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Carpenter, James R. "Simulated confidence regions for parameters in epidemiological models." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320182.
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Noland, Jeffrey Edward. "RISK PARAMETERS AND ASSESSMENT OF DIETARY dsRNA EXPOSURE IN FOLSOMIA CANDIDA." UKnowledge, 2017. http://uknowledge.uky.edu/entomology_etds/37.
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Assessing the risk of transgenic crop products is essential when determining the safety of a crop for deregulation and commercialization. The Organization of Economic and Cooperative Development (OECD), International Standards Organization (ISO), and governmental regulatory agencies require a battery of tests to demonstrate the safety of a GM product against several surrogate species of organisms that perform various ecosystem services. Assays are performed using toxicology methods established for pesticides. These methods have been applied to testing the safety, specificity and fate of Bacillus thuringiensis (Bt) Cry protein toxins engineered into crop plants and information exists on the effects on non-target organisms (NTOs). Toxicology assays are typically evaluated through a tier-based approach, where, if no or negligible risk via oral toxicity or phenotypic changes then a risk decision can be made. Long term exposure studies are often performed after commercial release of the crop occurs and provide a more in depth understanding of environmental impacts. Risk analyses are currently being performed on the product of the next generation of GM crops that express dsRNAs against Western Corn Rootworm. This thesis provides another such study, primarily focused on Folsomia candida, a microarthropod that is the subject of numerous toxicological studies. I describe the development of dsRNA stability assays, which indicate stability of dsRNA across assay time, both with and without F. candida. When exposed to dsRNA levels several orders of magnitude higher that what would be encountered in the environment, F. candida is not negatively impacted as seen through gene expression and life history trait analysis.
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Lança, Luís Jorge Oliveira Carrasco. "Radiological imaging in digital systems: the effect of exposure parameters in diagnostic quality and patient dose." Doctoral thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/3950.
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Doutoramento em Tecnologias da Saúde<br>Esta tese pretende contribuir para o estudo e análise dos factores relacionados
com as técnicas de aquisição de imagens radiológicas digitais, a qualidade
diagnóstica e a gestão da dose de radiação em sistema de radiologia digital.
A metodologia encontra-se organizada em duas componentes. A componente
observacional, baseada num desenho do estudo de natureza retrospectiva e
transversal. Os dados recolhidos a partir de sistemas CR e DR permitiram a
avaliação dos parâmetros técnicos de exposição utilizados em radiologia
digital, a avaliação da dose absorvida e o índice de exposição no detector. No
contexto desta classificação metodológica (retrospectiva e transversal),
também foi possível desenvolver estudos da qualidade diagnóstica em
sistemas digitais: estudos de observadores a partir de imagens arquivadas no
sistema PACS.
A componente experimental da tese baseou-se na realização de experiências
em fantomas para avaliar a relação entre dose e qualidade de imagem. As
experiências efectuadas permitiram caracterizar as propriedades físicas dos
sistemas de radiologia digital, através da manipulação das variáveis
relacionadas com os parâmetros de exposição e a avaliação da influência
destas na dose e na qualidade da imagem. Utilizando um fantoma contrastedetalhe,
fantomas antropomórficos e um fantoma de osso animal, foi possível
objectivar medidas de quantificação da qualidade diagnóstica e medidas de
detectabilidade de objectos.
Da investigação efectuada, foi possível salientar algumas conclusões. As
medidas quantitativas referentes à performance dos detectores são a base do
processo de optimização, permitindo a medição e a determinação dos
parâmetros físicos dos sistemas de radiologia digital. Os parâmetros de
exposição utilizados na prática clínica mostram que a prática não está em
conformidade com o referencial Europeu. Verifica-se a necessidade de avaliar,
melhorar e implementar um padrão de referência para o processo de
optimização, através de novos referenciais de boa prática ajustados aos
sistemas digitais. Os parâmetros de exposição influenciam a dose no paciente,
mas a percepção da qualidade de imagem digital não parece afectada com a
variação da exposição. Os estudos que se realizaram envolvendo tanto
imagens de fantomas como imagens de pacientes mostram que a sobreexposição
é um risco potencial em radiologia digital. A avaliação da qualidade
diagnóstica das imagens mostrou que com a variação da exposição não se
observou degradação substancial da qualidade das imagens quando a
redução de dose é efectuada. Propõe-se o estudo e a implementação de
novos níveis de referência de diagnóstico ajustados aos sistemas de radiologia
digital. Como contributo da tese, é proposto um modelo (STDI) para a
optimização de sistemas de radiologia digital.<br>In the present study an attempt has been made to contribute for the analysis of
the factors related with the technical acquisition, the quality of the diagnostic
image and dose management in digital detector systems for projection
radiography.
The thesis methodology is organized in two components. The observational
component is based on a retrospective and transversal design. The data
collected from CR and DR systems allowed the evaluation of exposure
parameters from digital images, absorbed dose and exposure index to the
detector. Under this classification (retrospective and transversal design) it was
also possible to develop diagnostic quality evaluations from digital radiographic
images: observer performance studies from digital images stored in the PACS.
Under the experimental component of this thesis several experiments using
phantoms were performed in order to evaluate the relation between dose and
image quality. The experiments allowed the characterization of physical
properties of digital image systems and manipulation of variables such as those
related to exposure parameters and evaluation of its influence in dose and
image quality. Using a contrast-detail phantom, anthropomorphic phantoms
and an animal bone phantom it was possible to provide objective measures
concerning the quantification of diagnostic quality and measures of object
detectability.
According to the research undertaken several conclusions could be highlighted.
Quantitative measures of DR and CR detectors performance provide a basis
for optimization, allowing to measure and determinate the physical properties of
digital radiology image systems. Exposure parameters being used in digital
radiography shows that current routine radiographic practice does not comply
with European guidelines concerning exposure techniques. There is a need to
evaluate, improve and establish a baseline reference aiming exposure
optimization and provide new guidelines for current digital systems. Exposure
parameters influence patient dose in digital radiology but image quality
perception seems not to be affected with exposure variation. Studies performed
both with phantoms and patients showed that overexposure is a potential risk
when working with digital systems. Evaluation of diagnostic quality of digital
images when a variation of exposure parameters is provided showed no
substantial decrease in image quality when dose reduction is achieved. New
dose reference levels should be studied and implemented according to the
digital system characteristics and performance.
A conceptual framework (STDI) is proposed as an attempt to provide a
practical method to optimize digital radiology systems.<br>FCT/PROTEC
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Esterhuizen, Bevan Peter. "The effects of titanium oxide nanoparticles on cultured cells and the immune system." University of Western Cape, 2021. http://hdl.handle.net/11394/8428.
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>Magister Scientiae - MSc<br>Engineered nanomaterials derived from various bulk materials are being developed in ever larger quantities and with very diverse chemical compositions. The physical and chemical properties of the smaller nanoparticles are very different compared to their larger bulk chemicals. Titanium dioxide nanoparticles (TiO2NPs) are an example of such an engineered nanomaterial. Titanium dioxide nanoparticles are mainly used as a pigment in many applications such as glazes, enamels, plastics, pharmaceuticals, cosmetics, and it is widely used in sunscreens. Human exposure to TiO2NPs can occur both during manufacturing and use.
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Cano, Tim. "The use of selected physiological parameters as indicators of polychlorinated biphenyl exposure of rainbow trout, Oncorhynchus mykiss." Thesis, University of Ottawa (Canada), 1996. http://hdl.handle.net/10393/9739.
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Hatchery reared rainbow trout (Oncorhynchus mykiss) were caged at two locations in the St. Lawrence river near Cornwall, Ontario. One cage was anchored in an area of high polychlorinated biphenyl (PCB) contamination, within an iron enclosure near the General Motors Foundry at Massena, N.Y. during a dredging operation designed to remove PCB contaminated sediments from the river. A second control cage was placed in the Snye channel, known to have low PCB concentrations. Hatchery fish were sampled to provide a time 0 control, and fish from each site were collected following 21 and 41 day exposure. Plasma, muscle, bone, and liver were harvested and assayed to determine muscle PCB levels, plasma cortisol, electrolyte, lactate and glucose concentrations, bone calcium, muscle water and the activity of a variety of liver enzymes. Total PCB levels were significantly higher in fish muscle from the General Motors site but few differences were found in any of the physiological parameters. Levels of bone calcium decreased in fish exposed to high PCB levels, suggesting an effect of PCBs on either the thyroid or ultimobranchial bodies. Pyruvate kinase activity in the liver of PCB exposed fish suggests a shift in energy metabolism to a greater reliance on glycogenolysis. Both parameters require further study to determine the feasibility of their use as bioindicators of PCB stress.
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Saccomano, Margaret Eloise. "The Effect of Prenatal Nicotine Exposure on Ventilation Parameters and Receptor Expression in the Neonatal Rat Brainstem." Thesis, The University of Arizona, 2010. http://hdl.handle.net/10150/146649.
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Prenatal nicotine exposure has recently been linked to respiratory dysfunction in infants and has been named one of the largest contributing factors in Sudden Infant Death Syndrome. Experiments were performed using the neonatal rat model to determine the mechanism behind the link between prenatal nicotine exposure and respiratory dysfunction, clinically manifesting itself as SIDS. Protocol called for full body plethysmography to be performed on nicotine exposed or saline exposed neonates on postnatal days 1, 3, 6, 9, 12, 18 and 21. However, a dysfunctioning apparatus impeded ventilation procedures. Animals were then transcardially perfused, postfixed and brains were dissected. Medullas were cut into 40 μm transverse slices and mounted on electrostatic slides. Immunohistochemistry was used to fluorescently tag cells containing important structure and receptors within the medulla including NeuN, NK-1R, nAChR, GABA-AR and Glutamate AMPAR. Cells were visualized for receptor expression and receptor density in control animals vs. PNE animals was studied. Needed changes in protocol prevented conclusive findings that established the relationship in question. These changes included the use of Trizma buffer over PBS and the reduction in the concentration of the fluorescent secondary antibodies used. However these changes will prove to be useful information in further experiments.
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Cui, Wenbin. "Comparative Evaluation on Human Infants Dietary Mercury Exposure through Consumption of Fish and Rice Products." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3464.
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Human exposure to methylmercury (MeHg) through diets (e.g., fish and rice) is a global health concern. Although MeHg exposure through fish consumption has long been considered the major route of mercury health risks, studies concerning the long-term changes in MeHg exposure from fish remain lacking. In sharply contrast to the fish MeHg issue, the presence of MeHg in rice has only been reported recently and its implications on MeHg exposure, albeit probably important, are still in infancy. Focusing on the discrepancies in the studies of MeHg exposure through fish and rice consumption, this study was aimed to assess the MeHg exposure of human infants through consumption of rice cereals and to evaluate the long-term changes in fish MeHg. The presence of MeHg in rice prompted the studies on MeHg concentrations and bioaccessibility in rice cereals and potential infant dietary exposure to MeHg through cereal consumption, which is believed to be the first of its kind. The analysis of a variety of infant cereals sampled from the common markets in the United States and China showed that the concentrations of MeHg in the cereals ranged from 0.07 to 13.9 µg/kg with a mean of 1.61 µg/kg. On the basis of these MeHg concentrations, the daily intake of MeHg through rice cereal consumption for infants was estimated to be 4-122% of the reference dose (RfD). The MeHg bioaccessibility in the cereals, determined using an in vitro digestion method, ranged from 25 to 74% with a mean of 48±16%. A further examination on these results, however, revealed the occurrence of MeHg re-adsorption during extraction steps, which leads to the underestimation of MeHg bioaccessibility and warrants cautions to be exercised when using these procedures to evaluate bioaccessibility in general. The long-term changes in fish MeHg were investigated through conducting a comprehensive data analysis on datasets for the Everglades, a well-studied aquatic ecosystem for Hg contamination. The results showed a clear decline of MeHg in mosquitofish in the Everglades during the past two decades, which was probably related to changes in environmental conditions (e.g., periphyton, dissolve organic matter, and sulfate) instead of mercury deposition.
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Reppas, Chrysovitsinos Efstathios. "In silico methods to prioritize chemicals with high exposure potential." Doctoral thesis, Stockholms universitet, Institutionen för miljövetenskap och analytisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-149358.
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Chemicals offer a wide range of desired functions and are used in a variety of consumer goods and industrial sectors. The number of individual synthetic organic chemicals produced and the total global chemical production volume are increasing. The majority of these anthropogenic chemicals are not monitored in environmental matrices nor in the indoor environment even though some are associated with undesirable consequences and the range of possible chemical impacts is still far from being fully understood. Chemicals that remain in the environment for a long time and/or distribute over a large area have high exposure potential, and will present particularly acute challenges if a currently unknown undesirable effect is discovered. This thesis describes the development of a set of in silico methods to identify and prioritize chemicals with high exposure potential that are currently not subject to national or international restrictions. In brief, we i) compiled databases of contaminants of potential concern, ii) established models to predict key properties to fill data gaps in the absence of experimental data, and iii) developed and applied methods to screen chemicals to identify those that should be assigned high priority for future study. Paper I delivers screening-level models to predict partition ratios of organic chemicals between polymeric materials commonly found indoors, and both air and water. These models can be used in high-throughput exposure assessment studies, passive sampling experiments, and models of emissions, fate and transport of chemicals. Paper II presents a scoring method to prioritize 464 organic chemicals of emerging Arctic concern for their potential to fit a set of four exposure-based hazard profiles. These four profiles represent persistent organic pollutants (POPs) regulated under the Stockholm Convention, very persistent and very bioaccumulative substances (vPvBs) regulated under REACH and for two novel and unregulated profiles derived from the planetary boundary threats framework; airborne persistent contaminants (APCs) and waterborne persistent contaminants (WPCs). APCs and WPCs are chemicals that are mobile in air and water, respectively, and that contaminate the environment in a poorly reversible manner due to their persistence. The prioritization method is based on a reference set of 148 chemicals that is used to contextualize the scoring results. Paper III describes the prioritization of 8,648 chemicals that were reportedly produced in five OECD countries. Paper III elucidates the relationship between the elemental composition of these chemicals and the exposure-based hazard scores, and presents a strategy to disentangle overlaps among the four exposure hazard profiles by categorizing chemicals according to the spatial coverage of profiles they best fit. Paper IV focuses on refining the prioritization method described in Papers II and III using a set of 5,600 hypothetical chemicals. The refined method is used to prioritize the chemicals from Papers II and III, and an additional 4,567 chemicals from the REACH database. The in silico methods developed in this thesis can be applied to conduct screening-level exposure assessments using only chemical structures as a starting point. Substances prioritized as having high potential to be POPs, vPvB, APC, or WPC should be considered for more detailed study to unequivocally determine their identity and physicochemical properties.<br><p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>
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Loef, David Szeinfeld. "Investigation of some biochemical parameters relating to energy metabolism in experimental rodent tumours after exposure to ionizing radiation and magnetic fields." Thesis, University of Cape Town, 1987. http://hdl.handle.net/11427/25636.
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Seitz, Mirjam [Verfasser], Sonja [Akademischer Betreuer] Kilo, and Hans [Gutachter] Drexler. "Validity of different biomonitoring parameters for the assessment of occupational exposure to N,N-dimethylformamide (DMF) / Mirjam Seitz ; Gutachter: Hans Drexler ; Betreuer: Sonja Kilo." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2018. http://d-nb.info/1194650821/34.
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McFarlane, Mary. "Butylated Hydroxytoluene treatment prior to and during pregnancy in the rat : effects of subsequent exposure on hepatic biochemical and histological parameters in male offspring." Thesis, University of Surrey, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259556.
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Keitel-Gröner, Frederike. "Physiological responses of Nile tilapia (Oreochromis niloticus) after exposure to diclofenac and metoprolol." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2017. http://dx.doi.org/10.18452/17723.
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(Oberflächen-) Gewässer weltweit sind mit geringen Mengen (ng/L bis wenige µg/L) humaner Pharmazeutika belastet. Diclofenac (DCF; nicht-steroidal, entzündungshemmend) und Metoprolol (MTP; ß-Blocker) gehören entsprechend ihres hohen Verbrauchs zu den am häufigsten gefundenen Substanzen. Deren biologische Aktivität ist nicht auf den Menschen beschränkt. Gut konservierte Enzyme innerhalb der Vertebraten legen Auswirkungen auf Nicht-Zielorganismen wie Fische nahe, die bisher in Langzeituntersuchungen mit umweltrelevanten Konzentrationen unzureichend untersucht wurden. In der vorliegenden Arbeit wurden die physiologischen Effekte von DCF und MTP auf die Nil-Tilapie (Oreochromis niloticus), einem der wichtigsten Aquakulturfische weltweit, untersucht. In vitro konnte anhand primärer Hepatozyten gezeigt werden, dass bereits umweltrelevante Konzentrationen von DCF zu einer erhöhten Genexpression verschiedener Schlüsselenzyme der Detoxifizierung führten. Nach MTP-Exposition waren die Veränderungen weniger eindeutig. Beide Substanzen induzierten die Vitellogenin Genexpression, nur DCF jedoch bereits in umweltrelevanter Konzentration. In vivo wurden in zwei Langzeit-Expositionsversuchen die physiologischen Effekte vom befruchteten Ei bis 80 Tage nach Schlupf in O. niloticus untersucht. Beide Substanzen hatte keinen Einfluss auf Schlupferfolg und Überleben, das Wachstum war nach 80 Tagen nach Schlupf leicht reduziert. Die deutlichsten Auswirkungen waren histopathologische Veränderungen der Kiemen, veränderte Genexpressionen der Gonadotropine und eine erhöhte Expression von Vitellogenin. Die Ergebnisse legen eine stärkere östrogene Aktivität von DCF im Vergleich zu MTP nahe. Zusammenfassend sind die Bedenken gegenüber den Einzelsubstanzen eher gering, negative Auswirkungen auf die Reproduktion und sich verstärkende Effekte bei zeitgleicher Exposition gegenüber DCF und MTP lassen sich jedoch nicht ausschließen und sollten im Weiteren untersucht werden.<br>Surface waters worldwide are contaminated with low levels (ng/L up to few µg/L) of human pharmaceuticals. Diclofenac (DCF; non-steroidal, anti-inflammatory) and metoprolol (MTP; ß-blocker) are highly consumed and therefore commonly detected. Their biological activity is not restricted to humans. Well conserved enzymes within the vertebrates suggest effects on non-target organisms such as fish, poorly studied in long-term exposure experiments using environmentally relevant concentrations. In the presented work, physiological effects of DCF and MTP on the Nile tilapia (Oreochromis niloticus), an important aquaculture fish species, were studied. Using primary hepatocytes, it was shown in vitro that environmentally relevant concentrations of DCF increased the gene expression of different key enzymes of the detoxification, while MTP exposure had a less clear effect. Both substances induced vitellogenin gene expression, but only after DCF exposure this was significantly elevated already at the environmentally relevant concentration. In vivo, two long-term exposure studies on the physiological effects from the fertilized egg until 80 days post-hatch were evaluated. Both substances did not affect hatching success and survival, while growth was slightly reduced after 80 days post-hatch. Histopathological alterations of the gills, changed gene expression patterns of the gonadotropins and induced vitellogenin gene expression were the most dominant findings. The results indicate a stronger estrogenic mode of action of DCF compared to MTP. Overall, the risk due to a single substance exposure seems to be relatively low but adverse effects on reproduction and additive effects during simultaneous exposure to DCF and MTP cannot be excluded and should be investigated further.
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Wall, Rudolf [Verfasser]. "The effects of standing exposure on venous and muscular stress parameters : influence of dynamic muscle activity in the lower extremities, age and gender, in healthy individuals / Rudolf Wall." Tübingen : Universitätsbibliothek Tübingen, 2021. http://d-nb.info/1236994027/34.
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Phillips, Roger. "The predictive value of in vitro chemosensitivity tests of anticancer drugs : in vitro chemosensitivity of a panel of murine colon tumours determined by a colony forming assay at drug exposure parameters measured in vivo." Thesis, University of Bradford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329305.
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Figueiró, Micheli. "Sensibilidade da enzima acetilcolinesterase (e.c. 3.1.1.7) à nicotina in vitro e in vivo." Universidade Federal de Santa Maria, 2005. http://repositorio.ufsm.br/handle/1/11166.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>This work valued the sensibility of the acetylcholinesterase from different sources and brain regions at nicotine in vitro, and the effects of the acute and subchronic exposures at the alkaloid on the brain acetylcholinesterase and serum cholinesterase activities, body weight gain and cerebral weight of female rats. The activity of cholinesterases was determined by spectrophotometric method of Ellman (1961), using acetylthiocholine as substrate. In the nicotine in vitro study, the enzymatic analysis was performed with nicotine concentrations ranging from 0 to 1 mM and substrate concentration of 0 -1 mM. In the ex vivo enzymatic assay, 0.8 mM of acetyltiocholine was used. The results regarding at the effects of the nicotine in vitro demonstrated that the enzyme activity from rat brain, human blood and purified of Electric Eel was competitively inhibited by lower nicotine concentrations. The similar effect may be due to the predominance of the G4 molecular globular form in these three sources. The acetylcholinesterase activity from brain structures: cortex, striatum, hippocampus, hypothalamus and cerebellum, was inhibited by nicotine. Considering the IC50, the inhibitory effect was similar among the structures, although the striatum and cortex enzyme seems to be more sensitive, whereas the hypothalamus seems to be less sensitive to alkaloid. The kinetics constants calculated by Michaelis-Menten methods for striatum, cortex and hypothalamus demonstrated that the nicotine induce an increase of Km and a decrease of Vmax. These results showed that the increase of the substrate concentration was not enough for to reach the original Vmax (absence of inhibitor), even in the presence of the low nicotine concentrations. The effects of ex vivo nicotine exposure were investigated after acute or subchronic alkaloid administration. Female Wistar rats with 30 days old received one dose of 0, 0.5, 1 or 5 mg/kg (i.p.) of nicotine (acute exposure) and 10 minutes later were anesthetized and killed by decapitation. Brain was removed and homogenized, the blood was colleted and both centrifuged for obtain the S1 fraction and serum, respectively. In the subchronic exposure, female Wistar rats of 30 days old received doses of 0, 0.5 or 1.0 mg/kg (s.c.) of nicotine for 15 or 30 days, administered twice a day (0, 1 or 2 mg/kg/day). The animals were weighed every two days and killed 12 h after the last injection. The brain and the blood were prepared as previously described. The results demonstrated that the cerebral AChE and serum ChE activities were not changed by acute or subchronic exposure (15 or 30 days) at nicotine. The body weight gain and the cerebral weight also were not altered by alkaloid exposure.
The absence of effect on the enzymatic activities ex vivo may be related at least the two possibilities: low levels of nicotine reached in vivo; or a possible enzymatic inhibition present in vivo induced by treatments but not apparent due to substrate excess assayed ex vivo, since the in vitro inhibitory effect of the nicotine on the AChE presents an competitive component.<br>Este trabalho avaliou a sensibilidade da enzima acetilcolinesterase de diferentes fontes e regiões cerebrais à nicotina in vitro, e os efeitos da exposição aguda e subcrônica ao alcalóide sobre as atividades da acetilcolinesterase cerebral e colinesterase sérica, ganho de peso corporal e peso cerebral de ratas. As atividades enzimáticas foram determinadas segundo o método espectrofotométrico de Ellman (1961), utilizando-se acetiltiocolina como substrato. No estudo in vitro, os efeitos da nicotina foram analisados em concentrações que variaram de 0 a 1 mM do alcalóide e de 0 a 1 mM de substrato. Nos ensaios enzimáticos ex vivo foram utilizadas concentrações fixas de 0,8 mM de acetiltiocolina. Os resultados referentes aos efeitos da nicotina in vitro demonstram que a atividade da enzima de cérebro de ratas, de sangue humano e purificada de órgão Elétrico de Enguia foi inibida competitivamente pelas menores concentrações de nicotina testadas. O efeito semelhante sobre as três fontes pode ser conseqüência da predominância da forma molecular G4 da enzima. A atividade da acetilcolinesterase das estruturas cerebrais: córtex, estriado, hipocampo, hipotálamo e cerebelo, mostrou-se inibida pela nicotina. De acordo com o IC50, o efeito inibitório foi similar entre as estruturas, embora a enzima de
estriado e córtex tenha sido mais sensível e a de hipotálamo menos sensível ao alcalóide. As constantes cinéticas calculadas de acordo com o método de Michaelis-Menten para estriado, córtex e hipotálamo demonstraram que a nicotina induz um aumento de Km e diminuição de Vmax. Estes resultados revelam que o aumento da concentração de substrato não foi suficiente para recuperar a velocidade da reação, mesmo na presença das menores concentrações de nicotina. Os efeitos da nicotina ex vivo foram investigados administrando-se o alcalóide aguda ou subcronicamente. Ratas Wistar com 30 dias de idade receberam uma dose de 0, 0,5, 1,0 ou 5,0 mg/kg (i.p.) de nicotina (exposição aguda) e após 10 minutos foram anestesiadas e mortas por decapitação. O cérebro foi removido e homogeneizado, o sangue coletado e ambos submetidos à centrifugação a fim de obter-se a fração S1 e soro, respectivamente. Na exposição subcrônica, ratas Wistar de 30 dias receberam doses de 0, 0,5 ou 1,0 mg/kg (s.c.) de nicotina por 15 ou 30 dias, 2 vezes ao dia (0, 1,0 ou 2,0 mg/kg/dia). Os animais foram pesados a cada 2 dias e 12 horas após a administração da última dose foram sacrificados. O cérebro e o sangue foram preparados como descrito anteriormente. Os resultados demonstram que as atividades da AChE cerebral e ChE sérica não se apresentaram modificadas pela exposição aguda ou subcrônica (15 ou 30 dias) à nicotina. O ganho de peso corporal e o peso cerebral também não foram alterados pela exposição ao alcalóide. A ausência de efeitos da nicotina sobre as atividades enzimáticas ex vivo pode estar relacionada pelo menos a duas hipóteses: níveis baixos de nicotina atingidos in vivo; ou uma possível inibição enzimática presente in vivo induzida pelos tratamentos, mas não aparente devido ao excesso de substrato ensaiado ex vivo, uma vez que o efeito inibitório da nicotina sobre a AChE in vitro possui um componente competitivo.
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James, Kelley J. "Impact of Heat Exposure on Postural Balance of Firefighters." University of Cincinnati / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1397235487.
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Fourie, Marilize. "Tissue Parameter Mapping in Children with Fetal Alcohol Spectrum Disorders." Master's thesis, Faculty of Health Sciences, 2020. http://hdl.handle.net/11427/32252.
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Background: Fetal alcohol spectrum disorders (FASD), which are caused by prenatal alcohol exposure (PAE), affects people around the world. Certain communities in South Africa have among the highest reported incidences of fetal alcohol syndrome (FAS) in the world. Although PAE-related brain alterations have been widely documented, the mechanisms whereby alcohol affects the brain are not clearly understood. MRI relaxation parameters T1, T2, T2* and proton density (PD), are basic tissue properties that reflect the underlying biology. The present study aims to advance our understanding of how PAE alters the microstructural properties of tissue by examining PAE-related changes in these tissue parameters in adolescents with FASD. Methods: The final sample used in this study consisted of 53 children from a previously studied longitudinal cohort (Jacobson et al., 2008) and 12 additionally recruited subjects. Of the 65 participants, 18 were diagnosed with FAS or partial FAS (PFAS) and made up the FAS/PFAS group, 18 were diagnosed as heavily exposed non-syndromal (HE) and 29 were age matched controls. Subjects were scanned at the Cape Universities Body Imaging Centre (CUBIC) located at Groote Schuur Hospital on a 3T Siemens Skyra MRI. Structural images were obtained using the MEMPRAGE sequence. From these images T1, T2, T2* and PD parameter maps were constructed and segmented into 43 regions of interest (ROI) using Freesurfer, FSL and AFNI. Linear regression analyses were used to analyse group differences as well as correlations between parameter values and the amount of alcohol the mother consumed during pregnancy. Results: Significant T1 differences were found in the caudate, cerebellar cortex, hippocampus, accumbens, putamen, choroid plexus, ventral diencephalon (DC), right vessel and ventricles. Significant T2 differences were found in the caudate, brain stem, corpus callosum (CC), amygdala, cerebral cortex, choroid plexus, vessels and ventricles. Significant T2* differences were found in the cerebellar cortex, optic chiasm and ventricles. Significant PD differences were found in the hippocampus and left lateral ventricle. The exploratory nature of this study resulted in none of the results surviving FDR correction for multiple comparisons. Conclusions: Overall, our findings point to regional PAE-related increases in water content and cellular and molecular changes in underlying tissue of the anatomical structure. Exceptions were the right cerebral cortex, brain stem, hippocampus, amygdala and ventral diencephalon where our findings point to less free water and increased cell density, and cerebellar cortex where simultaneous reductions in T1 and T2* suggest the possibility of increased iron content. In highly myelinated white matter structures, such as the CC and optic chiasm, our results point to PAErelated demyelination, and possibly increased iron. These findings extend previous knowledge of effects of PAE and demonstrate that tissues are affected at a microstructural level.
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Major, Andrea Claudia. "Exposure of cats to low doses of FeLV : seroconversion as the sole parameter of infection /." [S.l.] : [s.n.], 2009. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000282964.
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Lavelle, Karlene Sellani Olshan Andrew F. "Effects of lifestyle exposures and body mass index on sperm quality parameters of fertile men." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1857.
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Thesis (Ph. D.)--University of North Carolina at Chapel Hill, 2008.<br>Title from electronic title page (viewed Dec. 11, 2008). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Epidemiology, School of Public Health." Discipline: Epidemiology; Department/School: Public Health.
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Maitre, Léa. "Metabonomic and epidemiological analyses of maternal parameters and exposures during pregnancy and their influence on fetal growth amongst the INMA birth cohort." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/39755.
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Fetal growth aberrations, including fetal growth restriction (FGR) and macrosomia, convey the highest risk of perinatal mortality and morbidity, as well as increasing the chance of developing chronic disease in later life. Using Metabolic profiling/metabolomics approaches in maternal urine samples collected in a prospective mother-child cohort can provide information on the early-life exposome and can be linked to child health outcomes as well as potentially identify new biomarkers of exposure. The aims of this PhD were to characterise intra and inter-individual variations in maternal urine profiles during pregnancy, predict fetal growth outcomes and identify environmental sources of metabolic variations. We applied an exploratory metabolic profiling approach using 1H nuclear magnetic resonance (NMR) spectroscopy to maternal urine samples at the first (n=806) and third trimesters of gestation (n=886), collected as part of the Infancia y Medio Ambiente (INMA)-Environment and Childhood Study, a large prospective mother-child population-based cohort study cohorts based in eight Spanish cities. An exploratory metabolomics approach was applied using 1H nuclear magnetic resonance (NMR) spectroscopy for profiling and LC-MS/MS for metabolite identification. Metabolites were used to predict longitudinal measures of fetal growth in terms of body weight and head size (estimated at 12th, 20th and 34th gestational weeks and at birth) and placental weight at birth using linear regression adjusting for main confounding factors. To our knowledge the present study represents the largest human investigation (n > 800) in which non-targeted proton nuclear magnetic resonance spectroscopy has been used to understand the progression of normal fetal growth in two different Spanish populations. We identified 10 reproducible metabolic associations at week 34 with estimated fetal weight, birth weight and placental weight. These signatures included pregnancy-related hormone breakdown products that were newly characterised in our study and branched-amino acids (BCAAs) isoleucine, valine and leucine with its catabolic intermediate 3-hyrdoxyisobutyrate. Overall metabolic phenotypes at week 12 could not predict fetal weight at week 34 or at birth, but only at weeks 12 and 20 and with little consistency across the two populations. Unique adverse metabolic signatures at week 12 of fetal growth were found in Sabadell related to mitochondrial oxidative stress, systemic inflammation and renal function. These findings captured the metabolic signatures of a myriad of physiological (both maternal and fetal), environmental, and other lifestyle characteristics associated with fetal growth. Sensitive measures of environmental exposure to HAA toxins were also created using LC-MS, a non-volatile sub-type of water contaminants, using gold-standard urine biomarker (TCAA), in a case-control study for use in future epidemiological studies of fetal growth outcomes. This work provides ground breaking evidence of clinical relevance with the potential to personalise pre-natal care and ensure healthy fetal development.
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Tylš, Ladislav. "Získávání dat z kamer." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-217760.
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This thesis describes the principles of making application which is able to set and control camera. The first part describes basic camera connections and it explains definition and specification of camera’s features. The second part of my thesis describes implementation of application, which can use more cameras to image preview, image acquisition and to simply set of camera’s features. To implement the applications we can use MATLAB and C++BUILDER uses opencv libraries.
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Chou, Ying-Liang, and 周英樑. "The Changes of Ocular Physiological Parameters after High-G Exposure." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/20465191688596498802.
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碩士<br>國防醫學院<br>航太醫學研究所<br>92<br>Introduction. The effect of sustained high-G exposure on ocular hemodynamics and visual function is not clear. Visual biological parameters could vary after high-G exposure.
Material & Methods. Nineteen subjects were divided into two groups: a centrifuge group (high-G exposure, n=13) and a control group (n=6). Intraocular pressure (IOP), visual acuity and manifest refraction were measured 30 minutes before centrifugation, 2 minutes, 10 minutes and 20 minutes after centrifugation, respectively.
Results. Two subjects were excluded from the experiment because of G tolerance less then 6G. There was no statistical difference in refractive errors in both groups. Most subjects in centrifuge group improved their best corrected visual acuity (BCVA) after high-G exposure. Also high-G exposure made a significant effect on intraocular pressure.
Conclusion. IOP reduced after high-G exposure, it might be related to the improvement of visual function.
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Chang, Wunching. "Evaluation of parameters influencing skin irritation and design criteria for prolonged pressure exposure." 1997. http://catalog.hathitrust.org/api/volumes/oclc/37821912.html.
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Thesis (Ph. D.)--University of Wisconsin--Madison, 1997.<br>Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 164-173).
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Lu, Yi-Fang, and 盧奕方. "An Investigation of Environmental Exposure Parameters of Extremely-Low-Frequency Magnetic Field in School Children." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/835uh9.
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碩士<br>輔仁大學<br>公共衛生學系碩士班<br>96<br>Background and Objectives: The International Agency for Research on Cancer affiliated with the World Health Organization reported in 2002 that environmental exposure ( >4 milli-Gauss, mG) to extremely-low-frequency magnetic field (ELF-MF) is a possible cause of leukemia in children aged 15 years or less, suggesting that children are potentially vulnerable to the leukemogenic risk posed by ELF-MF exposure. Because ELF-MF can only be quantified by instrumental dosimetry, which is usually costly and less comfortable perceived by the study subjects being measured, many epidemiological studies alternatively performed “spot” or “short-term” measurements of ELF-MF. However, it has not been very clear whether the data taken from a short-term period can be well representative of long-term exposure. Additionally, there has been a lot of discussion regarding what summary measures are the best representative of long-term continuously measured data. This study used the data of 24-h continuously measured ELF-MF (sampling interval：1∕6 sec.) along with the logged diaries among 227 school children (7～15 years of age) to quantify children’s ELF-MF exposure levels at different time periods during a day and their respective associations with 24-hr exposure level. This study also explored the inter-correlations among various 24-h exposure parameters.
Materials and Methods: Data used in this study were obtained from a previous Taiwan EPA sponsored research project conducted by Li. This project collected 24-h continuously measured personal ELF-MF among 227 children from 32 elementary and junior high schools in northern Taiwan. Based the logged diary, the 24-h ELF-MF data were was divided into several time periods with specific exposure levels, including periods for indoor and outdoor environments at campus, day care center after-school, and non-sleep and sleep time at home. Various exposure parameters, including arithmetic and geometric means (AM∕GM) (standard deviations, SD), coefficient of variation (CV), rate of change metric, and proportions of time ＞3 mG and 4 mG, were calculated for each time period during a day. Using Spearman correlation coefficient, sensitivity, and specificity, this study examined the exposure parameters-specific associations between 24-h exposure and the exposure at each time period. The inter-correlations among exposure parameters in 24-h were assessed by Spearman correlation coefficient and Kappa statistic.
Results: The average 24-h AM was 1.76 ± 1.77 mG for the study children. The estimated proportion of children with the 24-h AM exposure levels of > 3 mG or > 4 mG was 14.5% or 3.52%, respectively. The highest (2.52 ± 3.79 mG) and the lowest (1.24 ± 1.16 mG) time period specific AM exposure was noted at after-school day care centers and outdoor areas at campus, respectively. The after-school day care centers also had higher threshold（% of time ＞3∕4 mG）and categorical exposure parameters（% of individuals ＞3∕4 mG）. Additionally, the 24-h central tendency exposure parameters had high associations with the threshold exposure parameters（r＝0.69～0.86）, but had lower associations with dispersion exposure parameters（r＝-0.26～0.70）. The analyses of parameters-specific exposure associations between exposures at various time periods and that of 24-h showed that the association between short term measures and 24-h measures were higher for central tendency and threshold parameters. The data also showed that the AM of exposure to ELF-MF measured at home was able to well predict the 24-h AM, whereas that measured at campus showed a poor predictive capability.
Conclusions: This study indicated that children’s exposure to ELF-MF at after-school day care centers was high in this urban sample, suggesting a need for concern regarding children’s exposure in that environment. Additionally, home exposure to ELF-MF during non-sleep hours can be alternatively used as children’s 24-h exposure level, if long term measurements were not possible due to limited resources. This study also suggests that both central tendency and dispersion exposure parameters should be calculated simultaneously as exposure indices in order to better represent children’s 24-h exposure.
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Bo-ShiouGuo and 郭柏秀. "Study on the Priority of Parameters in HARP for Air Toxics Exposure and Risk Assessment." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/9yy7tx.
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Shu-HanTsai and 蔡舒涵. "Optimizing parameters of SMAIT, MDF and XCMS for toxicant exposure marker discovery using mass spectrometry-based metabolomics approaches." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/bf2245.
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碩士<br>國立成功大學<br>環境醫學研究所<br>103<br>Phthalates are widely used in many products and regarded as endocrine disrupters. Di-isononyl phthalate (DINP) is one of phthalates may induce many health problems. Due to this reason, toxicant exposure marker discovery becomes an important issue. Metabolomics is the study of metabolite and liquid chromatography coupled with mass spectrometry (LC-MS) can develop the identification of metabolites. Once these metabolites are validated in biological samples, they are considered exposure markers. Owing to a large number of data generated from LC-MS, many methods such as signal mining algorithm with isotope tracing (SMAIT), mass defect filter (MDF) and XCMS are used in processing data to select out probable metabolite signals. Here, we used 14 validated exposure markers to optimize parameters of three methods, SMAIT, MDF and XCMS for toxicant exposure marker discovery. Except for these 14 exposure markers, the other signals filtered by these three methods were defined as false-positive hits. We adjusted parameters of SMAIT, MDF and XCMS to investigate how many of these 14 exposure markers covered in the results. The optimized parameters of SMAIT, MDF and XCMS were obtained when the maximized number of these 14 exposure markers was filtered out in an HPLC-MS dataset with the least number of false-positive hits. The optimized parameters of SMAIT were 0.004 Da set at mass shift in isotopic pair (IP) finding step, and 0.003 Da at mass shift between IPs in IP response ratio analysis. MDF method yielded optimal results when all signals with S/N ≥ 3 were included for consideration. The optimized parameters of XCMS were 1 profstep, 0.01 at mzwid, 0.5 at minfrac and 6 at bw. These optimized parameters of SMAIT, MDF and XCMS can be applied in the future investigations for toxicant exposure marker discovery.
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Huang, Cha-Chi, and 黃家麒. "The influences of exposure and development parameters on the shape and depth of micro-structure for four-beam interferometric lithography." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/7h54pq.
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碩士<br>國立中央大學<br>機械工程研究所<br>94<br>Abstract
In this research, we have developed laser interference lithography system, such as one dimension linear gratings or two dimension arrays of dots and grids, to create periodical structures. The method of maskless laser interference lithography used for generation of infinite depth of focus, relative simplicity, low cost, deep sub-micron patterns and high resolution in large field of view is investigated.
The main advantage of four-beam exposure is that higher throughput process for patterning arrays and higher contrast images can be obtained. According to theoretical analysis and experimental results, four-beam exposure allows a greater percentage of the incident energy to be redistributed near the intensity maxima and generates structures sharper.
The effects of the process parameters on the shape and depth of the structure have been discussed. According to different critical dimension, this thesis also suggests several parameters for exposure and development, with which best pattern had been acquired in our experiments.
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Wall, Judith S. "Investigation of attribution of cause, exposure factors and psychosocial stress parameters as they relate to musculoskeletal complaints in keyboard operators." Thesis, 1985. http://hdl.handle.net/1885/143898.
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Page, Tamara Elaine. "The impact of exposure time on biophysical parameters of the wound environment and patient comfort during dressing changes: a descriptive study." Thesis, 2015. http://hdl.handle.net/2440/93923.
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Wound healing is a complex milieu that affects millions of people around the world every day. Practice based concerns have been described anecdotally by nurses in acute care facilities where wounds requiring an assessment by health care professionals have been left without their primary dressings for a considerable length of time. A number of studies have demonstrated that the temperature, transepidermal water loss (TEWL) and pH of a wound's microenvironment influence wound healing; however, there is limited research on the effect of the dressing changes on these parameters as well as the risk of contamination of the wound through prolonged exposure. The impact of prolonged exposure throughout delays in a dressing change on these biophysical wound bed parameters and the possible contamination of the wound during the wound dressing procedure; and the affect delays have on patient pain, comfort and activities of daily living, were investigated through a descriptive correlational study. Demographics and participant questionnaire data were analysed using descriptive statistics and frequency distributions. Patterns of distribution of the wound temperature, TEWL and pH data were reviewed before being further analysed along with the bacterial and patient questionnaire data using Generalised Estimating Equations regression models. A GEE linear regression model was used for normally distributed data; and GEE logistic regression models for data which were not normally distributed, using the Statistical Analysis System (SAS) 9.3. The results identified that the participants’ wounds were hypothermic as well as alkaline at dressing removal and throughout the period of exposure. The mean wound temperature increased throughout the total duration of the down time which was contrary to expectation, although despite this all wounds remained hypothermic. The pH became more alkaline with the chance of having a pH of >8.5, 12% higher than having a pH of <8.5. There was no relationship between the size of the wound and any of the wound bed parameters; however, there was a relationship between the type of wound, the temperature and pH. No associations could be made in regards to the participant’s body temperature and wound temperature. In addition to the investigation into the wound bed parameters, agar plates placed in proximity to the exposed wounds grew pathogens which could potentially contaminate the wound. The third issue investigated was the affect wound dressing changes on the participant's pain, comfort and activities of daily living, an important aspect of the holistic approach to patient care. Participants were noted to be unable to perform some activities of daily living; including hygiene, toileting, nutrition and positioning during the wound down time. Analgesia was offered haphazardly despite the majority of patients having a pain score pre dressing removal that would indicate analgesia was required and an associated increase in their pain score during the dressing procedure. The impact of delayed wound dressing changes on the patient’s activities of daily living and pain are important in the delivery of patient centred care; however the major findings of the study relate to the poor state of the wounds immediately following removal of the dressing. Hypothermic, alkaline wound beds are not conducive to healing and warrant further investigation.<br>Thesis (Ph.D.) -- University of Adelaide, School of Nursing, 2015
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Pereira, Sara Diana Moreira. "Estrogenic exposure impacts in the frequency and stereological parameters of both induced preneoplastic liver lesions and normal hepatocytes of the brown trout." Master's thesis, 2014. https://repositorio-aberto.up.pt/handle/10216/88647.
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Pereira, Sara Diana Moreira. "Estrogenic exposure impacts in the frequency and stereological parameters of both induced preneoplastic liver lesions and normal hepatocytes of the brown trout." Dissertação, 2014. https://repositorio-aberto.up.pt/handle/10216/88647.
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Gemmill, Bonnie. "Dietary exposure of 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane to juvenile brown trout (Salmo trutta): bioaccumulation parameters and effects on circulating plasma sex hormones." 2010. http://hdl.handle.net/1993/4105.
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1,2-Dibromo-4-(1,2 dibromoethyl)cyclohexane or tetrabromoethylcyclohexane (TBECH) is an additive bromine based flame retardant used primarily in expandable polystyrene beads that are used mainly to produce thermal insulation for housing. Secondary uses include extrusion into polystyrene foam, adhesive in fabric and vinyl lamination, electrical cable coatings and construction materials. The technical formulation contains two diastereoisomers, α- and β-, which are present in equimolar amounts. Under elevated temperatures two other isomers, γ- and δ-, can be formed. The recent detection of TBECH in the environment and suggestions that all four isomers are androgenic prompted me to examine the bioaccumulation and biochemical effects of one of the isomers, β-, in a controlled laboratory environment. I purposely chose to examine this isomer as it has been detected in biota. Juvenile brown trout (Salmo trutta) were exposed to three different amounts of the β-isomer via their to three different amounts of the β-isomer via their food for 56 days (uptake phase). This was followed by a depuration phase in which all fish were exposed to unfortified food for 77 days. A fourth group of fish were exposed to unfortified food for the duration of the experiment. On days 0, 7, 14, 35, 49, 56, 63, 77, 91, 105, and 133 eight fish from each treatment group were sacrificed and liver, plasma, thyroid and gonad gland were collected and whole-fish (carcass minus tissues above) were collected. Residues of β-isomer were analyzed in the whole-fish and in liver extracts by gas chromatography mass spectrometry in the electron ionization while estradiol (E2), 11-ketotestosterone (11-KT) and testosterone (T) were extracted from plasma and analysed by liquid chromatography tandem mass spectrometry. The bioaccumulation of β-isomer was similar in fish from all treatment groups with steady-state occurring before the end of the uptake phase. Depuration of the β-isomer from fish obeyed first order kinetics and there were no statistically significant differences in the depuration half life (t1/2) among the treatment groups: 22.5 ± 10.4 (low), 13.5 ± 5.9 (med) and 13.8 ± 2.2 (high) days. Steady-state biomagnification factors were much smaller than 1 for fish in all treatment groups. I was unable to detect debrominated metabolites in liver or whole-fish extracts and I also found no evidence of isomerization of the β-isomer to other isoforms in vivo. While there were some differences in E2, T and 11-KT levels in plasma of fish from the treated groups relative to plasma in fish from the control group there were no clear, consistent, discerning trends.
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Wu, Wen-Hua, and 吳文化. "Body dose of toxic metal in community residents and the relations to occupation and cigarette smoking - and the association between the metal exposure and erythrocyte parameters." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/04653660252783807368.
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碩士<br>高雄醫學大學<br>職業安全衛生研究所碩士班<br>95<br>Objective: The Changhua area occupied 24％ of metal manufacturing industry in Taiwan. Combinations of industry related metals in soil has been verified, but there are no accurate information shown on human exposure studies. Therefore this study made further understands of the residents’ toxic metal exposure levels, and emphasized the effect of occupational exposure , smoking behavior and anemia.
Method: This is a community-based study carried out during 2001-2002 and 2005-2006. The research areas from the areas of high industry density collected 532 effective samples and the areas of low industry density collected 543 effective samples. Subjects were between 35 to 65 years old who reside in the areas of research longer than 5 years. The basic information of research targets was collected through the designed questionnaires and the samples of urine, blood, and hair were gathered for the analyzing body burden heavy metal concentration medium.
Result: There are significant differences (p<0.05) between high industrial and the lower industrial areas in age,length of residence, habit of milk drinking ,occupation, 50 meter distance of electroplate or steel factory with residence ,use of groundwater,. Metal related occupation (i.e. electroplating ones) tend to correlate with increased concentrations of lead (Pb),nickel(Ni),cadimum(Cd),arsenic(AS). Multivarientlinear regression results positive relation of urinary-Pb (β=0.1, p= 0.013);U-Cd (β=0.177 , p <0.001) and blood-Cd (β=0.318 , p<0.001) to number of cigarette smoked per day. By the analyze of lead, nickel,cadmium and arsenic, the coeelation of nickel and cadmium with erythrocyte parameters and renal function was discovered.
Discussion: We found that in industrial areas, lead and cadmium may cause a positive significant between exposure of metal levels and cigarette smoking. Blood-Pb have a add of interaction with cigarette smoking and occupation.In addition, nickel and cadmium has significant correlation with erythrocyte parameters and renal function; which worth further study.
Conclusion: Smoking may increases lead and cadmium concentration. The significant relevance of exposure to nickel and cadmium with erythrocyte parameters and renal function ,therefore tobacco control in the workplace need to emphasized.
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Tseng, Hsuan-Hao, and 曾炫皓. "Research of the adaptive parameter by using space-variant of the gamma correction for high-exposure and low-exposure image." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/08252906296654051686.
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碩士<br>國立勤益科技大學<br>資訊工程系<br>101<br>The main object of the image enhancement is increasing quality and visibility in the image. In the thesis, we proposed a simple and effective color enhancement method for the local approach that improved some quality and visibility for the low-exposure and high-exposure image. In the traditional gamma correction, the gamma parameter γis set by user. So many method have been proposed to determine the gamma parameter γ. We are interested in resolving this problem.
In this thesis, we proposed the contrast enhancement, sharpness enhancement and color enhancement. As we know, each block of the image that has their luminance. In this ideal, we proposed the adaptive gamma correction by using the local approach and using the RGB color model to design a simple color enhancement method.
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Lee, Chou-Hsuan, and 李洲亘. "Parameter determination of infrared thermography toward the inspection of concrete surfaces after fire exposure." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/83rh9z.
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碩士<br>朝陽科技大學<br>營建工程系碩士班<br>94<br>The objective of current study is to explore the feasibility of post-fire assessment of concrete surface using infrared thermography, or IRT. Fire exposure of concrete specimens was simulated using electric ovens at different temperatures lasting for two hours. Uniform heat flux was applied to the surface of the specimen after cooling to room temperature. The thermal images were then taken immediately following the heat flux was terminated. In some cases, surface cracks may be associated with the area of higher temperature in thermal images. Similar results were found based on two- and three-dimensional modeling using finite element analysis. Furthermore, the effect of concrete surface emissivity on the thermal images was also investigated.