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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.
131

Condutância lateral em filme de Langmuir e filmes mistos de fármacos com fosfolipídios / Lateral conductance in Langmuir films of phospholipids and mixed with pharmaceutical drugs

Cavalli, Ailton 24 July 1997 (has links)
Um sistema diferencial foi desenvolvido para resolver as principais dificuldades na medida do aumento da condução protônica na interface filme de Langmuir-água, a saber: a) pequeno aumento da condução devido ao filme comparado com a condução da água; b) diminuição da área imersa dos eletrodos para tensões superficiais diferentes da tensão da água; c) obtenção de uma subfase isenta de impurezas. Com o novo sistema mediu-se a condutância de filmes de Langmuir tradicionais (moléculas anfipáticas com cadeias de hidrocarbonos longas), de filmes mistos de fosfolipídio-fármacos e de um polímero condutor. Realizaram-se, também, medidas de pressão de superfície e potencial de superfície. Os resultados da condutância lateral e do potencial de superfície obtidos com os filmes tradicionais indicam que a área crítica (área em que a condutância do filme aparece e o potencial de superfície aumenta abruptamente) é área em que se forma uma rede de pontes de hidrogênio. Cálculos de área crítica realizados para os ácidos graxos, utilizando um modelo unidimensional para a transferência de prótons, reproduzem os resultados experimentais. Resultados obtidos com o polímero condutor mostram que é possível medir a contribuição eletrônica para a condutância com o novo sistema diferencial. Um estudo de filmes mistos de fosfolípídios-anestésicos locais (tetracaína e dibucaína) foi realizado utilizando a técnica de coespalhamento. Está técnica tem a vantagem, sobre as de adsorção de Langmuir usada tradicionalmente, de se ter certeza de que todas as mudanças nas propriedades do filme sejam causadas pelos compostos adicionados na monocamada. Ambos os anestésicos expandiram a matriz de fosfolípidios. Os resultados mostraram que a tetracaína possui ligações hidrofóbicas mais fortes que a dibucaína, fazendo com que a tetracaína penetrasse mais profundamente na matriz de fosfolipídio / A different system has been developed for overcoming the main difficulties associated with the measurement of an enhanced protonic conductance at the Langmuir film/water interface. These difficulties are: a) small increase in conductance due to the film as compared to the bulk water conductance; b) decrease in the electrode immersed area for surface tensions lower than that of the subphase water; c) obtaining an impurity-free subphase. With the new system the lateral conductance of traditional Langmuir films (possessing amphiphilic molecules with long hydrocarbon tails), of mixed films madeup of phospholipid and pharmaceutical drugs and of a conducting polymer. Measurements were also performed of monolayer surface pressure and surface potential. The conductance and surface potential results obtained with the traditional compounds have indicated that the critical area (at which the conductance appears and the surface potential increase abruptly) is the area for which a H-bonded network is formed. The critical area for fatty acids was calculated , employing a unidimensional proton transfer model, which is consistent with the measured value. Results obtained using the differential system with a conducting polymer also show that it is a possible to detect an electronic contribution to the lateral conductance. A study of mixed films from phospholipid and local anesthetics (tetracaine and dibucaine) was conducted using the co-spreading technique. This method offers the advantage, compared to the traditionally employed Langmuir adsorption method, of making sure that all changes in the film properties are caused by incorporation of the drugs added to the phospholipid monolayer. Both anesthetics caused the phospholipid matrix to expand. The results showed that tetracaine has stronger hydrophobic interaction than dibucaine, and therefore tetracaine penetrates deeper into the phospholipid matrix
132

Caracterização da capacidade fotossintética e da condutância estomática em sete clones comerciais de Eucalyptus e seus padrões de resposta ao déficit de pressão de vapor / Photosynthetic capacity and stomatal conductance characterization for seven commercial Eucalyptus clones and their variation due to vapor pressure deficit

Marrichi, Ana Heloisa Carnaval 30 March 2009 (has links)
O estudo caracterizou as variáveis fisiológicas da fotossíntese, em 7 clones de Eucalyptus de alta produtividade, determinando-se as capacidades fotossintéticas máximas (Amax), e o comportamento da fotossíntese (A), condutância (gs) e transpiração (E) em relação ao Déficit de Pressão de Vapor (DPV). Para isso, um ensaio foi instalado em 2004, na ESALQ/USP, contendo os clones do Projeto BEPP (Brasil Eucalyptus Produtividade Potencial), sendo cada parcela composta de 49 plantas (7x7) no espaçamento de 3,0m x 2,7m. Mediram-se as alturas ou DAPs e selecionaram-se 3 árvores médias para as mensurações fisiológicas, aos 16 e 36 meses. A amostragem para Amax foi composta de duas posições superiores da copa (2 e 3), dois galhos por posição e duas folhas por galho. As medições foram feitas das 8 às 10 horas (baixo DPV). Para o comportamento de A e gs frente ao DPV, as medições continuaram, de hora em hora, das 11 às 15 horas, nas folhas do primeiro galho da posição 2. Ao final as folhas foram coletadas para determinação da área foliar específica (AFE) e do nitrogênio (N). Aos 16 meses, foram feitas curvas A/Ci, para posterior cálculo de Vcmax (taxa máxima de carboxilação), Jmax (taxa máxima de transporte de elétrons) e VTPU (utilização da triose fosfato), pelo programa Photosyn Assistant. As curvas foram feitas em 2 árvores por clone, nas posições superiores e inferiores da copa. Todas mensurações foram realizadas com o aparelho LiCor-6400. Os resultados mostraram que Amax foi similar para as posições 2 e 3. Entre os clones, houve variação, porém não consistente entre idades, e todos mostraram altos valores de Amax na idade de 16 meses (entre 26 e 31, com média de 29 µmol m-2s-1), reduzindo-se aos 36 meses (entre 19 e 26, com média de 22 µmol m-2s-1). A AFE e o N também foram similares entre as posições 2 e 3 e maiores na idade mais jovem (11 versus 8 m²kg-1, 29 versus 21 gN kg-1), podendo estar associados à queda de Amax. A, gs e E também apresentaram menores valores aos 36 meses, para todos os clones (23 versus 18 µmol m-2s-1; 0,41 versus 0,26 mol m-2s-1; 9,2 versus 6,1 mmol m-2s-1). Os clones mostraram sensibilidade ao DPV, reduzindo os valores de gs e A ao longo do dia, sendo a sensibilidade menor aos 36 meses. As sensibilidades foram distintas, evidenciando potencial de seleção de materiais mais aptos a tolerarem estresse hídrico. Em geral, maiores valores de fotossíntese estão relacionados a maiores valores de transpiração, evidenciando a necessidade de se conhecer a disponibilidade hídrica local quando do uso de clones de alta produtividade. Vcmax, Jmax e VTPU foram maiores para as posições superiores da copa, e não diferiram entre os clones. Devido à semelhança fisiológica entre as posições 2 e 3, pode-se sugerir que não haja distinção entre elas em futuras medições de fotossíntese, essenciais para a parametrização de modelos. Não houve relação direta entre crescimento do tronco e fotossíntese, evidenciando a necessidade de integração com estudos relacionados à alocação do carbono dentro da planta. / This study aimed to characterize the physiological variables related to photosynthesis, in seven commercial Eucalyptus clones with high productivity, by evaluating maximum photosynthetic capacity (Amax), and the response of photosynthesis (A), stomatal conductance (gs) and transpiration (E) to Vapor Pressure Deficit (VPD). A trial was installed in 2004, at ESALQ/USP, with the clones that were part of BEPP Project (Brazil Eucalyptus Potential Productivity), and each plot had 49 plants (7x7) in a 3 m x 2.7m spacing. We measured tree height or DBHs and three average trees were selected for measurements, at 16 and 36 months. The sample to estimate Amax was: two crown positions (2 and 3), two branches per tree and two leaves per branch. The measurements which were taken from 8 to 10 am (low VPD). To get the response of A and gs to VPD measurements continued hourly, from 11 am to 3 pm, on the leaves from the first branch and position 2. At the end of the measurements leaves were collected for specific leaf area (SLA) and nitrogen (N) determination. Additionally, at 16 months, A/Ci curves were established, and parameters Vcmax, Jmax and VTPU were estimated through the program Photosyn Assistant. The curves were done for 2 trees per clone, at superior crown positions (2 and 3) and inferior ones (4 and 5). The physiological measurements and A/Ci curves were made using LiCor-6400. The results showed that Amax was similar for positions 2 and 3. There was variation among clones, but not consistent between ages, and all the clones had high Amax at 16 months (between 26 and 31 µmol m-2s-1, with an average of 29 µmol m-2s-1), decreasing at 36 months (between 19 and 26 µmol m-2s-1, with an average of 22 µmol m-2s-1). SLA and N were also similar between positions 2 and 3 and higher at younger age (11,1 versus 8,3 m²kg-1, 29,6 versus 21,1 gN kg-1;), what may be associate with Amax decrease. A, gs and E also showed lower values at age 36, for all the clones (23 versus 18 µmol m-2s-1; 0,41 versus 0,26 mol m-2s-1; 9,2 versus 6,1 mmol m-2s-1). All clones showed sensitivity to VPD, reducing gs and A with increasing VPD. However, the clones showed different sensitivities and all of them were less sensitive to VPD at age 36, highlighting a selection potential of genetic materials for water stress. In general, higher photosynthesis values were associated with higher transpiration, showing the necessity to know the water conditions of sites when planting genetic materials with high productivity. Vcmax, Jmax and VTPU were greater for superior positions compared to inferior ones, and were not different among clones. Due to a similarity in SLA, N and physiological and biochemical traits between positions 2 and 3, no distinction on future photosynthesis measurements between these positions is needed. Finally, there was not a direct relation between stem growth and photosynthesis, at both ages, showing that photosynthesis at crown level by itself can not capture all the ecophysiological processes related to wood productivity, being necessary the integration with studies related to carbon allocation inside the plant.
133

Protecting Synaptic Function From Acute Oxidative Stress: A Novel Role For Big K+ (BK) Channels And Resveratrol-Like Compounds

Unknown Date (has links)
Oxidative stress causes neural damage and inhibits essential cellular processes, such as synaptic transmission. Despite this knowledge, currently available pharmaceutical agents cannot effectively protect neural cells from acute oxidative stress elicited by strokes, heart attacks, and traumatic brain injuries in a real life clinical setting. Our lab has developed an electrophysiology protocol to identify novel drugs that protect an essential cellular process (neurotransmission) from acute oxidative stress-induced damage. Through this doctoral dissertation, we have identified three new drugs, including a Big K+ (BK) K+ channel blocker (iberiotoxin), resveratrol, and a custom made resveratrol-like compound (fly2) that protect synaptic function from oxidative stress-induced insults. Further developing these drugs as neuroprotective agents may prove transformative in protecting the human brain from acute oxidative stress elicited by strokes, heart attacks, and traumatic brain injuries. Inhibiting the protein kinase G (PKG) pathway protects neurotransmission from acute oxidative stress. This dissertation has expanded upon these findings by determining that the PKG pathway and BK K+ channels function through independent biochemical pathways to protect neurotransmission from acute oxidative stress. Taken together, this dissertation has identified two classes of compounds that protect neurotransmission from acute oxidative stress, including resveratrol-like compounds (resveratrol, fly2) and a BK K+ channel inhibitor (iberiotoxin). Further developing these drugs in clinical trials may finally lead to the development of an effective neuroprotective agent. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
134

Avaliação da estabilidade da aplicação de um híbrido experimental em diferentes concentrações sobre a dentina sensível - in vitro / Evaluation of the stability of application of an experimental hybrid on the sensitive dentin in differents concentrations - in vitro

Oliveira, Tatiane Alexandre de 08 November 2016 (has links)
O objetivo deste estudo foi avaliar, in vitro, quantitativamente e qualitativamente, a estabilidade de um híbrido experimental em duas concentrações diferentes (concentrado e diluído) aplicado sobre a simulação de uma dentina sensível. Dentes molares humanos foram selecionados e tiveram suas coroas seccionadas abaixo do sulco oclusal de forma a obter espécimes de discos de dentina que foram planificados e polidos até atingirem a espessura de 1,0 milímetro. Os espécimes foram divididos em 4 grupos (n=9) de acordo com os tratamentos de superfície propostos: saliva artificial (SAL), adesivo dentinário autocondicionante (AD), híbrido experimental concentrado (TC) e híbrido experimental diluído na proporção de 1:3 (TD). Dois métodos foram empregados para avaliar a estabilidade: condutância hidráulica (permeabilidade dentinária) e microscopia eletrônica de varredura. Foi realizada a leitura da permeabilidade dentinária em 6 tempos experimentais: Mínima (sem tratamento), Máxima (com túbulos abertos), Tratamento (após aplicação dos respectivos tratamentos), Erosão (após 5 minutos de imersão em ácido cítrico 0,05M pH 3,8), Escovação (após escovação de 3900 ciclos) e Erosão Pós (repetição da erosão após o processo de escovação). A microscopia eletrônica de varredura foi realizada em espécimes de dentina com área central de aplicação dos tratamentos e tecido natural nas laterais para evidenciar as características da película aplicada. As leituras foram feitas após a aplicação dos tratamentos, após a erosão, após a escovação e após a erosão pós escovação, para todos os 4 tratamentos propostos. O teste de análise de variância (ANOVA) de Medidas Repetidas com 2 fatores de variação foi aplicado juntamente com o teste de comparações múltiplas pareadas (Tukey). Para permeabilidade dentinária todos os tratamentos reduziram a condutância hidráulica (Lp) em relação à Máxima. TC e TD apresentaram os menores valores (24% e 15%) respectivamente. O TD continuou apresentando valores semelhantes estatisticamente após a Erosão (36%), sendo estatisticamente semelhante ao TC (55%).. No tempo Escovação o TD apresentou Lp estatisticamente semelhante aos tempos Tratamento e Erosão. Todos os grupos apresentaram-se estatisticamente semelhantes entre os tratamentos nos tempos Escovação e Erosão Pós. A análise das MEVs evidencia túbulos dentinários com conteúdo no seu interior nos grupos TC e TD, mantendo-se durante todos os tempos experimentais. O AD apresentou uma película evidente, que começou a se destacar e exibir falhas a partir do tempo Erosão. Conclui-se que o TD apresentou o melhor comportamento sendo capaz de diminuir a permeabilidade dentinária, formando uma película fina, transparente, imperceptível, capaz de vedar (totalmente ou parcialmente) e penetrar dentro dos túbulos dentinários, resistindo aos desafios erosivos e abrasivos. / The aim of this study was to evaluate, in vitro, quantitatively and qualitatively, the stability of an experimental hybrid with two different concentrations (concentrated and diluted) applied at a simulation of a sensitive dentin. Human molar teeth were selected and their crowns were sectioned below the occlusal groove in order to obtain specimens of dentine disks that were ground flat and polished to achieve a thickness of 1.0 millimeter. The specimens were divided into 4 groups (n = 9) in accordance with proposed surface treatments: Artificial saliva (SAL) dentinal self-etching adhesive (AD), concentrated experimental hybrid (TC) and experimental hybrid diluted in the ratio 1: 3 (TD). Two methods were used to assess the stability: hydraulic conductance (dentin permeability) and scanning electron microscopy. The dentin permeability in 6 experimental times was carried out: Minimum (no treatment), Maximum (with open tubules), treatment (after application of their treatments), erosion (after 5 minutes of immersion in citric acid 0.05M pH 3, 8), brushing (brushing after 3900 cycles) and Post erosion (erosion was repeated after brushing). The scanning electron microscopy was performed on dentin specimens with a central area of application of treatments and natural tissues on the sides to show the film characteristics applied. Readings were made after application of treatments, after erosion, after brushing and after erosion after brushing, for all 4 treatments proposed. The analysis of variance (ANOVA) for repeated measures with two variation factors was applied with the multiple comparisons paired test (Tukey). For dentin all treatments reduced hydraulic conductance (Lp) in relation to Maximum. TC and TD showed the lowest values (24% and 15%) respectively. The TD continued to show statistically similar values after erosion (36%), being statistically similar to TC (55%). In brushing time the TD Lp was statistically similar to Treatment and erosion times. All groups were statistically similar between treatments in brushing and Post Erosion times. The analysis of SEM shows dentinal tubules with content inside on the TC and TD groups, remaining during all experimental period. AD presented a clear film, which began to stand out and show failure from erosion time. It follows that the TD had better behavior being able to decrease permeability of dentin by forming a thin film transparent, imperceptible, capable of sealing (fully or partially) and penetrate within the dentine tubules, resisting the erosive and abrasive challenges.
135

Regulatory mechanisms governing fluid formation in mouse uterus: role of endometrial ion channels, transporters and their interactions. / CUHK electronic theses & dissertations collection

January 2002 (has links)
Wang Xiaofei. / "June 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 152-167). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
136

Involvement of CFTR in prostatitis and prostate cancer development. / CUHK electronic theses & dissertations collection

January 2010 (has links)
In summary, the present findings have demonstrated the important roles of CFTR in prostatitis and cancer development, which may provide new insight into the understanding of the prostate in health and disease. The present findings may also have potential application in diagnosis and prognosis of cancer. / In the first part of the study, the possible role and a bacterial killing mechanism involving CFTR-mediated bicarbonate secretion in prostatitis were investigated in a rat prostate model. CFTR was found to be expressed in the epithelium of rat ventral prostate. Experiments using cultured rat primary prostate epithelial cells demonstrated that CFTR was involved in mediating bicarbonate extrusion across the prostate epithelium. The expression of CFTR and carbonic anhydrase II (CAII), a key enzyme involved in cellular HCO 3- production, along with several pro-inflammatory cytokines including IL-6, IL-1beta, TNF-alpha, was significantly up-regulated in the primary culture of rat prostate epithelial cells upon E.coli-LPS challenge. Inhibition of CFTR function in vitro or in vivo resulted in reduced bacterial killing by prostate epithelial cells or the prostate. High HCO3- content (>50mM), rather than alkaline pH, was found to be responsible for bacterial killing. The direct action of HCO 3- on bacterial killing was confirmed by its ability to suppress bacterial initiation factors in E coli. The relevance of the CFTR-mediated HCO3- secretion in human was demonstrated by the upregulated expression of CFTR and CAII in human prostatitis tissues. The present results have demonstrated that CFTR plays a previously undefined role in prostatitis and could be up-regulated during the inflammation in prostate as a host defense mechanism to increase bicarbonate secretion for bacterial killing. / In the second part of the study, the possible role of CFTR in prostate cancer development and the underlying mechanisms were investigated. Our results showed that the expression of CFTR and CAII in prostate was remarkably decreased in aged rat prostate. We observed that testosterone could up-regulate the expression of CFTR and CAII in vitro and in vivo , indicating that the declined male hormones during aging may be responsible for the observed age-dependent expression of CFTR. In the present study, we found that inhibition of CFTR enhanced cell proliferation/anti-apoptosis in the prostate primary epithelial cells. CFTR was detected in all examined prostate cell lines, but with relatively higher expression levels in immortalized cell lines (PZ-HPV-7, PNT1A, PNT2C2) than in cancer cell lines (PC-3, DU-145, LNCaP). Immunohistological studies showed that the expression of CFTR was dramatically reduced in prostate cancer specimens as compared to that in normal prostate tissues. Furthermore, our gain and loss of function studies showed that knockdown of CFTR profoundly enhanced cell proliferation, cell adhesion, invasion and migration, while inhibited apoptosis in prostate cancer cell lines, overexpression of CFTR dramatically suppressed tumorigenic phenotype of cancer cells. Soft agar anchorage-independent growth assay showed that knockdown of CFTR in prostate cancer cells increased the number of colonies formed in soft agar. More importantly, we demonstrated that CFTR knockdown promoted the tumor growth in vivo and forced overexpression of CFTR in prostate cancer cells and ultrasound-mediated gene transfer of CFTR inhibited xenograft tumor growth in vivo. Mechanistically, multiple mechanisms were identified to contribute to the CFTR- mediated tumor suppressive effects. Firstly, CFTR chloride channel function was implicated in the regulation of apoptosis in prostate cancer cells. Secondly, CFTR up-regulated the transcription level of miR-34a and miR-193b, both of which have been indicated as tumor suppressors in multiple cancers. Thirdly, 11 cancer-related genes were found to be up- or down-regulated by CFTR using PCR-array. These data demonstrated that CFTR may play an important role in prostate cancer development by acting as a tumor suppressor. / The cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel conducting both Cl- and HCO3 -. It is expressed in epithelial cells of a wide variety of tissues. CFTR is also known to be expressed in human prostate; however, the physiological role of CFTR in the prostate and related diseases remains largely unknown. This thesis explored the biological roles of CFTR in prostatitis and cancer development. / Xie, Chen. / Adviser: Chan LiShaw Chang. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 175-192). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
137

The role of CFTR in male reproduction and the underlying mechanisms. / CUHK electronic theses & dissertations collection

January 2008 (has links)
As CFTR plays an important role in HCO3- transport, and HCO3- sensitive soluble adenylyl cyclase (sAC) has been shown to be largely responsible for the cAMP production in spermatogenetic cells, we hypothesized that CFTR-mediated HCO3- transport was important to spermatogenesis via sAC pathway in spermatogenetic and Sertoli cells. Using intracellular pH measurement, we demonstrated that CFTR is involved in HCO3- transport in Sertoli cells. RT-PCR results showed that increased HCO3- concentrations in the culture medium resulted in upregulation of CFTR expression. The results also showed that the intracellular cAMP level in Sertoli cells increased as the extracellular HCO3- concentration increased. HCO3- also caused phosphorylation of the cAMP response element binding (pCREB) proteins transcription factor on serine 133, a modification known to be required by Sertoli cells to support spermatogenesis. This phosphorylation could be inhibited by CFTR inhibitor, further lending support to the notion that CFTR is important for HCO3- transport in Sertoli cells, leading to HCO3- dependent events that are important for spermatogenesis. / CFTR is known to be widely expressed in epithelial cells of male reproductive tracts, but its expression in spermatogenic cells is less well known. We first confirmed the expression of CFTR in spermatogenic cells and mature sperm in rodents. Our study thus focused on the important role of CFTR in the processes related to male fertility including spermatogenesis and sperm capacitation. / Cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel, mutations of which cause cystic fibrosis, a disease characterized by defective Cl- and HCO3- transport. While over 95% of CF male patients are infertile because of congenital bilateral absence of the vas deferens (CBAVD), the question whether CFTR mutations are involved in other forms of male infertility is under intense debates. / In conclusion, our study has demonstrated the role of CFTR in male reproductive system. We have further elucidated its possible physiological role and the underlying molecular mechanisms. These studies may pave the way for the development of method strategies for diagnosis and treatment of CFTR related infertility in male. / Our study also detected CFTR in both human and mouse sperm. CFTR inhibitor or antibody significantly reduced sperm capacitation, and the associated HCO 3--dependent events including increases in intracellular pH, cAMP production and membrane hyperpolarization. The fertilizing capacity of the sperm obtained from heterozygous CFTR mutant mice is also significantly lower as compared to that of the wild type. These results suggest that CFTR in sperm may be involved in the transport of HCO3- important for sperm capacitation and that CFTR mutations with impaired CFTR function may lead to reduced sperm fertilizing capacity and male infertility other than CBAVD. / We further demonstrated the physiological role of CFTR in spermatogenesis using CFTR knockout mice as an in vivo model. Although TUNNEL staining showed normal percentage of apoptotic cells in seminiferous tubules, Cftr -/- mice had spermatogenetic defects in histology section and fewer number of mature sperm compared with wild type (WT) mice. Consistent with the proposed role of CFTR in spermatogenesis, RT-PCR and Western blot results showed reduced expression of spennatids specific gene, Protamine 1, Protamine 2, and CREM, which have been known to be involved in the process of spermatogenesis, in Cftr-/- mice. / Xu, Wenming. / "January 2008." / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4506. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 121-138). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
138

Expression regulation of endometrial ion channels by steroid hormones.

January 2001 (has links)
Tsang Lai-Ling Angel. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 136-145). / Abstracts in English and Chinese. / Abstract --- p.i / 論文撮要 --- p.iv / Acknowledgment --- p.vi / Table of Content --- p.vii / List of Publications --- p.xii / List of Figures --- p.xiv / List of Tables --- p.xvii / Abbreviations --- p.xviii / Chapter Chapter1 --- Introduction --- p.1 / Chapter 1.1 --- The Human Uterus Vs Rat Uterus --- p.1 / Chapter 1.1.1 --- Myometrium --- p.1 / Chapter 1.1.2 --- Endometrium --- p.1 / Chapter 1.2 --- The Human Endometrium Vs Rat Endometrium --- p.2 / Chapter 1.2.1 --- The structure of Human Endometrium --- p.2 / Chapter 1.2.2 --- Cyclic Changes in the Endometrium --- p.4 / Chapter 1.2.3 --- Physiological Roles of the Endometrium --- p.7 / Chapter 1.2.4 --- Uterine Fluid Volume and its Composition --- p.7 / Chapter 1.2.4.1 --- Regulation of Uterine Fluid Volume and Composition --- p.7 / Chapter 1.2.4.2 --- Role of Endometrial Epithelium in the Regulation of Uterine Fluid Volume --- p.9 / Chapter 1.3 --- Epithelial Ion Channels --- p.9 / Chapter 1.3.1 --- Epithelial CI- Channels in Secretory Epithelia --- p.11 / Chapter 1.3.1.1 --- Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) --- p.13 / Chapter 1.3.2 --- Epithelial Na+ Channel (ENaC) in Absorbing Epithelia --- p.18 / Chapter 1.3.3 --- ENaC and CFTR in Endometrial Epithelia --- p.26 / Chapter 1.4 --- Hormonal Regulation of the Endometrial Epithelium --- p.29 / Chapter 1.4.1 --- Estrogen and Progesterone --- p.29 / Chapter 1.4.2 --- Aldosterone --- p.32 / Chapter 1.5 --- Aim of Study --- p.35 / Chapter Chapter2 --- Materials and Methods --- p.38 / Chapter 2.1 --- Materials --- p.38 / Chapter 2.1.1 --- Culture Medium and Enzymes --- p.38 / Chapter 2.1.2 --- Drugs --- p.38 / Chapter 2.1.3 --- Molecular Biology --- p.39 / Chapter 2.1.4 --- Experimental Tissues and Animals --- p.39 / Chapter 2.2 --- Preparations --- p.39 / Chapter 2.2.1 --- Pervious Support for Cell Growth --- p.39 / Chapter 2.2.2 --- Growth Medium --- p.40 / Chapter 2.2.3 --- Culture of Mouse Endometrium Epithelial Cells --- p.43 / Chapter 2.2.4 --- Solutions for the Short-Circuit Current Measurement --- p.44 / Chapter 2.2.5 --- Electrodes for the Short-Circuit Current Measurement --- p.44 / Chapter 2.2.6 --- Solutions for Molecular Biology Experiment --- p.44 / Chapter 2.2.6.1 --- Diethyl Pyrocarbonate (DEPC)-treated Water --- p.44 / Chapter 2.2.6.2 --- lx TAE (DNA gel electrophoresis and its running buffer) --- p.45 / Chapter 2.2.6.3 --- 5x MOPS (RNA gel electrophoresis and its running buffer) --- p.45 / Chapter 2.2.6.4 --- Formaldehyde Gel-loading Buffer --- p.45 / Chapter 2.3 --- Protocols --- p.46 / Chapter 2.3.1 --- Effect of Ovarian Hormones and Aldosterone on CFTR and ENaC Expression --- p.45 / Chapter 2.3.2 --- Possible Interaction between CFTR and ENaC upon Hormones Stimulation --- p.47 / Chapter 2.4 --- Methods of Measurement --- p.48 / Chapter 2.4.1 --- The Short-Circuit Current Technique --- p.48 / Chapter 2.4.1.1 --- The Short-Circuit Current Setup --- p.48 / Chapter 2.4.1.2 --- Experimental Procedures --- p.52 / Chapter 2.4.1.3 --- Data Analysis --- p.55 / Chapter 2.4.2 --- Reverse Transcription - Polymerase Chain Reaction (RT-PCR) --- p.55 / Chapter 2.4.2.1 --- RNA Isolation --- p.55 / Chapter 2.4.2.2 --- RNA Gel Electrophoresis --- p.56 / Chapter 2.4.2.3 --- Reverse Transcription (RT) --- p.57 / Chapter 2.4.2.4 --- Primer used for the Polymerase Chain Reaction (PCR) --- p.58 / Chapter 2.4.2.5 --- General Procedure of PCR and Competitive RT-PCR --- p.59 / Chapter 2.4.2.6 --- DNA Gel Electrophoresis --- p.61 / Chapter 2.4.3 --- Capillary Electrophoresis - Laser Induced Fluorescence (CE-LIF) --- p.62 / Chapter 2.4.3.1 --- Capillary Tube --- p.54 / Chapter 2.4.3.2 --- Detection System --- p.65 / Chapter 2.4.3.3 --- Experimental Procedures --- p.65 / Chapter 2.4.3.4 --- Data Analysis --- p.66 / Chapter 2.4.4 --- Statistical Analysis / Chapter Chapter3 --- Results --- p.68 / Chapter 3.1 --- Influence of Ovarian Hormones on Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) and Epithelial Na+ Channel (ENaC) Expression in Mouse Endometrial Epithelium --- p.68 / Chapter 3.2 --- Culture Condition on Expression and Function of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) in Mouse Endometrial Epithelial Cells --- p.92 / Chapter 3.3 --- Expression Regulation of Endometrial Epithelial Na+ Channel (ENaC) Subunits and Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) by Na+ Diet During the Estrus Cycle in Mice --- p.98 / Chapter 3.4 --- Enhanced Epithelial Na+ Channel (ENaC) Activity in Mouse Endometrial Epithelium by Upregulation of γ-ENaC Subunit --- p.114 / Chapter Chapter4 --- General Discussion --- p.127 / Appendix --- p.132 / Chapter A. --- RNA Isolation --- p.132 / Chapter B. --- Reverse Transcription (RT) --- p.133 / Chapter C. --- Polymerase Chain Reaction (PCR) --- p.134 / Chapter D. --- Sequences and Conditions of All Primers --- p.135 / References --- p.136
139

Caracterização da capacidade fotossintética e da condutância estomática em sete clones comerciais de Eucalyptus e seus padrões de resposta ao déficit de pressão de vapor / Photosynthetic capacity and stomatal conductance characterization for seven commercial Eucalyptus clones and their variation due to vapor pressure deficit

Ana Heloisa Carnaval Marrichi 30 March 2009 (has links)
O estudo caracterizou as variáveis fisiológicas da fotossíntese, em 7 clones de Eucalyptus de alta produtividade, determinando-se as capacidades fotossintéticas máximas (Amax), e o comportamento da fotossíntese (A), condutância (gs) e transpiração (E) em relação ao Déficit de Pressão de Vapor (DPV). Para isso, um ensaio foi instalado em 2004, na ESALQ/USP, contendo os clones do Projeto BEPP (Brasil Eucalyptus Produtividade Potencial), sendo cada parcela composta de 49 plantas (7x7) no espaçamento de 3,0m x 2,7m. Mediram-se as alturas ou DAPs e selecionaram-se 3 árvores médias para as mensurações fisiológicas, aos 16 e 36 meses. A amostragem para Amax foi composta de duas posições superiores da copa (2 e 3), dois galhos por posição e duas folhas por galho. As medições foram feitas das 8 às 10 horas (baixo DPV). Para o comportamento de A e gs frente ao DPV, as medições continuaram, de hora em hora, das 11 às 15 horas, nas folhas do primeiro galho da posição 2. Ao final as folhas foram coletadas para determinação da área foliar específica (AFE) e do nitrogênio (N). Aos 16 meses, foram feitas curvas A/Ci, para posterior cálculo de Vcmax (taxa máxima de carboxilação), Jmax (taxa máxima de transporte de elétrons) e VTPU (utilização da triose fosfato), pelo programa Photosyn Assistant. As curvas foram feitas em 2 árvores por clone, nas posições superiores e inferiores da copa. Todas mensurações foram realizadas com o aparelho LiCor-6400. Os resultados mostraram que Amax foi similar para as posições 2 e 3. Entre os clones, houve variação, porém não consistente entre idades, e todos mostraram altos valores de Amax na idade de 16 meses (entre 26 e 31, com média de 29 µmol m-2s-1), reduzindo-se aos 36 meses (entre 19 e 26, com média de 22 µmol m-2s-1). A AFE e o N também foram similares entre as posições 2 e 3 e maiores na idade mais jovem (11 versus 8 m²kg-1, 29 versus 21 gN kg-1), podendo estar associados à queda de Amax. A, gs e E também apresentaram menores valores aos 36 meses, para todos os clones (23 versus 18 µmol m-2s-1; 0,41 versus 0,26 mol m-2s-1; 9,2 versus 6,1 mmol m-2s-1). Os clones mostraram sensibilidade ao DPV, reduzindo os valores de gs e A ao longo do dia, sendo a sensibilidade menor aos 36 meses. As sensibilidades foram distintas, evidenciando potencial de seleção de materiais mais aptos a tolerarem estresse hídrico. Em geral, maiores valores de fotossíntese estão relacionados a maiores valores de transpiração, evidenciando a necessidade de se conhecer a disponibilidade hídrica local quando do uso de clones de alta produtividade. Vcmax, Jmax e VTPU foram maiores para as posições superiores da copa, e não diferiram entre os clones. Devido à semelhança fisiológica entre as posições 2 e 3, pode-se sugerir que não haja distinção entre elas em futuras medições de fotossíntese, essenciais para a parametrização de modelos. Não houve relação direta entre crescimento do tronco e fotossíntese, evidenciando a necessidade de integração com estudos relacionados à alocação do carbono dentro da planta. / This study aimed to characterize the physiological variables related to photosynthesis, in seven commercial Eucalyptus clones with high productivity, by evaluating maximum photosynthetic capacity (Amax), and the response of photosynthesis (A), stomatal conductance (gs) and transpiration (E) to Vapor Pressure Deficit (VPD). A trial was installed in 2004, at ESALQ/USP, with the clones that were part of BEPP Project (Brazil Eucalyptus Potential Productivity), and each plot had 49 plants (7x7) in a 3 m x 2.7m spacing. We measured tree height or DBHs and three average trees were selected for measurements, at 16 and 36 months. The sample to estimate Amax was: two crown positions (2 and 3), two branches per tree and two leaves per branch. The measurements which were taken from 8 to 10 am (low VPD). To get the response of A and gs to VPD measurements continued hourly, from 11 am to 3 pm, on the leaves from the first branch and position 2. At the end of the measurements leaves were collected for specific leaf area (SLA) and nitrogen (N) determination. Additionally, at 16 months, A/Ci curves were established, and parameters Vcmax, Jmax and VTPU were estimated through the program Photosyn Assistant. The curves were done for 2 trees per clone, at superior crown positions (2 and 3) and inferior ones (4 and 5). The physiological measurements and A/Ci curves were made using LiCor-6400. The results showed that Amax was similar for positions 2 and 3. There was variation among clones, but not consistent between ages, and all the clones had high Amax at 16 months (between 26 and 31 µmol m-2s-1, with an average of 29 µmol m-2s-1), decreasing at 36 months (between 19 and 26 µmol m-2s-1, with an average of 22 µmol m-2s-1). SLA and N were also similar between positions 2 and 3 and higher at younger age (11,1 versus 8,3 m²kg-1, 29,6 versus 21,1 gN kg-1;), what may be associate with Amax decrease. A, gs and E also showed lower values at age 36, for all the clones (23 versus 18 µmol m-2s-1; 0,41 versus 0,26 mol m-2s-1; 9,2 versus 6,1 mmol m-2s-1). All clones showed sensitivity to VPD, reducing gs and A with increasing VPD. However, the clones showed different sensitivities and all of them were less sensitive to VPD at age 36, highlighting a selection potential of genetic materials for water stress. In general, higher photosynthesis values were associated with higher transpiration, showing the necessity to know the water conditions of sites when planting genetic materials with high productivity. Vcmax, Jmax and VTPU were greater for superior positions compared to inferior ones, and were not different among clones. Due to a similarity in SLA, N and physiological and biochemical traits between positions 2 and 3, no distinction on future photosynthesis measurements between these positions is needed. Finally, there was not a direct relation between stem growth and photosynthesis, at both ages, showing that photosynthesis at crown level by itself can not capture all the ecophysiological processes related to wood productivity, being necessary the integration with studies related to carbon allocation inside the plant.
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Desenvolvimento da técnica analítica para determinar a resistência térmica de contato no processo de forjamento

Polozine, Alexandre January 2009 (has links)
A Resistência Térmica de Contato entre a ferramenta de forjamento e a peça é um parâmetro importante para a otimização, por simulação computacional, do comportamento do material forjado. Os procedimentos atuais destinados à determinação da Resistência Térmica de Contato apresentam discrepância significativa nos resultados. A falta de valores confiáveis deste parâmetro afeta a precisão da simulação. Visando a importância das ferramentas computacionais para a otimização do processo de forjamento, no presente trabalho foi desenvolvida uma nova técnica para determinar a Resistência Térmica de Contato. A técnica inovadora inclui o método de medição de temperaturas interfaciais desconhecido anteriormente, a montagem para realizá-lo e o sistema de medição de temperaturas volumétricas. Esta técnica é destinada ao uso sob condições de altas e moderadas temperatura e pressão muito grande, o que é característico da zona de contato material forjado–ferramenta. A inovação foi testada com sucesso para alguns materiais típicos (aço, liga de alumínio e liga de titânio) utilizados no forjamento a quente ou a morno. Os valores da Resistência Térmica de Contato, obtidos nos testes, são recomendados para uso em programas de simulação computacional. / The Thermal Contact Resistance between a die and a blank is an important parameter in the computer simulation used for the optimization of the blank plastic deformation. The known procedures intended for the determination of the Thermal Contact Resistance show significant discrepancy in results. The lack of reliable values of this parameter affects the precision of the simulation. Taking in account the importance of computer tools for the optimization of the forging process, a new technique for the determination of the Thermal Contact Resistance has been developed in the present study. The developed technique includes a method for the measurement of the interface temperatures, which was unknown before, and the equipment for the realization of this method as well as the system for the measurement of the volumetric temperatures. This technique is intended for use under moderate and high temperature / high pressure conditions at the die–workpiece interface. The innovation has been tested successfully on some typical materials (steel, aluminium alloy e titanium alloy) used in warm and hot forging. Values of the Thermal Contact Resistance obtained by these tests are recommended for use in computer simulations.

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