Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Utah State University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 13201 - 13230 of 16525

Full-Text Articles in Entire DC Network

The Legal Environment For Landscape Architecture In Utah, Jeffrey J. Scarborough May 1996

The Legal Environment For Landscape Architecture In Utah, Jeffrey J. Scarborough

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper explores and delineates the legal environment for the practice of landscape architecture in Utah. The national, state, and local (city and county), codes that apply to landscape architecture and the related professions of architecture, engineering, and land surveying are documented, as is pertinent case law. Figures allow comparisons to be made between the various government levels to demonstrate contradictions and congruencies, as well as the clarity of the ordinances. Major findings include significant differences among the city and county regulations of landscape architecture and the related professions, and weaknesses in the state law for landscape architecture. Major recommendations …


Guidelines For Roadside Revegetation To Create Wildlife Habitat In Northern Utah, Lars D. Anderson May 1996

Guidelines For Roadside Revegetation To Create Wildlife Habitat In Northern Utah, Lars D. Anderson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many species of wildlife use roadside vegetation as habitat. The ring-necked pheasant (Phasianus colchicus) utilizes roadsides for all types of cover. Because pheasants are nonmigratory and generally live their entire lives within a 1- to 2-mile radius, pheasants are excellent indicator species to predict both quantity and quality of roadside wildlife habitat. Pheasants were introduced to Utah in the late 1800's. Populations climbed until pheasant habitat occupied 2-4 percent of the total land area in Utah. Populations began to decrease in the 1950's. Since 1962, pheasant populations in Cache County, Utah have dropped 2.71 percent annually. Experts believe …


A Survey Of Employees Of The United States Department Of Agriculture's Animal Damage Control Program, Susan A. Schroeder May 1996

A Survey Of Employees Of The United States Department Of Agriculture's Animal Damage Control Program, Susan A. Schroeder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined the attitudes of employees of the United States Department of Agriculture's Animal Damage Control (ADC) Program. This research examined ADC employees' attitudes about wildlife, the ADC program and ADC employment, wildlife damage management methods, euthanasia and the killing process, and the role of various public and private groups on ADC policy. This study also applied the theory of organizational capture to the ADC program to test its utility in explaining the attitudes and behaviors of employees. Results were based on a survey of ADC employees conducted in January 1995.

Survey responses were analyzed to explore associations between …


Physical Factors Influencing Survival To Emergence And Time Of Emergence Of Shoreslope-Spawned Kokanee Salmon In Flaming Gorge Reservoir, Utah-Wyoming, Randall J. Jeric May 1996

Physical Factors Influencing Survival To Emergence And Time Of Emergence Of Shoreslope-Spawned Kokanee Salmon In Flaming Gorge Reservoir, Utah-Wyoming, Randall J. Jeric

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I used incubation baskets containing viable eggs and spawning substrate to estimate the survival to emergence and time of emergence of kokanee salmon Oncorhynchus nerka at depths to 20 m in Flaming Gorge Reservoir, Utah-Wyoming. Traps on the incubation baskets captured fry emerging from a known quantity of eggs. Water drawn into a syringe from an intragravel pipe buried near each incubation basket was used to determine intragravel dissolved oxygen concentrations throughout the intragravel period. Water from control baskets without eggs did not have significantly greater dissolved oxygen concentrations than adjacent water. A jar associated with each incubation basket collected …


Effectiveness Of Carbaryl And Pyrethroid Insecticides For Protection Of Engelmann Spruce From Attack By Spruce Beetle (Coleoptera: Scolytidae), Karen J. Johnson May 1996

Effectiveness Of Carbaryl And Pyrethroid Insecticides For Protection Of Engelmann Spruce From Attack By Spruce Beetle (Coleoptera: Scolytidae), Karen J. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A field experiment tested the effectiveness of carbaryl and two pyrethroid insecticides, cyfluthrin and esfenvalerate, in protecting high-value Engelmann spruce trees from attack by Dendroctonus rufipennis Kirby. Carbaryl suspension at the 2% registered rate and a reduced rate of 1 % were both effective in protecting Engelmann spruce from attack by D. rufipennis through two pheromone baiting periods and 24 months following insecticide application. Cyfluthrin at 0.025% rate and esfenvalerate at 0.025 and 0.05% rates provided effective protection through one pheromone baiting and 12 months following insecticide application. Only cyfluthrin at 0.008% rate was judged ineffective protection 12 months following …


A Study Of The Effects Of Body Image Education On Body Image In Adults Aged 60 And Older, Amy Peterson Hirtle May 1996

A Study Of The Effects Of Body Image Education On Body Image In Adults Aged 60 And Older, Amy Peterson Hirtle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Body image has been addressed through weight loss, but little research has been done that addresses accepting one's body. Even less research has been done on the body image concerns of older adults. Adults over age 60 who live in Arizona and spend their summers in Logan, Utah, participated in a body image education at Utah State University. The Body Esteem Scale and the Inventory of Positive Psychological Attitudes were used to measure the effect of the course on the participants. Older adults on average scored as high or higher than did younger older adults on both measurements.

Body image …


Imaging Molecular Structure Of Channels And Receptors With An Atomic Force Microscope, Ratneshwar Lal Apr 1996

Imaging Molecular Structure Of Channels And Receptors With An Atomic Force Microscope, Ratneshwar Lal

Scanning Microscopy

Biological membranes contain specialized protein macromolecules such as channels, pumps and receptors. Physiologically, membranes and their constituent macromolecules are the interface surfaces toward which most of the regulatory biochemical and other signals are directed. Yet very little is known about these surfaces. The structure of biological membranes has been analyzed primarily using imaging techniques that are limited in their resolution of surface topology. An atomic force microscope (AFM) developed by Binnig, Quate and Gerber, can image molecular structures on specimen surfaces with subnanometer resolution, under diverse environmental conditions. Also, AFM can manipulate surfaces with molecular precision: it can nanodissect, translocate, …


Crystallization During Volume Reduction Of Solutions With An Ion-Composition Corresponding To That In The Distal Tubuli, Inge Hojgaard, Anne-Marie Fornander, Mari-Anne Nilsson, Hans Goran Tiselius Apr 1996

Crystallization During Volume Reduction Of Solutions With An Ion-Composition Corresponding To That In The Distal Tubuli, Inge Hojgaard, Anne-Marie Fornander, Mari-Anne Nilsson, Hans Goran Tiselius

Scanning Microscopy

The effect of macromolecules on the crystallization in solutions with an ion-composition and a pH corresponding to that of urine in the distal part of the distal tubuli was examined by recording the number and volume of crystals in a Coulter Multisizer and by studying the crystal morphology with scanning electron microscopy at different degrees of evaporation. The experiments were carried out with 100 ml samples of salt solutions with and without different concentrations of dialysed urine (dU) from normal subjects. Addition of dU resulted in a greater number of crystals and a reduction in the mean crystal volume (MCV). …


Energy Dispersive X-Ray Microanalysis Of The Dentin In Rat Molars After Corticosteroid Treatment, Karin Nasstrom, Rolf Odselius, Arne Petersson Mar 1996

Energy Dispersive X-Ray Microanalysis Of The Dentin In Rat Molars After Corticosteroid Treatment, Karin Nasstrom, Rolf Odselius, Arne Petersson

Scanning Microscopy

The aim of this study was to investigate whether the calcium (Ca) and phosphorus (P) composition of corticosteroid induced dentin was the same as in normally developed dentin. Seven rats were given corticosteroids intravenously and three rats served as controls. Energy dispersive X-ray microanalysis (EDX) was carried out on the axially sawn roots of the molars. Measurements were made at 20 sites, equally distributed in the buccal, mesial, lingual and distal direction. The results showed that the Ca/P ratio (weight %) was slightly above 2.0 in both the experimental and the control group, indicating that the corticosteroid induced dentin had …


Long-Term Surveillance Plan For The South Clive Disposal Site, Clive, Utah, Jacobs Engineering Group Inc. Mar 1996

Long-Term Surveillance Plan For The South Clive Disposal Site, Clive, Utah, Jacobs Engineering Group Inc.

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.


Formation Of Hydrated Calcium Oxalates In The Presence Of Poly-L-Aspartic Acid, Jeffrey A. Wesson, Elaine Worcester Feb 1996

Formation Of Hydrated Calcium Oxalates In The Presence Of Poly-L-Aspartic Acid, Jeffrey A. Wesson, Elaine Worcester

Scanning Microscopy

The effect of poly-L-aspartic acid (PA) on the crystal structure of calcium oxalate crystals grown after spontaneous nucleation was evaluated as a function of relative supersaturation and calcium:oxalate ratio in a buffered salt solution, with pH and ionic strength in the range of normal human urine. PA was used as a model for naturally occurring acidic urine proteins that have been shown to inhibit nucleation and growth of calcium oxalate crystals. The crystals grown were characterized by optical microscopy and X-ray powder diffraction. It was observed that calcium oxalate monohydrate was the preferred crystalline form in the absence of added …


Early Post-Radiation Changes Of Red Blood Cell Shape In Rats, V. D. Zharskaya, A. B. Chukhlovin Feb 1996

Early Post-Radiation Changes Of Red Blood Cell Shape In Rats, V. D. Zharskaya, A. B. Chukhlovin

Scanning Microscopy

Scanning electron microscopy (SEM) of red blood cells in whole blood samples from rats was performed following acute γ-irradiation of animals with 0.25 to 1 Gy. Increased incidence of echinocytosis was observed and found to be dose- and time-dependent. At a higher radiation dose (1 Gy), echinocytosis was revealed within 5 minutes after treatment and persisted up to 3 weeks. The data demonstrate the applicability of SEM for detecting minimal radiation-induced lesions of red blood cells.


Multiple Labeling In Electron Microscopy: Its Application In Cardiovascular Research, M. M. H. Marijianowski, P. Teeling, K. P. Dingemans, A. E. Becker Jan 1996

Multiple Labeling In Electron Microscopy: Its Application In Cardiovascular Research, M. M. H. Marijianowski, P. Teeling, K. P. Dingemans, A. E. Becker

Scanning Microscopy

The heart is a muscular pump kept together by a network of extracellular matrix components. An increase in collagens, as in chronic congestive heart failure (CHF), is thought to have a negative effect on cardiac compliance and, thus, on the clinical condition. Conventional electron microscopy allows for the study of cellular and extracellular components and scanning electron microscopy (SEM) can put these structures in three-dimensional perspective. However, in order to study extracellular matrix components in relation to cells, immunoelectron microscopy is superior. We have used this technique in our studies on heart failure. Heart specimens were fixed in 4% paraformaldehyde …


Neural Transplant Staining With Dii And Vital Imaging By 2-Photon Laser-Scanning Microscopy, Steve M. Potter, Jerome Pine, Scott E. Fraser Jan 1996

Neural Transplant Staining With Dii And Vital Imaging By 2-Photon Laser-Scanning Microscopy, Steve M. Potter, Jerome Pine, Scott E. Fraser

Scanning Microscopy

We are developing a multielectrode silicon "neuroprobe" for maintaining a long-term, specific, two-way electrical interface with nervous tissue. Our approach involves trapping a neuron (from an embryonic rat hippocampus) in a small well with a stimulation/ recording electrode at its base. The well is covered with a grillwork through which the neuron's processes are allowed to grow, making synaptic contact with the host tissue, in our case a cultured slice from a rat hippocampus. Each neuroprobe can accommodate 15 neurons, one per well. As a first step in studying neurite outgrowth from the neuroprobe, it was necessary to develop new …


Diffuse Neuroendocrine System: Structural And Functional Effects Of Radiation Injury To Amine Precursor Uptake And Decarboxylation (Apud) Cells, I. M. Kvetnoy, V. V. Yuzhakov, A. O. Molotkov, L. N. Bandurko, R. A. Brodsky, N. D. Yakovleva Jan 1996

Diffuse Neuroendocrine System: Structural And Functional Effects Of Radiation Injury To Amine Precursor Uptake And Decarboxylation (Apud) Cells, I. M. Kvetnoy, V. V. Yuzhakov, A. O. Molotkov, L. N. Bandurko, R. A. Brodsky, N. D. Yakovleva

Scanning Microscopy

The paper presents a review of the results obtained by the authors on the study of external (gamma) and internal (I-131) radiation effects on the functional morphology and linkage of the diffuse neuroendocrine system (DNES) and amine precursor uptake and decarboxylation (APUD) cells of the stomach and duodenum. The investigations performed enabled us to determine that the morphological changes noted in APUD cells had a dose and time dependency. The present study supports the point of view that the radiation initiates serotonin release from APUD cells, which appears to initiate the mechanism of early postirradiation dysfunctions of the gastrointestinal tract …


Specimen Preparation Of The Human Cerebellar Cortex For Scanning Electron Microscopy Using A T-Butyl Alcohol Freeze-Drying Device, Teruyuki Hojo Jan 1996

Specimen Preparation Of The Human Cerebellar Cortex For Scanning Electron Microscopy Using A T-Butyl Alcohol Freeze-Drying Device, Teruyuki Hojo

Scanning Microscopy

A freeze-drying device was applied to t-butyl alcohol substituted nerve cells, fibers and synaptic terminals. Ten percent formalin-fixed human cerebellar cortex specimens were postfixed in 2.5% glutaraldehyde in 0.1 M cacodylate buffer solution and were rinsed three times in 5% sucrose solution in the same buffer. After the postfixed specimens were dehydrated using a graded series of ethanols and then transferred into a graded series of t-butyl alcohols (freezing point 25.4°C), the t-butyl alcohol substituted specimens were freeze-dried at 15°C and at high vacuum (5x10-2 Torr). The freeze-dried specimens were sputter coated with gold. Scanning electron …


Calcium Oxalate Crystallization In Urine Of Healthy Men And Women: A Comparative Study, Niels-P. Buchholz, Dong Sun Kim, Phulwinder K. Grover, Rosemary L. Ryall Jan 1996

Calcium Oxalate Crystallization In Urine Of Healthy Men And Women: A Comparative Study, Niels-P. Buchholz, Dong Sun Kim, Phulwinder K. Grover, Rosemary L. Ryall

Scanning Microscopy

This study aimed to compare calcium oxalate (CaOx) crystallization in undiluted urine from healthy men and women with the object of clarifying the difference in stone incidence between the two sexes. Twenty-four hour urine specimens were collected from 37 men and 28 women. Urinary pH, and concentrations of Ca, oxalate and urate were measured, and indices of crystallization determined by Coulter Counter particle analysis following induction of CaOx crystallization by addition of oxalate. The amount of oxalate required to induce crystallization was significantly (p < 0.01) higher in females than in males, as was the overall particle volume deposited after 90 minutes incubation (p < 0 .006). Scanning electron microscopy revealed larger individual crystals in female urine, and a greater degree of crystal aggregation in male urine, although the average overall size of the precipitated crystal particles did not differ between the two sexes. There were no significant differences between men and women with regard to median pH, or Ca and oxalate concentrations, but the median urate concentrations were slightly, but significantly, higher (p < 0.05) in the women's urines than in the men's. It was concluded that the greater risk of CaOx stones in men is related to an increased propensity to nucleate CaOx crystals per se, rather than to a tendency to form larger crystalline particles.


Laboratory Growth Systems In Biofilm Research, Julian W. T. Wimpenny Jan 1996

Laboratory Growth Systems In Biofilm Research, Julian W. T. Wimpenny

Cells and Materials

The huge variety of ecosystems that we collectively refer to as "biofilm" is reflected by the numerous different systems available to grow them in the laboratory. The relationship between in situ systems, microcosms and laboratory models is defined and discussed. The first two represent holistic approaches designed to assess the structure and function of particular biofilms: the last is analytical and reductionist, aiming to isolate specific functions of biofilms in order to understand properties that can apply to biofilm in general. Properties of a model can be completely understood whilst this is unlikely with natural ecosystems because of the possibility …


Initial Biodeterioration Of Silicone Rubber By C. Albicans And C. Aropicalis Strains Isolated From Voice Prostheses, H. C. Van Der Mei, B. Van De Belt-Gritter, F. Dijk, H. J. Busscher Jan 1996

Initial Biodeterioration Of Silicone Rubber By C. Albicans And C. Aropicalis Strains Isolated From Voice Prostheses, H. C. Van Der Mei, B. Van De Belt-Gritter, F. Dijk, H. J. Busscher

Cells and Materials

Silicone rubber voice prostheses m patients after total laryngectomy become rapidly colonized by a biofilm, consisting of yeasts and bacteria. An especially troublesome feature of these biofilms is the ingrowth into the silicone rubber by colonizing yeasts. Microcolonies of ingrowing yeasts have been frequently observed on explanted voice prostheses after 3-4 months use. Incubation of silicone rubber samples in a modified Robbins device with a culture of Candida tropicalis, isolated from a Groningen button voice prosthesis, while passing the yeasts through a cycle of feasts (7 days) and famine (also 7 days) demonstrated, by electron microscopy, the onset of the …


Gap Junctional Intercellular Communication In Bone, Henry J. Donahue, Monique A. Vander Molen, Clare E. Yellowley, Zhongyong Li Jan 1996

Gap Junctional Intercellular Communication In Bone, Henry J. Donahue, Monique A. Vander Molen, Clare E. Yellowley, Zhongyong Li

Cells and Materials

Gap junctional intercellular communication has been demonstrated in bone cells and may contribute to the mechanism by which osteoblasts integrate and amplify extracellular signals, both chemical (hormonal) and biophysical (electrical and mechanical). Connexin 43 (Cx43) is the predominant gap junction protein expressed by bone cells. Experiments with osteoblastic cells in which Cx43 expression was diminished by antisense transfection demonstrate that cell-to-cell coupling in osteoblastic ROS 17/2.8 cells is via gap junctions composed of Cx43. Cellular networks of these coupling deficient clones are dramatically less responsive to parathyroid hormone (PTH) suggesting that coupling contributes to hormonal responsiveness. Furthermore, PTH per se …


Forest Resources Of Northern Utah Ecoregions, Renee A. O'Brien Jan 1996

Forest Resources Of Northern Utah Ecoregions, Renee A. O'Brien

Elusive Documents

No abstract provided.


Economic Impact Of The Usu Uintah Basin Education Centers And The Lds Vernal Temple, Donald L. Snyder Jan 1996

Economic Impact Of The Usu Uintah Basin Education Centers And The Lds Vernal Temple, Donald L. Snyder

Economic Research Institute Study Papers

Uintah County and the Uintah Basin COG have benefitted from the existence of the USU Centers as well as from the construction and operation of the LDS Vernal Temple. The one-time beneficial impacts for final demand (Centers' construction and renovation and Temple construction) range from $2.95 to $2.97 million. Ongoing beneficial impacts for fmal demand (Centers and Temple operations) contribute another $1.95 million in total industry sales per year. Employee income due to the operations of these two entities was over $650,000/year, with other $1.1 million in value added to the community. These two projects also increased local employment by …


Recreation As An Economic Development Strategy: Some Evidence From Utah, John E. Keith, Christopher Fawson, Tsangyao Chang Jan 1996

Recreation As An Economic Development Strategy: Some Evidence From Utah, John E. Keith, Christopher Fawson, Tsangyao Chang

Economic Research Institute Study Papers

An examination of employment patterns in rural Utah counties suggests that those counties that primarily rely on tourism and recreation to maintain economic viability exhibit annual employment variability much greater than those counties that rely on alternative economic activity. Compared to long-run boomlbust employment cycles, which are prevalent in counties that rely on resource extraction, annual recreation, and tourism employment cycles, are at least as variable and of much shorter duration due to the seasonal nature of tourist visitation patterns. As a result, local infrastructure planning for an economy based on recreation and tourism will likely involve considerable fiscal stress …


Economies Of Scale In Public Education: An Econometric Analysis, Kalyan Chakraborty, Basudeb Biswas, W. Cris Lewis Jan 1996

Economies Of Scale In Public Education: An Econometric Analysis, Kalyan Chakraborty, Basudeb Biswas, W. Cris Lewis

Economic Research Institute Study Papers

The purpose of this paper is to investigate the sources of economies of scale in the production of public education. The relationship between the average cost ofproducing educational output and other school characteristics including the school and district size is estimated using a neoclassical cost function. The empirical analysis uses panel data from Utah school districts and estimates the function using the covariance and error component models after making necessary corrections for heteroscedasticity and autocorrelation. The evidence indicates that there are scale economies associated with school size but not district size.


The Economic Impact Of Uintah County's Western Park, Donald L. Snyder Jan 1996

The Economic Impact Of Uintah County's Western Park, Donald L. Snyder

Economic Research Institute Study Papers

Uintah County is home to a multi activity conference complex located in Vernal, Utah. The complex is almost in constant use and includes locally sponsored activities, as well as regional and national activities. An estimate of local and nonlocal users were identified from Mr. Derk Hatch, manager of Western Park. I assumed that "nonlocal" use originated outside the county. Taking into account the "local" and "nonlocal" mix, it is estimated that the center annually generates over $4.8 million dollars in economic activity, with approximately 60% a result of direct expenditures. The complex also results in additional employment opportunities for approximately …


Application Of Confocal Laser Scanning Microscopy To Cytocompatibility Testing Of Potential Orthopaedic Materials In Immortalised Osteoblast-Like Cell Lines, R. Macnair, R. Wilkinson, C. Macdonald, I. Goldie, D. B. Jones, M. H. Grant Jan 1996

Application Of Confocal Laser Scanning Microscopy To Cytocompatibility Testing Of Potential Orthopaedic Materials In Immortalised Osteoblast-Like Cell Lines, R. Macnair, R. Wilkinson, C. Macdonald, I. Goldie, D. B. Jones, M. H. Grant

Cells and Materials

Confocal laser scanning microscopy (CLSM) was used in conjunction with in vitro cell culture to investigate cellular interactions with orthopaedic biomaterials. Transfected rat and human osteoblasts were seeded on two potential isoelastic hip prosthesis materials, carbon fibre reinforced polyetheretherketone (PEEK) and epoxy. Titanium 318 alloy was employed as a control. Determination of the material surface contour, an important factor influencing cellular adhesion, proliferation and function, was performed using the industry standard Talysurf® and compared to analogous results obtained using the CLSM. The latter technique consistently gave higher values of material roughness but offers the advantage that it can be used …


A Microstructural Investigation Of Calcium Hydroxyapatites Synthesized From Cahpo4•2h2o And Ca4(Po4)2o, Kevor S. Tenhuisen, Boyd A. Clark, Maria Klimkiewicz, Paul W. Brown Jan 1996

A Microstructural Investigation Of Calcium Hydroxyapatites Synthesized From Cahpo4•2h2o And Ca4(Po4)2o, Kevor S. Tenhuisen, Boyd A. Clark, Maria Klimkiewicz, Paul W. Brown

Cells and Materials

This investigation determined the effects of reaction temperature and bulk composition on the microstructural features of hydroxyapatites (HAp) synthesized from reaction between particulate CaHPO4·2H2O and Ca4(PO4)2O. These data were used in combination with previous work to further elucidate the mechanistic reaction path taken by these calcium phosphate cements. HAps having two different compositions (Ca/P = 1.50 and 1.67) were synthesized between 15.0 and 70.0°C. All reactions reached completion as indicated by X-ray diffraction. Single point nitrogen absorption was performed on all samples to determine specific surface areas. The HAp which …


Time Course Of Recruitment, Pit Formation And Apoptosis Of Osteoclast Populations On Dentin In Vitro, Jihyun Kang, Rigoberto Cornejo, Kevin J. Hirokawa, Susan M. Digiorgio, Darlene F. Howard, Susan F. Silverton Jan 1996

Time Course Of Recruitment, Pit Formation And Apoptosis Of Osteoclast Populations On Dentin In Vitro, Jihyun Kang, Rigoberto Cornejo, Kevin J. Hirokawa, Susan M. Digiorgio, Darlene F. Howard, Susan F. Silverton

Cells and Materials

The resorptive capacity of osteoclasts in vitro has been used as an indicator of bone resorption. However, the kinetics of osteoclast development and senescence is not well understood. It has been noted that mononuclear precursors migrate to calcified substrate and after multi-nucleation become competent bone resorbing cells. Osteoclasts, once finished a wave of resorption, become senescent. In order to determine the survival characteristics of osteoclast populations involved in calcified tissue destruction, we have investigated the time course of the recruitment to dentin and apoptosis of osteoclasts. We have established the linkage between these measurements and the time course of the …


In Vivo Early Plaque Colonization On Smooth Titanium Surface, A. Carrassi, A. Sardella, L. Rimondini Jan 1996

In Vivo Early Plaque Colonization On Smooth Titanium Surface, A. Carrassi, A. Sardella, L. Rimondini

Cells and Materials

Plaque development on pure titanium in a 24-hour period is described in an in vivo human model. Stents with titanium and root cementum specimens were applied to volunteers, who suspended oral hygiene procedures for 24 hours. The specimens were removed at 2, 4 and 24 hours and studied with a scanning electron microscope. A global area of 240 µm x 300 µm, composed of the sum of twelve 20 µm x 25 µm fields randomly selected, was examined for each specimen. The presence of cocci, short rods, long rods and bacterial aggregation, and bacteria density was recorded for each field. …


Physical And Biological Evaluation Of Hydroxylapatite Films Formed On Ti6a14v Substrates By Excimer Laser Ablation, Tatjana Dostálová, Miroslav Jelínek, Lucie Himmlová, Vlasta Pesáková, Milan Adam Jan 1996

Physical And Biological Evaluation Of Hydroxylapatite Films Formed On Ti6a14v Substrates By Excimer Laser Ablation, Tatjana Dostálová, Miroslav Jelínek, Lucie Himmlová, Vlasta Pesáková, Milan Adam

Cells and Materials

Thin films of hydroxylapatite, about 500 nm, were formed on Ti6Al4V by excimer laser ablation. Ten different deposition conditions were used such as deposition atmosphere (vacuum, pure water vapor, mixture of Ar and water vapor), substrate temperature, target-substrate distance and energy density. Mechanical and physical analyses were carried out by Rutherford backscattering and particle induced X-ray emission; crystallinity of films was determined by X-ray diffraction, surface topography by scanning electron microscopy and adhesion by a scratch test. Biological evaluation of samples was also performed. The fibroblast proliferation test was used, morphological evaluation of macrophages was carried out, and the activity …