by Leung Sze-wing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1999. / Includes bibliographical references (leaves 79-84). / Abstracts in English and Chinese. / ACKNOWLEDGEMENT --- p.II / ABSTRACT --- p.III / 摘要 --- p.V / CONTENTS --- p.VI / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter 1.1 --- Objectives --- p.1 / Chapter 1.2 --- Prevalence of Heart Diseases --- p.1 / Chapter 1.3 --- Importance of ECG Monitoring --- p.2 / Chapter 1.4 --- Wireless Electrode --- p.2 / Chapter 1.5 --- Analogue-to-Digital Converters --- p.3 / Chapter 1.6 --- Organization of Thesis --- p.4 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.5 / Chapter 2.1 --- Telemetry --- p.5 / Chapter 2.1.1 --- "Definitions of ""Telemetry “" --- p.5 / Chapter 2.1.2 --- Advantages of Telemetry --- p.6 / Chapter 2.1.3 --- History of Telemetry --- p.7 / Chapter 2.1.4 --- Special Considerations on Telemetry System --- p.10 / Chapter 2.2 --- Sigma-Delta Converter --- p.12 / Chapter 2.2.1 --- Conventional Digitizing Circuitry --- p.12 / Chapter 2.2.2 --- "Single, Dual-Slope A/D Converters" --- p.13 / Single-Slope A/D Converter --- p.13 / Dual-Slope Converter --- p.75 / Chapter 2.2.3 --- Successive Approximation (SAR) --- p.17 / Chapter 2.2.4 --- Flash Converters --- p.18 / Chapter 2.2.5 --- Sigma-Delta Converter --- p.18 / Chapter 2.3 --- Conclusion --- p.20 / Chapter CHAPTER 3 --- WIRELESS ELECTRODE --- p.21 / Chapter 3.1 --- """Single Electrode"" Measurement" --- p.21 / Chapter 3.2 --- VSE (Virtual Single Electrode) --- p.21 / Concentric Electrode --- p.21 / Chapter 3.3 --- WE (Wireless Electrode) --- p.24 / Chapter 3.4 --- Discussion --- p.29 / Chapter CHAPTER 4 --- SIGMA-DELTA CONVERTER FOR ECG SIGNALS --- p.30 / Chapter 4.1 --- Motivations --- p.30 / Chapter 4.2 --- Baseband Application --- p.31 / Chapter 4.2.1 --- Simulation Results --- p.31 / Chapter 4.2.2 --- Experimental Results --- p.48 / Chapter 4.3 --- Wireless Application --- p.58 / Chapter 4.3.1 --- General Description --- p.58 / Chapter 4.3.2 --- Simulation Results --- p.59 / Chapter 4.3.3 --- Scenario 1 (Analogue Decoding) --- p.70 / Chapter 4.3.4 --- Scenario II (Digital Decoding) --- p.73 / Chapter 4.4 --- Discussion and Conclusion --- p.76 / Chapter CHAPTER 5 --- CONCLUSION AND FUTURE WORK --- p.77 / Chapter 5.1 --- General Conclus ion --- p.77 / Chapter 5.2 --- Future Work --- p.78 / BIBLIOGRAPHY --- p.79 / LIST OF ABBREVIATIONS --- p.85

青少年特發性脊柱側凸(Adolescent idiopathic scoliosis , AIS)是一種複雜的脊柱三維畸形，常見於10-16 歲處於生長發育高峰期的青少年女性。儘管AIS 發生率較高並且臨床影響較大，但是到目前為止其病因未明。在眾多關於AIS 病因學的假設和理論研究中，普遍認為低骨密度是AIS 的一個重要影響因素。然而近年來對於AIS 患者低骨密度研究不足，其潛在的機制尚不明確。我們之前初步的組織學研究發現，AIS 患者的松質骨中成骨細胞功能下降，此研究為AIS中存在骨礦化異常提供了初步依據。 / 骨橋蛋白是骨組織中一種重要的非膠原細胞外基質蛋白，其在骨礦化過程中起著重要作用。近期的研究報導AIS 患者血漿中骨橋蛋白水準高於年齡匹配的正常對照。因此本研究假設AIS 患者血漿及骨組織中骨橋蛋白高於正常對照，并可能影響了骨基質的礦化，從而導致低骨密度。 / 本系列研究的第一部分旨在通過外周定量電腦斷層掃描（pQCT）明確AIS患者中皮質骨密度及松質骨密度是否均低於正常對照。pQCT 可以準確地三維評估皮質骨密度，松質骨密度及其他骨品質的相關參數。採用雙能X 線骨密度儀（DXA）測量受試者的非優勢側近端股骨面積骨密度（包括股骨頸，Ward’s 三角及大轉子）。而採用pQCT 測量受試者非優勢側橈骨遠端容積骨密度，包括皮質骨密度及松質骨密度。結果顯示AIS 患者面積骨密度，皮質骨密度及松質骨密度在不同年齡段和月經時間分組中均低於正常對照。並且AIS 與正常對照皮質骨密度的差異隨著年齡增長越來越大，而松質骨密度差異則隨著年齡增長越來越小。 / 第二部分通過顯微CT 及組織形態測定研究AIS 及正常骨組織的骨礦化及骨微結構。採用顯微CT 檢測骨組織的三維結構參數，包括材料骨密度及骨微結構。未脫鈣骨組織的切片通過Goldner’s 染色進行組織形態學測量。結果顯示AIS患者的骨體積分數，骨小梁數目，骨小梁厚度及結構模型指數與正常對照之間均無顯著差異，而材料骨密度顯著低於正常對照。組織形態學分析結果顯示AIS中低礦化骨顯著多於正常對照。 / 第三部分旨在研究AIS 及正常對照血漿中骨橋蛋白水準及其與骨密度的關係。採用酶聯吸附免疫法測量AIS 患者及年齡匹配的正常對照血漿中的骨橋蛋白水準。血漿骨橋蛋白水準與骨密度的關係採用多元回歸分析。研究結果顯示AIS 患者及正常對照血漿骨橋蛋白水平均與年齡及月經時間呈負相關。AIS 患者的血漿骨橋蛋白水準顯著高於正常對照，並且與松質骨密度呈顯著負相關。 / 本研究第四部分旨在探討骨組織中的骨橋蛋白表達與骨形態學及骨礦化指標在AIS 及正常對照中的關係。骨組織中骨橋蛋白的表達採用半定量免疫組織化學法評估。研究結果顯示在AIS 中血漿骨橋蛋白水準與骨組織中骨橋蛋白的表達呈正相關。且AIS 骨組織中骨橋蛋白的表達也顯著高於正常對照。進一步的研究發現骨組織中骨橋蛋白的表達與材料骨密度呈負相關，而與低礦化骨量呈正相關。 / 本研究明確了AIS 中骨礦化水準低於正常對照，進一步證明AIS 患者中的皮質骨及松質骨密度下降可能與骨礦化的調控異常有關。本研究發現的骨橋蛋白與低骨密度及低骨礦化水準的關係，可以推測AIS 患者中異常升高的骨橋蛋白水準可能在骨礦獲取的調解中起重要作用。本系列研究提供證據支援AIS 患者中骨橋蛋白的異常表達可能影響了骨基質的礦化，從而導致低骨密度。本研究為AIS 中低骨密度可能的機制提供了全新的見解，並可能進一步解釋AIS 的發病機理及其發生，發展。 / Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine occurring most commonly in girls between ages 10-16 during the pubertal growth spurt. Despite its high prevalence and clinical impact, etiology of AIS remains largely unknown. Among the number of proposed hypothesis and observations on the etiopathogenesis of AIS, low bone mineral density (BMD) is one of the most reported factor (Cheng et al. 1999; Hung et al. 2005; Cheung et al. 2006; Hui et al. 2011). However, the underlying mechanism of low BMD in AIS has not been sufficiently studied scientifically and its link to the etiopathogenesis is still not clear. From a previous pilot study, our group has reported the histological features of reduced osteoblastic activity in bone biopsy specimens obtained from AIS subjects intraoperatively, thus providing the early evidence of abnormal bone mineral acquisition and mineralization (Cheng et al. 2001). / Osteopontin (OPN) has been recognized as one the major non-collagen extracellular matrix proteins in bone and plays an important role in bone mineralization. Recent report suggested that AIS patients have higher OPN level than normal controls (Moreau et al. 2009). It was hypothesized that the low BMD in AIS is associated with abnormal bone matrix mineralization which may be related to abnormal expression of OPN in the plasma and at tissue level. / In this series of studies, the first part aimed to investigate the differential cortical and trabecular bone mineral density of AIS Vs normal controls. The non-dominant proximal femur areal BMD (aBMD) (femoral neck, Ward’s triangle and greater trochanter) of the subjects were measured with dual-energy x-ray absorptiometry (DXA). The volumetric bone mineral density (vBMD) in non-dominant distal radius was measured with peripheral quantitative computed tomography (pQCT) that allows accurate three dimensional assessment of the cortical and trabecular bone mineral density and other parameters of bone quality. AIS was found to have lower aBMDs, trabecular BMD (TBMD) and cortical BMD (CBMD) in different age groups and year since menarche (YSM) groups. Furthermore, the percentage difference of CBMD between AIS and controls was increased with age while a decreasing trend was observed in the TBMD. / The second part of the study investigated the bone mineralization and bone micro-architecture with micro-computed tomography (micro-CT) and histomorphometry study of bone biopsies obtained from AIS and normal controls. Three-dimensional structural parameters including material bone mineral density (mBMD) and bone architecture were evaluated by micro-CT. Bone histomorphometry was assessed by undecalcified sectioning with Goldner’s trichrome staining. mBMD of trabecular bone in AIS was found to be significantly lower than the normal control while no difference could be demonstrated in BV/TV, Tb.N, Tb.Th and SMI measurement between the two groups. It was also shown that the percentage of low-mineralized bone in AIS was significantly higher than that in normal controls. / The third part aimed to study the plasma OPN level and its association with the BMD in AIS Vs normal controls. Plasma OPN level in AIS and age-matched controls was measured by ELISA. With multivariate regression analysis, the plasma OPN level was found to be negatively correlated with Age and YSM in both AIS and normal controls. In addition, the plasma OPN level in AIS was significantly higher and correlated with the low trabecular BMD. / The fourth part of the study investigated the OPN expression in bone tissues level and its association with histomorphometric bone mineralization and bone micro-architectural parameters in AIS Vs normal controls. OPN expression in bone biopsy was semi-quantified by immunohistochemistry. It was found that the bone tissue OPN level was significantly higher in AIS and also positively correlated with plasma OPN level. In addition, in this pilot study, we found the trend that OPN expression in trabecular bone was negatively associated with mBMD, and positively with the percentage of low-mineralized bone. / The present study showed that AIS had lower bone mineralization than normal controls. The low cortical and trabecular BMD found in AIS is likely to be resulting from abnormal regulation of bone mineralization. The association of OPN with abnormal BMD and bone mineralization further suggested that abnormal OPN level might play an important role in affecting the bone mineral acquisition in AIS. All of these findings strongly supported the hypothesis that the low BMD in AIS is associated with abnormal bone matrix mineralization which could be related to abnormal expression of OPN. This study provided important additional insight into the possible mechanism of lower bone mineral density that might be linked to theetiopathogenesis, development and progression of the spinal deformity in AIS. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Sun, Guangquan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 143-160). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract and appendix A also in Chinese. / THE CHINESE UNIVERSITY OF HONG KONG --- p.I / ACKNOWLEDGEMENTS --- p.II / ABSTRACT --- p.IV / ABBREVIATION --- p.XI / TABLE OF CONTENTS --- p.XIII / LIST OF TABLES --- p.XVII / LIST OF FIGURES --- p.XIX / LIST OF PUBLICATIONS --- p.XXI / Chapter CHAPTER 1 --- STUDY BACKGROUND --- p.1 / Chapter 1.1 --- GENERAL OVERVIEW OF ADOLESCENT IDIOPATHIC SCOLIOSIS (AIS) --- p.2 / Chapter 1.1.1 --- NATURAL HISTORY --- p.4 / Chapter 1.1.2 --- CURRENT TREATMENTS --- p.6 / Chapter 1.1.2.1 --- Observation --- p.7 / Chapter 1.1.2.2 --- Bracing --- p.7 / Chapter 1.1.2.3 --- Surgical treatments --- p.9 / Chapter 1.1.3 --- CURRENT HYPOTHESIS ON THE ETIOLOGY OF AIS --- p.11 / Chapter 1.1.3.1 --- Genetic factors --- p.12 / Chapter 1.1.3.2 --- Neuromuscular impairment --- p.14 / Chapter 1.1.3.3 --- Abnormalities in skeletal development --- p.16 / Chapter 1.1.3.4 --- Low bone mineral density in AIS --- p.16 / Chapter 1.2 --- BONE MINERALIZATION --- p.18 / Chapter 1.2.1 --- Overview of bone mineralization --- p.18 / Chapter 1.2.2 --- Bone modeling --- p.18 / Chapter 1.2.3 --- Bone remodeling --- p.19 / Chapter 1.2.4 --- Factors affecting bone mineralization --- p.21 / Chapter 1.3 --- OSTEOPONTIN --- p.23 / Chapter 1.3.1 --- Structure of osteopontin --- p.23 / Chapter 1.3.2 --- Osteopontin - cellular and tissue distribution --- p.24 / Chapter 1.3.3 --- Osteopontin functions --- p.25 / Chapter 1.3.4 --- Osteopontin functions in bone --- p.25 / Chapter 1.3.5 --- Osteopontin and bone mineral density in human --- p.29 / Chapter CHAPTER 2 --- STUDY HYPOTHESIS AND PLAN --- p.31 / Chapter 2.1 --- INTRODUCTION --- p.32 / Chapter 2.2 --- HYPOTHESIS --- p.33 / Chapter 2.3 --- OBJECTIVES --- p.34 / Chapter 2.4 --- STUDY PLAN --- p.34 / Chapter CHAPTER 3 --- LOW BONE MINERAL DENSITY IN ADOLESCENT IDIOPATHIC SCOLIOSIS - AREAL VS VOLUMETRIC, CORTICAL VS TRABECULAR BONE MINERAL DENSITY --- p.36 / Chapter 3.1 --- INTRODUCTION --- p.37 / Chapter 3.2 --- SUBJECTS AND METHODS --- p.39 / Chapter 3.2.1 --- Subjects --- p.39 / Chapter 3.2.2 --- BMD Measurement --- p.40 / Chapter 3.2.3 --- Statistical Analysis --- p.41 / Chapter 3.3 --- RESULTS --- p.42 / Chapter 3.3.1 --- aBMD of AIS and normal controls by age groups --- p.42 / Chapter 3.3.2 --- TBMD and CBMD in AIS and normal controls by age groups --- p.42 / Chapter 3.3.3 --- aBMD in AIS and normal controls by year since menarche --- p.43 / Chapter 3.3.4 --- TBMD and CBMD in AIS and normal controls by year since menarche --- p.43 / Chapter 3.3.5 --- Correlation between CBMD & TBMD and chronological age or year since menarche --- p.44 / Chapter 3.3.6 --- Comparisons adjusted for chronological age or year since menarche --- p.44 / Chapter 3.4 --- DISCUSSION --- p.45 / Chapter 3.5 --- TABLES AND FIGURES --- p.50 / Chapter CHAPTER 4 --- ABNORMAL BONE MATRIX MINERALIZATION AND BONE MICROARCHITECTURE IN ADOLESCENT IDIOPATHIC SCOLIOSIS - A HISTOMORPHOMETRIC AND MICRO-CT STUDY --- p.60 / Chapter 4.1 --- INTRODUCTION --- p.61 / Chapter 4.2 --- SUBJECTS AND METHODS --- p.62 / Chapter 4.2.1 --- Subjects --- p.62 / Chapter 4.2.2 --- Micro-computed tomography --- p.63 / Chapter 4.2.3 --- Bone histomorphometry --- p.64 / Chapter 4.2.4 --- Statistical analysis --- p.68 / Chapter 4.3 --- RESULTS --- p.68 / Chapter 4.3.1 --- Results of micro-CT analysis --- p.68 / Chapter 4.3.2 --- Results of histomorphometric analysis --- p.69 / Chapter 4.3.3 --- Relationship of mBMD and percentage of low-mineralized bone --- p.69 / Chapter 4.4 --- DISCUSSION --- p.70 / Chapter 4.5 --- TABLES AND FIGURES --- p.74 / Chapter CHAPTER 5 --- PLASMA OSTEOPONTIN LEVEL AND ITS ASSOCIATION WITH BONE MINERAL DENSITY IN ADOLESCENT IDIOPATHIC SCOLIOSIS --- p.82 / Chapter 5.1 --- INTRODUCTION --- p.83 / Chapter 5.2 --- SUBJECTS AND METHODS --- p.84 / Chapter 5.2.1 --- Subjects --- p.84 / Chapter 5.2.2 --- Anthropometric assessment --- p.84 / Chapter 5.2.3 --- Plasma osteopontin measurement --- p.85 / Chapter 5.2.4 --- BMD Measurement --- p.86 / Chapter 5.2.5 --- Statistical Analysis --- p.86 / Chapter 5.3 --- RESULTS --- p.86 / Chapter 5.3.1 --- Comparison of anthropometric parameters between AIS and controls --- p.86 / Chapter 5.3.2 --- Correlation between OPN plasma level with age or YSM in AIS and controls --- p.87 / Chapter 5.3.3 --- Comparison of OPN plasma level between AIS and controls --- p.87 / Chapter 5.3.4 --- Correlation between OPN plasma level and curve severity in AIS --- p.87 / Chapter 5.3.5 --- Relationship between OPN plasma level and vBMD --- p.88 / Chapter 5.4 --- DISCUSSION --- p.88 / Chapter 5.5 --- TABLES AND FIGURES --- p.94 / Chapter CHAPTER 6 --- OSTEOPONTIN EXPRESSION IN BONE TISSUE AND ITS ASSOCIATION WITH BONE MATRIX MINERALIZATION IN ADOLESCENT IDIOPATHIC SCOLIOSIS - A PILOT STUDY --- p.102 / Chapter 6.1 --- INTRODUCTION --- p.103 / Chapter 6.2 --- SUBJECTS AND METHODS --- p.104 / Chapter 6.2.1 --- Subjects --- p.104 / Chapter 6.2.2 --- Micro-computed tomography --- p.104 / Chapter 6.2.3 --- Bone histomorphometry --- p.104 / Chapter 6.2.4 --- Semi-quantification of OPN expression in bone biopsy by immunohistochemistry --- p.105 / Chapter 6.2.5 --- Plasma osteopontin measurement --- p.107 / Chapter 6.2.6 --- Statistical Analysis --- p.108 / Chapter 6.3 --- RESULTS --- p.108 / Chapter 6.3.1 --- Comparison of anthropometric parameters between AIS and control subjects --- p.108 / Chapter 6.3.2 --- Comparison of OPN expression detected by immunohistochemistry in bone biopsy between AIS and control groups --- p.108 / Chapter 6.3.3 --- Comparison of histomorphometric and micro-CT results between AIS and control groups --- p.109 / Chapter 6.3.4 --- Relationship between plasma OPN level and OPN expression in bone biopsy --- p.109 / Chapter 6.3.5 --- Relationship between percentage of low-mineralized bone and OPN expression in bone biopsy --- p.109 / Chapter 6.3.6 --- Relationship between material bone mineral density and OPN expression in bone biopsy --- p.110 / Chapter 6.4 --- DISCUSSION --- p.110 / Chapter 6.5 --- TABLES AND FIGURES --- p.114 / Chapter CHAPTER 7 --- SUMMARY STUDY FLOWCHART, OVERALL DISCUSSION, CONCLUSIONS, LIMITATIONS AND FURTHER STUDIES --- p.119 / Chapter 7.1 --- SUMMARY OF THE STUDY FLOW CHART WITH KEY FINDINGS --- p.120 / Chapter 7.2 --- OVERALL DISCUSSION --- p.125 / Chapter 7.2.1 --- The novel findings on bone mineralization abnormality in AIS in this study --- p.125 / Chapter 7.2.2 --- OPN is a key modulator in AIS --- p.128 / Chapter 7.3 --- OVERALL CONCLUSIONS --- p.130 / Chapter 7.4 --- LIMITATION OF THIS STUDY AND FUTURE RESEARCH --- p.131 / Chapter APPENDIX A. --- CONSENT FORM OF AIS RESEARCH --- p.135 / Chapter APPENDIX B. --- CONSENT FORM OF BONE BIOPSY COLLECTION --- p.137 / Chapter APPENDIX C. --- MATERIALS AND REAGENTS INFORMATION AND PROTOCOL FOR SOLUTIONS PREPARATION --- p.138 / BIBLIOGRAPHY --- p.143

1. An explicit mathematical description of PEP in terms of DBP was proposed, which in the first time quantitatively clarified the ventricular and arterial effects on PEP timing. / 2. A nonlinear pressure-volume relationship which reflected the natural arterial wall properties was introduced into the asymmetric T-tube arterial model, which effectively and quantitatively described the effect of pulsatile BP on arterial parameters, e.g., compliance, PTT etc. / 3. A mathematical relationship between PAT and BP was firstly proposed as a result of the heart-arterial interaction, which simulated a significantly strong and negative relationship between PAT and SBP and between PAT and MBP but a much weaker negative relationship between PAT and DBP during exercise. The hypothesis was supported by the experiment data. To our knowledge, it is the first study describing the quantitative relation of PAT and BP by both model-based study and experimental data. / 4. A novel wearable measurable CO parameter, PTRR, was proposed and it successfully showed a significantly high and positive correlation with CO during exercise both in model simulation and in the experiments. / 5. Linear prediction models using PAT to estimate MBP and using PTRR to estimate CO were proposed and evaluated in two exercise experiments conducted on 84 subjects with different ages and cardiovascular diseases. Results showed the proposed method could achieve the accuracy required for medical diagnosis. / 6. Taken the findings in 3, 4 and 5 together, this study in the first time provided both the theoretical basis and experimental verifications of developing a wearable and direct measurement technique of CPO in dynamic exercise using multiple physiological signals measured on body surface. / Cardiac power output (CPO) is defmed as the product of mean arterial blood pressure (MBP) and cardiac output (CO), and CPO measured during peak dynamic exercise (i.e. peak CPO) has been shown as a powerful predictor of death for heart failure patients. However, so far there has been no existing device which directly measures CPO, and CPO is acquired from simultaneous measurement of MBP and CO. Further, simultaneous MBP and CO measurement during dynamic exercise is a challenge for current BP and CO methods. Therefore, there is an urgent need to develop new devices which are fully wearable and unobtrusive for monitoring of CPO during dynamic exercise. Since the core problem in most wearable devices is how to estimate the target cardiovascular parameter, e.g. CPO in this study, through physiological signals measured from body surface, this thesis focus on developing a direct measurement technique of CPO in dynamic exercise using multiple physiological signals measured on body surface, specifically, electrocardiogram (ECG) and photoplehtysmogram (PPG). / Finally, based on the theoretical and experimental verifications, linear prediction models were proposed to estimate MBP from PAT and estimate CO from PTRR. The results showed that PAT can estimate MBP with a standard deviation of 7.42 mmHg, indicating PAT model has the potential to achieve the accuracy required by AMMI standard (mean error within +/- 5 mmHg and SD less than 8 mmHg). The results also showed that PTRR can estimate CO with a percent error of 22.57%, showing an accuracy which was considered as clinically acceptable (percent error less than 30%). / Heart failure is the end stage of many cardiovascular diseases, such as hypertension, coronary heart disease, diabetes mellitus, etc. Around 5.8 million people in the United States have heart failure and about 670,000 people are diagnosed with it each year. In 2010, heart failure will cost the United States $30.2 billion, and the cost of healthcare services is a major component of this total. With the resultant burden on health care resources it is imperative that heart failure patients with different risk stages are identified, ideally with objective indicators of cardiac dysfunction, in order that appropriate and effective treatment can be instituted. / In order to verify the theoretical findings, two experiments were carried out. One was incremental supine bicycle exercise conducted on 19 young healthy subjects and the other was incremental to maximum supine bicycle exercise conducted on 65 subjects, including heart failure patients, cardiovascular patients and healthy elderly. PAT showed significantly high and negative correlation with SBP and MBP, but lower correlation with DBP. PTRR showed significantly high and positive correlation with CO. / In this thesis, a model based study is conducted to address the above problem. Firstly, we deduced the mathematical expression of PEP as a function of DBP by introducing the arbitrary heart rate into the exponential mathematical description of a pressure-source model. Secondly, an asymmetric T-tube model was modified by introducing a nonlinear pressure-volume relationship where PTT was expressed as a dependent variant of BP. Thirdly, we proposed the mathematical equation between PAT and BP by coupling the modified ventricular and arterial models. Then, the relationships between PAT with systolic blood pressure (SBP), MBP and DBP were simulated under changing heart contractility, preload, heart rate, peripheral resistance, arterial stiffness and a mimic exercise condition. The simulation results indicated significantly high and negative correlations between PAT and SBP and between PAT and MBP whereas the correlation between DBP and PAT was low. / Next, we developed a novel CO index, namely pulse time reflection ratio (PTRR), expressed in terms of MBP and mean aortic reflection coefficient (Gamma(0)), from the modified asymmetric T-tube model. PTRR was further expressed in terms of PAT and inflection point area (IPA), a surrogate of Gamma(0) from the shape feature of PPG. The simulation results suggested significantly and positive relationship between PTRR and CO and between IPA and Gamma(0) during dynamic exercise. / Recently, a wearable measurable parameter, pulse arrival time or PAT, has been developed for BP measurement. PAT is the time delay from the R peak of ECG to the systolic foot of PPG. PAT consists of two timing components, the pre-ejection period (PEP) of the heart and pulse transit time (PTT). PTT is related to BP by an arterial elastic model and thus can be used to estimate beat-to-beat BP. However, PTT is difficult to be measured through a wearable device, and thus PAT is usually used as a surrogate of PTT for BP estimation, under the assumption of a constant PEP. However, PEP is not a constant but changing with physiological conditions, which may alter the PAT-BP relationship. Thus, it is important to clarify the PAT-BP relationship and address the feasibility of MBP estimation using PAT during dynamic exercise. / To summarize, the original contributions of this thesis are: / Wang, Ling. / Adviser: Y.T. Zhang. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Submitted by (lucia.rodrigues@ufrpe.br) on 2017-02-14T14:53:53Z No. of bitstreams: 1 Emanoel Cabral de Medeiros.pdf: 910531 bytes, checksum: a49d49dbcc2fa0475cf92eaff69ab023 (MD5) / Made available in DSpace on 2017-02-14T14:53:53Z (GMT). No. of bitstreams: 1 Emanoel Cabral de Medeiros.pdf: 910531 bytes, checksum: a49d49dbcc2fa0475cf92eaff69ab023 (MD5) Previous issue date: 2011-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Opuntia stricta Haw, cactus of great economic importance as forage in northeastern Brazil, was subjected to different in vitro systems and their performance was assessed by physiological and biochemical variables. We established three different cropping systems: temporary immersion system (TIS), with low frequency of immersion (immersion of one minute every 48 hours) and high-frequency TIS (immersion for five minutes every three hours); static culture in semi-solid medium (6.0 g.L-1 agar); static culture in liquid medium. The middle for inducing proliferation in vitro consisted of Murashige and Skoog (1962) salts and vitamins plus 30.0 g.L-1 sucrose and 0.0, 0.25, 0.5 or 1.0 mg.L-1 6-benzilaminpurine (BAP). Cultures were maintained in a growth room with 25 ± 2 º C under cool white light (40 mol.m-2.s-1), with 16 hours photoperiod. The experimental design was completely randomized factorial arrangement with 4 x 4 (cropping systems x BAP concentrations in the middle). After cultivation in vitro shoots of each treatment were acclimatized. Biochemical and biometrics analysis were performed on the material in vitro and biometrics on the acclimatized material. The static culture on solid medium, provided more stability since the multiplication by the acclimatization of the seedlings, while the systems with liquid presented limitations in some stages of micropropagation. The vitrification and the presence of betacyanin can be used as quality indicators physiological of the Elephant Ear Mexicana and its potential for acclimatization. / A Opuntia stricta Haw, cactácea de grande importância econômica como forrageira na região Nordeste do Brasil, foi submetida a distintos sistemas de cultivo in vitro e seu desempenho foi avaliado mediante variáveis fisiológicas e bioquímicas. Foram estabelecidos quatro diferentes sistemas de cultivo: sistema de imersão temporária (SIT), com baixa freqüência de imersões (imersão de um minuto a cada 48 horas); alta freqüência (imersão de cinco minutos a cada três horas); cultivo estático em meio semi-sólido (6,0 g.L-1 de ágar); cultivo estático em meio líquido. Os meios para indução de multiplicação in vitro constaram dos sais e vitaminas de Murashige e Skoog (1962) acrescidos de 30,0 g.L-1 de sacarose e 0,0; 0,25; 0,5 ou 1,0 mg.L-1 de 6 benzilaminopurina (BAP). As culturas foram mantidas em sala de crescimento com 25±2ºC, sob luz branca fria (40 μmol.m-2.s-1), com 16 horas de fotoperíodo. O desenho experimental foi o inteiramente casualizado com arranjo fatorial 4 x 4 (sistemas de cultivo x concentrações de BAP no meio). Após o cultivo in vitro, brotações de cada tratamento foram aclimatizadas. Análises bioquímicas e biométricas foram realizadas no material in vitro e biométricas no material aclimatizado. O cultivo estático em meio sólido, proporcionou mais estabilidade desde a multiplicação até a aclimatização das mudas, enquanto os sistemas com meio líquido apresentaram limitações em alguma das fases da micropropagação. A hiperidricidade e a presença de betacianina podem ser usadas como indicadores da qualidade fisiológica das mudas micropropagadas da Orelha de Elefante Mexicana e do seu potencial para aclimatização.

Submitted by (edna.saturno@ufrpe.br) on 2017-03-22T11:45:02Z No. of bitstreams: 1 Amanda Menino Leite.pdf: 391546 bytes, checksum: 52bc8a5614355c53ce9715b63d0dc59f (MD5) / Made available in DSpace on 2017-03-22T11:45:02Z (GMT). No. of bitstreams: 1 Amanda Menino Leite.pdf: 391546 bytes, checksum: 52bc8a5614355c53ce9715b63d0dc59f (MD5) Previous issue date: 2010-02-01 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The objective of this work was to investigate the physiological responses of cattle and buffaloes to warm temperatures is affected when fed diets with different proportions of forage and concentrate. The experiment was conducted in the Animal Science Department at the Federal Rural University of Pernambuco, from February to June 2006. Four male buffaloes and four steers were fed diets with increasing levels of concentrate, on dry matter basis (DM). Animals were housed in individual pens with cemented floor and covered with asbestos-cement tiles. It was used a split-plot arrangement in a complete randomized experimental design. The experiment lasted for 114 days. The environment was monitored bya meteorological station installed at the experimental area. Thermoregulation was evaluated by measures of rectal temperature (RT), respiratory rate (RR), skin temperature (TP), and sweating rate (TSUD). Average air temperature ranged from 25.6 to 31.0 ºC, the temperature and humidity index (THI) from 76.0 to 81.6 the black globe temperature and humidity index (BGHI) from 77.7 to 84.8, and Radiant Thermal Charge (RTC) from 480.1 to 538.4 watts/m².Higher levels of concentrate in the diet of cattle and buffaloes increased RT, RR, and TP of animals, but these values remained within the normal physiological range. / O objetivo deste trabalho foi verificar as respostas fisiológicas de bovinos e bubalinos, recebendo dietas com diferentes proporções de volumoso e concentrado. O experimento foi conduzido no Departamento de Zootecnia da Universidade Federal Rural de Pernambuco, no período de fevereiro a junho de 2006. Foram utilizados quatro bubalinos e quatro bovinos, alimentados com rações contendo níveis crescentes de concentrado, com base da matéria seca (MS). Os animais foram alojados em baias individuais de piso concretado, em galpão coberto com telha de fibrocimento. O delineamento experimental foi inteiramente casualizado com arranjo em parcelas subdivididas, sendo a parcela composta por um arranjo fatorial 2 x 4 (duas espécies e quatro níveis de concentrado: 0, 24, 48, 72%) e na subparcela o período de avaliação. O ensaio foi analisado por turnos, manhã e tarde. O experimento teve duração de 114 dias. O ambiente foi monitorado por intermédio de um abrigo termométrico, localizado no interior do galpão. A termorregulação foi avaliada por medidas da temperatura retal (TR), frequência respiratória (FR), temperatura de pele (TP) e taxa de sudação (TSUD). Durante o período experimental, a temperatura do ar variou de 25,6 a 31,0 ºC, o Índice de temperatura e umidade (ITU) de 76,0 a 81,6 e o Índice de temperatura de globo e umidade (ITGU) de 77,7 a 84,8 e a Carga Térmica de Radiação (CTR) de 480,1 a 538,4. O aumento nos níveis de concentrado na dieta de bovinos e bubalinos ocasionou aumentos na TR, FR e TPL dos animais, entretanto, esses valores se mantiveram dentro da faixa fisiológica normal.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2007. / Title from PDF title page (viewed on Feb. 19, 2010). Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 106-135).

Diss. (sammanfattning) Linköping : Univ., 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2005. / Härtill 5 uppsatser.