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Tonelli R, Rizzoni R, Grasso S, Cortegiani A, Ball L, Samarelli AV, Fantini R, Bruzzi G, Tabbì L, Cerri S, Manicardi L, Andrisani D, Gozzi F, Castaniere I, Smit MR, Paulus F, Bos LDJ, Clini E, Marchioni A. Stress-strain curve and elastic behavior of the fibrotic lung with usual interstitial pneumonia pattern during protective mechanical ventilation. Sci Rep 2024; 14:13158. [PMID: 38849437 PMCID: PMC11161630 DOI: 10.1038/s41598-024-63670-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 05/30/2024] [Indexed: 06/09/2024] Open
Abstract
Patients with acute exacerbation of lung fibrosis with usual interstitial pneumonia (EUIP) pattern are at increased risk for ventilator-induced lung injury (VILI) and mortality when exposed to mechanical ventilation (MV). Yet, lack of a mechanical model describing UIP-lung deformation during MV represents a research gap. Aim of this study was to develop a constitutive mathematical model for UIP-lung deformation during lung protective MV based on the stress-strain behavior and the specific elastance of patients with EUIP as compared to that of acute respiratory distress syndrome (ARDS) and healthy lung. Partitioned lung and chest wall mechanics were assessed for patients with EUIP and primary ARDS (1:1 matched based on body mass index and PaO2/FiO2 ratio) during a PEEP trial performed within 24 h from intubation. Patient's stress-strain curve and the lung specific elastance were computed and compared with those of healthy lungs, derived from literature. Respiratory mechanics were used to fit a novel mathematical model of the lung describing mechanical-inflation-induced lung parenchyma deformation, differentiating the contributions of elastin and collagen, the main components of lung extracellular matrix. Five patients with EUIP and 5 matched with primary ARDS were included and analyzed. Global strain was not different at low PEEP between the groups. Overall specific elastance was significantly higher in EUIP as compared to ARDS (28.9 [22.8-33.2] cmH2O versus 11.4 [10.3-14.6] cmH2O, respectively). Compared to ARDS and healthy lung, the stress/strain curve of EUIP showed a steeper increase, crossing the VILI threshold stress risk for strain values greater than 0.55. The contribution of elastin was prevalent at lower strains, while the contribution of collagen was prevalent at large strains. The stress/strain curve for collagen showed an upward shift passing from ARDS and healthy lungs to EUIP lungs. During MV, patients with EUIP showed different respiratory mechanics, stress-strain curve and specific elastance as compared to ARDS patients and healthy subjects and may experience VILI even when protective MV is applied. According to our mathematical model of lung deformation during mechanical inflation, the elastic response of UIP-lung is peculiar and different from ARDS. Our data suggest that patients with EUIP experience VILI with ventilatory setting that are lung-protective for patients with ARDS.
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Affiliation(s)
- Roberto Tonelli
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
- Laboratory of Cell Therapies and Respiratory Medicine, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
| | - Raffaella Rizzoni
- Department of Engineering, University of Ferrara, via Saragat 1, Ferrara, Italy.
| | - Salvatore Grasso
- Dipartimento di Medicina di Precisione e Rigenerativa e Area Ionica (DiMePre-J) Sezione di Anestesiologia e Rianimazione, Università degli Studi di Bari "Aldo Moro", Ospedale Policlinico, Bari, Italy
| | - Andrea Cortegiani
- Department of Surgical, Oncological and Oral Science (Di.Chir.On.S.), University of Palermo, Palermo, Italy
- Department of Anesthesia, Intensive Care and Emergency, Policlinico Paolo Giaccone, Palermo, Italy
| | - Lorenzo Ball
- Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Genoa, Italy
| | - Anna Valeria Samarelli
- Laboratory of Cell Therapies and Respiratory Medicine, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
| | - Riccardo Fantini
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
| | - Giulia Bruzzi
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
- Laboratory of Cell Therapies and Respiratory Medicine, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
| | - Luca Tabbì
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
| | - Stefania Cerri
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
- Laboratory of Cell Therapies and Respiratory Medicine, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
| | - Linda Manicardi
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
| | - Dario Andrisani
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
| | - Filippo Gozzi
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
| | - Ivana Castaniere
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
| | - Marry R Smit
- Department of Intensive Care, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Frederique Paulus
- Department of Intensive Care, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Lieuwe D J Bos
- Department of Intensive Care, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Enrico Clini
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
- Laboratory of Cell Therapies and Respiratory Medicine, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
| | - Alessandro Marchioni
- Respiratory Diseases Unit, Department of Medical and Surgical Sciences, University Hospital of Modena, University of Modena Reggio Emilia, Modena, Italy
- Laboratory of Cell Therapies and Respiratory Medicine, Department of Medical and Surgical Sciences for Children and Adults, University Hospital of Modena, Modena, Italy
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Zitnay RG, Herron MR, Carney KR, Potter S, Emerson LL, Weiss JA, Mendoza MC. Mechanics of lung cancer: A finite element model shows strain amplification during early tumorigenesis. PLoS Comput Biol 2022; 18:e1010153. [PMID: 36279309 PMCID: PMC9632844 DOI: 10.1371/journal.pcbi.1010153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 11/03/2022] [Accepted: 10/06/2022] [Indexed: 11/05/2022] Open
Abstract
Early lung cancer lesions develop within a unique microenvironment that undergoes constant cyclic stretch from respiration. While tumor stiffening is an established driver of tumor progression, the contribution of stress and strain to lung cancer is unknown. We developed tissue scale finite element models of lung tissue to test how early lesions alter respiration-induced strain. We found that an early tumor, represented as alveolar filling, amplified the strain experienced in the adjacent alveolar walls. Tumor stiffening further increased the amplitude of the strain in the adjacent alveolar walls and extended the strain amplification deeper into the normal lung. In contrast, the strain experienced in the tumor proper was less than the applied strain, although regions of amplification appeared at the tumor edge. Measurements of the alveolar wall thickness in clinical and mouse model samples of lung adenocarcinoma (LUAD) showed wall thickening adjacent to the tumors, consistent with cellular response to strain. Modeling alveolar wall thickening by encircling the tumor with thickened walls moved the strain amplification radially outward, to the next adjacent alveolus. Simulating iterative thickening in response to amplified strain produced tracks of thickened walls. We observed such tracks in early-stage clinical samples. The tracks were populated with invading tumor cells, suggesting that strain amplification in very early lung lesions could guide pro-invasive remodeling of the tumor microenvironment. The simulation results and tumor measurements suggest that cells at the edge of a lung tumor and in surrounding alveolar walls experience increased strain during respiration that could promote tumor progression.
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Affiliation(s)
- Rebecca G. Zitnay
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
- Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Michael R. Herron
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
| | - Keith R. Carney
- Department of Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
| | - Scott Potter
- Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
- Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
| | - Lyska L. Emerson
- Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
- Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
| | - Jeffrey A. Weiss
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
- Scientific Computing and Imaging Institute, Salt Lake City, Utah, United States of America
| | - Michelle C. Mendoza
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, United States of America
- Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
- Department of Oncological Sciences, University of Utah, Salt Lake City, Utah, United States of America
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Shi L, Herrmann J, Bou Jawde S, Bates JHT, Nia HT, Suki B. Modeling the influence of gravity and the mechanical properties of elastin and collagen fibers on alveolar and lung pressure-volume curves. Sci Rep 2022; 12:12280. [PMID: 35853981 PMCID: PMC9294799 DOI: 10.1038/s41598-022-16650-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 07/13/2022] [Indexed: 11/13/2022] Open
Abstract
The relationship between pressure (P) and volume (V) in the human lung has been extensively studied. However, the combined effects of gravity and the mechanical properties of elastin and collagen on alveolar and lung P–V curves during breathing are not well understood. Here, we extended a previously established thick-walled spherical model of a single alveolus with wavy collagen fibers during positive pressure inflation. First, we updated the model for negative pressure-driven inflation that allowed incorporation of a gravity-induced pleural pressure gradient to predict how the static alveolar P–V relations vary spatially throughout an upright human lung. Second, by introducing dynamic surface tension and collagen viscoelasticity, we computed the hysteresis loop of the lung P–V curve. The model was tested by comparing its predicted regional ventilation to literature data, which offered insight into the effects of microgravity on ventilation. The model has also produced novel testable predictions for future experiments about the variation of mechanical stresses in the septal walls and the contribution of collagen and elastin fibers to the P–V curve and throughout the lung. The model may help us better understand how mechanical stresses arising from breathing and pleural pressure variations affect regional cellular mechanotransduction in the lung.
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Affiliation(s)
- Linzheng Shi
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA
| | - Jacob Herrmann
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA
| | - Samer Bou Jawde
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA
| | - Jason H T Bates
- Department of Medicine, University of Vermont, Burlington, VT, USA
| | - Hadi T Nia
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA
| | - Béla Suki
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA, 02215, USA.
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Suki B, Bates JHT, Bartolák-Suki E. Remodeling of the Aged and Emphysematous Lungs: Roles of Microenvironmental Cues. Compr Physiol 2022; 12:3559-3574. [PMID: 35766835 DOI: 10.1002/cphy.c210033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Aging is a slow process that affects all organs, and the lung is no exception. At the alveolar level, aging increases the airspace size with thicker and stiffer septal walls and straighter and thickened collagen and elastic fibers. This creates a microenvironment that interferes with the ability of cells in the parenchyma to maintain normal homeostasis and respond to injury. These changes also make the lung more susceptible to disease such as emphysema. Emphysema is characterized by slow but progressive remodeling of the deep alveolar regions that leads to airspace enlargement and increased but disorganized elastin and collagen deposition. This remodeling has been attributed to ongoing inflammation that involves inflammatory cells and the cytokines they produce. Cellular senescence, another consequence of aging, weakens the ability of cells to properly respond to injury, something that also occurs in emphysema. These factors conspire to make alveolar walls more prone to mechanical failure, which can set emphysema in motion by driving inflammation through immune stimulation by protein fragments. Both aging and emphysema are influenced by microenvironmental conditions such as local inflammation, chemical makeup, tissue stiffness, and mechanical stresses. Although aging and emphysema are not equivalent, they have the potential to influence each other in synergistic ways; aging sets up the conditions for emphysema to develop, while emphysema may accelerate cellular senescence and thus aging itself. This article focuses on the similarities and differences between the remodeled microenvironment of the aging and emphysematous lung, with special emphasis on the alveolar septal wall. © 2022 American Physiological Society. Compr Physiol 12:3559-3574, 2022.
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Affiliation(s)
- Béla Suki
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Jason H T Bates
- Depatment of Medicine, University of Vermont Larner College of Medicine, Burlington, Vermont, USA
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Neelakantan S, Xin Y, Gaver DP, Cereda M, Rizi R, Smith BJ, Avazmohammadi R. Computational lung modelling in respiratory medicine. J R Soc Interface 2022; 19:20220062. [PMID: 35673857 PMCID: PMC9174712 DOI: 10.1098/rsif.2022.0062] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Computational modelling of the lungs is an active field of study that integrates computational advances with lung biophysics, biomechanics, physiology and medical imaging to promote individualized diagnosis, prognosis and therapy evaluation in lung diseases. The complex and hierarchical architecture of the lung offers a rich, but also challenging, research area demanding a cross-scale understanding of lung mechanics and advanced computational tools to effectively model lung biomechanics in both health and disease. Various approaches have been proposed to study different aspects of respiration, ranging from compartmental to discrete micromechanical and continuum representations of the lungs. This article reviews several developments in computational lung modelling and how they are integrated with preclinical and clinical data. We begin with a description of lung anatomy and how different tissue components across multiple length scales affect lung mechanics at the organ level. We then review common physiological and imaging data acquisition methods used to inform modelling efforts. Building on these reviews, we next present a selection of model-based paradigms that integrate data acquisitions with modelling to understand, simulate and predict lung dynamics in health and disease. Finally, we highlight possible future directions where computational modelling can improve our understanding of the structure–function relationship in the lung.
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Affiliation(s)
- Sunder Neelakantan
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
| | - Yi Xin
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Donald P. Gaver
- Department of Biomedical Engineering, Tulane University, New Orleans, LA, USA
| | - Maurizio Cereda
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Rahim Rizi
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Bradford J. Smith
- Department of Bioengineering, University of Colorado Denver
- Anschutz Medical Campus, Aurora, CO, USA
- Department of Pediatric Pulmonary and Sleep Medicine, School of Medicine, University of Colorado, Aurora, CO, USA
| | - Reza Avazmohammadi
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- J. Mike Walker '66 Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA
- Department of Cardiovascular Sciences, Houston Methodist Academic Institute, Houston, TX, USA
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Yuan Z, Herrmann J, Murthy S, Peters K, Gerard SE, Nia HT, Lutchen KR, Suki B. A Personalized Spring Network Representation of Emphysematous Lungs From CT Images. FRONTIERS IN NETWORK PHYSIOLOGY 2022; 2:828157. [PMID: 36926064 PMCID: PMC10013051 DOI: 10.3389/fnetp.2022.828157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022]
Abstract
Emphysema is a progressive disease characterized by irreversible tissue destruction and airspace enlargement, which manifest as low attenuation area (LAA) on CT images. Previous studies have shown that inflammation, protease imbalance, extracellular matrix remodeling and mechanical forces collectively influence the progression of emphysema. Elastic spring network models incorporating force-based mechanical failure have been applied to investigate the pathogenesis and progression of emphysema. However, these models were general without considering the patient-specific information on lung structure available in CT images. The aim of this work was to develop a novel approach that provides an optimal spring network representation of emphysematous lungs based on the apparent density in CT images, allowing the construction of personalized networks. The proposed method takes into account the size and curvature of LAA clusters on the CT images that correspond to a pre-stressed condition of the lung as opposed to a naïve method that excludes the effects of pre-stress. The main findings of this study are that networks constructed by the new method 1) better preserve LAA cluster sizes and their distribution than the naïve method; and 2) predict different course of emphysema progression compared to the naïve method. We conclude that our new method has the potential to predict patient-specific emphysema progression which needs verification using clinical data.
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Affiliation(s)
- Ziwen Yuan
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Jacob Herrmann
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Samhita Murthy
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Kevin Peters
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Sarah E Gerard
- Department of Radiology, University of Iowa, Iowa City, IA, United States
| | - Hadi T Nia
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Kenneth R Lutchen
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
| | - Béla Suki
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
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Jawde SB, Karrobi K, Roblyer D, Vicario F, Herrmann J, Casey D, Lutchen KR, Stamenović D, Bates JHT, Suki B. Inflation instability in the lung: an analytical model of a thick-walled alveolus with wavy fibres under large deformations. J R Soc Interface 2021; 18:20210594. [PMID: 34637644 DOI: 10.1098/rsif.2021.0594] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Inflation of hollow elastic structures can become unstable and exhibit a runaway phenomenon if the tension in their walls does not rise rapidly enough with increasing volume. Biological systems avoid such inflation instability for reasons that remain poorly understood. This is best exemplified by the lung, which inflates over its functional volume range without instability. The goal of this study was to determine how the constituents of lung parenchyma determine tissue stresses that protect alveoli from instability-related overdistension during inflation. We present an analytical model of a thick-walled alveolus composed of wavy elastic fibres, and investigate its pressure-volume behaviour under large deformations. Using second-harmonic generation imaging, we found that collagen waviness follows a beta distribution. Using this distribution to fit human pressure-volume curves, we estimated collagen and elastin effective stiffnesses to be 1247 kPa and 18.3 kPa, respectively. Furthermore, we demonstrate that linearly elastic but wavy collagen fibres are sufficient to achieve inflation stability within the physiological pressure range if the alveolar thickness-to-radius ratio is greater than 0.05. Our model thus identifies the constraints on alveolar geometry and collagen waviness required for inflation stability and provides a multiscale link between alveolar pressure and stresses on fibres in healthy and diseased lungs.
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Affiliation(s)
- Samer Bou Jawde
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Kavon Karrobi
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Darren Roblyer
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | | | - Jacob Herrmann
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Dylan Casey
- Pulmonary/Critical Care Division, University of Vermont, Burlington, VT, USA
| | - Kenneth R Lutchen
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Dimitrije Stamenović
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
| | - Jason H T Bates
- Pulmonary/Critical Care Division, University of Vermont, Burlington, VT, USA
| | - Béla Suki
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, MA 02215, USA
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