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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.
11

A inteligência cultural na construção de joint ventures de países emergentes em setores de alta tecnologia: o caso HT Micron

Hommerding, Thiago Alberto January 2013 (has links)
Submitted by William Justo Figueiro (williamjf) on 2015-07-09T21:40:27Z No. of bitstreams: 1 20b.pdf: 3176393 bytes, checksum: b85ec1ddba048cc511f230d9d7018d2c (MD5) / Made available in DSpace on 2015-07-09T21:40:27Z (GMT). No. of bitstreams: 1 20b.pdf: 3176393 bytes, checksum: b85ec1ddba048cc511f230d9d7018d2c (MD5) Previous issue date: 2013 / Nenhuma / O presente estudo teve como finalidade compreender a utilização da inteligência cultural em joint ventures internacionais em setores de alta tecnologia, tendo como estudo de caso a HT Micron, que nasceu da união do Grupo Parit, brasileiro, e da Hana Micron, sul-coreana, para compreensão dos passos realizados para a consolidação do negócio. A utilização da inteligência cultural ainda é um desafio para muitas pessoas e empresas, além de ser uma área pouco conhecida na academia, como aponta Livermore (2010), havendo um vasto campo de pesquisa a ser explorado e desenvolvido. Buscou-se apresentar uma série de informações sobre a empresa, avaliando os aspectos culturais envolvidos, a gestão intercultural e a inteligência cultural numa perspectiva melhor visualizada através do lado brasileiro da joint venture. Com base na fundamentação teórica, realizada através de pesquisa bibliográfica relacionada ao assunto, foi feito um estudo de caso exploratório, através de entrevistas e visitas pessoais a diferentes áreas da empresa e a pessoas que estiveram envolvidas na criação da empresa, desenvolvendo-se uma análise de conteúdo. A dissertação contextualiza sobre a área de semicondutores, descreve o processo de construção da joint venture HT Micron, apresenta como se dá a gestão intercultural na HT Micron e a utilização da inteligência cultural nesse contexto, além de sugerir um conjunto de recomendações nessa área para joint ventures internacionais, como a HT Micron. Como resultado da pesquisa, pode-se verificar que a empresa acaba por utilizar ações esporádicas para o desenvolvimento cultural, caracterizando uma baixa utilização de princípios de inteligência cultural na formação da joint venture, que poderiam ser melhor explorados no seu dia-a-dia. / The present study aimed to understand the use of cultural intelligence in international joint ventures in high-technology sectors, taking as case study the HT Micron, which was born from the union of the Brazilian Parit Group and South Korean Hana Micron to understand the steps performed to consolidate the business. The use of cultural intelligence still a challenge for many people and companies, as well as being an area little known in academy, as pointed Livermore (2010), with a wide field of research to be explored and developed. In this research was tried to provide a sequence of information about the company, assessing the cultural aspects involved in intercultural management and cultural intelligence, more visualized through the Brazilian side of the joint venture. Based on the theoretical reasons, performed through a literature research related to the subject, was created an exploratory case study, conducting interviews and personal visits to different areas of the company and people who were involved in the creation of the company, developing a content analysis. The theses contextualizes the semiconductor area, identifies the cultural aspects of the realization of the joint venture, shows how is the HT Micron in intercultural management and use of cultural intelligence, and suggest a set of recommendations in the area of cultural intelligence for international joint ventures as the HT Micron. As a result of the research can be seen that the company had sporadic actions in the cultural development, featuring a low utilization of the principles of cultural intelligence in the shaping of the joint venture, which could be better explored in the day-by-day operation.
12

Conception de transmetteurs 1,3 µm par épitaxie sélective en phase vapeur aux organo-métalliques / Design of 1.3 µm transmitters by metalorganic vapor phase selective area growth

Binet, Guillaume 13 December 2016 (has links)
Le développement des réseaux optiques et l’augmentation des interconnexions à courtes distances, amènent un besoin croissant en transmetteurs émettant à 1,3 µm, performants, peu énergivores et fabriqués à bas coût.Ainsi, l’intégration photonique monolithique, qui vise à juxtaposer plusieurs fonctions optiques dans un même circuit, est une solution. L’épitaxie sélective en phase vapeur aux organo-métalliques est une technique prometteuse pour cela. Elle permet, en une seule étape de croissance, de définir les structures des différents composants unitaires constituant le circuit intégré photonique. Il est nécessaire d’avoir un outil de simulation qui permet de modéliser la croissance sélective. Auparavant la modélisation proposée ne prenait en compte que des phénomènes de diffusion en phase vapeur et négligeait les phénomènes de surface. Une modélisation plus précise a été développée, fondée sur la relaxation de l’interface. En parallèle, nous avons conçu sept différentes structures actives, à base de multi-puits quantiques en matériaux AlGaInAs pour des composants DML et EML émettant à 1.3 µm. Nous avons fait des mesures de laser à contacts larges et des mesures d’absorption en photo-courant, pour sélectionner la meilleure structure.Une étude expérimentale de la croissance, à partir de microscopie électronique en transmission et de micro-diffraction aux rayons X, a permis de réaliser l’épitaxie sélective de la structure sélectionnée. Les composants fabriqués ont des performances à l’état de l’art avec une bande passante de 12,5 GHz pour un DML de 250 µm ainsi qu’un diagramme de l’œil ouvert à 32 Gbit/s avec un taux d’extinction dynamique de 10 dB, pour en EML. / The development of passive optical networks and the increase of short-reach connections make an increasing need for efficient, energy-friendly and low-cost transmitters emitting at 1.3 µm.To this end, monolithic photonic integration, which aims to embed several optical functions into the same circuit, is a solution. Selective area growth (SAG) by metal-organic vapor-phase-epitaxy (MOVPE) seems to be an attractive technique to achieve this integration. This approach allows defining, in a single epitaxial step, the structures of the different unitary photonic functions constituting the photonic integrated circuit. One issue of this technique is the growth modeling, necessary to predict the material distribution. Previously, the model was only taking into account vapor phase diffusion phenomena, neglecting surface phenomena. Consequently a more accurate approach was developed, based on interface relaxation.Simultaneously, we designed seven different active structures, all based on AlGaInAs multi-quantum wells, in order to optimize the DML and EML devices emitting at 1.3µm . We performed wide area laser and photocurrent absorption measurements to select the best trade-off design for devices fabrication.In order to perform accurate SAG of the selected structure, experimental study has been done to optimize the growth using transmission electronic microscopy and X-ray micro-diffraction. Devices have been processed and exhibit state of the art performances. A bandwidth of 12.5 GHz was demonstrated for a 250 µm long DML and 32 Gbit/s open eye diagram with a 10 dB dynamic extinction ratio has been shown, on a EML with a 100 µm long EAM.
13

Precipitation Study in a High Temperature Austenitic Stainless Steel using Low Voltage Energy Dispersive X-ray Spectroscopy

Gharehbaghi, Ali January 2012 (has links)
Precipitation of second phase particles is a key factor dominating the mechanical properties of high temperature alloys. In order to control and optimize the precipitation effect it is of great importance to study the role of alloying elements in the formation and stability of precipitates. As a favored family of corrosion and creep resistant austenitic stainless steels the 20Cr-25Ni alloy was modified by addition of copper, molybdenum, nitrogen, niobium and vanadium. A set of alloys with similar matrix but varying contents of niobium, vanadium and nitrogen were prepared. Sample preparation process included melting, hot forging, solution annealing and finally aging for 500 h at 700, 800 and 850 ºC. Light optical and scanning electron microscopy revealed micron-scale precipitates on grain and twin boundaries as well as sub-micron intragranular precipitates in all samples. Characterization of precipitates was carried out by means of energy dispersive X-ray spectroscopy (EDS). Among micron-scale precipitates M23C6 carbide was the dominant phase at 700 ºC aging temperature; whereas silicon-rich eta phase (M5SiC) was the main precipitate in samples aged at 800 and 850 ºC. A few sigma phase particles were found in one of the niobium containing samples aged at 700 and 800 ºC. Sub-micron intragranular precipitates were analyzed using low voltage EDS. The spatial resolution of EDS microanalysis at 5 kV accelerating voltage was estimated as almost 100 nm which was at least eight times better than that using the ordinary 20 kV voltage. Also, low voltage EDS revealed the presence of light elements (carbon, nitrogen and boron) in the composition of sub-micron particles thanks to the less matrix effect in absorption of low energy X-rays of light elements. In samples aged at 700 ºC niobium-rich and vanadium-rich carbonitrides were found as the dominant precipitates; whereas they contained much less carbon in samples aged at 800 ºC and mostly became carbon-free nitrides with well-defined cuboidal shapes at 850 ºC aging temperature. This showed that niobium/vanadium-rich nitride phases are stable precipitates at aging temperatures above 700 ºC. The drawbacks of low voltage EDS were indicated as high detection limit (no detection of low- content elements), poor accuracy of quantitative analysis and high sensitivity to surface contamination. Some possible ways to improve the accuracy of low voltage EDS, e.g. longer acquisition time were examined and some other suggestions are proposed for future works.
14

Precipitation Study in a High Temperature Austenitic Stainless Steel using Low Voltage Energy Dispersive X-ray Spectroscopy

Gharehbaghi, Ali January 2012 (has links)
Precipitation of second phase particles is a key factor dominating the mechanical properties of high temperature alloys. In order to control and optimize the precipitation effect it is of great importance to study the role of alloying elements in the formation and stability of precipitates. As a favored family of corrosion and creep resistant austenitic stainless steels the 20Cr-25Ni alloy was modified by addition of copper, molybdenum, nitrogen, niobium and vanadium. A set of alloys with similar matrix but varying contents of niobium, vanadium and nitrogen were prepared. Sample preparation process included melting, hot forging, solution annealing and finally aging for 500 h at 700, 800 and 850 ºC.Light optical and scanning electron microscopy revealed micron-scale precipitates on grain and twin boundaries as well as sub-micron intragranular precipitates in all samples. Characterization of precipitates was carried out by means of energy dispersive X-ray spectroscopy (EDS). Among micron-scale precipitates M23C6 carbide was the dominant phase at 700 ºC aging temperature; whereas silicon-rich eta phase (M5SiC) was the main precipitate in samples aged at 800 and 850 ºC. A few sigma phase particles were found in one of the niobium containing samples aged at 700 and 800 ºC. Sub-micron intragranular precipitates were analyzed using low voltage EDS. The spatial resolution of EDS microanalysis at 5 kV accelerating voltage was estimated as almost 100 nm which was at least eight times better than that using the ordinary 20 kV voltage. Also, low voltage EDS revealed the presence of light elements (carbon, nitrogen and boron) in the composition of sub-micron particles thanks to the less matrix effect in absorption of low energy X-rays of light elements. In samples aged at 700 ºC niobium-rich and vanadium-rich carbonitrides were found as the dominant precipitates; whereas they contained much less carbon in samples aged at 800 ºC and mostly became carbon-free nitrides with well-defined cuboidal shapes at 850 ºC aging temperature. This showed that niobium/vanadium-rich nitride phases are stable precipitates at aging temperatures above 700 ºC.The drawbacks of low voltage EDS were indicated as high detection limit (no detection of low- content elements), poor accuracy of quantitative analysis and high sensitivity to surface contamination. Some possible ways to improve the accuracy of low voltage EDS, e.g. longer acquisition time were examined and some other suggestions are proposed for future works.
15

Characterisation of airborne dust in South African underground and opencast coal mines : a pilot study / Machiel Jacobus Wentzel

Wentzel, Machiel Jacobus January 2015 (has links)
Dust is a well-known occupational hygiene challenge and has been throughout the years, especially in the coal mining industry. The hazards arising from coal dust will differ between geographical areas due to the unique characteristics of dust from the coal mining environment. It is therefore of upmost importance to identify these qualities or characteristics of coal dust in order to understand the potential hazards it may pose. It is also important to consider the presence of nanoparticles which until recently remained neglected due to the absence of methods to study them. Aim: The aim of this study was to collect significant quantities of airborne dust through static sampling to characterise the physical, morphological as well as elemental properties of inhalable and respirable dust produced at two South African underground and two opencast coal mines. Personal exposure quantification was therefore not the primary concern in this study. Method: Static dust sampling was done at two mining areas of the two opencast and underground coal mines using four Institute of Occupational Medicine (IOM) and four cyclone samplers per area at each mine. A condensation particle counter (CPC) was also used at the opencast areas. The opencast areas included blast hole drilling, drag line and power shovel operations. The underground areas included the continuous miner and roof bolter operations. Gravimetric analyses of the cyclone and IOM samples were done as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. Results: Mine A (opencast and underground) produces higher grade coal in comparison to mine B (opencast and underground). Gravimetric analysis indicated higher average inhalable (55.35 mg/m3) and respirable (2.13 mg/m3) concentrations of dust in the underground areas when compared to the opencast areas (34.73 mg/m3 and 0.33 mg/m3). Blast hole drilling operations indicated higher average inhalable and respirable dust concentrations (39.02 mg/m3 and 0.41 mg/m3) when compared to the drag line and power shovel operations (30.44 mg/m3 and 0.246 mg/m3). CPC results showed higher average concentrations of sub-micron particles at the blast hole drilling areas per cubic metre (63132 x 106) compared to the drag line and power shovel operations (38877 x 106). EDS analysis from the opencast areas indicated much higher concentrations of impurities (with lower concentrations of carbon – 33.33%) when compared to samples taken from the underground mining activities (65.41%). The EDS results from the opencast areas differed substantially. The highest concentrations of silica were found at the blast hole drilling areas. EDS results from the underground areas indicated that mine A has slightly higher concentrations of carbon (66.2%) with less impurities when compared to mine B (64.62%). The continuous miner operations showed a higher concentration of impurities when compared to the dust from the roof bolter. SEM results from the opencast areas revealed that the majority of particles are irregularly shaped and the presence of quartz and agglomerations are evident. SEM results from the underground areas were similar except that the roof bolter produced smaller sized particles when compared to the continuous miner. It also seemed that the areas with higher levels of impurities produced more sub-micron particles. Conclusions: It is possible to identify the majority of physical and elemental characteristics of coal dust by means of gravimetric analysis, particle counting, SEM and EDS. There were differences found, regarding the morphological; chemical and physical characteristics, between the different opencast and underground areas at mine A and mine B due to the type of mining activity and amount of overburden present. Silicosis, Pneumoconiosis and Chronic obstructive pulmonary disease are some of the possible health concerns. It has been seen that dust from higher grade coal mines contributed to more developed stages of these diseases. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015
16

Characterisation of airborne dust in South African underground and opencast coal mines : a pilot study / Machiel Jacobus Wentzel

Wentzel, Machiel Jacobus January 2015 (has links)
Dust is a well-known occupational hygiene challenge and has been throughout the years, especially in the coal mining industry. The hazards arising from coal dust will differ between geographical areas due to the unique characteristics of dust from the coal mining environment. It is therefore of upmost importance to identify these qualities or characteristics of coal dust in order to understand the potential hazards it may pose. It is also important to consider the presence of nanoparticles which until recently remained neglected due to the absence of methods to study them. Aim: The aim of this study was to collect significant quantities of airborne dust through static sampling to characterise the physical, morphological as well as elemental properties of inhalable and respirable dust produced at two South African underground and two opencast coal mines. Personal exposure quantification was therefore not the primary concern in this study. Method: Static dust sampling was done at two mining areas of the two opencast and underground coal mines using four Institute of Occupational Medicine (IOM) and four cyclone samplers per area at each mine. A condensation particle counter (CPC) was also used at the opencast areas. The opencast areas included blast hole drilling, drag line and power shovel operations. The underground areas included the continuous miner and roof bolter operations. Gravimetric analyses of the cyclone and IOM samples were done as well as scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analysis. Results: Mine A (opencast and underground) produces higher grade coal in comparison to mine B (opencast and underground). Gravimetric analysis indicated higher average inhalable (55.35 mg/m3) and respirable (2.13 mg/m3) concentrations of dust in the underground areas when compared to the opencast areas (34.73 mg/m3 and 0.33 mg/m3). Blast hole drilling operations indicated higher average inhalable and respirable dust concentrations (39.02 mg/m3 and 0.41 mg/m3) when compared to the drag line and power shovel operations (30.44 mg/m3 and 0.246 mg/m3). CPC results showed higher average concentrations of sub-micron particles at the blast hole drilling areas per cubic metre (63132 x 106) compared to the drag line and power shovel operations (38877 x 106). EDS analysis from the opencast areas indicated much higher concentrations of impurities (with lower concentrations of carbon – 33.33%) when compared to samples taken from the underground mining activities (65.41%). The EDS results from the opencast areas differed substantially. The highest concentrations of silica were found at the blast hole drilling areas. EDS results from the underground areas indicated that mine A has slightly higher concentrations of carbon (66.2%) with less impurities when compared to mine B (64.62%). The continuous miner operations showed a higher concentration of impurities when compared to the dust from the roof bolter. SEM results from the opencast areas revealed that the majority of particles are irregularly shaped and the presence of quartz and agglomerations are evident. SEM results from the underground areas were similar except that the roof bolter produced smaller sized particles when compared to the continuous miner. It also seemed that the areas with higher levels of impurities produced more sub-micron particles. Conclusions: It is possible to identify the majority of physical and elemental characteristics of coal dust by means of gravimetric analysis, particle counting, SEM and EDS. There were differences found, regarding the morphological; chemical and physical characteristics, between the different opencast and underground areas at mine A and mine B due to the type of mining activity and amount of overburden present. Silicosis, Pneumoconiosis and Chronic obstructive pulmonary disease are some of the possible health concerns. It has been seen that dust from higher grade coal mines contributed to more developed stages of these diseases. / MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2015
17

Avalia??o da velocidade de prolifera??o celular, citomorfometria e dano gen?tico no campo de canceriza??o bucal : um estudo citopatol?gico

Paiva, Ricardo Losekann 29 November 2017 (has links)
Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-03-09T17:42:57Z No. of bitstreams: 1 RICARDO_LOSEKANN_PAIVA_TES.pdf: 1108231 bytes, checksum: a32ed38f5354b3e7c925afdd81c861e4 (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2018-03-15T13:00:03Z (GMT) No. of bitstreams: 1 RICARDO_LOSEKANN_PAIVA_TES.pdf: 1108231 bytes, checksum: a32ed38f5354b3e7c925afdd81c861e4 (MD5) / Made available in DSpace on 2018-03-15T13:37:24Z (GMT). No. of bitstreams: 1 RICARDO_LOSEKANN_PAIVA_TES.pdf: 1108231 bytes, checksum: a32ed38f5354b3e7c925afdd81c861e4 (MD5) Previous issue date: 2017-11-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Oral cytopathology may be used to monitor individuals exposed to risk factor for oral cancer. In this context, the study of field cancerization, a phenomenon involved in the initial stages of oral carcinogenesis, has gained relevance for the establishment of biomarkers that may identify individuals exposed to carcinogens with the greatest risk for developing oral cancer. The first article of this study aimed to compare cytopathological and histopathological characteristics of the clinically normal mucosa adjacent to oral squamous cell carcinoma. The nuclear area of cells obtained by cytological smear of this region was also analyzed and compared to that of individuals without lesions but exposed to smoking and/or alcohol and of patients not exposed to these risk factors. Ninety patients of both sexes over 40 years old were included. In patients with carcinoma, in addition to exfoliative cytology, tissue was obtained from the area adjacent to the tumor for histopathological examination. In smears stained with Papanicolaou, the nuclei of 50 intermediate cells were measured. Both histological sections and cytological smears were classified as low or high-risk. The sensitivity, specificity and accuracy of the cytopathological diagnosis in relation to the histopathological diagnosis, considered the gold standard, were 100, 75 and 75.86%, respectively. The mean nuclear area was significantly lower (p<0.05) in the patients not exposed to the risk factors in relation to the others. The cyto-histopathological comparison of the area adjacent to oral cancer showed good sensitivity, specificity and accuracy. In conclusion, this article demonstrated that nuclear area can be used to detect early cellular changes in the oral mucosa exposed to carcinogens and that mean percentage of nuclei larger than 100 ?m2 is the most indicated method for the assessment of these changes. The second article aimed to assess genetic damage and cell proliferation rate in the field of cancerization, i.e., the clinically normal mucosa adjacent to oral carcinoma. Cytologic smears from the same scrapes used in the first article were stained with silver and with the Feulgen reaction. The mean number of AgNORs/nucleus and micronuclei (MN) was significantly higher (p<0.05) in the Tobacco/Alcohol and Oral Cancer Groups than in the Control Group. Conversely, the mean number of NBUDs was higher in the Control Group compared with the other groups. The number of AgNORs/nucleus and MN/1,000 cells provide evidence of initial oral carcinogenesis at field cancerization areas. Cutoff values for inclusion of individuals exposed to carcinogens in longitudinal monitoring were ? 3.38 AgNORs/nucleus and/or ? 3 MN/1,000 cells. A prospective model including the biomarkers assessed in this study was proposed. / A citopatologia bucal pode ser aplicada como m?todo de monitoramento em indiv?duos expostos a fatores de risco ao c?ncer de boca. O campo de canceriza??o, representando as etapas iniciais da carcinog?nese bucal, torna-se uma ?rea atrativa ao estudo de biomarcadores que poder?o ser utilizados para identificar indiv?duos expostos a carcin?genos com maior risco ao desenvolvimento do c?ncer bucal. O primeiro artigo deste estudo visou comparar as caracter?sticas citopatol?gicas e histopatol?gicas da mucosa clinicamente normal adjacente ao carcinoma espinocelular bucal. Al?m disso, a ?rea nuclear das c?lulas obtidas desta regi?o, por meio de esfrega?o citol?gico, foi mensurada e comparada ? das c?lulas de indiv?duos sem les?o expostos ao fumo e/ou ?lcool e a de pacientes n?o expostos a estes fatores de risco. Foram inclu?dos 90 pacientes de ambos os sexos com idade superior a 40 anos. Nos pacientes com carcinoma, al?m da citologia esfoliativa, foi obtido material para exame histopatol?gico da ?rea adjacente ao tumor. Nos esfrega?os, corados com Papanicolaou, foram mensurados os n?cleos de 50 c?lulas intermedi?rias. Tanto os cortes histol?gicos, quanto os esfrega?os citol?gicos foram classificados em baixo ou alto risco. Ao associar as caracter?sticas citopatol?gicas e histopatol?gicas, verificou-se sensibilidade, especificidade e acur?cia de 100%, 75% e 75,86%, respectivamente. A m?dia da ?rea nuclear foi menor no grupo n?o exposto ao fumo e ao ?lcool, com diferen?a significativa (p<0,05) em rela??o aos demais. A associa??o cito-histopatol?gica da ?rea adjacente ao c?ncer bucal apresentou boa sensibilidade, especificidade e acur?cia. Al?m disso, constatou-se que a ?rea nuclear ? pass?vel de ser utilizada para detectar altera??es celulares precoces na mucosa bucal exposta a carcin?genos, sendo a m?dia percentual de n?cleos com mais de 100 ?m2 o m?todo de avalia??o mais indicado. O segundo artigo objetivou avaliar o dano gen?tico e a velocidade de prolifera??o celular no campo de canceriza??o, ou seja, na mucosa clinicamente normal adjacente ao c?ncer bucal. Os esfrega?os citol?gicos foram corados com a t?cnica das AgNORs e rea??o de Feulgen, utilizando o mesmo raspado citol?gico obtido no primeiro artigo. A m?dia das AgNORs/n?cleo e do micron?cleo (MN) dos grupos fumo/?lcool e carcinoma bucal foi superior, com diferen?a estatisticamente significativa (p<0,05) em rela??o ao grupo controle. Este, por sua vez, obteve m?dia superior de bot?es nucleares (NBUDs) em rela??o aos grupos fumo/?lcool e carcinoma bucal. Ambos os marcadores, n?mero das AgNORs/n?cleo e MN, evidenciaram a fase inicial da carcinog?nese bucal, representada no campo de canceriza??o. Valores iguais ou superiores a 3.38 AgNORs/n?cleo e/ou 3 MN/1000 c?lulas foram identificados como ponto de corte ideal para incluir um indiv?duo exposto a carcin?genos no monitoramento longitudinal. Um modelo prospectivo dos marcadores foi sugerido.
18

Avalia??o do teste de micron?cleo em linf?citos para uso como biomarcador de risco de c?ncer em usu?rios de esteroides anabolizantes androg?nicos

Souza, Leonardo da Cunha Menezes 30 September 2013 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-08-07T01:02:49Z No. of bitstreams: 1 DISSERTA??O- LEONARDO DA CUNHA MENEZES SOUZA.pdf: 2029455 bytes, checksum: 2374a0c5996ead5ddad034150d2e36b7 (MD5) / Made available in DSpace on 2015-08-07T01:02:49Z (GMT). No. of bitstreams: 1 DISSERTA??O- LEONARDO DA CUNHA MENEZES SOUZA.pdf: 2029455 bytes, checksum: 2374a0c5996ead5ddad034150d2e36b7 (MD5) Previous issue date: 2013-09-30 / Funda??o de Amparo ? Pesquisa do Estado da Bahia - FAPEB / The use of anabolic androgenic steroids (AAS) has grown among practitioners of recreational bodybuilding, with significant contributions of "Designer Steroids" (DS), EAA designed aiming muscle hypertrophy in healthy subjects. The abusive use of AAS in general is associated with adverse effects, one of the most worrisome is cancer development. Given that cancer is a genetic disease resulting from changes in genes critical in maintaining genomic stability and in the control of proliferation and differentiation, biomarkers able to identify these changes can take predictive value and contribute to reducing the high rates of morbidity and mortality by this disease. The aim of this study was to evaluate the effectiveness of the Cytokinesis Block Micronucleus Test (CBMN) in human lymphocytes in identifying risk groups for cancer development in users of AAS. Was collected 5ml of blood from 15 AAS users bodybuilders (G1), 20 nonusers bodybuilders (G2) and 20 nonusers sedentary (G3). Lymphocytes were cultured with blocking of cytokinesis and subsequent processing for making slides. MN analysis was performed on a minimum of 1000 binucleated lymphocytes. The occurrence of MN was significantly higher (p <0.05) in individuals of G1 compared to G2 and G3. The results indicate the sensitivity of CBMN in human lymphocytes in the identification of chromosomal damage in consequence of AAS using, however, further studies are needed to determine their potential to predict the cancer risk in users of AAS. / O uso de esteroides anabolizantes androg?nicos (EAA) tem crescido entre praticantes recreativos de muscula??o, com contribui??es significativas dos Designer Steroids (DS), EAA projetados para fins de hipertrofia muscular em indiv?duos saud?veis. O uso abusivo de EAA em geral est? associado a efeitos adversos, sendo um dos mais preocupantes o desenvolvimento de c?ncer. Tendo em vista que o c?ncer ? uma doen?a gen?tica resultante de altera??es em genes cr?ticos na manuten??o da estabilidade gen?mica e do controle da prolifera??o e diferencia??o, biomarcadores capazes de identificar estas altera??es podem assumir valor preditivo e contribuir para diminui??o das altas taxas de morbidade e mortalidade por esta doen?a. O objetivo deste estudo foi avaliar a efic?cia do Teste de Micron?cleo com Bloqueio da Citocinese (MNCtB) em linf?citos humanos na identifica??o de grupos de risco para o desenvolvimento de c?ncer em usu?rios de EAA. Foram coletados 5ml de sangue de 15 usu?rios de EAA praticantes de muscula??o (Grupo I), 20 n?o usu?rios praticantes de muscula??o (Grupo II) e 20 n?o usu?rios sedent?rios (Grupo III). Foi realizada cultura de linf?citos com o bloqueio da citocinese e posterior processamento para confec??o de l?minas. A an?lise de MN foi realizada em um m?nimo de 1000 linf?citos binucleados. A ocorr?ncia de MN foi significativamente maior (p<0,05) nos indiv?duos do Grupo I comparados aos do Grupo II e Grupo III. Os resultados apontam para a sensibilidade do MNCtB na identifica??o de danos cromoss?micos decorrentes do uso de EAA. Estudos subsequentes para determinar seu potencial preditivo para o risco de c?ncer em usu?rios de EAA s?o necess?rios.
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Avalia??o da ocorr?ncia de danos cromoss?micos, apoptose e necrose em c?lulas esfoliadas da mucosa oral de usu?rios de ester?ides anabolizantes androg?nicos

Souza, Jeanderson Pereira 25 March 2013 (has links)
Submitted by Verena Bastos (verena@uefs.br) on 2015-10-08T12:18:43Z No. of bitstreams: 1 Jeanderson_Disserta??o_vers?o final.pdf: 369468 bytes, checksum: 851a8492d73fc0106bfe7784166fdf98 (MD5) / Made available in DSpace on 2015-10-08T12:18:43Z (GMT). No. of bitstreams: 1 Jeanderson_Disserta??o_vers?o final.pdf: 369468 bytes, checksum: 851a8492d73fc0106bfe7784166fdf98 (MD5) Previous issue date: 2013-03-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Exposure to genotoxic agents induces changes in the DNA molecule to commit that genes involved with the repair mechanisms and the control of cell proliferation and differentiation pathways or genes associated with apoptosis can lead to cancer development. Among the many chemicals that have been identified as mutagenic action, include the Androgenic Steroids (AAS), hormones widely used in the search for improved physical performance and increased muscle mass. Objective: In this context, the aim of the development of this study was to evaluate the potential of androgenic anabolic steroid nandrolone decanoate, testosterone propionate and testosterone cypionate to induce chromosome damage, apoptosis and necrosis, using the micronucleus test in exfoliated cells from the oral mucosa of users of AAS with a view to its application as a tool in cancer prevention. Method: The study sample consisted of 55 volunteers, male, divided into two (02) groups, matched for age: 25 subjects (G1) users of nandrolone decanoate, testosterone propionate and testosterone cypionate (alone or simultaneously ) and 30 subjects in the control group (G2). The collection methodology and cytological analysis followed the protocol of Tolbert et al. (1992) and Thomas et al. (2009), which includes, in addition to micronuclei, the computation of degenerative nuclear changes indicative of apoptosis (cariorr?xis, condensed chromatin and pyknosis) and necrosis (karyolysis, cariorr?xis, condensed chromatin and pyknosis). Statistical analysis of the endpoints analyzed (micronucleus, cariorr?xis, condensed chromatin, karyolysis, pyknosis and broken eggs) was performed using the conditional test to compare proportions in situations of rare events. Results: Statistical analysis revealed no significant difference in the occurrence of micronuclei, karyolysis and broken eggs between groups. The occurrence of apoptosis was significantly greater in cells from control individuals. Conclusion: The results show inhibition of apoptosis induced by EAA, suggesting that the described association between the use of these substances and the carcinogenic process can be permeated by this mechanism. / A exposi??o a agentes genot?xicos induz altera??es na mol?cula do DNA que ao comprometerem genes envolvidos com os mecanismos de reparo e com o controle da prolifera??o e diferencia??o celular ou genes associados ?s vias de apoptose, podem levar ao desenvolvimento de c?ncer. Entre os muitos agentes qu?micos que t?m sido identificados como de a??o mutag?nica, incluem-se os Ester?ides Anabolizantes Androg?nicos (EAA), horm?nios amplamente utilizados na busca da melhoria do desempenho f?sico e aumento da massa muscular. Objetivo: Neste contexto, objetivou-se com o desenvolvimento do presente estudo, avaliar o potencial dos ester?ides anabolizantes androg?nicos decanoato de nandrolona, propionato de testosterona e cipionato de testosterona em induzir danos cromoss?micos, apoptose e necrose, atrav?s do uso do Teste de Micron?cleo em c?lulas esfoliadas da mucosa oral de usu?rios de EAA com vista ? sua aplica??o como ferramenta na preven??o do c?ncer. M?todo: A amostra do estudo foi composta por 55 volunt?rios, do sexo masculino, distribu?dos em dois (02) grupos, pareados por idade: 25 indiv?duos (G1) usu?rios de decanoato de nandrolona, propionato de testosterona e cipionato de testosterona (isoladamente ou simultaneamente) e 30 indiv?duos no grupo controle (G2). A metodologia de coleta e an?lise citol?gica seguiu o protocolo de Tolbert et al. (1992) e Thomas et al. (2009), que inclui, al?m de micron?cleos, o computo de altera??es nucleares degenerativas indicadoras de apoptose (cariorr?xis, cromatina condensada e picnose) e necrose (cari?lise, cariorr?xis, cromatina condensada e picnose). A an?lise estat?stica dos endpoints analisados (micron?cleo, cariorr?xis, cromatina condensada, cari?lise, picnose e broken eggs) foi realizada com o uso do teste condicional para compara??o de propor??es em situa??es de eventos raros. Resultados: A an?lise estat?stica revelou que n?o houve diferen?a significativa na ocorr?ncia de micron?cleo, cari?lise e broken eggs entre os grupos. A ocorr?ncia de apoptose foi, significativamente, maior em c?lulas dos indiv?duos do grupo controle. Conclus?o: Os resultados obtidos mostram inibi??o da apoptose induzida pelo uso de EAA, sugerindo que a associa??o descrita entre uso destas subst?ncias e o processo carcinog?nico possa ser permeada por este mecanismo.
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Delay and Power Reduction in Deep Submicron Buses

Babvey, Sharareh 12 May 2005 (has links)
As technology scales down, coupling between nodes of the circuits increases and becomes an important factor in interconnection analysis. In many cases like the deep submicron technology (DSM), the coupling between lines (inter-wire capacitance) is strong and the energy consumption caused by parasitic capacitance is non-negligible. In this work, we employ the differential low-weight encoding [1] to reduce energy and delay (transmission cost) on DSM buses. We propose an enumeration method that reduces the encoder table-size from O(2n) words to O(n) words, for an n-bit DSM bus, and so reduces the memory complexity significantly and facilitates energy and delay reduction due to addressing and fetching data from large lookup tables. We modify the energy and delay equations for DSM buses and develop new representations in terms of number of the same and opposite direction transitions on the bus and use them in our interconnect analysis. We also use these equations to develop formulas for computing the mean transmission cost per bit on DSM buses for both differential low-weight encoding and uncoded schemes. Using the interconnect analysis, we compute a help codeword (from the set of unselected codewords) on the fly and assign to each selected codeword. This low complexity step consists of simple operations and enables us to gain more cost reduction without increasing the table size or number of the bus lines. The simulation results for 16-bit, 32-bit and 64-bit buses at maximum rate (only one extra line added) show that the proposed encoding scheme achieves more than 10% cost reduction, and performs more than 2.5% better than to the original differential low-weight scheme, in the worst case.

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