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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

An evaluation of freezing and soil presence on volatile organic compounds emitted by decomposing pig tissues using SPME GC/MS

Miller, Erin 12 March 2016 (has links)
The ability to quickly and efficiently locate concealed human remains is crucial in forensic investigations and when locating disaster victims. On occasions when human remains are recovered, correctly assigning a postmortem interval (PMI) may become necessary to corroborate statements or make an identification. While Human Remains Detection canines (HRD canines) provide rapid and sensitive searches, the mechanisms behind their sense of smell remain poorly understood. Over the past ten years, volatile organic compounds (VOCs) have been investigated in an effort to address questions concerning PMI, optimization of training aids, and portable 'sniffing' devices. The approaches taken for investigating VOCs emitted from decomposing tissues buried or otherwise have been diverse. They range from burying entire human bodies and sampling the above-ground volatiles using triple-sorbent traps (TSTs) to isolating small amounts of tissue into glass vials whereby the volatiles are sampled by Solid Phase Microextraction (SPME). The resulting studies have led to large quantities of data that are difficult to interpret and compare between studies. Furthermore, the restrictions surrounding access to human remains have caused many studies to use other animals, (pigs, chickens, cows, and deer) in particular the domestic pig, due to its similarities in hair coverage and tissue ratios. There have been several studies that attempt to address the effects that burial has on the resulting VOCs. However, the addition of a complex matrix to a process that already has many variables has caused difficulty in data interpretation. The purpose of this study was to identify how freezing and the presence of soil affect the VOC profiles of various tissue types (blood, bone, fat, small intestine, muscle, and skin) obtained over six weeks of decomposition. In order to accomplish this, the study was performed in three parts. The first part used fresh pig samples obtained only hours after euthanization, the second part utilized tissues from the same areas of the pig after the samples had been frozen for 6 weeks and the third part combined soil with three of the tissue types (blood, bone, muscle). SPME was employed at room temperature using a 65 µm PDMS/DVB coated fiber as the adsorbent material to extract the VOCs from the headspace. The use of SPME as the extraction method allowed for direct desorption and subsequent analysis into the injection port of the GC/MS. User-defined integration parameters were applied to each resulting chromatogram in an effort to identify what impact, if any, freezing and soil had on the resulting VOC profiles. The results obtained in this study suggest that the freezing and thawing of tissue samples have varying effects on the resulting chromatograms based on the complexity of the tissue-type. This implies that prolonged use and storage of some, commonly utilized, training aids may not be providing the most reliable scent profile for the HRD canines. Results obtained from the soil study were complex, but several overall trends were observed in the release and production of different compound classes. Comparisons to previous studies using similar extraction procedures demonstrate the need for a standardized protocol for future decomposition studies.
92

The effects of transcranial direct current stimulation on dual-task walking in Parkinson's disease

Nguyen, Victoria 18 June 2016 (has links)
BACKGROUND: Parkinson’s disease (PD) is a common debilitating disorder that largely effects the aging population. It is associated with a loss of dopamine-producing brain cells, which leads to abnormal brain activity and ultimately, a loss of locomotor control. Transcranial direct current stimulation (tDCS) is a technology that effectively modulates brain excitability by sending low electric current through the scalp. It has been demonstrated to improve working memory, intelligence, learning ability, as well as relieving symptoms of depression, Alzheimer’s and schizophrenia (Kekic, Boysen, Campbell, & Schmidt, 2015; Khedr et al., 2014; Manor et al., 2015). tDCS may thus serve as an effective therapeutic strategy for this vulnerable PD population. OBJECTIVE: The primary purpose of this study was to examine the acute effects of single sessions of tDCS targeting different brain networks on locomotor control metrics and other outcomes in patients with PD. DESIGN: A pilot, double-blinded, sham-controlled study. METHODS: A total of 15 older adults between the ages of 40-85 with a physician diagnosis of PD will be recruited. Participants are screened with questionnaires to determine eligibility. If eligible, participants will undergo a dual task assessment and a freezing of gait (FOG) provoking protocol prior to, as well as immediately after, a 20-minute session of tDCS. The acute effects of each stimulation session will be observed. There will be three different stimulation conditions that each target different areas of the brain: the motor cortex (M1), the motor cortex and the dorsolateral prefrontal cortex (DLPFC), and a sham (i.e., control) condition. Multiple aspects of locomotion (i.e., FOG, gait speed, stride time variability, percent of each walking stride spent with both feet on the ground) and cognition are assessed. RESULTS: This study began enrolling participants on March 3rd, 2016. To date, one participant has been enrolled and completed baseline testing as well as all three tDCS visits. This 42-year-old participant was diagnosed with PD two years ago and symptoms are mild. No side effects were observed during tDCS and the participant was unable to decipher between the M1 and the sham stimulation, but was able to tell the difference between sessions when receiving multi-focal stimulation. DISCUSSION: In this case study, tDCS was well tolerated by the patient and double-blinding procedures were effective. Thus, while tDCS did not induce significant improvements in gait or cognition in this relatively high functioning patient, the developed study protocol and tDCS intervention are highly feasible in the PD population.
93

Comparação entre diferentes taxas de sêmen na viabilidade espermática em garanhões de alta e baixa congelabilidade /

Maziero, Rosiára Rosária Dias. January 2010 (has links)
Orientador: Frederico Ozanam Papa / Banca: José Antonio Dell'Aqua Júnior / Banca: Rubens Paes de Arruda / Resumo: A criopreservação de sêmen equino mostra-se como importante instrumento no ganho genético de rebanhos pela maximização do uso de bons reprodutores. Porém, nos programas de inseminação artificial, a utilização de espermatozóides criopreservados apresenta índices de fertilidade inferiores aos obtidos com sêmen a fresco, constituindo um dos maiores entraves à plena difusão dessa biotecnologia. Assim, o experimento 1 teve como objetivo avaliar o movimento espermático pelo sistema computadorizado (CASA) e a integridade da membrana plasmática por microscopia de epi-fluorescência de espermatozóides equino congelados em palhetas de 0,5 e 0,25 mL, em diferentes taxas de congelação na viabilidade espermática. Para desenvolver o projeto foram utilizadas três metodologias de congelação: o método convencional em caixa de isopor e dois equipamentos automatizados, um deles a máquina Mini Digitcool® (IMV - Technologies - França), que possibilita uma variação de -10ºC a -60ºC por minuto e o outro equipamento TK® 4000C (TK Equipamentos para Congelação) que possibilita uma variação de -10ºC a -40ºC por minuto. Para tanto foram utilizados 3 ejaculados de 4 garanhões de diferentes raças, para cada protocolo de congelação, sendo o protocolo 1: caixa de isopor x máquina TK® 4000C na taxa de -20ºC/min x máquina Mini Digitcool® na taxa de -20ºC/min; protocolo 2: caixa de isopor x máquina TK® 4000C na taxa de -40ºC/min x máquina Mini Digitcool® na taxa de -40ºC/min e protocolo 3: caixa de isopor x máquina TK® 4000C na taxa de -40ºC/min x máquina Mini Digitcool® na taxa de -60ºC/min. Para a análise pós-descongelação as palhetas de 0,5 mL foram descongeladas a 46ºC por 20 segundos e as palhetas de 0,25 mL a 46ºC por 15 segundos. A análise estatística das variáveis estudadas no sêmen congelado/descongelado foi realizada mediante o pacote... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Equine semen cryopreservation comes as an important tool to enhance the herd gene pool by maximizing the use of the top genetic merit stallions. However, the use of frozen semen in the artificial insemination programs presents reduced fertility rates in comparison to those obtained with fresh semen, being one of the biggest hindrances to spread this biotechnology. Thus, Experiment 1 aimed to evaluate the motility pattern using a computer-assisted sperm analysis (CASA) and plasma membrane integrity by epifluorescence microscopy of equine semen that were frozen in 0.5 and 0.25mL straws at different freezing rates and their relationship with sperm viability. Three different methodologies were used: conventional method with isothermic box and two automated systems: the Mini Digitcool® machine (IMV - Technologies - France), which allows a range from -10oC to -60oC per minute, and the TK® 4000C (TK Equipamentos para Congelação, Brazil), that provides a range from -10ºC to -45ºC per minute. Therefore 3 ejaculates for 4 animals were used for each freezing protocol. On protocol 1 we compared isothermic box vs. TK® 4000C machine at a -20ºC/min rate vs. Mini Digitcool® at a -20ºC/min rate; Protocol 2 compared isothermic box vs. TK® 4000C machine at a -40ºC/min rate vs. Mini Digitcool® at a -40ºC/min rate; and Protocol 3 compared isothermic box vs. TK® 4000C machine at a -40ºC/min rate vs. Mini Digitcool® at a -60ºC/min rate. The 0.5mL-straw samples were thawed at 46oC/20 sec whereas samples from the 0.25mL straws were thawed at 46oC/15 sec for post-thawing analysis. Statistical analysis from the frozen-thawed semen evaluated parameters was performed using the statistics software SAS 9.1. At first, it was used the descriptive analysis Box Plot R program. Then, data were analyzed using Proc. MIXED, a variance analysis to investigate the treatment effect (freezing rates and... (Complete abstract click electronic access below) / Mestre
94

Análise comparativa entre diferentes sistemas de criopreservação de tecido ovariano de ratas wistar / Comparative analysis among different cryopreservation systems of ovarian tissues in female wistar rats

Oliveira, Isabel Cirne Lima de January 2011 (has links)
O objetivo deste trabalho foi determinar o protocolo mais eficiente de criopreservação de tecido ovariano utilizando o sistema automático de congelação, que requer rampas de resfriamento gradativo, modelo Freeze Control®, para comparar a integridade do tecido ovariano congelado através de duas diferentes curvas de congelação combinadas com dois diferentes crioprotetores: dimetilsulfóxido (DMSO) e etileno glicol (EG). Para a realização do trabalho foram utilizadas 20 ratas Wistar que foram submetidas à oofarectomia bilateral. Os ovários foram divididos em duas partes, uma parte foi criopreservada em DMSO 1,5M e a outra em EG 1,5M. Ainda, foram analisadas duas curvas de congelamento (curva lenta com duração de 1h e 50min, e uma curva rápida com duração de 35 min). As amostras de tecido, após congelação, foram descongeladas, fixadas e processadas para a coloração com hematoxilina e eosina para a análise da integridade dos oócitos. Finalmente fez-se a análise e quantificação dos folículos íntegros versus os não íntegros, como também o dano tecidual. Para a análise folicular foi utilizado o microscópio óptico em aumento de 400x e realizou-se a classificação dos folículos pré-antrais de acordo com o estágio de desenvolvimento em primordiais e primários. Os resultados foram submetidos à ANOVA e as comparações entre as médias feitas pelo teste de Tukey com (P<0,05). Nos resultados foi observado que no tecido criopreservado os folículos que persistiram íntegros em cada ovário foram os primordiais em 79% e primários em 29%. Já no tecido não congelado (controle) foram encontrados todos os tipos foliculares, primordiais, primários, secundários, pré-antrais e antrais. Entre as alterações reversíveis identificaram-se vacuolizacão citoplasmática e contorno irregular. Quanto às alterações irreversíveis foi encontrado picnose. Concluindo, no tecido ovariano criopreservado, foram encontrados apenas folículos primordiais e primários apresentando alterações histológicas reversíveis e irreversíveis. Além disso, o crioprotetor EG promoveu uma melhor preservação destes folículos, comparado com o DMSO. Não foi encontrada diferença estatisticamente significativa, na preservação dos folículos, quando se comparou as duas curvas de congelação. / The aim of this study was to determine the most efficient protocol of cryopreservation of ovarian tissue using authomatic freezing system. This system requires Freeze Control® ramps of gradative cooling to compare the integrity of frozen ovarian tissue through two different freezing curves together with two different cryoprotectants: dimethilsulphoxide (DMSO) and ethylene glycol (EG). In this work 20 Wistar female rats were submitted to bilateral oophorectomy. The ovaries were divided in two parts, one part was cryopreserved in DMSO 1,5M and the other in EG 1,5M. Two frozen curves (a slow curve lasting 1h and 50min and a rapid curve lasting 35min) were analyzed. The tissue samples were frozen and after defrosted, fixed, and processed to hematoxylin and eosin staining to analyse oocyte. The analysis and quantification of integrated follicles, non-integrated, and tissue damage was performed. In the follicular analysis it was used 400x optical microscope and performed the classification of pre-antral follicles in primordial and primary according to their stage of development. The results were submitted to ANOVA and the comparasions between the averages were done using the Tukey test (P<0,05). It was observed that in the cryopreserved tissue the follicles remaining integrated in each ovary were 79% primordial and 29% primary. In the non-frozen tissue (control) were found all kinds follicular primordial, primary, secondary, preantral and antral follicles. Cytoplasmic vacuolization and irregular cell outline were identified among reversible alterations. Picnosis was found as an irreversible alteration. To conclude only primordial and primary follicles were enconutered in the ovarian tissue cryopreserved and there are revisable and irreversible histological alterations. Furthermore, the crioprotectant EG was more efficient then DMSO in other to preserve a higher number of primordial and primary viable folicules. No statistical significant difference was detected when we compare the two curves of cryopreservation system.
95

Avaliação da viabilidade e da variabilidade da microbiota salivar armazenada em diferentes temperaturas

Rojas, Elisabete Ulsenheimer January 2007 (has links)
O armazenamento de saliva para avaliação da microbiota bucal muitas vezes é necessário, principalmente em estudos epidemiológicos. O objetivo desse estudo foi avaliar a viabilidade e a variabilidade da microbiota bucal, de amostras de saliva armazenadas em temperaturas de -20ºC e em nitrogênio liquido (N2L), após 3 e 10 meses. Uma alíquota de cada amostra de saliva estimulada, usando goma de mascar sem açúcar, foi processada em até 45 minutos após a sua coleta. As amostras foram armazenadas seguindo três métodos diferentes: no primeiro método, as amostras de saliva foram preparadas com glicerol 10% (G) e mantidas a -20ºC durante 8 horas e então armazenadas em botijão com N2L; no segundo foi utilizado o mesmo protocolo, porém, sem glicerol; no terceiro método as alíquotas foram preparadas com glicerol 10% e mantidas a -20ºC. Após semeadura das amostras e incubação o número de unidades formadoras de colônias (UFC) foi determinado e uma média de 30 colônias de cada amostra foi identificada por meio de provas bioquímicas. Não houve diferença significativa na contagem de UFC/mL das amostras processadas imediatamente após a coleta (2,1 x 107 UFC/mL) e após 3 meses de armazenamento em N2L (G) (4,5 x 106 UFC/mL), N2L (1,6 x 106 UFC/mL), e -20ºC (2,2 x 106 UFC/mL). Porém, após 10 meses de preservação em N2L (G) (4,5 x 105 UFC/mL), e N2L (2,3 x 105 UFC/mL), observou-se uma redução (p=0.0183) do número de UFC/mL em comparação com a avaliação inicial. Não houve diferença significativa no número de UFC nas amostras armazenadas com e sem crioprotetor. A determinação da variabilidade da microbiota bucal mostrou que as bactérias presentes nas amostras frescas dos gêneros Streptococcus, Staphylococcus e Bacillus mantiveram-se nos diferentes tempos de avaliação, mesmo que em diferentes concentrações. Baseado nos resultados obtidos pode-se sugerir que preservação de saliva a -20ºC e a -196ºC, são métodos de armazenamento eficazes, para avaliação da microbiota bucal, por um período de 3 e 10 meses. / Saliva storage for oral microbiota evaluation often is required, especially in epidemiologic studies. The aim of the present study was to assess the effects of different storage methods upon viability and the variability of the oral microbiota in saliva samples. One aliquot of each saliva sample was processed until 45 minutes after collection. Saliva was stimulated using chewing gum sugar free. The samples were storage following three different methods: in the first method, aliquots of saliva were mixed with glycerol 10% (G) and maintained at -20ºC for 8 hours and then stored in N2L; the second followed the same protocol without glycerol; and in the third method aliquots were prepared with glycerol 10% and maintained at -20ºC. From each sample the number as the colony-forming units (CFU/mL) was determined and 30 colonies were chosen and cells were identified by biochemical assays. There was not statistically significant difference on the number of CFU/mL of samples processed immediately after de collection and after 3 months as storage. However, after 10 months of storage in N2L, there was a decrease in the number of CFU/mL (p=0.0183) in comparison with the initial evaluation, and the number of CFU/mL in the samples stored with and without glycerol did not showed statistically significant difference. Although in different percentages of cell number, the oral microbiota variability evaluation showed that Streptococcus, Staphylococcus and Bacillus were maintained in the different times of evaluation. Based on our results, it is possible to suggest that the preservation of saliva in -20ºC and -196ºC are efficient storage methods for oral microbiota evaluation for a period of 3 and 10 months.
96

Avaliação da viabilidade e da variabilidade da microbiota salivar armazenada em diferentes temperaturas

Rojas, Elisabete Ulsenheimer January 2007 (has links)
O armazenamento de saliva para avaliação da microbiota bucal muitas vezes é necessário, principalmente em estudos epidemiológicos. O objetivo desse estudo foi avaliar a viabilidade e a variabilidade da microbiota bucal, de amostras de saliva armazenadas em temperaturas de -20ºC e em nitrogênio liquido (N2L), após 3 e 10 meses. Uma alíquota de cada amostra de saliva estimulada, usando goma de mascar sem açúcar, foi processada em até 45 minutos após a sua coleta. As amostras foram armazenadas seguindo três métodos diferentes: no primeiro método, as amostras de saliva foram preparadas com glicerol 10% (G) e mantidas a -20ºC durante 8 horas e então armazenadas em botijão com N2L; no segundo foi utilizado o mesmo protocolo, porém, sem glicerol; no terceiro método as alíquotas foram preparadas com glicerol 10% e mantidas a -20ºC. Após semeadura das amostras e incubação o número de unidades formadoras de colônias (UFC) foi determinado e uma média de 30 colônias de cada amostra foi identificada por meio de provas bioquímicas. Não houve diferença significativa na contagem de UFC/mL das amostras processadas imediatamente após a coleta (2,1 x 107 UFC/mL) e após 3 meses de armazenamento em N2L (G) (4,5 x 106 UFC/mL), N2L (1,6 x 106 UFC/mL), e -20ºC (2,2 x 106 UFC/mL). Porém, após 10 meses de preservação em N2L (G) (4,5 x 105 UFC/mL), e N2L (2,3 x 105 UFC/mL), observou-se uma redução (p=0.0183) do número de UFC/mL em comparação com a avaliação inicial. Não houve diferença significativa no número de UFC nas amostras armazenadas com e sem crioprotetor. A determinação da variabilidade da microbiota bucal mostrou que as bactérias presentes nas amostras frescas dos gêneros Streptococcus, Staphylococcus e Bacillus mantiveram-se nos diferentes tempos de avaliação, mesmo que em diferentes concentrações. Baseado nos resultados obtidos pode-se sugerir que preservação de saliva a -20ºC e a -196ºC, são métodos de armazenamento eficazes, para avaliação da microbiota bucal, por um período de 3 e 10 meses. / Saliva storage for oral microbiota evaluation often is required, especially in epidemiologic studies. The aim of the present study was to assess the effects of different storage methods upon viability and the variability of the oral microbiota in saliva samples. One aliquot of each saliva sample was processed until 45 minutes after collection. Saliva was stimulated using chewing gum sugar free. The samples were storage following three different methods: in the first method, aliquots of saliva were mixed with glycerol 10% (G) and maintained at -20ºC for 8 hours and then stored in N2L; the second followed the same protocol without glycerol; and in the third method aliquots were prepared with glycerol 10% and maintained at -20ºC. From each sample the number as the colony-forming units (CFU/mL) was determined and 30 colonies were chosen and cells were identified by biochemical assays. There was not statistically significant difference on the number of CFU/mL of samples processed immediately after de collection and after 3 months as storage. However, after 10 months of storage in N2L, there was a decrease in the number of CFU/mL (p=0.0183) in comparison with the initial evaluation, and the number of CFU/mL in the samples stored with and without glycerol did not showed statistically significant difference. Although in different percentages of cell number, the oral microbiota variability evaluation showed that Streptococcus, Staphylococcus and Bacillus were maintained in the different times of evaluation. Based on our results, it is possible to suggest that the preservation of saliva in -20ºC and -196ºC are efficient storage methods for oral microbiota evaluation for a period of 3 and 10 months.
97

Análise comparativa entre diferentes sistemas de criopreservação de tecido ovariano de ratas wistar / Comparative analysis among different cryopreservation systems of ovarian tissues in female wistar rats

Oliveira, Isabel Cirne Lima de January 2011 (has links)
O objetivo deste trabalho foi determinar o protocolo mais eficiente de criopreservação de tecido ovariano utilizando o sistema automático de congelação, que requer rampas de resfriamento gradativo, modelo Freeze Control®, para comparar a integridade do tecido ovariano congelado através de duas diferentes curvas de congelação combinadas com dois diferentes crioprotetores: dimetilsulfóxido (DMSO) e etileno glicol (EG). Para a realização do trabalho foram utilizadas 20 ratas Wistar que foram submetidas à oofarectomia bilateral. Os ovários foram divididos em duas partes, uma parte foi criopreservada em DMSO 1,5M e a outra em EG 1,5M. Ainda, foram analisadas duas curvas de congelamento (curva lenta com duração de 1h e 50min, e uma curva rápida com duração de 35 min). As amostras de tecido, após congelação, foram descongeladas, fixadas e processadas para a coloração com hematoxilina e eosina para a análise da integridade dos oócitos. Finalmente fez-se a análise e quantificação dos folículos íntegros versus os não íntegros, como também o dano tecidual. Para a análise folicular foi utilizado o microscópio óptico em aumento de 400x e realizou-se a classificação dos folículos pré-antrais de acordo com o estágio de desenvolvimento em primordiais e primários. Os resultados foram submetidos à ANOVA e as comparações entre as médias feitas pelo teste de Tukey com (P<0,05). Nos resultados foi observado que no tecido criopreservado os folículos que persistiram íntegros em cada ovário foram os primordiais em 79% e primários em 29%. Já no tecido não congelado (controle) foram encontrados todos os tipos foliculares, primordiais, primários, secundários, pré-antrais e antrais. Entre as alterações reversíveis identificaram-se vacuolizacão citoplasmática e contorno irregular. Quanto às alterações irreversíveis foi encontrado picnose. Concluindo, no tecido ovariano criopreservado, foram encontrados apenas folículos primordiais e primários apresentando alterações histológicas reversíveis e irreversíveis. Além disso, o crioprotetor EG promoveu uma melhor preservação destes folículos, comparado com o DMSO. Não foi encontrada diferença estatisticamente significativa, na preservação dos folículos, quando se comparou as duas curvas de congelação. / The aim of this study was to determine the most efficient protocol of cryopreservation of ovarian tissue using authomatic freezing system. This system requires Freeze Control® ramps of gradative cooling to compare the integrity of frozen ovarian tissue through two different freezing curves together with two different cryoprotectants: dimethilsulphoxide (DMSO) and ethylene glycol (EG). In this work 20 Wistar female rats were submitted to bilateral oophorectomy. The ovaries were divided in two parts, one part was cryopreserved in DMSO 1,5M and the other in EG 1,5M. Two frozen curves (a slow curve lasting 1h and 50min and a rapid curve lasting 35min) were analyzed. The tissue samples were frozen and after defrosted, fixed, and processed to hematoxylin and eosin staining to analyse oocyte. The analysis and quantification of integrated follicles, non-integrated, and tissue damage was performed. In the follicular analysis it was used 400x optical microscope and performed the classification of pre-antral follicles in primordial and primary according to their stage of development. The results were submitted to ANOVA and the comparasions between the averages were done using the Tukey test (P<0,05). It was observed that in the cryopreserved tissue the follicles remaining integrated in each ovary were 79% primordial and 29% primary. In the non-frozen tissue (control) were found all kinds follicular primordial, primary, secondary, preantral and antral follicles. Cytoplasmic vacuolization and irregular cell outline were identified among reversible alterations. Picnosis was found as an irreversible alteration. To conclude only primordial and primary follicles were enconutered in the ovarian tissue cryopreserved and there are revisable and irreversible histological alterations. Furthermore, the crioprotectant EG was more efficient then DMSO in other to preserve a higher number of primordial and primary viable folicules. No statistical significant difference was detected when we compare the two curves of cryopreservation system.
98

Assessment of freezing desalination technologies

Ahmad, Mansour M. M. January 2012 (has links)
The production of both fresh water and waste streams are progressively increasing over the years due to ongoing population growth coupled with high levels of increase in water consumption. The ongoing growth of human activities, such as industry, recreation, and agriculture, are significantly contributing to the increase in both water demand and severity of degradation of natural water resources. The majority of the industrial wastewaters have a significant impact on the environment; some of which may pose a number of threats to human health and the surrounding environment. Thus, discharge of such waste streams into a surface water and/or groundwater presents a major source of water pollution in many countries. Therefore, these waste streams must be disposed of in an environmentally acceptable manner. The primary concern of the PhD thesis is to seek the most feasible and applicable freezing desalination technologies that are potentially capable to concentrate the dissolved ionic content of the liquid streams, especially for those causing severe pollution problems. Therefore, various forms of melt crystallisation processes, namely; agitated and static crystallisation processes, ice maker machines, a Sulzer falling film crystallisation process, the Sulzer suspension crystallisation process, and the Sulzer static crystallisation process, were experimentally used and investigated. The experimental investigations were carried out on the laboratory bench scale and/or straightforward pilot plant by using aqueous solutions of sodium chloride and/or process brines as feed samples. The study was focused on a number of important parameters influencing the separation performance of the investigated treatment systems. In general, the resulting experimental data for each innovative process were highly encouraging in minimising the volume of the waste stream, and substantially increasing the amount of product water. The obtained product water was ready for immediate use either as drinking water or as a saline water of near brackish water or seawater qualities. Also, relationships between the influences and the separation performance, in terms of salt rejection and water recovery ratios, were explored and determined for the investigated technologies. Based on the experimental results, the Sulzer melt crystallisation processes were scaled up and were combined into a commercial reverse osmosis membrane desalination plant. As a result, three novel treatment option configurations were proposed for minimising the waste stream, whilst increasing the production rate of drinking water and/or preserving a substantial amount of natural water resource from the RO plant's exploitation.
99

Teste do cometa como ferramenta de controle da cadeia do frio / Comet assay as a cold chain control tool

DUARTE, RENATO C. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:26:48Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:22Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
100

Análise comparativa entre diferentes sistemas de criopreservação de tecido ovariano de ratas wistar / Comparative analysis among different cryopreservation systems of ovarian tissues in female wistar rats

Oliveira, Isabel Cirne Lima de January 2011 (has links)
O objetivo deste trabalho foi determinar o protocolo mais eficiente de criopreservação de tecido ovariano utilizando o sistema automático de congelação, que requer rampas de resfriamento gradativo, modelo Freeze Control®, para comparar a integridade do tecido ovariano congelado através de duas diferentes curvas de congelação combinadas com dois diferentes crioprotetores: dimetilsulfóxido (DMSO) e etileno glicol (EG). Para a realização do trabalho foram utilizadas 20 ratas Wistar que foram submetidas à oofarectomia bilateral. Os ovários foram divididos em duas partes, uma parte foi criopreservada em DMSO 1,5M e a outra em EG 1,5M. Ainda, foram analisadas duas curvas de congelamento (curva lenta com duração de 1h e 50min, e uma curva rápida com duração de 35 min). As amostras de tecido, após congelação, foram descongeladas, fixadas e processadas para a coloração com hematoxilina e eosina para a análise da integridade dos oócitos. Finalmente fez-se a análise e quantificação dos folículos íntegros versus os não íntegros, como também o dano tecidual. Para a análise folicular foi utilizado o microscópio óptico em aumento de 400x e realizou-se a classificação dos folículos pré-antrais de acordo com o estágio de desenvolvimento em primordiais e primários. Os resultados foram submetidos à ANOVA e as comparações entre as médias feitas pelo teste de Tukey com (P<0,05). Nos resultados foi observado que no tecido criopreservado os folículos que persistiram íntegros em cada ovário foram os primordiais em 79% e primários em 29%. Já no tecido não congelado (controle) foram encontrados todos os tipos foliculares, primordiais, primários, secundários, pré-antrais e antrais. Entre as alterações reversíveis identificaram-se vacuolizacão citoplasmática e contorno irregular. Quanto às alterações irreversíveis foi encontrado picnose. Concluindo, no tecido ovariano criopreservado, foram encontrados apenas folículos primordiais e primários apresentando alterações histológicas reversíveis e irreversíveis. Além disso, o crioprotetor EG promoveu uma melhor preservação destes folículos, comparado com o DMSO. Não foi encontrada diferença estatisticamente significativa, na preservação dos folículos, quando se comparou as duas curvas de congelação. / The aim of this study was to determine the most efficient protocol of cryopreservation of ovarian tissue using authomatic freezing system. This system requires Freeze Control® ramps of gradative cooling to compare the integrity of frozen ovarian tissue through two different freezing curves together with two different cryoprotectants: dimethilsulphoxide (DMSO) and ethylene glycol (EG). In this work 20 Wistar female rats were submitted to bilateral oophorectomy. The ovaries were divided in two parts, one part was cryopreserved in DMSO 1,5M and the other in EG 1,5M. Two frozen curves (a slow curve lasting 1h and 50min and a rapid curve lasting 35min) were analyzed. The tissue samples were frozen and after defrosted, fixed, and processed to hematoxylin and eosin staining to analyse oocyte. The analysis and quantification of integrated follicles, non-integrated, and tissue damage was performed. In the follicular analysis it was used 400x optical microscope and performed the classification of pre-antral follicles in primordial and primary according to their stage of development. The results were submitted to ANOVA and the comparasions between the averages were done using the Tukey test (P<0,05). It was observed that in the cryopreserved tissue the follicles remaining integrated in each ovary were 79% primordial and 29% primary. In the non-frozen tissue (control) were found all kinds follicular primordial, primary, secondary, preantral and antral follicles. Cytoplasmic vacuolization and irregular cell outline were identified among reversible alterations. Picnosis was found as an irreversible alteration. To conclude only primordial and primary follicles were enconutered in the ovarian tissue cryopreserved and there are revisable and irreversible histological alterations. Furthermore, the crioprotectant EG was more efficient then DMSO in other to preserve a higher number of primordial and primary viable folicules. No statistical significant difference was detected when we compare the two curves of cryopreservation system.

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