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Shung CC, Hsin KY, Tan FJ, Chen SE. The Defeathering Effect by Scalding in Chickens Follows Their Intrinsic Dermal Histologies. Animals (Basel) 2023; 13:2584. [PMID: 37627375 PMCID: PMC10451932 DOI: 10.3390/ani13162584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/09/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
This study aimed to delineate the fundamental skin histology and its association with feathers in broilers and native Red-Feather (RF) chickens and further elucidate their thermal alterations in respect to the defeathering effect by scalding. Comparisons of skin thickness between fresh samples and those after dehydration and fixation, as well as their collagen contents and histological differences, suggested that RF chickens had a thicker dermal layer with more collagen deposition and compact architecture, particularly in the neck and abdominal skin, but a thinner hypodermal layer in the back, chest, and abdomen skin. Despite an adolescent age, RF chickens showed a shorter calamus depth of tail feathers but a larger calamus diameter of wing feathers. Within the feather follicle punch, a very intense follicle sheath layer with compact collagenous matrixes to fulfill the space next to the inner feather root sheath was observed in RF chickens. Under both soft and hard scalding, RF chickens showed a lower degree of denaturation on hip skins and were more resistant to structural disintegration, primarily within the epidermal and dermal layer. Accordingly, a much narrower gap space between the feather sheath and surrounding follicle sheath was observed, and the gap expansion was also resistant to thermal changes. These results suggest that the defeathering effect by scalding follows the intrinsic skin histologies in chickens of various breeds and ages, primarily depending on the interaction of the feather calamus with the surrounding follicle sheath and neighboring cutaneous tissues, reflecting their resistance to thermal denaturation, but is irrelevant to the feathers per se.
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Affiliation(s)
- Chia-Cheng Shung
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan; (C.-C.S.); (K.-Y.H.)
| | - Kun-Yi Hsin
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan; (C.-C.S.); (K.-Y.H.)
| | - Fa-Jui Tan
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan; (C.-C.S.); (K.-Y.H.)
| | - Shuen-Ei Chen
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan; (C.-C.S.); (K.-Y.H.)
- The iEGG and Animal Biotechnology Center, National Chung Hsing University, Taichung 40227, Taiwan
- i-Center for Advanced Science and Technology (iCAST), National Chung Hsing University, Taichung 40227, Taiwan
- Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing University, Taichung 40227, Taiwan
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Kirby MA, Tang P, Liou HC, Kuriakose M, Pitre JJ, Pham TN, Ettinger RE, Wang RK, O'Donnell M, Pelivanov I. Probing elastic anisotropy of human skin in vivo with light using non-contact acoustic micro-tapping OCE and polarization sensitive OCT. Sci Rep 2022; 12:3963. [PMID: 35273250 PMCID: PMC8913799 DOI: 10.1038/s41598-022-07775-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 02/24/2022] [Indexed: 12/19/2022] Open
Abstract
Skin broadly protects the human body from undesired factors such as ultraviolet radiation and abrasion and helps conserve body temperature and hydration. Skin's elasticity and its level of anisotropy are key to its aesthetics and function. Currently, however, treatment success is often speculative and subjective, and is rarely based on skin's elastic properties because there is no fast and accurate non-contact method for imaging of skin's elasticity. Here we report on a non-contact and non-invasive method to image and characterize skin's elastic anisotropy. It combines acoustic micro-tapping optical coherence elastography (AμT-OCE) with a nearly incompressible transversely isotropic (NITI) model to quantify skin's elastic moduli. In addition, skin sites were imaged with polarization sensitive optical coherence tomography (PS-OCT) to help define fiber orientation. Forearm skin areas were investigated in five volunteers. Results clearly demonstrate elastic anisotropy of skin in all subjects. AμT-OCE has distinct advantages over competitive techniques because it provides objective, quantitative characterization of skin's elasticity without contact, which opens the door for broad translation into clinical use. Finally, we demonstrate that a combination of multiple OCT modalities (structural OCT, OCT angiography, PS-OCT and AμT-OCE) may provide rich information about skin and can be used to characterize scar.
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Affiliation(s)
- Mitchell A Kirby
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Peijun Tang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Hong-Cin Liou
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Maju Kuriakose
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - John J Pitre
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Tam N Pham
- Harborview Medical Center, University of Washington, Seattle, WA, USA
| | | | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Matthew O'Donnell
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Ivan Pelivanov
- Department of Bioengineering, University of Washington, Seattle, WA, USA.
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Biaxial mechanics of thermally denaturing skin - Part 1: Experiments. Acta Biomater 2022; 140:412-420. [PMID: 34560301 DOI: 10.1016/j.actbio.2021.09.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 09/14/2021] [Accepted: 09/17/2021] [Indexed: 12/29/2022]
Abstract
The mechanics of collagenous soft tissues, such as skin, are sensitive to heat. Thus, quantifying and modeling thermo-mechanical coupling of skin is critical to our understanding of skin's physiology, pathophysiology, and its treatment. However, key gaps persist in our knowledge about skin's coupled thermo-mechanics. Among them, we haven't quantified the role of skin's microstructural organization in its response to superphysiological loading. To fill this gap, we conducted a comprehensive set of experiments in which we combined biaxial mechanical testing with histology and two-photon imaging under liquid heat treatment at temperatures ranging from 37∘C to 95∘C lasting between 2 seconds and 5 minutes. Among other observations, we found that unconstrained skin, when exposed to high temperatures, shrinks anisotropically with the principal direction of shrinkage being aligned with collagen's principal orientation. Additionally, we found that when skin is isometrically constrained, it produces significant forces during denaturation that are also anisotropic. Finally, we found that denaturation significantly alters the mechanical behavior of skin. For short exposure times, this alteration is reflected in a reduction of stiffness at high strains. At long exposure times, the tissue softened to a point where it became untestable. We supplemented our findings with confirmation of collagen denaturation in skin via loss of birefringence and second harmonic generation. Finally, we captured all time-, temperature-, and direction-dependent experimental findings in a hypothetical model. Thus, this work fills a fundamental gap in our current understanding of skin thermo-mechanics and will support future developments in thermal injury prevention, thermal injury management, and thermal therapeutics of skin. STATEMENT OF SIGNIFICANCE: Our work experimentally explores how skin reacts to being heated. That is, it measures how much skin shrinks, what forces it produces, and how its mechanical properties change; all as a function of temperature, but also of direction and time. Additionally, our work connects these measurements to changes in skin's microscopic make-up. This knowledge is important to our understanding of skin's function and dysfunction, especially during burn injuries or heat-dependent treatments.
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Rausch M, Meador WD, Toaquiza-Tubon J, Moreno-Flores O, Tepole AB. Biaxial mechanics of thermally denaturing skin - Part 2: Modeling. Acta Biomater 2022; 140:421-433. [PMID: 34856415 DOI: 10.1016/j.actbio.2021.11.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 11/02/2021] [Accepted: 11/22/2021] [Indexed: 11/01/2022]
Abstract
Understanding the response of skin to superphysiological temperatures is critical to the diagnosis and prognosis of thermal injuries, and to the development of temperature-based medical therapeutics. Unfortunately, this understanding has been hindered by our incomplete knowledge about the nonlinear coupling between skin temperature and its mechanics. In Part I of this study we experimentally demonstrated a complex interdependence of time, temperature, direction, and load in skin's response to superphysiological temperatures. In Part II of our study, we test two different models of skin's thermo-mechanics to explain our observations. In both models we assume that skin's response to superphysiological temperatures is governed by the denaturation of its highly collageneous microstructure. Thus, we capture skin's native mechanics via a microstructurally-motivated strain energy function which includes probability distributions for collagen fiber orientation and waviness. In the first model, we capture skin's response to superphysiological temperatures as a transition between two states that link the kinetics of collagen fiber denaturation to fiber coiling and to the transformation of each fiber's constitutive behavior from purely elastic to viscoelastic. In the second model, we capture skin's response to superphysiological temperatures instead via three states in which a sequence of two reactions link the kinetics of collagen fiber denaturation to fiber coiling, followed by a state of fiber damage. Given the success of both models in qualitatively and quantitatively capturing our observations, we expect that our work will provide guidance for future experiments that could probe each model's assumptions toward a better understanding of skin's coupled thermo-mechanics and that our work will be used to guide the engineering design of heat treatment therapies. STATEMENT OF SIGNIFICANCE: Quantifying and modeling skin thermo-mechanics is critical to our understanding of skin physiology, pathophysiology, as well as heat-based treatments. This work addresses a lack of theoretical and computational models of the coupled thermo-mechanics of skin. Our model accounts for skin microstructure through modeling the probability of fiber orientation and fiber stress-free states. Denaturing induces changes in the stress-free configuration of collagen, as well as changes in fiber stiffness and viscoelastic properties. We propose two competing models that fit all of our experimental observations. These models will enable future developments of thermal-therapeutics, prevention and management of skin thermal injuries, and set a foundation for improved mechanistic models of skin thermo-mechanics.
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Langton AK, Sherratt MJ, Sellers WI, Griffiths CEM, Watson REB. Geographical ancestry is a key determinant of epidermal morphology and dermal composition. Br J Dermatol 2014; 171:274-82. [PMID: 24484315 DOI: 10.1111/bjd.12860] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Geographical ancestry plays a key role in determining the susceptibility of human skin to external insults and dermatological disease. Despite this, studies of skin from individuals of diverse geographical ancestry focus primarily on epidermal pigmentation. Few reports characterize the gross morphology and composition of the dermis and dermal-epidermal junction (DEJ). OBJECTIVES To characterize epidermal morphology and dermal composition in skin from individuals of diverse geographical ancestry. METHODS Immunohistochemical techniques were used to assess epidermal morphology and protein composition of the DEJ and dermal extracellular matrix in photoprotected skin from young African, Eurasian and Far East Asian individuals (n = 7 per group; age 18-30 years). RESULTS The epidermis of African skin was thicker, with deeper rete ridges and a more convoluted DEJ than Eurasian and Far East Asian skin. Compared with Eurasians, protein composition of the DEJ was collagen VII poor in African and Far East Asian skin (P < 0·001 and P < 0·01, respectively); the dermis of African skin was enriched in fibrillar collagens (P < 0·05), but was relatively elastin poor (P < 0·05). African dermis was abundant in fibrillin-rich microfibrils and fibulin-5 (P < 0·001 and P < 0·001, respectively) compared with Eurasian and Far East Asian skin. CONCLUSIONS We demonstrate that fundamental differences exist in skin structure and composition in individuals of diverse geographical ancestry. Disparate environmental pressures encountered by ancestral human populations living at different latitudes may have driven adaptations in skin structure and composition. Further research into the functional significance and clinical consequences of these differences is warranted.
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Affiliation(s)
- A K Langton
- Centre for Dermatology, Institute of Inflammation and Repair, Manchester Academic Health Science Centre, The University of Manchester, Manchester, U.K; The Dermatology Centre, Salford Royal NHS Foundation Trust, Salford, U.K
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Lin M, Zhai X, Wang S, Wang Z, Xu F, Lu TJ. Influences of supra-physiological temperatures on microstructure and mechanical properties of skin tissue. Med Eng Phys 2012; 34:1149-56. [DOI: 10.1016/j.medengphy.2011.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2010] [Revised: 11/29/2011] [Accepted: 12/02/2011] [Indexed: 11/30/2022]
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Wei HL, Wang S, Xu F, Xu LF, Zheng JR, Chen Y. Evaluation of a 13-hexyl-berberine hydrochloride topical gel formulation. Drug Dev Ind Pharm 2012; 39:534-9. [PMID: 22612155 DOI: 10.3109/03639045.2012.687746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
13-hexyl-berberine hydrochloride (HB-13) is a derivative from berberine which finds widespread applications in the treatment of infectious pathogens including fungi, bacteria, parasites and viruses. As our continuing efforts for treatment of herpes simplex virus (HSV), we studied the topical delivery and safety of HB-13 in a gel formulation (0.5%) in a pig model. Our studies demonstrated the maximal HB-13 concentration was 2.51 µg/mL, which was more than the half maximal inhibitory concentration (IC50) as we previously reported. In addition, there was no sign of irritation or histological aberrance for stripped skin continuously applied with 0.5% HB-13 gel for 21 days. In conclusion, 0.5% HB-13 gel can achieve effective anti-HSV concentration in the dermis and it is safe to use.
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Affiliation(s)
- Hui Lin Wei
- Institute of Dermatology, Peking Union Medical College, Chinese Academy of Medical Science, Nanjing, People's Republic of China.
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XU F, WANG PF, LIN M, LU TJ, NG EYK. QUANTIFICATION AND THE UNDERLYING MECHANISM OF SKIN THERMAL DAMAGE: A REVIEW. J MECH MED BIOL 2012. [DOI: 10.1142/s0219519410003459] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Skin thermal damage is the most common thermal trauma in civilian and military communities. Besides, advances in laser, microwave, and similar technologies have led to recent developments of thermal treatments for diseases involving skin tissue aiming at inducing damage precisely within targeted tissue structures without affecting the surrounding healthy tissue. Pain sensation accompanying thermal damage is also a serious problem for burn patients. Therefore, it is of great importance to quantify the thermal damage in skin tissue. In this review, we detail the progress of the state-of-the-art mathematical models and experimental methods for the quantification of thermal damage (both heat damage and cold damage) and the general development of thermal treatments in tissue engineering. This could enable better understanding of the underlying mechanisms of skin thermal damage and the optimization of clinical thermal therapies.
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Affiliation(s)
- F. XU
- Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China
- HST-Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA 02129, USA
| | - P. F. WANG
- Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - M. LIN
- Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - T. J. LU
- Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - E. Y. K. NG
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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ZHU YJ, XU F, SU JH, ZHOU H, LU TJ. MATHEMATICAL MODELING FOR THE PREDICTION AND IMPROVEMENT OF TOOTH THERMAL PAIN: A REVIEW. J MECH MED BIOL 2012. [DOI: 10.1142/s0219519411004095] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Tooth pain, especially tooth thermal pain, is one of the most important symptoms and signs in dental clinic and daily life. As a special sensation, pain has been studied extensively in both clinic and experimental research aimed at reducing or eliminating the possible negative effects of pain. Unfortunately, the full underlying mechanism of pain is still unclear, because the pain could be influenced by many factors, including physiological, psychological, physical, chemical, and biological factors and so on. Besides, most studies on pain mechanisms in the literature are based on skin pain sensation and only few are based on tooth pain. In this paper, we present a comprehensive review on both neurophysiology of tooth pain mechanism, and corresponding thermal, mechanical, and thermomechanical behaviors of teeth. We also describe a multiscale modeling approach for quantifying tooth thermal pain by integrating the mathematic methods of engineering into the neuroscience. The mathematical model of tooth thermal pain will enable better understanding of thermal pain mechanism and optimization of existing diagnosis and treatment in dental clinic.
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Affiliation(s)
- Y. J. ZHU
- Stomatological Hospital, College of Medicine, Biomedical Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - F. XU
- Biomedical Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, P. R. China
- School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - J. H. SU
- Biomedical Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - H. ZHOU
- Stomatological Hospital, College of Medicine, Xi'an Jiaotong University, Xi'an 710004, P. R. China
| | - T. J. LU
- Biomedical Engineering and Biomechanics Center, Xi'an Jiaotong University, Xi'an 710049, P. R. China
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Xu F, Lin M, Lu T. Modeling skin thermal pain sensation: Role of non-Fourier thermal behavior in transduction process of nociceptor. Comput Biol Med 2010; 40:478-86. [DOI: 10.1016/j.compbiomed.2010.03.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 02/07/2010] [Accepted: 03/06/2010] [Indexed: 10/19/2022]
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Zhu YJ, Lu TJ. A multi-scale view of skin thermal pain: from nociception to pain sensation. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2010; 368:521-559. [PMID: 20047938 DOI: 10.1098/rsta.2009.0234] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
All biological bodies live in a thermal environment, including the human body, where skin is the interface with a protecting function. When the temperature is out of the normal physiological range, skin fails to protect, and the pain sensation is evoked. Furthermore, in medicine, with advances in laser, microwave and similar technologies, various thermal therapeutic methods have been widely used to cure disease/injury involving skin tissue. However, the corresponding problem of pain relief has limited further application and development of these thermal treatments. Skin thermal pain is induced through both direct (i.e. an increase/decrease in temperature) and indirect (e.g. thermomechanical and thermochemical) ways, and is governed by complicated thermomechanical-chemical-neurophysiological responses. However, a complete understanding of the underlying mechanisms is still far from clear. In this article, starting from an engineering perspective, we aim to recast the biological behaviour of skin in engineering system parlance. Then, by coupling the concepts of engineering with established methods in neuroscience, we attempt to establish multi-scale modelling of skin thermal pain through ion channel to pain sensation. The model takes into account skin morphological plausibility, the thermomechanical response of skin tissue and the biophysical and neurological mechanisms of pain sensation.
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Affiliation(s)
- Y J Zhu
- Stomatological Hospital, College of Medicine, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
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Zhou B, Xu F, Chen CQ, Lu TJ. Strain rate sensitivity of skin tissue under thermomechanical loading. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2010; 368:679-690. [PMID: 20047945 DOI: 10.1098/rsta.2009.0238] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
There have been limited studies addressing the thermally dependent mechanical properties of skin tissue, although this can contribute to a variety of medical applications. To address this, an experimental study on the tensile behaviour of pig skin tissue under different thermal loading conditions and different mechanical stretching rates was performed. The results indicate that there is a significant variation among skin tensile behaviours under different temperatures and loading rates, which is correlated with dermal collagen denaturation. The Ogden model was used to summarize the effect of the strain rate and the temperature upon the measured constitutive response through two parameters (alpha and mu). These results can be used in future models to improve clinical thermal treatments for skin tissue.
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Affiliation(s)
- B Zhou
- MOE Key Laboratory for Strength and Vibration, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
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