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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.
1

Development of an immunoassay for addressing the question #Do 15,16-dihydrocyclopenta[a]phenanthren-17-one analogues exist in man?'

Bartlet-Jones, Michael January 1994 (has links)
No description available.
2

An investigation into the adaptive response to MNNG of Chinese hamster cells in vitro

McDowall, Gordon David January 1988 (has links)
No description available.
3

Preventive effect of Oenothera rosea on N-methyl-N-nitrosourea- (NMU) induced gastric cancer in rats

Almora Pinedo, Yuan, Arroyo-Acevedo, Jorge Luis, Herrera-Calderon, Oscar, Chumpitaz Cerrate, Victor Manuel, Hañari Quispe, Renán, Tinco Jayo, Johnny Aldo, Franco Quino, Cesar, Figueroa Salvador, Linder 12 1900 (has links)
Background: Currently, gastric cancer (GC) is considered a public health problem worldwide. Using medicinal plants for the prevention of chronic diseases such as cancer constitutes new alternatives in traditional medicine. Oenothera rosea (OR) could be an option, but it needs to be evaluated. Aim: The main objective of this study was to evaluate the protective effect of OR extract on N-methyl-N-nitrosourea (NMU)-induced GC in rats. Methods: In total, 80 male Holtzman rats were randomized into five groups. Group A received the saline solution (5mL/kg), group B received NMU 500 μg/kg (cancer inductor) by oral administration for 16 weeks, and groups C, D, and E were treated with OR extract (100, 200, and 300 mg/kg, respectively) and NMU in order to evaluate the preventive effect on cancer induced by NMU for 16 weeks. Blood and histological samples of stomachs were collected to determine histopathological, biochemical, and hematological parameters between different experimental groups. Results: Groups C, D, and E presented less histopathological changes such as anaplastic and hyperplastic cells, compared with group B. Hematological and biochemical parameters were recorded, and superoxide dismutase, malondialdehyde, and nitric oxide levels were statistically less than those of NMU group (P<0.05, P<0.01, and P<0.01). Conclusion: Considering the histopathological signs and the antioxidant activity in vivo as well as hematological and biochemical parameters of ethanolic extract of OR, we concluded that its administration in rats has a protective effect on GC, which is induced experimentally. This species could be studied in clinical trials for patients with GC in the future.
4

Evaluation of Total Fume and Heavy Metal Emission Factors Applicable to Gas Metal Arc Welding

Jilla, Abhinay 23 May 2019 (has links)
Welding is a metal joining process widely used in many manufacturing facilities around the world. It involves the process of heating the base and filler metals to a high temperature that leads to the formation of fumes. Welding emissions consist of gaseous pollutants and micron and sub-micron particles consisting of different heavy metals. Health risks associated with exposures to weld fume is well recognized in the literature. This research evaluates emissions and emission factors applicable to gas metal arc welding (GMAW) on AH 36 (mild steel) and 316 L (stainless steel). Emission factors evaluated consisted, total fume, chromium, cobalt, lead, manganese, and nickel. A weld fume chamber is used to capture the welding fumes onto a filter and then further analyzed to quantify the total fume and heavy metal emissions. Critical operating parameters such as current, voltage, shielding gas, welding speed, and contact tube to work distance (CTWD) were considered while evaluating emissions and emission factors. The parameters with greater influence on emissions are selected, and then the heavy metal emissions are quantified by varying those parameters using inductively coupled plasma atomic emission spectrometry (ICP-AES) and portable XRF (X-Ray Fluorescence) analyzer. The heavy metal results from the ICP-AES and XRF are compared to explore the feasibility of using XRF analyzer in quantifying the heavy metals in welding fumes. Using the heavy metal emissions, the lifetime carcinogenic and non-carcinogenic risks are evaluated for the GMAW process. The mild steel (MS) and stainless steel (SS) statistical analysis results indicate current and voltage are most influencing parameters in generating the fumes in GMAW. This research found a significant linear relationship between ICP-AES and XRF heavy metal results. The lifetime carcinogenic and non-carcinogenic risks results indicate high potential health risks if not properly managed.
5

Moderní analytické metody pro detekci aminokyselin asociovaných se zhoubnými nádory prostaty

Cernei, Natalia January 2013 (has links)
In the present thesis called "The modern analytical methods for detection of aminoacids asociated with malignant prostate tumours" sarcosine has been studied as a potential tumor marker which has significance for the diagnosis of aggressive forms of prostate cancer. The effect of addition of sarcosine prostate line PC3 has been also studied as well. Next studied area were the the interactions with amino acid sarcosine, sodium chloride, uric acid and uracil. We have primarily focused also on the development of methods for the detection of sarcosine in urine samples of patients with Cap and prostate cells.
6

Implementering av kommande EU-förordning gällande tillsyn av CMR- ämnen i textil : En kartläggning på materialnivå

Rydenstrand, Sara January 2018 (has links)
The purpose of this study was to investigate how the upcoming EU-regulation regarding CMR-substances (Carcinogenic, Mutagenic or toxic for Reproduction) in textiles can be implemented in the supervision. The European Commission have used a simplified procedure provided by article 68(2) of REACH to restrict CMR-substances in textile that could be used by consumers. The parliament voted in favor on the 26th of April 2018 which has resulted in the ban coming into force by the end of 2020. The Swedish Chemical Agency therefore needs to know in which material or products these substances can be found. Data from various databases have been used and analyzed, then supplemented with reports. The substances have been categorized into functional chemical substances, auxiliary substances and chemical substances not intentionally added. Of these categories, functional chemical substances accounted for the greatest part. Classified azo dyes and carcinogenic amines were a big part of this category and the materials in which most chemicals were found were polyester and cotton. These are also the most frequently used textiles in the EU. It is therefore important to supervise these materials since the category functional chemical substances are found in highest concentrations in these materials. The supply chains are complex with a global span. To reduce hazardous chemicals in textile, it is important that the upstream information about which chemicals being used continues along the chain. Therefore, communication with suppliers and sub-suppliers is required. A regulation makes it easier for retailers to communicate their demands towards their suppliers.
7

Estudo das variantes alelicas da N-acetiltransferase 2 ( NAT2) em cancer de prostata e tireoide na população brasileira da região de Campinas / N-acetiltransferase-2 gene polymorphisms and the susceptibility to prostate and thyroid cancers in Brazilian patients

Guilhen, Ana Carolina Trindade 26 July 2006 (has links)
Orientador: Laura Sterian Ward / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T13:30:36Z (GMT). No. of bitstreams: 1 Guilhen_AnaCarolinaTrindade_M.pdf: 1692988 bytes, checksum: 1868d3d53c2dafca822a331ec40cac6d (MD5) Previous issue date: 2006 / Resumo: Os genes das N-acetiltransferases, que são polimórficos na população, codificam enzimas envolvidas na metabolização de drogas e de xenobióticos, como os provenientes do cozimento de carnes e do tabaco, e podem estar implicados no risco para o desenvolvimento de neoplasias. Para estudar o envolvimento dos genes NAT2 em tumores na população brasileira da região de Campinas, avaliamos seis polimorfismos (C282T; T481C; G590A; A803G; G857A; G191A) em câncer de tireóide e quatro (T481C; G590A; A803G e G857A) em câncer de próstata. Em um estudo de caso-controle, comparamos 126 indivíduos com câncer de próstata com 101 indivíduos controles com hiperplasia prostática benigna pareados para idade e condições de dieta e exposição ambiental; 139 indivíduos com câncer de tireóide (112 CP e 27CF) e 179 controles também adequadamente pareados. A análise foi feita pela extração de DNA com base no sangue periférico, PCR e restrição enzimática. Os polimorfismos T481C (76.24%) e A803G (59.41%) apareceram com maior freqüência entre os pacientes controles com hiperplasia prostática benigna do que nos com câncer da próstata (60.32% e 45.60%, p=0.0152 e 0.0186, respectivamente). Ao contrário, G857A foi mais freqüente entre os pacientes com câncer da próstata (18.4%) do que nos controles com hiperplasia prostática benigna (5.94%; p=0.0044). Assim, a presença do polimorfismo NAT2T481C reduziu o risco de câncer da próstata (OR=2.115; 95% C.I=1.155-3.872). Da mesma forma, a presença do polimorfismo NAT2A803G reduziu o risco de câncer da próstata (OR=1.973; 95%C.I=1.120-3.474; p=0.0186). Ao contrário, a presença do polimorfismo G857A aumentou o risco para câncer da próstata mais de quatro vezes (OR=4.095; 95%C.I=1.551-10.812). A presença de um fenótipo de acetilação lenta aumentou o risco para câncer de próstata em 24 vezes (OR=24.145;95%CI=1.416-411.63). Nos carcinomas da tireóide, observamos que mutações pontuais de tipo A803G apareceram com maior freqüência entre os casos de carcinomas (46.76%) do que nos controles (31.84%) (p=0.0069), enquanto que mutações pontuais de tipo G191A e C282T foram mais freqüentes nos controles (25,70% e 68.16% dos casos, respectivamente) do que nos casos (5,04% e 33,81%, respectivamente) (p=0,0001). Assim, a herança do polimorfismo A803G representou um risco de 1.8 vezes maior de desenvolver carcinoma diferenciado da tireóide (OR= 1.880; 95% IC= 1.189-2.973). Por outro lado, a herança dos polimorfismos G191A e C282T do gene NAT2 representou um fator de proteção de cerca de 80,6% contra o risco de desenvolver um carcinoma diferenciado da tireóide (OR=0.153; 95% IC=0.067-0.352 e OR=0.239; 95% IC=0.149-0.382, respectivamente). Em conclusão, nossos dados mostram que polimorfismos do gene NAT2 estão associados ao risco para o desenvolvimento tanto dos tumores de próstata quanto de tireóide, podendo vir a ser importantes marcadores de susceptibilidade para tais doenças em nossa população / Abstract: N-acetyltransferases (NAT), which are polymorphic in the population, metabolize important carcinogens such as different kinds of meat and tobacco products that have been directly implicated in the tumor initiation process. In order to investigate the role of NAT2 polymorphisms in the susceptibility to cancer in the Brazilian population from our region, we studied 6 polymorphisms (C282T; T481C; G590A; A803G; G857A; G191A) in differentiated thyroid cancer and 4 polymorphisms (T481C; G590A; A803G e G857A) in prostate cancer. We conducted a case-control prospective study comparing 126 prostate cancer to 101 benign prostatic hyperplasia patients paired for age, diet and environmental exposure; 139 thyroid cancer patients (112 papillary carcinomas and 27 follicular carcinomas) and 179 paired controls. Analyses were performed in DNA extracted from peripheral blood using the polymerase chain reaction-based restriction fragment length polymorphism method. We observed T481C (76.24%) and A803G (59.41%) polymorphisms with higher frequency among control patients than in prostate cancer cases (60.32% e 45.60%, p=0.0152 e 0.0186, respectively). On the contrary, G857A polymorphisms was more frequent among prostate cancer patients (18.4%) than in the benign hyperplasia control partients¿ group (5.94%; p=0.0044). Therefore, the presence of NAT2T481C polymorphism reduced the risk of prostate cancer (OR=2.115; 95% C.I=1.155-3.872). Likewise, the presence of NAT2A803G reduced the risk of prostate cancer (OR=1.973; 95%C.I=1.120-3.474; p=0.0186). On the contrary, the presence of G857A increased the risk for prostate cancer more than 4 times (OR=4.095; 95%C.I=1.551-10.812). The presence of a low acetylation phenotype increased the risk for prostate cancer more than 24 times (OR=24.145;95%CI=1.416-411.63). Regarding thyroid cancer, we observed that point mutations like A803G appears more frequently among thyroid carcinomas (46.76%) than in controls (31.84%) (p=0.0069), while G191A and C282T polymorphisms were more frequent among controls (25,70% and 68.16% of the cases, respectively) than among thyroid cancers (5,04% e 33,81%, respectively) (p=0,0001). Therefore, the inheritance of an A803G polymorphism represents an 1.8 times higher risk to thyroid cancer development (OR= 1.880; 95% IC= 1.189-2.973). On the other hand, the inheritance of G191A and C282T NAT2 polymorphisms represents a protection around 80,6% against the risk of thyroid cancer development (OR=0.153; 95% IC=0.067-0.352 and OR=0.239; 95% IC=0.149-0.382, respectively). In conclusion, our data demonstrate that NAT2 gene polymorphisms are associated to the risk to both prostate and thyroid cancer, suggesting they could become useful molecular markers of susceptibility to these tumors in our population / Mestrado / Clinica Medica / Mestre em Clinica Medica
8

The Immune-modulatory and Anti-carcinogenic Mechanisms of the Flavonoid Apigenin

Arango Tamayo, Daniel Alejandro 04 September 2015 (has links)
No description available.
9

Assessment of air pollution in residential areas : a case study of Kinondoni Municipality, Tanzania

Ndambuki, J.M., Rwanga, S. January 2008 (has links)
Published Article / Air pollution, just like any other type of pollution, produces harmful effects to man and his environment. In spite of knowing this, many less industrialised countries of the world have no air quality monitoring strategies in place. Consequently, documented evidence of air pollution studies in such countries is scarce. This is the case in Tanzania. This scenario is made worse by lack of scientific tools which could aid in identifying air pollution-prone areas with a view to aiding town planners in locating safe sites for schools, hospitals and residential areas as well as parks. In this paper, we present results of a study carried out in the city of Dar-es-Salaam, Tanzania on air pollution in residential areas. Results show significant air pollution in the studied areas. Moreover, both adults and children are at risk due to lead pollution in the air.
10

Estudo do risco de poluição das águas subterrâneas causada por vazamentos em postos de abastecimento de combustível, no município de Ribeirão Preto-SP / Study of pollution risk of groundwater caused by leaching at the fuels suppling services, in the city of Ribeirão Preto - SP

Barros, Regina Mambeli 22 September 2000 (has links)
No município de Ribeirão Preto - SP, a qualidade das águas subterrâneas está diante de uma ameaça potencial por vazamento dos diversos tanques de armazenamento de combustíveis. O abastecimento público de água é realizado totalmente a partir do manancial subterrâneo. Tendo em vista a toxidade de muitos dos componentes de derivados de petróleo, é de elevada importância a avaliação do risco de contaminação por tais substâncias, que é alvo do estudo aqui proposto. O objetivo do trabalho foi avaliar as distribuições espaciais e temporais das concentrações de hidrocarbonetos em torno dos poços de bombeamento ativados e delinear as áreas de proteção em torno dos poços de abastecimento público de água susceptíveis à contaminação por hidrocarbonetos. Para execução do objeto da presente pesquisa foram utilizados modelos semi-analíticos, através do software Well Head Protection Area (WHPA) e modelos da API (American Petroleum Institute), como SESOlL, AT123D e JURY, contidos no pacote DSS (Decision Support System), APIDSS. Foram aplicados os modelos SESOlL (zona não saturada) e AT123D (zona saturada) e avaliadas as concentrações nos pontos receptores (poços tubulares em operação). Também foi aplicado o módulo de entrada química para cálculo do risco para saúde humana para estes modelos tendo sido utilizadas as rotas de exposição de ingestão de água contaminada, inalação durante o banho e contato dermal com água contaminada. Analisou-se a sensibilidade dos modelos do APIDSS, simulando vazamentos baseados no trabalho de OLIVEIRA (1992) para valores de dispersividade longitudinal de 15 m e 20 m. A etapa seguinte foi a identificação dos pontos de maior risco e delimitação das Áreas de Proteção de Poços (APPs) através do software WHPA. A seguir estas áreas foram sobrepostas à carta de vulnerabilidade à contaminação das águas subterrâneas na região de Ribeirão Preto - SP (FERREIRA, 1992). Em torno dos poços de abastecimento de água foram observadas concentrações de BTEX fazendo-se uso do fotoionizador modelo DL-101. / In the city of Ribeirão Preto - SP, the quality of groundwater is in front of a potential threat by leaching of several fuels storage tanks. The public supply is fully performed from ground source. In the view of toxility of many of components of petroleum deriveds, it is high importance the assessment of risk of contamination by such substances, that is target of study intended here. The goal of this work was to assess the spatial and time distribution of hydrocarbons concentrations around the actived pumping wells and to outline the well head protection area around the public supply wells susceptibles to contamination by hyclrocarbons. For to perform the goal this research were used semi analytical models, by software well head protection area (WHPA) and API\'s models (American Petroleum Institute), like SESOIL, AT123D and Jury, inside of DSS package (Decision Support System) , APlDSS. It were applied the SESOIL (non satured) and AT123D (satured zone) models and assessed the receiver points concentrations. Also it were applied the chemical input module for risk assessment for human health for that models had been used contaminated water intake, inhalation during shower and dermal contact with contaminate water routes of exposition. It was assessed the sensibility of APIDDS\'s models, simulating leaching based on work of OLIVEIRA (1992) for values of longitudinal dispersivities of 15 and 20 meters. The following stage was the identification of greatest risk points and delimitation of well heads protection areas (WHPAs) throught software WHPA. Following these areas were puted on to vulnerability chart to groundwater contamination at the region of Ribeirão Preto - SP (FERREIRA, 1992). Around these water supply wells were observated BTEX concentrations throught use of photoionizatior DL-101.

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