provided via Transkribus is covered: however, this is the only publicly available platform for HTR on individual collections of historical documents at time of writing and it represents the current state-of-the-art in this field.
Social implications
The increased access to information contained within historical texts has the potential to be transformational for both institutions and individuals.
Originality/value
This is the first published overview of how HTR is used by a wide archival studies community, reporting and showcasing current application of handwriting technology in the cultural heritage sector.
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Retsinas G, Louloudis G, Stamatopoulos N, Gatos B. Efficient Learning-Free Keyword Spotting. IEEE Trans Pattern Anal Mach Intell 2019; 41:1587-1600. [PMID: 29994197 DOI: 10.1109/tpami.2018.2845880] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this article, a method for segmentation-based learning-free Query by Example (QbE) keyword spotting on handwritten documents is proposed. The method consists of three steps, namely preprocessing, feature extraction and matching, which address critical variations of text images (e.g., skew, translation, different writing styles). During the feature extraction step, a sequence of descriptors is generated using a combination of a zoning scheme and a novel appearance descriptor, referred as modified Projections of Oriented Gradients. The preprocessing step, which includes contrast normalization and main-zone detection, aims to overcome the shortcomings of the appearance descriptor. Moreover, an uneven zoning scheme is introduced by applying a denser zoning only on query images for a more detailed representation. This leads to a significant reduction in storage requirements of a document collection. The distance between the query and word sequences is efficiently computed by the proposed Selective Matching algorithm. This algorithm is further extended to handle an augmented set of images originating from a single query image. The efficiency of the proposed method is demonstrated by experimentation conducted on seven publicly available datasets. In these experiments, the proposed method significantly outperforms all state-of-the-art learning-free techniques.
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Louloudis G, Gatos B, Halatsis C. Text Line Detection in Unconstrained Handwritten Documents Using a Block-Based Hough Transform Approach. ACTA ACUST UNITED AC 2007. [DOI: 10.1109/icdar.2007.4376985] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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