• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 125
  • 54
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 196
  • 196
  • 110
  • 77
  • 66
  • 39
  • 34
  • 31
  • 27
  • 26
  • 25
  • 23
  • 23
  • 22
  • 20
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Dynamics of "conditioning" film formation on biomaterials

Meyer, Anne E. January 1990 (has links)
Thesis (doctoral)--Lunds universitet, Malmö, 1990. / Extra t.p. wih thesis statement inserted. Includes bibliographical references (p. 156-170).
12

Dynamics of "conditioning" film formation on biomaterials

Meyer, Anne E. January 1990 (has links)
Thesis (doctoral)--Lunds universitet, Malmö, 1990. / Extra t.p. wih thesis statement inserted. Bibliography: p. 156-170.
13

Characterisation, sintering and mechanical behaviour of hydroxyapatite ceramics

Best, Serena M. January 1990 (has links)
No description available.
14

Monocyte/macrophage and protein interactions with non-fouling plasma polymerized tetraglyme and chemically modified polystyrene surfaces : in vitro and in vivo studies /

Shen, Mingchao. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 232-255).
15

Platelet and protein interactions with foreign materials /

Tsai, Wei-Bor, January 1998 (has links)
Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [263]-275).
16

Flow conductane property of cancellous bone graft and its effect on bone incorporation.

January 1994 (has links)
by Pang Sai Yau. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves [87-90]). / Chapter chapter one: --- introduction / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- biology of cancellous bone grafts --- p.2 / Chapter 1.2.1 --- Biology of bone graft incorporation --- p.2 / Chapter 1.2.1.1 --- Osteogenesis --- p.2 / Chapter 1.2.1.2 --- Vascularization --- p.3 / Chapter 1.2.1.3 --- Osteoinduction --- p.3 / Chapter 1.2.1.4 --- Osteoconduction --- p.4 / Chapter 1.2.2 --- Histological changes of bone grafts after bone transplantation --- p.4 / Chapter 1.2.2.1 --- Histologic pictures of cancellous autograft --- p.4 / Chapter 1.2.2.2 --- Histologic pictures of cancellous bone allograft --- p.5 / Chapter 1.2.2.3 --- Summary of the histologic changes of bone grafts --- p.5 / Chapter 1.3 --- application of cancellous bone grafts --- p.6 / Chapter 1.3.1 --- Principles of graft incorporation --- p.6 / Chapter 1.3.1.1 --- Operative site --- p.6 / Chapter 1.3.1.2 --- Graft material --- p.7 / Chapter 1.3.1.2.1 --- Autogenic cancellous bone --- p.8 / Chapter 1.3.1.2.2 --- Autogenic cortical bone --- p.9 / Chapter 1.3.2.2.3 --- Vascularized autogenic bone grafts --- p.9 / Chapter 1.3.2.2.4 --- Bone allografts --- p.10 / Chapter 1.3.2.2.5 --- Graft adjuncts and substitutes --- p.11 / Chapter 1.3.2.3 --- Systemic factors influencing gaft incorporation --- p.13 / Chapter 1.3.2.4 --- Local factors influencing graft incorporation --- p.13 / Chapter 1.3.3 --- Bone graft complications --- p.13 / Chapter 1.3.4 --- Placement of a graft --- p.14 / Chapter 1.3.5 --- Bone graft harvesting --- p.15 / Chapter 1.3.5.1 --- Iliac bone graft --- p.15 / Chapter 1.3.5.2 --- Femoral head bone allograft --- p.16 / Chapter 1.4 --- Application of flow conductance concept in a cancellous bone graft --- p.17 / Chapter 1.4.1 --- Physical structure of cancellous bone --- p.17 / Chapter 1.4.2 --- Porosity of cancellous bone --- p.17 / Chapter 1.4.3 --- Flow conductance concept --- p.18 / Chapter chapter two: --- material and method / Chapter 2.1 --- Transplantation of cancellous bone graft - Rabbit model --- p.19 / Chapter 2.1.1 --- Preparation of porcine cancellous bone graft --- p.19 / Chapter 2.1.1.1 --- Bone drilling --- p.19 / Chapter 2.1.1.2 --- Defat and freeze-dry --- p.20 / Chapter 2.1.2 --- Flow conductance measurement --- p.21 / Chapter 2.1.2.1 --- Porosity measurement --- p.21 / Chapter 2.1.2.2 --- Conductance measurement --- p.24 / Chapter 2.1.3 --- Rabbit model --- p.26 / Chapter 2.1.4 --- Methods of assessment --- p.29 / Chapter 2.1.4.1 --- Intraosseous pressure measurement --- p.29 / Chapter 2.1.4.2 --- Histologic study --- p.30 / Chapter 2.1.4.3 --- Blood flow study - use of tracer microspheres --- p.30 / Chapter 2.2 --- Flow conductance measurement of human cancellous bone --- p.34 / Chapter chapter three: --- results / Chapter 3.1 --- Results of the effects of various conductance of the grafts on bone healing in animal model --- p.38 / Chapter 3.1.1 --- Intraosseous pressure measurement --- p.38 / Chapter 3.1.2 --- Histological study --- p.40 / Chapter 3.1.3 --- Blood flow study of cancellous bone grafts --- p.52 / Chapter 3.2 --- Human specimens study --- p.62 / Chapter chapter four: --- discussion / Chapter 4.1 --- Discussion of the results in vivo study --- p.66 / Chapter 4.1.1 --- Intraosseous pressure measurement - a baseline study --- p.66 / Chapter 4.1.2 --- Effects of flow conductance of porcine cancellous grafts on bone regeneration --- p.67 / Chapter 4.1.2.1. --- Threshold conductance --- p.67 / Chapter 4.1.2.2. --- Histological score --- p.68 / Chapter 4.1.3 --- Discussion of graft healing from the blood flow study --- p.70 / Chapter 4.1.3.1 --- Tibia blood supply in relation to bone healing --- p.70 / Chapter 4.1.3.2 --- Effect of different flow conductance on blood flow changes in the tibia-graft structure --- p.72 / Chapter 4.1.4 --- "Comparison of length, porosity and conductance as the parameter on graft healing" --- p.74 / Chapter 4.2 --- Discussion on human bone specimens study --- p.76 / Chapter 4.3 --- General discussion --- p.78 / Chapter 4.3.1 --- The limitation of the animal model --- p.78 / Chapter 4.3.2 --- Some problems related to the clinical aspects --- p.79 / Chapter chapter five: --- conclusion --- p.81
17

Release of Cardiac Biomarkers and Inflammatory Response during Cardiopulmonary Bypass: Comparison of Different Biocompatible Materials Used in Cardiopulmonary Bypass

Sohn, Namseok 26 August 2008
Coronary Artery Bypass Grafting (CABG) is an effective and invasive cardiac surgery to salvage blocked coronary artery. Cardiopulmonary bypass (CPB) is usually applied to support circulation during temporary cardiac arrest. Studies have demonstrated that cardiac injury, inflammation, and oxidative stress could be induced during CABG with CPB. We conducted two studies to investigate the release of cardiac biochemical markers and inflammatory response as well as to compare the effect of different coating biomaterial of CPB on the induction of inflammation and oxidative stress during CPB. We investigated the release patterns and the serum levels of cardiac markers as well as inflammatory markers in patients undergoing elective CABG at different time points after initiation of CPB. In this study, we demonstrated that cardiac markers such as creatine kinase isoenzyme MB (CK-MB), and cardiac troponin I (cTnI) and inflammatory markers such as tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and high sensitivity C-reactive protein (hsCRP) were highly elevated after CPB. Moreover, we confirmed that cTnI is still a better biochemical marker for cardiac injury than others following CABG with CPB. Other nonspecific but highly sensitive markers such as lactate dehydrogenase (LDH), lactate, TNF-alpha, IL-6, and hsCRP could be potential surrogate markers for evaluation of cardiac injury following CPB. Based on these findings, we conducted a further investigation to demonstrate our hypothesis that different biocompatible materials used in CPB may affect the inflammation and oxidative stress differently. Biocompatible materials are thinly coated on CPB tubes to provide similar environment like endothelial cells during cardiac surgery. There are several biocompatible materials available in the market. Each of them has unique characteristics. Inflammatory response is one of the bodys fundamental defense mechanisms against foreign invaders. However, inappropriate or excessive response can lead to harmful, potentially life-threatening consequences due to severe inflammatory tissue destruction. CPB-induced inflammatory response can be one of the factors, which can affect surgical outcomes. Depending on the presence of different biocompatible materials in CPB circuits, the degree of immunoreactions can be varied. In this study, we analyzed hsCRP, an acute phase protein, and tau protein, a marker of neurocognitive deficiency. Furthermore we analyzed inflammatory cytokines including TNF-alpha, IL-6, IL-10, and interferon-gamma (IFN-gamma) to evaluate the levels of inflammation. Serum levels of oxidized nitric oxide as a marker of oxidative stress were also assessed. We demonstrated that different biocompatible material has different impacts on inflammation and oxidative stress. In the aspect of anti-inflammation, heparin-coated biocompatible material is better than others whereas surface-modifying additives biocompatible material is worse than others. Overall, different coating biomaterial of CPB results in various inflammatory response. In terms of oxidative stress, we did not observe significant difference between different biomaterial-coated CPB.
18

Release of Cardiac Biomarkers and Inflammatory Response during Cardiopulmonary Bypass: Comparison of Different Biocompatible Materials Used in Cardiopulmonary Bypass

Sohn, Namseok 26 August 2008 (has links)
Coronary Artery Bypass Grafting (CABG) is an effective and invasive cardiac surgery to salvage blocked coronary artery. Cardiopulmonary bypass (CPB) is usually applied to support circulation during temporary cardiac arrest. Studies have demonstrated that cardiac injury, inflammation, and oxidative stress could be induced during CABG with CPB. We conducted two studies to investigate the release of cardiac biochemical markers and inflammatory response as well as to compare the effect of different coating biomaterial of CPB on the induction of inflammation and oxidative stress during CPB. We investigated the release patterns and the serum levels of cardiac markers as well as inflammatory markers in patients undergoing elective CABG at different time points after initiation of CPB. In this study, we demonstrated that cardiac markers such as creatine kinase isoenzyme MB (CK-MB), and cardiac troponin I (cTnI) and inflammatory markers such as tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and high sensitivity C-reactive protein (hsCRP) were highly elevated after CPB. Moreover, we confirmed that cTnI is still a better biochemical marker for cardiac injury than others following CABG with CPB. Other nonspecific but highly sensitive markers such as lactate dehydrogenase (LDH), lactate, TNF-alpha, IL-6, and hsCRP could be potential surrogate markers for evaluation of cardiac injury following CPB. Based on these findings, we conducted a further investigation to demonstrate our hypothesis that different biocompatible materials used in CPB may affect the inflammation and oxidative stress differently. Biocompatible materials are thinly coated on CPB tubes to provide similar environment like endothelial cells during cardiac surgery. There are several biocompatible materials available in the market. Each of them has unique characteristics. Inflammatory response is one of the bodys fundamental defense mechanisms against foreign invaders. However, inappropriate or excessive response can lead to harmful, potentially life-threatening consequences due to severe inflammatory tissue destruction. CPB-induced inflammatory response can be one of the factors, which can affect surgical outcomes. Depending on the presence of different biocompatible materials in CPB circuits, the degree of immunoreactions can be varied. In this study, we analyzed hsCRP, an acute phase protein, and tau protein, a marker of neurocognitive deficiency. Furthermore we analyzed inflammatory cytokines including TNF-alpha, IL-6, IL-10, and interferon-gamma (IFN-gamma) to evaluate the levels of inflammation. Serum levels of oxidized nitric oxide as a marker of oxidative stress were also assessed. We demonstrated that different biocompatible material has different impacts on inflammation and oxidative stress. In the aspect of anti-inflammation, heparin-coated biocompatible material is better than others whereas surface-modifying additives biocompatible material is worse than others. Overall, different coating biomaterial of CPB results in various inflammatory response. In terms of oxidative stress, we did not observe significant difference between different biomaterial-coated CPB.
19

Multivariate analysis of TOF-SIMS spectra from self-assembled monolayers /

Graham, Daniel J. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 216-234).
20

Surface Finish Modeling in Micromilling of Biocompatible Materials

Berestovskyi, Dmytro V 16 December 2013 (has links)
Over the last few decades, miniaturization of the product became a necessity for many industries to achieve successful technological development, satisfy customer needs, and stay economically competitive in the market. Thus, many medical, aerospace, and electronic devices tend to decrease in size. Along with the strong demand for miniaturization, new cutting-edge micromanufacturing techniques are developing in order to produce microcomponents with a smooth surface finish and high dimensional accuracy. In the medical industry, some devices require manufacturing of fluidic microchannels on biocompatible materials for transportation of exact amount of medicine to a defined location. Often such microchannels must be manufactured to achieve a high aspect ratio, a submicron surface finish, and an anisotropic controlled profile. The fabrication of such channels on biocompatible materials still poses a challenge. This study developed micromanufacturing technique to produce the microchannels and satisfy all the requirements listed above. Computer controlled micromilling on a high speed machine system in minimum quantity lubrication was used to remove most materials and define a channel pattern. Microchannels were machined with ball end mills of diameters from Ø152μm to Ø198μm on NiTi alloy, 304 and 316L stainless steels. Assessment of microchannel was performed with optical microscopy, scanning electron microscopy, and white light interferometry. The theoretical surface roughness in ball end milling was derived using geometrical approach. The theoretical surface finish model was compared and validated with the experimental surface finish data. Meso- and macro-scale milling confirmed the validity of the model, but surface finish in micro-scale milling was measured to be a few orders of magnitude higher due to size effect and build-up edge. The build-up-edge was reduced when using AlTiN coated tools and milling in minimum quantity lubrication. The empirical surface roughness model obtained in this study shows the dependence of surface finish on chip load in micromilling. In order to further enhance the surface finish of milled microchannels additional finishing technique was identified. A separate study developed an effective electrochemical polishing technique to remove burrs and enhance surface finish of milled microchannels. When applying to 304, 316L stainless steel alloys and NiTi alloy, this hybrid technique can repeatedly produce microchannels with an average surface finish less than 100nm.

Page generated in 0.1164 seconds