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Mortazavy Beni H, Mortazavi H, Paul G. Relaxation and creep response of the alveolar lung to diagnosis and treatments for respiratory and lung disorders. Perfusion 2023; 38:1637-1643. [PMID: 36128762 DOI: 10.1177/02676591221128141] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND The lung Extracellular Matrix (ECM) contains a considerable part of the parenchymal cells. It contains three essential components: elastin and collagen within a proteoglycan (PG) viscoelastic network. Elastin provides the lung's elasticity property, a necessity for normal breathing, while collagen prepares structural support and strength, and PGs give stability and cushioning within tissue loading. Bacterial and viral respiratory diseases are dependent on changes in the ECM ingredients, which result in an alteration of the lung tissue strength. PURPOSE In the present study, this variation was investigated by changing the volume ratio of the ECM ingredients in the viscoelastic model. RESULTS As a result, the relaxation curves continuously declined by reducing the volume ratios of elastin, collagen, and PGs; subsequently, the lung stiffness decreased. Also, the Standard Linear Solid (SLS) model-based results demonstrated excellent accordance with empirical data with only minor deviations. The resting relaxation modulus and the creep modulus for the ECM tissue were 51 kPa and approximately 0.02 kPa, respectively, and the maximum total modulus of elasticity reached 121 kPa. CONCLUSIONS Moreover, this model demonstrates individual alveolar mechanical behaviours and adds another pathway to the generalized Kelvin-Voigt and Maxwell models in predicting the progress of lung diseases.
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Affiliation(s)
| | - Hamed Mortazavi
- Department of Biomedical Engineering, Arsanjan Branch, Islamic Azad University, Arsanjan, Iran
| | - Gunther Paul
- Australian Institute of Tropical Health and Medicine, James Cook University, Mackay, QLD, Australia
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Hu Z, Dong J, Lou M, Zhang J, Ma R, Wang Y, Gong M, Wang B, Tong Z, Ren H, Zheng G, Zhang Y. Effect of different degrees of adenoid hypertrophy on pediatric upper airway aerodynamics: a computational fluid dynamics study. Biomech Model Mechanobiol 2023; 22:1163-1175. [PMID: 37256522 DOI: 10.1007/s10237-023-01707-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 02/22/2023] [Indexed: 06/01/2023]
Abstract
To improve the diagnostic accuracy of adenoid hypertrophy (AH) in children and prevent further complications in time, it is important to study and quantify the effects of different degrees of AH on pediatric upper airway (UA) aerodynamics. In this study, based on computed tomography (CT) scans of a child with AH, UA models with different degrees of obstruction (adenoidal-nasopharyngeal (AN) ratio of 0.9, 0.8, 0.7, and 0.6) and no obstruction (AN ratio of 0.5) were constructed through virtual surgery to quantitatively analyze the aerodynamic characteristics of UA with different degrees of obstruction in terms of the peak velocity, pressure drop (△P), and maximum wall shear stress (WSS). We found that two obvious whirlpools are formed in the anterior upper part of the pediatric nasal cavity and in the oropharynx, which is caused by the sudden increase in the nasal cross-section area, resulting in local flow separation and counterflow. In addition, when the AN ratio was ≥ 0.7, the airflow velocity peaked at the protruding area in the nasopharynx, with an increase 1.1-2.7 times greater than that in the nasal valve area; the △P in the nasopharynx was significantly increased, with an increase 1.1-6.8 times greater than that in the nasal cavity; and the maximum WSS of the posterior wall of the nasopharynx was 1.1-4.4 times larger than that of the nasal cavity. The results showed that the size of the adenoid plays an important role in the patency of the pediatric UA.
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Affiliation(s)
- Zhenzhen Hu
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Jingliang Dong
- Institute for Sustainable Industries & Liveable Cities, Victoria University, PO Box 14428, Melbourne, VIC, 8001, Australia
- First Year College, Victoria University, Footscray Park Campus, Footscray, VIC, 3011, Australia
- School of Engineering, RMIT University, Bundoora, VIC, 3083, Australia
| | - Miao Lou
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Jingbin Zhang
- Department of Imaging, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Ruiping Ma
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Yusheng Wang
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Minjie Gong
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Botao Wang
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China
| | - Zhenbo Tong
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Hongxian Ren
- School of Energy and Environment, Southeast University, Nanjing, China
| | - Guoxi Zheng
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China.
| | - Ya Zhang
- Department of Otolaryngology Head and Neck Surgery, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xiwu Road, Xi'an, 710004, Shaanxi, China.
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Wang X, Cui L, Hong J, Wang Z, Li J, Liu Z, Zhu Z, Hao Y, Cheng G, Jiang J. Incorporating GSE4 peptide in PEG/hyaluronic acid hydrogels to promote the alveolar epithelial differentiation of mesenchymal stem cells. POLYMER 2023. [DOI: 10.1016/j.polymer.2023.125861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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Zandvakili H, Hassani K, Khorramymehr S. A mathematical model for biomechanical behavior of the aortic arch. Perfusion 2022:2676591221093195. [PMID: 35596511 DOI: 10.1177/02676591221093195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aortic arch plays a significant role in homeostatic mechanisms to retain blood pressure at stable balance in the cardiovascular system. Therefore, the objective is to estimate and identify cardiovascular illness imposed by the abnormal blood hemodynamic domain. In this regard, hemodynamic forces are monitored by the baroreflex of the artery wall. Therefore, these receptors quickly detect the abnormal stress magnitudes in the aortic arterial wall. The present study presents a 3D aortic arch model extracted by a Computerized tomography scan. Also, the numerical solution was carried out by ANSYS 2020 R1 in view of Fluid-Structure Interaction After that, we found wall shear stress (WSS), pressure, and velocity in the fluid domain. Also, the normal stress was analyzed to determine the aortic arch baroreflex location in the solid range. In this regard, higher WSS values are measured at the supra-aortic branches going out the aortic arch that reached 42.5 Pa. Also, higher normal stress happened at the aortic root and the supra-aortic branches and reached approximately 200 kPa at peak systole.
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Affiliation(s)
- Hamid Zandvakili
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Kamran Hassani
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Siamak Khorramymehr
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
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