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  • 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.
91

Influencia de la distribución del remanente coronario sobre la resistencia a la fractura de dientes tratados endodónticamente reconstruidos con un sistema espiga-muñón de fibroresina : (in vitro)

Arancibia Peña, Jami Lorena January 2016 (has links)
Trabajo de Investigación Requisito para optar al Título de Cirujano Dentista / Introducción: El objetivo de este estudio fue evaluar la influencia de la ubicación del remanente coronario parcial con distintas distribuciones tras la preparación periférica, sobre la resistencia a la fractura en premolares endodónticamente tratados, reconstruidos con postes de fibra de vidrio y muñones de compósite. Materiales y métodos: Un total de cuarenta premolares unirradiculares humanos recientemente' extraídos fueron usados para este estudio, estandarizados en volumen y longitud, para ser divididos en cuatro grupos de 10 especímenes cada uno. Todos los grupos fueron tratados endodóticamente y preparados periféricamente para recibir una prótesis fija. A los dientes de cada grupo se les seccionó el munón natural resultante a una altura de 3 mm y se eliminó una pared del remanente coronario: . Grupo A: eliminación de pared palatina/lingual . Grupo B: eliminación de pared Vestibular . Grupo C: eliminación de pared mesial . Grupo D: eliminación de pared distal Posteriormente se ancló un poste de fibra de vidrio (Reforpost®, Angelus) y se realizó la confección del muñón con composite. Los dientes fueron montados en probetas acrilicas de modo tal que recibieran la carga respecto a su eje mayor, con una inclinación de 50° en relación a la vertical. Para la valoración de la resistencia a la fractura, se utilizó una máquina de ensayo de fuerza lnstron® modelo 3369 (USA, 2010). Los resultados de fuerzas de fractura fueron obtenidos por el programa Instron Bluehill Lite y analizados con el programa STATA 12. Resultados: Los promedios en resistencia a la fractura en los grupos A, B, C y D fueron de 317(N), 352(N), 418(N) y 417(N) respectivamente, arrojando una probabilidad de error O (p<0,05), por lo cual hay diferencias estadísticamente significativas entre los grupos. Las fracturas fueron parecidas entre los grupos tanto en forma como cantidad (aproximadamente la mitad de las muestras presentan fracturas reparables), por lo que no se observó un tipo de fractura predominante. Conclusiones: La ubicación de la pared ausente del remanente coronario sí influye en la resistencia a la fractura del sistema espiga-muñón de fibroresina en dientes tratados endodónticamente. La pared que genera mayor resistencia según los resultados obtenidos es la pared palatina. / Adscrito a Proyecto PRI-ODO 14/009.
92

Clinical evaluation of shade improvement after in-office vital bleaching

Salem, Yousef January 2010 (has links)
Magister Scientiae Dentium - MSc(Dent) / Tooth discoloration has increased the demand by patients to pursue aesthetic treatment options. Bleaching is considered a conservative approach in performing an aesthetic treatment for discolored teeth; however colour rebound and post-operative sensitivity are among the adverse effects associated with vital bleaching. In-office bleaching systems employ the use of high hydrogen peroxide concentrations. The effects of in-office bleaching agents on the degree of colour change and the gender differences in relation to bleaching outcomes are questionable. Post-operative sensitivity can be considered a bleaching side effect and the number of patients that experience it is unknown.Aim: The aim of this study was to assess the outcome of an in-office vital bleaching technique. Objectives: The objectives of this study were to evaluate the degree of colour change after vital tooth bleaching using a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain), using a spectrophotometer (CM-2600d Konica, Minolta) to measure the colour change at each intervention during the bleaching process, to assess the post-operative sensitivity during the first week of the intervention, to evaluate the patients' perception of the colour change and to compare it to the colour change (ΔE) expressed in numeric values and to investigate whether gender differences exist in relation to the outcome of the bleaching procedure. Materials and Methods: The maxillary anterior teeth of 22 patients comprising of 11 males and 11 females were bleached with a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain). Pre-treatment readings of the two maxillary central incisors using a spectrophotometer (CM-2600d Konica, Minolta) were obtained. Subsequent readings were obtained after scaling and polishing, before bleaching (which was used as a baseline reading), immediately after bleaching, one week and one month post-operatively. Patients were requested to complete a form regarding post-operative tooth sensitivity and their colour perception toward the bleaching treatment. Results: The quantitative effect of the bleaching material on tooth colour showed an increase in L* values and a decrease in a* and b* values, the changes were significant (p values ≤ 0.05) except for the mean value of b* one month after bleaching which was only significant between five and ten percent.The mean values of colour change measured as ΔE between baseline and after bleaching was found to be 3.4 which did not exceed the visible colour change perceptible clinically at a difference of 3.7 units according to the literature. However nine patients exceeded the visible clinical colour change immediately after bleaching. There was no gender difference in the ΔE values in the entire bleaching process. Tooth sensitivity is considered a bleaching side effect and in this study sensitivity was traced until the fifth day after bleaching. The mean value of patients' tooth sensitivity was found to be 1.73 in the first day on a 4 point visual analog scale. The mean value of patients' colour perception was found to be 2.14 immediately after bleaching on a 3 point visual analog scale. Spearman correlation tests showed a positive relationship between ΔE values immediately and one week after bleaching and a weak relationship one week and one month after bleaching. There was significant consistency in the patients‟ colour perception data immediately and one week after the bleaching process and a weak relationship between ΔE values and patients' colour perception one month after bleaching. Conclusion: Yotuel® Special, Biocosmetics Laboratories, (Spain) an in-office bleaching material consisting of 35% hydrogen peroxide was able to bleach patients' teeth with a perceptible colour change however the chalky white teeth desired were not obtained for all the patients. Tooth sensitivity was a temporary side effect.
93

Capacidad ventilatoria forzada en trabajadores de una empresa metalúrgica en la región central del Perú 2012

Cipriano Arellano, Jesús Salvador January 2015 (has links)
El estudio se realizó en la ciudad de La Oroya, capital de la Provincia de Yauli, en el Departamento de Junín a 3730 m.s.n.m., en las instalaciones del Centro Médico de Chulec perteneciente a la Empresa Doe Run Perú S.R.L. en trabajadores de la fundición del Complejo Metalúrgico, quienes participaron en forma voluntaria. Objetivo: Determinar la capacidad ventilatoria de los trabajadores de una empresa metalúrgica que laboran en zona de altura en la región central del Perú; según los indicadores espirométricos siguientes: Capacidad Vital Forzada (CVF), Volumen Espiratorio Forzado en el primer segundo (VEF1), relación entre Volumen Espiratorio Forzado en el primer segundo sobre la Capacidad Vital Forzada (VEF1/CVF), y el Flujo Espiratorio Pico de las siglas en inglés (PEF). La investigación servirá de aproximación a los valores de referencia, para trabajadores en zona de altura en el Perú. Metodología: Se realizó un estudio observacional, descriptivo y transversal en 385 trabajadores nativos o con un tiempo de residencia igual o mayor a 5 años, cuyas edades fueron entre 20 a 60 años, y a quienes se les practicó la prueba de espirometría forzada para determinar la capacidad funcional respiratoria, en base a los criterios de la Sociedad Americana de Tórax (ATS). Resultados: Los valores fueron los siguientes: Capacidad Vital Forzada: 4.83 l/s, el Volumen Espiratorio Forzado al primer segundo fue de: 4.02 l/s, la relación FEV1/FVC fue de 83.45%, y el Flujo Espiratorio Pico fue de 9.46 l/s. Conclusión: El 94,6% de los trabajadores evaluados, la Capacidad Vital Forzada estaba dentro de rangos normales. Un 5.2% de la población estudiada es portadora de procesos obstructivos leves, y el 0.2% es portadora de probable proceso restrictivo. / --- This study was conducted in the city of La Oroya, capital of the Province of Yauli, Department of Junín located at 3730 meters above sea level. The study took place in the installations of the Medical Center Chulec which belongs to the company Doe Run Peru SRL. The workers of the Metallurgical Complex voluntarily participated. Objective To determine the ventilatory capacity of workers in a metallurgical company performing their work at high altitudes in the central region of Peru. According to the following spirometric indicators: Forced Vital Capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory volume ratio in the first second of the FVC (FEV1) / FVC, and peak expiratory flow the acronym (PEF). The research will approach the reference values for workers in the highlands in Peru. Methodology An observational, descriptive and cross-sectional study involved 385 native workers with a residence time equal to or more than five years. The ages were between 20-60 years and the participants underwent spirometry testing to determine the respiratory function, based on the criteria of the American Thoracic Society (ATS). Results The values were the following : Forced Vital Capacity, FVC: 4.83 l / s, the forced expiratory volume at the first second was 4 .02 l / s, The FEV1 / FVC ratio was 83.45%, and the peak expiratory flow was 9.46 l Conclusion 94.6% of workers evaluated showed their FVC within normal ranges. 5.2% of the studied population are carriers of mild obstructive processes, and 0.2% are carriers of a likely restrictive process. Keywords: Respiratory function, vital capacity, workers, height, occupational health. / Tesis
94

Clinical evaluation of shade improvement after in-office vital bleaching

Salem, Yousef January 2010 (has links)
Magister Chirurgiae Dentium - MChD / Tooth discoloration has increased the demand by patients to pursue aesthetic treatment options. Bleaching is considered a conservative approach in performing an aesthetic treatment for discolored teeth; however colour rebound and post-operative sensitivity are among the adverse effects associated with vital bleaching. In-office bleaching systems employ the use of high hydrogen peroxide concentrations. The effects of in-office bleaching agents on the degree of colour change and the gender differences in relation to bleaching outcomes are questionable. Post-operative sensitivity can be considered a bleaching side effect and the number of patients that experience it is unknown. Aim: The aim of this study was to assess the outcome of an in-office vital bleaching technique. Objectives: The objectives of this study were to evaluate the degree of colour change after vital tooth bleaching using a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain), using a spectrophotometer (CM-2600d Konica, Minolta) to measure the colour change at each intervention during the bleaching process, to assess the post operative sensitivity during the first week of the intervention, to evaluate the patients' perception of the colour change and to compare it to the colour change (~E) expressed in numeric values and to investigate whether gender differences exist in relation to the outcome of the bleaching procedure. Materials and Methods: The maxillary anterior teeth of 22 patients comprising of 11 males and 11 females were. bleached with a 35% hydrogen peroxide gel (Yotuel® Special, Biocosmetics Laboratories, Spain). Pre-treatment readings of the two maxillary central incisors using a spectrophotometer (CM-2600d Konica, Minolta) were obtained. Subsequent readings were obtained after scaling and polishing, before bleaching (which was used as a baseline reading), immediately after bleaching, one week and one month postoperatively. Patients were requested to complete a form regarding postoperative tooth sensitivity and their colour perception toward the bleaching treatment. Results: The quantitative effect of the bleaching material on tooth colour showed an increase in L * values and a decrease in a* and b* values, the changes were significant (p values- 0.05) except for the mean value of b* one month after bleaching which was only significant between five and ten percent.
95

Towards a Contactless Vital Sign System

Ma, Xiaocong 28 September 2020 (has links)
Human vital signs are crucial parameters which reflect essential body functions and are often accessed by medical professionals at the first place during clinical diagnostics to provide immediate assistance in health status measurements. However, due to the recent COVID-19 pandemic, measurements made with direct body contact have become increasingly challenging and costly because of the spreading nature of this virus. Therefore, contactless vital sign measurements are highly desirable, and it motivates us to research and develop a new solution which is capable of performing real time heart rate (HR) detection, respiratory (RR) detection, and body temperature (BT) measurement together from a distant human subject under an ambient light environment. The thesis describes a new system framework, which utilizes the power of computer vision to collect remote video image data, processes them using signal processing and machine learning (ML) technologies simultaneously, and produces rapid updates on display. Furthermore, our validation analysis on the system has showed varied results based on different methodologies used, which enables us to apply the most suitable approach on each component for an optimized final integration. At the time of completing this thesis, we have achieved a complete system integrated with remote HR, RR estimations and BT detection, which are all fully functional in both real-time and offline. To further refine the performance on HR estimation, we selected the extreme gradient boost model through a number of ML models we tested, as it not only gives the lowest root mean square error of 8.2 but also produces stable and robust output.
96

Greater Sage-Grouse Vital Rate and Habitat Use Response to Landscape Scale Habitat Manipulations and Vegetation Micro-Sites in Northwestern Utah

Sandford, Charles P. 01 May 2016 (has links)
The greater sage-grouse (Centrocercus urophasianus; sage-grouse) has been a species of conservation concern since the early 20th century due to range-wide population declines. To contribute to knowledge of the ecology of sage-grouse populations that inhabit the Box Elder Sage Grouse Management Area (SGMA) in northwestern Utah and quantify their responses to landscape scale habitat manipulations, I monitored vital rates and habitat selection of 45 female sage-grouse from 2014 to 2015. Using telemetry locations of female sage-grouse with known nest and brood fates, I created Generalized Linear Mixed Models to estimate the influence of proximity to pinyon (Pinus spp.) and juniper (Juniperus spp.; conifer) encroachment, and removal projects may have on sagegrouse reproductive fitness in the Box Elder SGMA. The best fit model suggested that for every 1 km a nest was located away from a conifer removal area, probability of nest success was reduced by 9.1% (β = -0.096, P < 0.05). Similarly, for every 1 unit increase in the log-odds of selection for distance to treatment, probability of brood success declined by 52.6% (P = 0.09). The probability of brood success declined by 77.2% (P < 0.05) as selection for conifer canopy cover increased. To evaluate sage-grouse habitat use, I used fecal pellet surveys to estimate relative pellet density in conifer encroachment, removal, and undisturbed sagebrush areas. Sage-grouse pellet densities were estimated at 4.6 pellets/ha (95% CI = 1.2, 10.9), 8.6 pellets/ha (95% CI = 3.8, 15.2), and 50.6 pellets/ha (95% CI = 36.8, 69.6), in conifer encroachment, removal, and undisturbed sagebrush areas respectively. Density estimates did not statistically differ between conifer encroachment and removal areas. To determine if vegetation micro-site characteristics at sage-grouse use sites influenced nest or brood fate, I recorded standard vegetation measurements for all radio-marked sage-grouse nests and a stratified random sample of brood-use sites from 2014- 2015 and compared them to random sites. Micro-site vegetation characteristics measured did not differ for successful and unsuccessful nests. Many characteristics differed between micro-sites used by successful broods and those used by unsuccessful broods. Sites used by successful broods also differed from random sites.
97

Impact of introducing an electronic physiological surveillance system on hospital mortality

Schmidt, P.E., Meredith, P., Prytherch, D.R., Watson, D., Watson, V., Killen, R.M., Greengross, P., Mohammed, Mohammed A., Smith, G.B. January 2015 (has links)
Yes / Avoidable hospital mortality is often attributable to inadequate patient vital signs monitoring, and failure to recognise or respond to clinical deterioration. The processes involved with vital sign collection and charting; their integration, interpretation and analysis; and the delivery of decision support regarding subsequent clinical care are subject to potential error and/or failure. Objective To determine whether introducing an electronic physiological surveillance system (EPSS), specifically designed to improve the collection and clinical use of vital signs data, reduced hospital mortality. Methods A pragmatic, retrospective, observational study of seasonally adjusted in-hospital mortality rates in three main hospital specialties was undertaken before, during and after the sequential deployment and ongoing use of a hospital-wide EPSS in two large unconnected acute general hospitals in England. The EPSS, which uses wireless handheld computing devices, replaced a paper-based vital sign charting and clinical escalation system. Results During EPSS implementation, crude mortality fell from a baseline of 7.75% (2168/27 959) to 6.42% (1904/29 676) in one hospital (estimated 397 fewer deaths), and from 7.57% (1648/21 771) to 6.15% (1614/26 241) at the second (estimated 372 fewer deaths). At both hospitals, multiyear statistical process control analyses revealed abrupt and sustained mortality reductions, coincident with the deployment and increasing use of the system. The cumulative total of excess deaths reduced in all specialties with increasing use of the system across the hospital. Conclusions The use of technology specifically designed to improve the accuracy, reliability and availability of patients’ vital signs and early warning scores, and thereby the recognition of and response to patient deterioration, is associated with reduced mortality in this study.
98

Understanding and applying practitioner and patient views on the implementation of a novel automated Computer-Aided Risk Score (CARS) predicting the risk of death following emergency medical admission to hospital: qualitative study

Dyson, J., Marsh, C., Jackson, N., Richardson, D., Faisal, Muhammad, Scally, Andy J., Mohammad, Mohammad A. 11 March 2019 (has links)
Yes / Objectives The Computer-Aided Risk Score (CARS) estimates the risk of death following emergency admission to medical wards using routinely collected vital signs and blood test data. Our aim was to elicit the views of healthcare practitioners (staff) and service users and carers (SU/C) on (1) the potential value, unintended consequences and concerns associated with CARS and practitioner views on (2) the issues to consider before embedding CARS into routine practice. Setting This study was conducted in two National Health Service (NHS) hospital trusts in the North of England. Both had in-house information technology (IT) development teams, mature IT infrastructure with electronic National Early Warning Score (NEWS) and were capable of integrating NEWS with blood test results. The study focused on emergency medical and elderly admissions units. There were 60 and 39 acute medical/elderly admissions beds at the two NHS hospital trusts. Participants We conducted eight focus groups with 45 healthcare practitioners and two with 11 SU/Cs in two NHS acute hospitals. Results Staff and SU/Cs recognised the potential of CARS but were clear that the score should not replace or undermine clinical judgments. Staff recognised that CARS could enhance clinical decision-making/judgments and aid communication with patients. They wanted to understand the components of CARS and be reassured about its accuracy but were concerned about the impact on intensive care and blood tests. Conclusion Risk scores are widely used in healthcare, but their development and implementation do not usually involve input from practitioners and SU/Cs. We contributed to the development of CARS by eliciting views of staff and SU/Cs who provided important, often complex, insights to support the development and implementation of CARS to ensure successful implementation in routine clinical practice. / Health Foundation, National Institute for Health Research (NIHR) Yorkshire and Humber Patient Safety Translational Research Centre (NIHR Yorkshire and Humber PSTRC)
99

Development and validation of a novel computer-aided score to predict the risk of in-hospital mortality for acutely ill medical admissions in two acute hospitals using their first electronically recorded blood test results and vital signs: a cross-sectional study

Faisal, Muhammad, Scally, Andy J., Jackson, N., Richardson, D., Beatson, K., Howes, R., Speed, K., Menon, M., Daws, J., Dyson, J., Marsh, C., Mohammad, Mohammad A. 19 October 2019 (has links)
Yes / Objectives There are no established mortality risk equations specifically for emergency medical patients who are admitted to a general hospital ward. Such risk equations may be useful in supporting the clinical decision-making process. We aim to develop and externally validate a computer-aided risk of mortality (CARM) score by combining the first electronically recorded vital signs and blood test results for emergency medical admissions. Design Logistic regression model development and external validation study. Setting Two acute hospitals (Northern Lincolnshire and Goole NHS Foundation Trust Hospital (NH)—model development data; York Hospital (YH)—external validation data). Participants Adult (aged ≥16 years) medical admissions discharged over a 24-month period with electronic National Early Warning Score(s) and blood test results recorded on admission. Results The risk of in-hospital mortality following emergency medical admission was 5.7% (NH: 1766/30 996) and 6.5% (YH: 1703/26 247). The C-statistic for the CARM score in NH was 0.87 (95% CI 0.86 to 0.88) and was similar in an external hospital setting YH (0.86, 95% CI 0.85 to 0.87) and the calibration slope included 1 (0.97, 95% CI 0.94 to 1.00). Conclusions We have developed a novel, externally validated CARM score with good performance characteristics for estimating the risk of in-hospital mortality following an emergency medical admission using the patient’s first, electronically recorded, vital signs and blood test results. Since the CARM score places no additional data collection burden on clinicians and is readily automated, it may now be carefully introduced and evaluated in hospitals with sufficient informatics infrastructure. / The Health Foundation, National Institute for Health Research (NIHR) Yorkshire and Humberside Patient Safety Translational Research Centre
100

Avaliação da evolução respiratória em pacientes com Distrofia Muscular de Duchenne submetidos à corticoterapia / Evalutation of respiratory evolution in patients with Duchenne muscular dystrophy in corticosteroids therapy

Machado, Darlene Lessa 27 October 2010 (has links)
Além do comprometimento motor, os pacientes com Distrofia Muscular de Duchenne cursam com queda da função respiratória que está associada à fraqueza muscular. O objetivo do estudo foi avaliar a evolução da função pulmonar e a força dos músculos respiratórios em diferentes estágios da doença, comparando-os com o tempo e idade de início da corticoterapia e com o quadro motor. A função pulmonar e as pressões respiratórias de 87 pacientes com idade entre sete e 23 anos foram avaliadas durante dois anos, totalizando cinco visitas para função pulmonar e três para as pressões respiratórias. Além disto, parte da amostra (n: 21) completou três avaliações de função pulmonar com aproximadamente um ano de intervalo. Para a comparação, considerouse: idade cronológica; idade de início e tempo de duração da corticoterapia, e se o paciente deambulava ou não. Na avaliação transversal, observou-se que em valores absolutos a CVF, o VEF1 e a PImáx, mantiveram-se até a faixa etária de 13 a 14 anos e a PEmáx até nove a 10 anos; em valores relativos (aos valores de pacientes saudáveis) notou-se queda constante da função pulmonar e das pressões respiratórias. No acompanhamento longitudinal, a função pulmonar e a força muscular respiratória mostraram aumento em valores absolutos, principalmente nos pacientes deambuladores, sendo este aumento influenciado pelo crescimento; em valores relativos houve manutenção pelo período de dois anos. Em conclusão, durante o tempo de estudo, a corticoterapia pode ter contribuído para o retardo da progressão da doença, através da intervenção na musculatura respiratória da mesma forma que atua na musculatura proximal dos membros. O tempo e a idade de início do medicamento não mostraram relação clara com a manutenção da função respiratória, porém o início da corticoterapia abaixo de sete anos de idade parece ser mais efetivo para a preservação da força dos músculos respiratórios e da função pulmonar / Besides motor impairment, patients with DMD show loss of respiratory function which one is associated to muscle weakness. The aim of the study was to evaluate the pulmonary function evolution and the respiratory muscle strength in different stages and then to compare them to duration and initial age of corticostheroids treatment age as well as the function motor. The pulmonary function and the maximal respiratory pressure of the 87 patients aged 7-23 years were evaluated over the course of two years. The patients\' pulmonary function was assessed over five visits and their maximum respiratory pressure was assessed during three visits. Moreover, the sample (n = 21) completed three assessments of lung function with approximately one year apart. For comparison, we considered: chronological age, age of onset and duration of corticosteroid therapy, and if patient were ambulant or not. In the transversal evaluation we noticed that CVF, VEF1and PImax in absoluts values showed no changes until age of 13-14 years and no changes for the PEmax until age of 9-10 years. In predicted for their actual height values we noticed a constant decline for loss of pulmonary function and maximal respiratory pressure. In the longitudinal follow, the pulmonary function and the respiratory muscle strength raised in absolutes values, mainly in ambulatory patients due to the growth. In relatives values the pulmonary function and maximal respiratory pressure showed stability for 2 years. In conclusion, during the study, corticosteroid treatment may have contributed to the delay of disease progression, through intervention in the respiratory muscles in the same way that acts in the proximal muscles of limbs. Both time and the initial age of corticosteroids treatment didn´t show relationship with respiratory function. But the beginning of corticosteroids bellow seven years old seems to be more effective for preserving respiratory muscle strength and pulmonary function

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