# Biomedical Engineering and Bioengineering Commons™

Articles 301 - 320 of 320

## Full-Text Articles in Biomedical Engineering and Bioengineering

Apr 2003

#### Cloning, Expression, And Characterization Of Gfp:Xkcm1 Deletion Constructs, Patrick Thorsen

##### Life and Environmental Sciences Undergraduate Theses

Kinesins are a type of motor protein that use the energy of ATP hydrolysis to move along microtubules. Kinesin Catastrophe Modulator One (XKCM1) of Xenopus laevis was recently identified as a kinesin that is essential for the establishment and maintenance of mitotic spindles by affecting the microtubule dynamics in Xenopus egg extracts. In the present research, three different deletion constructs of XKCM1 fused with Green Flourescent Protein (GFP) were cloned, expressed, and characterized in order to determine which part of the XKCM1 structure was necessary for proper destabilization of microtubules. These deletion constructs have previously been studied z'n vivo ...

#### Evapotranspiration Using A Satellite-Based Surface Energy Balance With Standardized Ground Control, Ricardo Trezza

##### All Graduate Theses and Dissertations

This study evaluated the potential of using the Surface Energy Balance Algorithm for Land (SEBAL) as a means for estimating evapotranspiration (ET) for local and regional scales in Southern Idaho. The original SEBAL model was refined during this study to provide better estimation of ET in agricultural areas and to make more reliable estimates of ET from other surfaces as well, including mountainous terrain. The modified version of SEBAL used in this study, termed as SEBALID (lD stands for Idaho) includes standardization of the two SEBAL "anchor" pixels, the use of a water balance model to track top soil moisture ...

Design Of A Bioartificial Nerve Graft , Gregory Edward Rutkowski Jan 1999

#### Design Of A Bioartificial Nerve Graft , Gregory Edward Rutkowski

##### Retrospective Theses and Dissertations

Nerve injuries complicate successful rehabilitation more than any other form of trauma because of loss of protective sensibility and tactile discrimination, denervation atrophy of muscles, and pain syndromes. While achieving full function and organ reinnervation after peripheral nerve injury is a challenge, a promising method of improving the rate and success of regeneration is the bioartificial nerve graft (BNG). The BNG developed in the laboratory consists of a porous bioresorbable tube containing cultured Schwann cells that help to direct and support nerve regeneration when used to bridge the gap between the ends of the severed nerve;To aid in the ...

Jan 1998

#### Development Of A Coupled Model Of The Cardiorespiratory And Thermoregulatory Systems , Dawn Denise Downey

##### Retrospective Theses and Dissertations

A model of the human body which integrates the variables involved in temperature regulation and blood gas transport within the cardiovascular and respiratory systems is presented in this dissertation. It expands upon previous work developed by the author to model the competition between skin and muscles when both require increased blood flows during exercise and/or heat stress. First, a detailed study of the control relations used to predict skin blood flow was undertaken. Four other control relations employed in the model were also examined and modified as indicated by empirical results found in literature;Several important cases were then ...

Jan 1998

#### The Effects Of Physiological Levels Of Intermittent Pressure On The Development Of Articular Cartilage In Vitro , Scott Edward Carver

##### Retrospective Theses and Dissertations

A semi-continuous perfusion system has been designed and constructed to deliver physiological levels of hydrostatic pressure to regenerating cell/polymer constructs of articular cartilage over the long term (weeks to months). Prior to being transferred to the pressurized system, equine articular chondrocytes were dynamically seeded onto nonwoven meshes of polyglycolic acid which provide the cells with a three-dimensional growth environment similar to that found in vivo. When applied in an intermittent manner, physiological pressurization at 500 psi was found to stimulate articular chondrocytes to produce regenerated constructs with greater concentrations of sulfated glycosaminoglycan compared to control (unpressurized) constructs, while the ...

Jan 1997

#### A Quantitative Estimation Of Regulation And Transport Limitations In The Human Cardiopulmonary System , Sharmista Chatterjee

##### Retrospective Theses and Dissertations

The object of this dissertation is to quantitatively describe the regulation of some of the exchange processes within the human body. Conceptually this dissertation is divided into two sections. In the first section a macroscopic view was adopted to describe the overall regulation of the cardiovascular and respiratory systems. These overall system models were used as heuristic tools to gain an understanding of physiological behavior in micro-gravity. In the second section, a microscopic view was used to estimate the role played by the surfactant system of the lung in regulating the transfer of fluid across the pulmonary-capillary wall;The basis ...

Computer Simulation Of Coronary Blood Flow , Brian Christopher Frake Jan 1995

#### Computer Simulation Of Coronary Blood Flow , Brian Christopher Frake

##### Retrospective Theses and Dissertations

A computer model to simulate coronary fluid dynamics has been developed which can give some insight into the role of hemodynamics in health and disease. Although this study focuses mainly on coronary blood flow, the complete model consists of all major branches of the systemic circulation as well as the left epicardial coronary circulation;The flow equations are obtained by integrating the one-dimensional continuity and momentum equations over the cross-section of the artery to give a relationship between the primary variables of interest, the pressure and flowrate. An arctangent model was used as a constitutive equation to describe the pressure-area ...

The Production Of Textile Fibers From Soy Proteins , Hsin-Chi Huang Jan 1994

#### The Production Of Textile Fibers From Soy Proteins , Hsin-Chi Huang

##### Retrospective Theses and Dissertations

The use of soy protein presently is limited mostly to animal feeds, but the markets for soy protein could be expanded by industrial applications. In these studies, soy fibers were produced from soy protein isolate using both wet spinning and extrusion methods. The wet spinning process consisted of forcing an aged alkaline protein solution through a spinnerette having 368-[mu] openings into an acid coagulating bath. The extrusion process employed a twin screw extruder to force a protein-water mixture with "dough-like" consistency through a die also with 368-[mu] openings. The physical properties of the fibers were measured at 11 ...

Jan 1994

#### An Investigation Into The Role Of Arterial Wall Vibration In The Pathogenesis Of Atherosclerosis , Becky Bellatti Bittle

##### Retrospective Theses and Dissertations

Fifty percent of all the deaths in the Western world can be attributed to diseases of the cardiovascular system. A major player amongst these diseases is atherosclerosis. Atherosclerosis is the localized thickening of the arterial wall and is primarily due to the proliferation of fibrous tissue and smooth muscle cells in conjunction with the deposition of lipids within the wall. The hypothesis investigated was that high frequency, low amplitude vibratory environments similar to those found in regions of disturbed flow, which are coincident with intimal thickenings, the earliest stage of atherosclerosis, do elicit a proliferative response in vascular smooth muscle ...

Jan 1994

#### Evaluation Of A Direct Systolic Cardiac Augmentation Device On A Canine Heart During Global Postischemic Dysfunction , Raymond Kenneth Kudej

##### Retrospective Theses and Dissertations

The performance of a direct systolic cardiac augmentation device, called a heart cuff, was evaluated during application of the device to canine hearts following a period of global ischemia. The heart cuff was developed to provide temporary, partial assistance to a heart experiencing postischemic myocardial dysfunction (myocardial stunning);Myocardial stunning is a postischemic mechanical dysfunction which results from a sublethal tissue injury occurring at the time of reperfusion. The injury will resolve if the myocardial tissue is given sufficient time to recover. Stunning may significantly contribute to the morbidity and mortality of many cardiac procedures because of the temporary inability ...

#### Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen

##### Electronic Theses and Dissertations

Chlamydia trachomatis (CT) replicates in macrophages, but is inhibited by IFN-$\gamma$ or LPS. IFN-$\gamma$ and/or LPS induced nitrite production in mouse peritoneal macrophages, macrophage cell lines (RAW264.7 and J774A.1) and McCoy cells. Kinetic studies indicated that peak production occurred 48 hours post-treatment. CT infection itself was insufficient to induce nitrite production, but resulted in enhancement of nitrite production in IFN-$\gamma$-treated cells. Treatment with IFN-$\gamma$ or LPS resulted in significant inhibition of CT replication in these cells. Strong correlation between nitrite production and inhibition of CT replication was observed in RAW264.7 and ...

A Field Portable Ultrasound System For Bovine Tissue Characterization , Kyle Harold Holland Jan 1993

#### A Field Portable Ultrasound System For Bovine Tissue Characterization , Kyle Harold Holland

##### Retrospective Theses and Dissertations

Efforts by beef producers and beef packers to reduce carcass losses and to move the industry to a value-based marketing system have renewed their interest in the development of new electronic grading techniques for assessing beef carcass composition. A custom ultrasonic data acquisition system has been developed for the purpose of investigating the feasibility of beef tissue characterization. The unit developed is a compact, hand-held, six channel battery-operated data logger capable of sampling A-mode ultrasound signals at a rate of 15 megasamples per second. A custom epoxy encapsulated ultrasound transducer array was developed to fit the inner curvature of the ...

Jan 1993

#### Practice, Transfer And Performance Enhancement Of Fast Single-Joint Movements In Individuals With Down Syndrome , Gil Lúcio Almeida

##### Retrospective Theses and Dissertations

Eight individuals with Down syndrome practiced performing 100 elbow movements over one distance (36°), under the instruction to move "as fast as possible." The subjects were also pretested and posttested performing elbow flexion movements over four distances (18°, 36°, 54°, and 72°) "as fast as possible", and at a "comfortable speed" over 36°. For two of these distances (18° and 36°), the movements were also performed from a second starting position. They improved their motor performance between training sessions (110 movements), as measured by the kinematic and EMG parameters. This improvement performance was described by a logarithmic function. With training ...

In Vivo And In Vitro Evaluations Of A Bioactive Ceramic Tooth Root Implant , Gabriele Gruss Niederauer Jan 1993

#### In Vivo And In Vitro Evaluations Of A Bioactive Ceramic Tooth Root Implant , Gabriele Gruss Niederauer

##### Retrospective Theses and Dissertations

The objective of this research was to test both the in vitro and in vivo effects of implant surface properties on soft tissue attachment to a bioactive ceramic tooth root implant. The ceramic material used for the tooth root was a composite of tricalcium phosphate and magnesium aluminate spinel, which is called "osteoceramic." For the in vitro cell attachment assays, pure tricalcium phosphate and spinel materials were used in addition to the osteoceramic. The osteoceramic was treated to produce three different surface structures: smooth, irregular and rough. Characterization of the materials included scanning electron microscopy, elemental dispersive analysis, wetting angle ...

Jan 1992

#### Transcranial Doppler Sonography: A New Noninvasive Method For Measuring Toxicant-Induced Alterations In Cerebral Blood Flow , Michael Edward Drues

##### Retrospective Theses and Dissertations

The purpose of this experiment was to use transcranial Doppler sonography (TCD) in the dog to noninvasively measure changes in cerebral blood flow (CBF) resulting from a low-level exposure to the commonly used pyrethroid insecticide deltamethrin. Deltamethrin has previously been shown to increase CBF in rats as determined by other techniques. In this experiment, deltamethrin was dissolved in glycerol-formal solvent and administered intravenously at dosage levels of 5% and 10% of the LD[subscript]50 value to 12 adult dogs 48 hours apart. It was expected that vascular changes resulting from these low-level deltamethrin exposures would be subtle and occur ...

#### 1-Nitronaphthalene Causes Ultrastructural Changes Primarily In Nonciliated Bronchiolar Epithelium Followed By Ciliated Epithelium In The Rat, John-Michael Sauer

##### Master's Theses

This study describes morphological changes in the lung at several time intervals following a single injection of 1-Nitronaphthalene (100 mg/kg intraperitoneal) in male Sprague-Dawley rats using transmission and scanning electron microscopy. Dilation of the smooth endoplasmic reticulum and mitochondrial distension in the nonciliated bronchiolar (Clara) cells was apparent as early as 1 hour after injection, while adjacent ciliated cell showed minimal changes. At 6 hours, when respiratory distress was apparent in the animals, Clara and ciliated cells exhibited chromatin clumping, loss of mitochondrial cristae and cytoplasmic vacuolization. Also at 6 hours, the interstitial area around the terminal bronchioles was ...

#### Metabolism Of Arachidonate-Containing Phospholipid Molecular Species In The Murine Macrophage-Like Cell Line, P388d1, Crystal R. Waites

##### Electronic Theses and Dissertations

Glycerophospholipids of mammalian cells exist as chemically diverse structures with various fatty acids at the sn-1 and sn-2 positions. Arachidonic acid, a polyunsaturated fatty acid, which may be converted to biologically active eicosanoids such as prostaglandins, thromboxanes, and leukotrienes, is found predominantly in the sn-2 position of glycerophospholipids. The purpose of this study was to examine, at the level of the individual molecular species, the incorporation of arachidonate into phospholipids and its release from phospholipids during stimulation. In this way, the specificity of the enzymes controlling arachidonate metabolism could be examined in order to clarify the processes that control the ...

Development Of An Ocular Drug Release System For Cattle , Thomas Quang Dinh Jan 1991

#### Development Of An Ocular Drug Release System For Cattle , Thomas Quang Dinh

##### Retrospective Theses and Dissertations

An erodible ring-shaped ocular insert containing an antibiotic (tylosin tartrate) has been developed for treatment of infectious bovine keratoconjunctivitis (IBK). Four additional tasks have been completed: (1) a test to determine the retention time of the ocular device in the eyes of the calves, (2) an in vitro test to determine the degradation characteristics of the device, (3) an in vitro study to obtain the drug release profiles of the insert, and (4) a study to compare the use of rings and a field treatment method using infected cattle;The device remained in the eyes an average of 3.92 ...

Computer Simulation Of Arterial Blood Flow , Nikolaos Stergiopulos Jan 1990

#### Computer Simulation Of Arterial Blood Flow , Nikolaos Stergiopulos

##### Retrospective Theses and Dissertations

Computer models have been widely used to simulate pressure and flow propagation in the arterial system. While experimentation involving the human arterial system is difficult and impractical, computer models offer an attractive alternative for the study of arterial hemodynamics. The purpose of the present study was to develop a computer model of the whole systemic circulation and to use this model to study pressure and flow propagation under normal flow conditions, as well as under conditions of arterial disease;The mathematical model used to describe flow in an arterial segment was based on the one-dimensional continuity and momentum equations. The ...

X-Ray-Induced Specific-Locus Mutation Rates In Newborn And Young Mice, Paul Bruce Selby Aug 1972

#### X-Ray-Induced Specific-Locus Mutation Rates In Newborn And Young Mice, Paul Bruce Selby

##### Doctoral Dissertations

The specific-locus mutation frequency resulting from 300 R of acute X irradiation has been determined for the germ cells present in male mice at 0, 2, 4, 6, 8, 10, 14, 21, 28, and 35 days of age and also for female mice at 0 days of age, Sample size was much larger for the males irradiated on day 0 than for other age groups but in all groups it was large enough to insure that an extremely high rate would be noticed. At 35 days of age the testis is histologically similar to that of the adult. It was ...