Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 33 for “"collagen fiber"”.
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Quantification of collagen fiber organization in biological tissues at cellular and molecular scales using second-harmonic generation imaging
Collagen is the most abundant structural protein found in the human body, and is responsible for providing structure and function to tissues. Collagen molecules organize naturally into structures called fibers on the scale of the wavelength of light and lack inversion symmetry, thus allowing for …
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Enhancing the mechanical properties of a hydroxyapatite-collagen bone surrogate
<p>The synthesis of biomimetic hydroxyapatite-collagen composites is desirable from the perspective of graft elimination and load-bearing support when treating damaged or diseased bone. Bone is an organized network of carbonated hydroxyapatite mineralized collagen, whose strength and toughness is …
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Identification of quantitative second-harmonic generation imaging metrics for collagenous tissue
… generation (SHG) imaging has high specificity to collagen, sub-micrometer resolution, and optical sectioning capability. It is applied to various unstained collagenous specimens to explore the microstructure. Since collagen is one of the most abundant proteins in biological tissue, understanding …
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Biomechanical properties of engineered collagen scaffolds
… the effect of crosslinking on the stiffness of collagen scaffolds. Engineered non-crosslinked and dehydrothermally crosslinked chondroitin-6-sulfate collagen scaffolds were hydrated and loaded in tension, and their mechanical properties were compared. It was found that non-crosslinked scaffolds …
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Histological Changes in Photorejuvenation Induced by 5-Aminolevulinic Acid Photodynamic Therapy in a Photoaged Mouse Model
… histologivally characterized by degradation of collagen fiber and accumulation of abnormal elastotic material in the dermis. Photodynamic therapy (PDT) is a noninvasive technique used in the treatment of various skin disorders, and recently it has been shown to be effective for photoaged skins. …
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Quantifying collagen-based biological tissues using Fourier-transform-second-harmonic generation imaging
… (FT-SHG) imaging to quantify the arrangement of collagen fibers in biological tissues in 3D. Collagen is the primary structural protein in the human body. Depending on the spatial arrangement of collagen fibers, collagen-based biological tissues can have a wide range of functions and mechanical …
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Application of quantitative second-harmonic generation imaging to dynamic systems
… the 2 dimensional spatial orientation of collagen fiber samples under dynamic conditions. The technique is demonstrated both for a well aligned tendon sample and a randomly aligned, sparsely distributed collagen scaffold sample. For a fixed signal-to-noise ratio, the applicability of this …
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Fabrication and evaluation of a collagen-based fiber-gel three-dimensional construct for peripheral nerve repair
… nervous tissue constructs consisting of type I collagen are fabricated into a composite biomaterial scaffold to promote contact-guided growth of neuronal and glial cultures in vitro. The growth of adult tissue on these collagen-based materials is further evaluated. These constructs are assembled …
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Methods to improve indentation results on soft materials and anisotropic biological tissues
… moduli of a locally transversely isotropic collagenous material as well as the correlation between the aspect ratios (ARs) of contact and correction coefficients for contact areas (RCA). Lastly, this study designs a method for selecting the spherical tip size for indentation based on the …
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Equine superficial digital flexor tendon evaluation using low field magnetic resonance imaging and ultrasonography
… at 3, 4, 6, 8, and 16 week time points post collagenase injection. MR signal intensities (T1-weighted, T2-weighted, and STIR sequences) and tendon histology (collagen content, proteoglycan content, and collagen fiber alignment) was performed at the same time points. At four weeks following …
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Label-free breast histopathology using quantitative phase imaging
… investigation. 2. Quantifying tumor adjacent collagen structure in breast tissue using SLIM: Recent evidence shows that the structure of tumor adjacent collagen fibers influences tumor progression. In particular, collagen fiber alignment and orientation can facilitate epithelial invasion to …
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Dynamic Changes in Collagen Organization Modulate Cervical Remodeling During Pregnancy and Parturtion: New Insights and the Potential for Improved Clinical Tools to Combat Preterm Birth
… focus of this study was to identify how cervical collagen is reorganized throughout pregnancy to allow the cervix to become compliant for parturition. Beginning early in pregnancy a reduction in cervical collagen cross-links as well as a decline in matricellular proteins contribute to the changing …
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Photo-biomodulation of human skin fibroblast sub-populations: a systematic approach for the optimization of optical treatment parameters
… 450-nm light inhibited the production of procollagen I in human reticular and papillary fibroblasts in a dose-dependent manner. Gene expression results were in agreement i.e., the same light parameter down-regulated collagen fiber genes, integrins and up-regulated collagenase MMP1. This …
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Evidence That Endogenous Relaxin Promotes Vaginal Growth and Softening in Pregnant Rats
… Within the stroma relaxin reduced the density of collagen fiber bundles, reduced the length of elastin fibers, and enlarged blood vessels. These changes in the stroma appear to account for the hormone's softening effect on the vagina. Within the epithelium relaxin promoted a two-fold increase in …
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Mechanics and Modeling of Postnatal Arterial Development in Mouse Models of Varying Elastin
… that could be made in future modeling efforts. A fiber-based microstructural constitutive model was fitted to experimental mechanical data from wild-type: WT) and Eln+/- mice, which have reduced elastin. The model parameters were found to change with age and genotype in a fashion that correlated …
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Computational Modeling and Simulation Study of Dermal Wound Healing Proliferative Phase
… interactive dynamics of vasculature growth and collagen network growth. Our model further examine the effects of tissue oxygen tension (hypoxia, normoxia, hyperoxia) on healing process. Wound contraction is generally beneficial for the overall healing since it reduces the wound size thus reduces …
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An Organ Culture Technique for Maintaining the Pulp Tissue of Intact Human Teeth
… fixed teeth revealed good cellular detail, collagen fiber integrity, and normal appearing odontoblasts in many areas of the pulp in teeth perfused for periods up to 14 days. The non-perfused counterparts demonstrated little cellular detail, no odontoblastic layer, and frank necrosis in many …
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Fibromodulin and Dystrophin in Atherosclerosis: Novel roles for extracellular matrix in plaque development
… in this connection – whether through a modified collagenous ECM, or modification in a cellular protein directly linking cells to ECM components – have a significant impact on atherosclerotic plaque structure and stability. Fibromodulin is a small leucine-rich repeat proteoglycan of the ECM …
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Engineering scaffold and soluble cues for cell-instruction
… modified the microenvironmental scaffold cues of collagen-based scaffolds through various approaches. These approaches included (i) covalent cross-linking of collagen scaffolds to increase their bulk stiffness (chapter 4), (ii) enzymatic degradation of covalently cross-linked collagen scaffolds to …
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Nonlinear Viscoelastic Behavior of Ligaments and Tendons: Models and Experiments
… tendons. The mechanical behavior of bundles of collagen fibers which form ligaments and tendons was investigated. Axial stress-stretch data and stress relaxation data at different axial stretches were collected by testing rat tail tendon fascicles. The experimental results demonstrated, for the …
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