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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

Development of Dual Fluorescent Probes by Controlling Photophysical Properties of Flapping Fluorophores / 羽ばたく蛍光団の光物性制御による二重蛍光性プローブの創出

Yamakado, Takuya 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23735号 / 理博第4825号 / 新制||理||1690(附属図書館) / 京都大学大学院理学研究科化学専攻 / (主査)准教授 齊藤 尚平, 教授 依光 英樹, 教授 若宮 淳志 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
12

DEVELOPMENT OF NOVEL CHEMICAL TOOLS FOR PROTEASOME BIOLOGY & A NEW APPROACH TO 1-AZASPIROCYCLIC RING SYSTEM

Kumar, Lalit 01 January 2012 (has links)
The proteasome, a multiprotease complex, is clinically validated as an anticancer target by the FDA approval of bortezomib and carfilzomib for the treatment of multiple myeloma. The emergence of resistance to proteasome inhibitors however remains a major clinical challenge. Recently, distinct types of proteasomes termed ‘intermediate proteasomes’, which contain unconventional mixtures of catalytic subunits, have been implicated with drug resistance of tumor cells. In elucidating the role of intermediate proteasomes in drug resistance, a crucial step is to unequivocally determine the subunit composition of intermediate proteasomes in cells. With this in mind, the goal of the studies reported in this dissertation is to develop novel chemical tools which can facilitate the investigation of intermediate proteasomes via two complementary approaches: a FRET-based approach and a bifunctional cross-linking approach. Chapter 2 describes the structure-based design, synthesis, and characterization of a peptide epoxyketone-based fluorescent probe, named as LKS01-B650, which selectively targets the immunoproteasome subunit β5i/LMP7. In addition to its utility in determining the identity of intermediate proteasomes as FRET-based probe, this imaging agent may also serve as a valuable tool in visualizing the immunoproteasome in living cells. Chapter 3 describes the design and synthesis of various epoxyketone-based bifunctional agents. The ability of these bifunctional agents to cross-link different catalytic subunits within a proteasome complex is shown by mobility shift assays.These bifunctional agents may provide important information in determining the subunit composition of proteasomes. Chapter 4 describes a systematic study of the relationship between the proteasome inhibitor structure and the inhibitory activity against critical subunits of the proteasome. Given the reported role of β5i/LMP7 in autoimmune diseases, this study may provide useful insights in developing therapeutic agents for autoimmune diseases as well as other diseases. Chapter 5 describes a separate study which is not related to proteasome biology. A concise approach to synthesize 1-azaspirocyclic ring systems is developed by utilizing a novel semi-pinacol/Beckmann rearrangement. Additionally, an environmentally benign, microwave-assisted, and solvent-free self-condensation of carbonyl compounds is reported.
13

Small molecule colorimetric and fluorescent probes for specific protein detection

Egleton, James Edward January 2015 (has links)
This thesis describes the design, synthesis, analysis, mechanistic evaluation and optimisation of small molecule probes for the specific detection of proteins, focusing on the target protein human arylamine <i>N</i>-acetyltransferase type 1 (HUMAN(NAT1)) and its murine homologue, mouse arylamine <i>N</i>-acetyltransferase type 2 (MOUSE(NAT2)). The HUMAN(NAT1) gene is reported to be one of the most highly overexpressed genes in estrogen-receptor-positive (ER+) breast tumours, leading to its potential use as both a novel diagnostic biomarker and a novel therapeutic target for this disease. <strong>Chapter 1</strong> reviews the literature on optical methods for the specific detection of a protein target, exploring strategies both based on biosensors and on chemical probes, before introducing the arylamine <i>N</i>-acetyltransferases as a family of enzymes. In <strong>Chapter 2</strong>, a family of naphthoquinone inhibitors of HUMAN(NAT1) are introduced, which undergo a colour change from red to blue upon binding specifically to the enzyme. The mechanism of this colour change, a proton transfer-mediated process, is discussed via the synthesis, pharmacological and colorimetric evaluation of close analogues of the hit compound lacking a key acidic sulfonamide-N<i>H</i> proton. During these studies, it was found that direct <i>O</i>-methylation of a sulfonamide is possible under certain conditions; such a reaction has not previously been reported. Furthermore, upon heating in polar solvents the <i>O</i>-methylated sulfonamide was observed to undergo rearrangement, and the mechanism of this process is investigated via NMR and kinetic studies. In <strong>Chapter 3</strong>, the design, synthesis and evaluation of HUMAN(NAT1) inhibitors with improved pharmacological and colorimetric profiles over the initial hit are described. From this optimisation, structure-activity relationships and an in silico model of interactions between the inhibitors and enzyme are evaluated. Testing of these compounds in cellular environments, however, exposes some limitations of this approach, notably the lack of sensitivity of the probes when dosed at low concentrations in cellular samples. In order to overcome this limitation, in <strong>Chapter 4</strong> fluorescent analogues of the hit compound are designed and synthesised. Initial compounds developed in this series possess promising properties, but each compound generated suffers from either a low fluorescent intensity, lack of a <i>p</i>H-dependent switch in fluorescence or a low fluorescence excitation wavelength, which overlaps with those of tryptophan or tyrosine residues in proteins. Insights into the mechanism of molecular fluorescence and application of some simple quantum mechanical principles, however, lead to the design of a species which possesses all the required properties. The fluorescent emission intensity of this probe correlates linearly with [MOUSE(NAT2)] in E. coli cell extracts, and can quantify as little as 0.64% MOUSE(NAT2) in the samples; furthermore, the probe is capable of unambiguously detecting HUMAN(NAT1) within a cell extract from the ER+ breast cancer cell line ZR-75-1; future work on this probe may therefore enable its clinical use in improved early diagnosis of breast tumours. This study also represents, to the best of our knowledge, the first ever example of a small molecule, non-covalent probe capable of quantifying the concentration of a target protein in cellular extracts. In <strong>Chapter 5</strong>, the series of naphthoquinone probes is further optimised in order to study the roles of HUMAN(NAT1) in a cellular environment. Firstly, structure-activity relationships are utilised to design inhibitors with improved physical properties such as aqueous solubility and cell membrane permeability, in order to test the effect of HUMAN(NAT1) inhibitors in tumour cell models, which could have implications for the future use of a HUMAN(NAT1) inhibitor as a therapeutic agent in oncology. Secondly, the effect of the cofactor folic acid on the function and activity of HUMAN(NAT1) is explored. Finally, in <strong>Chapter 6</strong>, the conclusions of this study are outlined and a hypothesis as to how the concepts developed in this thesis might be applied to alternative, more ubiquitous biological targets is discussed, paving the way for future investigations.
14

Efeito do uso dos antioxidantes melatonina, ácido ferúlico e mioinositol sobre a motilidade, integridade de membranas e produção de espécies reativas de oxigênio em sêmen equino refrigerado / Effect of the use of the antioxidants melatonin, ferulic acid and myoinositol on motility, membrane integrity and oxygen reactive species production in cooled equine semen

Affonso, Fernanda Jordão 26 July 2013 (has links)
O estresse oxidativo é prejudicial a diversas características espermáticas, como motilidade e integridade das membranas plasmática, acrossomal e mitocondrial, podendo levar a redução da fertilidade, inclusive no sêmen refrigerado. Poucos estudos foram realizados utilizando-se a melatonina com o intuito de melhorar as características espermáticas em equinos. O mioinositol e o ácido ferúlico, por sua vez, nunca foram utilizados nessa espécie. O presente trabalho teve como objetivo avaliar a influência desses compostos nas características do sêmen equino refrigerado. Para isso, foram utilizadas quatro ejaculados, de quatro animais conhecidamente férteis, com idade entre 4 e 8 anos. Após a coleta, o sêmen foi distribuído entre os quatro tratamentos, sendo eles, melatonina, ácido ferúlico, mioinositol e controle, utilizando-se diluidor á base de leite desnatado, na concentração de 25 milhões de espermatozoides por mL. As amostras foram refrigeradas à 5°C, sob uma curva de refrigeração de 0,09°C/min e avaliadas com 0, 4 e 8 horas de refrigeração, quanto às características de motilidade (CASA), integridade das membranas plasmática, acrossomal e o potencial de membrana mitocondrial (utilizando-se as sondas fluorescentes PI, H342, FITC-PSA e JC-1, por microscopia de epifluorescência), e quantificação da produção de espécies reativas de oxigênio (utilizando-se a sonda fluorescente DCFH-DA, por fluorímetria). Os dados obtidos foram analisados pelo programa SAS, versão 9.3 (SAS, 2011). As características de motilidade não foram afetadas pelos tratamentos, com exceção da Amplitude Lateral de Cabeça (ALH, µm/s), que foi maior nas amostras tratadas com mioinositol (8,34± 0,21), em relação ao grupo controle (7,87 ± 0,20). Foi observado efeito de interação entre tempo e tratamento para a variável Velocidade de Trajeto (VAP; P<0,05). Quanto à integridade das membranas, todas as variáveis sofreram efeito dos tratamentos, com exceção da porcentagem de células com membrana plasmática intacta (MPI). A porcentagem de células com membranas íntegras (membrana plasmática intacta, acrossomo intacto e alto potencial de mitocôndria; PIAIA), foi maior nos grupos tratados com melatonina (78,07 ± 2,02) e com ácido ferúlico (78,78 ± 1,66), em comparação ao grupo controle (73,75 ± 2,01). A porcentagem de células com alto potencial de mitocôndria (APM), também foi maior nos grupos tratados com melatonina (80,11± 1,85) e com ácido ferúlico (81,01 ± 1,50), em relação ao grupo controle (76,56 ± 1,99). Já a porcentagem de membrana acrossomal intacta (MAI), foi maior no grupo tratado com melatonina (99,69± 0,07), em relação a todos os outros grupos (99,41 ± 0,09; 99,33 ± 0,09; 99,39 ± 0,09; mioinositol, acido ferúlico e controle, respectivamente). A fluorescência emitida, relativa à quantidade de espécies reativas de oxigênio presentes na amostra não foi alterada pelos tratamentos, em nenhum dos tempos. Com isso conclui-se que a adição de melatonina e ácido ferúlico aumenta a porcentagem de células com alto potencial de mitocôndria, sugerindo a adição desses compostos ao diluidor visando maior manutenção da viabilidade por até 8 horas de refrigeração. / Oxidative stress is detrimental to several sperm characteristics such as motility, plasma, acrosomal and mitochondrial membrane integrity, and can lead to reduced fertility, also in cooled semen. Few studies were performed using melatonin intending an improvement in equine sperm characteristics. Para isso, foram utilizadas quatro ejaculados, de quatro animais conhecidamente férteis, com idade entre 4 e 8 anos. Myoinositol and ferulic acid, in turn, were never used in this species. The objective of the present study was to evaluate the influence of these compounds in equine cooled semen characteristics. Four collections from four stallions of known fertility aged between 4 and 8 years old were used. After collection, semen was distributed in one of the four treatments, melatonin, ferulic acid, myoinositol and control. A skim milk based extender was used and semen was diluted to a final concentration of 25 million sperm per mL. Samples were cooled at 5°C, at a cooling rate of 0.09°C/min and evaluated at 0, 4 and 8 hoours of cooling. CHaracteristics anlyzed were motility (CASA), plasma and acrosomal membrane integrity mytochondrial membrane potential (using florescente probes PI, H342, FITC-PSA e JC-1, using epifluorescence microscopy), and reactive oxygen species production quantification (using DCFH-DA fluorescente probe, by fluorimetry. Data obtained were analyzed using SAS program, 9.3 version (SAS, 2011). Motility characteristics were not affected by treatments, with the exception of average of lateral head displacement (ALH, µm/s), which was greater in myoinositol treated samples (8.34± 0,21), in comparison to the control group (7.87 ± 0.20). An interaction effect was detected between time and treatment for the velocity of the average path (VAP; P<0.05). Regarding membrane integrity, all variables were affected by treatments, with the exception of the percentage of intact plasma membrane cells (IPM). The percentage of cells with intact membranes (intact plasma membrane, intact acrosome, high mytochondrial potential; IPIAH) was greater for the groups treated with melatonin (78.07 ± 2.02) and ferulic acid (78.78 ± 1.66), comparing to the control group (73.75 ± 2.01). The percentage of cells with high mytochondrial potential (HMP) was also greater in melatonina treated group (80.11± 1.85) and ferulic acid (81.01 ± 1.50) comparing to the control group (76.56 ± 1.99). Percentage of cells with intact acrosomal membrane (IAM) was higher in melatonin treated group (99.69± 0.07) than all the other groups (99.41 ± 0.09; 99.33 ± 0.09; 99.39 ± 0.09; myoinositol, ferulic acid and control, respectively). Concerning reactive oxygen species in the sample, emitted fluorescence was not altered by treatments at any moment evaluated. It can be concluded that the addition of melatonin and ferulic acid the percentage of high mitochondrial potential cells, suggesting a beneficial utilization of these coumpounds in the extender for a greater maintenance of viability up to 8 hours of cooling.
15

Efeito do uso dos antioxidantes melatonina, ácido ferúlico e mioinositol sobre a motilidade, integridade de membranas e produção de espécies reativas de oxigênio em sêmen equino refrigerado / Effect of the use of the antioxidants melatonin, ferulic acid and myoinositol on motility, membrane integrity and oxygen reactive species production in cooled equine semen

Fernanda Jordão Affonso 26 July 2013 (has links)
O estresse oxidativo é prejudicial a diversas características espermáticas, como motilidade e integridade das membranas plasmática, acrossomal e mitocondrial, podendo levar a redução da fertilidade, inclusive no sêmen refrigerado. Poucos estudos foram realizados utilizando-se a melatonina com o intuito de melhorar as características espermáticas em equinos. O mioinositol e o ácido ferúlico, por sua vez, nunca foram utilizados nessa espécie. O presente trabalho teve como objetivo avaliar a influência desses compostos nas características do sêmen equino refrigerado. Para isso, foram utilizadas quatro ejaculados, de quatro animais conhecidamente férteis, com idade entre 4 e 8 anos. Após a coleta, o sêmen foi distribuído entre os quatro tratamentos, sendo eles, melatonina, ácido ferúlico, mioinositol e controle, utilizando-se diluidor á base de leite desnatado, na concentração de 25 milhões de espermatozoides por mL. As amostras foram refrigeradas à 5°C, sob uma curva de refrigeração de 0,09°C/min e avaliadas com 0, 4 e 8 horas de refrigeração, quanto às características de motilidade (CASA), integridade das membranas plasmática, acrossomal e o potencial de membrana mitocondrial (utilizando-se as sondas fluorescentes PI, H342, FITC-PSA e JC-1, por microscopia de epifluorescência), e quantificação da produção de espécies reativas de oxigênio (utilizando-se a sonda fluorescente DCFH-DA, por fluorímetria). Os dados obtidos foram analisados pelo programa SAS, versão 9.3 (SAS, 2011). As características de motilidade não foram afetadas pelos tratamentos, com exceção da Amplitude Lateral de Cabeça (ALH, µm/s), que foi maior nas amostras tratadas com mioinositol (8,34± 0,21), em relação ao grupo controle (7,87 ± 0,20). Foi observado efeito de interação entre tempo e tratamento para a variável Velocidade de Trajeto (VAP; P<0,05). Quanto à integridade das membranas, todas as variáveis sofreram efeito dos tratamentos, com exceção da porcentagem de células com membrana plasmática intacta (MPI). A porcentagem de células com membranas íntegras (membrana plasmática intacta, acrossomo intacto e alto potencial de mitocôndria; PIAIA), foi maior nos grupos tratados com melatonina (78,07 ± 2,02) e com ácido ferúlico (78,78 ± 1,66), em comparação ao grupo controle (73,75 ± 2,01). A porcentagem de células com alto potencial de mitocôndria (APM), também foi maior nos grupos tratados com melatonina (80,11± 1,85) e com ácido ferúlico (81,01 ± 1,50), em relação ao grupo controle (76,56 ± 1,99). Já a porcentagem de membrana acrossomal intacta (MAI), foi maior no grupo tratado com melatonina (99,69± 0,07), em relação a todos os outros grupos (99,41 ± 0,09; 99,33 ± 0,09; 99,39 ± 0,09; mioinositol, acido ferúlico e controle, respectivamente). A fluorescência emitida, relativa à quantidade de espécies reativas de oxigênio presentes na amostra não foi alterada pelos tratamentos, em nenhum dos tempos. Com isso conclui-se que a adição de melatonina e ácido ferúlico aumenta a porcentagem de células com alto potencial de mitocôndria, sugerindo a adição desses compostos ao diluidor visando maior manutenção da viabilidade por até 8 horas de refrigeração. / Oxidative stress is detrimental to several sperm characteristics such as motility, plasma, acrosomal and mitochondrial membrane integrity, and can lead to reduced fertility, also in cooled semen. Few studies were performed using melatonin intending an improvement in equine sperm characteristics. Para isso, foram utilizadas quatro ejaculados, de quatro animais conhecidamente férteis, com idade entre 4 e 8 anos. Myoinositol and ferulic acid, in turn, were never used in this species. The objective of the present study was to evaluate the influence of these compounds in equine cooled semen characteristics. Four collections from four stallions of known fertility aged between 4 and 8 years old were used. After collection, semen was distributed in one of the four treatments, melatonin, ferulic acid, myoinositol and control. A skim milk based extender was used and semen was diluted to a final concentration of 25 million sperm per mL. Samples were cooled at 5°C, at a cooling rate of 0.09°C/min and evaluated at 0, 4 and 8 hoours of cooling. CHaracteristics anlyzed were motility (CASA), plasma and acrosomal membrane integrity mytochondrial membrane potential (using florescente probes PI, H342, FITC-PSA e JC-1, using epifluorescence microscopy), and reactive oxygen species production quantification (using DCFH-DA fluorescente probe, by fluorimetry. Data obtained were analyzed using SAS program, 9.3 version (SAS, 2011). Motility characteristics were not affected by treatments, with the exception of average of lateral head displacement (ALH, µm/s), which was greater in myoinositol treated samples (8.34± 0,21), in comparison to the control group (7.87 ± 0.20). An interaction effect was detected between time and treatment for the velocity of the average path (VAP; P<0.05). Regarding membrane integrity, all variables were affected by treatments, with the exception of the percentage of intact plasma membrane cells (IPM). The percentage of cells with intact membranes (intact plasma membrane, intact acrosome, high mytochondrial potential; IPIAH) was greater for the groups treated with melatonin (78.07 ± 2.02) and ferulic acid (78.78 ± 1.66), comparing to the control group (73.75 ± 2.01). The percentage of cells with high mytochondrial potential (HMP) was also greater in melatonina treated group (80.11± 1.85) and ferulic acid (81.01 ± 1.50) comparing to the control group (76.56 ± 1.99). Percentage of cells with intact acrosomal membrane (IAM) was higher in melatonin treated group (99.69± 0.07) than all the other groups (99.41 ± 0.09; 99.33 ± 0.09; 99.39 ± 0.09; myoinositol, ferulic acid and control, respectively). Concerning reactive oxygen species in the sample, emitted fluorescence was not altered by treatments at any moment evaluated. It can be concluded that the addition of melatonin and ferulic acid the percentage of high mitochondrial potential cells, suggesting a beneficial utilization of these coumpounds in the extender for a greater maintenance of viability up to 8 hours of cooling.
16

Viabilidade de embriões caprinos e ovinos produzidos in vivo após criopreservação utilizando etilenoglicol,dimetilsulfóxido e dimetilformamida / Viability of goats and sheep embryos produced in vivo after cryopreservation using ethylene glycol, dimethylsulfoxide and dimethylformamide

LEMOS, Paula Fernanda Barbosa de Araújo 25 February 2010 (has links)
Submitted by (edna.saturno@ufrpe.br) on 2016-10-21T12:27:30Z No. of bitstreams: 1 Paula Fernanda Barbosa Araujo Lemos.pdf: 3078966 bytes, checksum: 8a115f68bff79f88ab9763ce148e7321 (MD5) / Made available in DSpace on 2016-10-21T12:27:30Z (GMT). No. of bitstreams: 1 Paula Fernanda Barbosa Araujo Lemos.pdf: 3078966 bytes, checksum: 8a115f68bff79f88ab9763ce148e7321 (MD5) Previous issue date: 2010-02-25 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The possibility of using a practical, fast and effective protocol for embryo cryopreservation such as glazing, may stimulate the application of the technique associated with embryo transfer by a larger number of teams at field level. However, it is necessary to develop specific protocols that result in increased embryonic viability. The objective of this study was to identify the damage caused by cryopreservation, assessing the morphological and ultrastructural feasibility of goat and sheep embryos undergoing cryopreservation of classic and vi trification in OPS (Open Pulled Straw). In experiment 1, embryos (N = 246) were obtained from superovulated Boer goats. The embryos were randomly divided into three groups: control group (n = 75) - freezing the classic method, DMSO group (n = 74) - vitrification and Group DF (n = 74) - vitrification. Embryos in the classic metod group were frozen using automatic freezing. Before freezing the embryos were left five minutes in the stabilizing solution of Ethylene glycol (EG). The embryos of the second group were placed in a DMSO solution containing 10% EG and 10% dimethyl sulfoxide (DMSO) and then transferred to a vitrification solution with 20% EG and 20% DMSO +0.5 sucrose. The embryos ofthe third group were placed in a balanced so lution containing 10% EG and 10% Dimethylformamide (DF) and then transferred to a vitrification solution with 20% EG and 20% sucrose +0.5 DF. In experiment 2, sheep embryos (N = 186) were obtained from superovulated Santa Ines ewes. The embryos were randomly divided into three groups: control group (n = 55) - freezing the classic method, DMSO group (n = 54) - vitrification and Group DF (n = 55) - vitrification. Embryos in the classic metod group were frozen using automatic freezing. Before freezing the embryos were left five minutes in the stabilizing solution of Ethylene glycol (EG). The embryos of the second group were placed in a DMSO solution containing 10% EG and 10% dimethyl sulfoxide (DMSO) and then transferred to a vitrification solution with 20% EG and 20% DMSO+0.5 sucrose. The embryos of group three were placed in a balanced solution containin g 10% EG and 10% Dimethylformamide (DF) and then transferred to a vitrification solution with 20% EG and 20% sucrose +0.5 DF. The embryos were evaluated by analysis of embryonic viability by the use of fluorescent probes, in this case propidium iodide and Hoechst 33342 Results indicate that in goat embryos, the control group maintained most of its viable cells after thawing with 33 33% of samples injured. Of embryos in the DMSO group, 26.66% had totally damaged cells. The DF group had 60% of samples with lesions. The ultrastructural study by transmission electron microscopy showed that the vitrified embryos had a greater preservation of cells. The vitrified embryos with DMSO had higher rates of in vitro survival (47.36%), followd by embryos glazed with the DF with a lower in vitro survival rate (31.58%), and lastly embryos frozen by the traditional method (25%). In sheep embryos found in theanalysis by fluorescent probe, cells in t he control group remained viable in all embryos analyzed, a similar result occurred with the DF group, where 80% of samples were deemed feasible, other than the DMSO group, which had 50% viability. The ultrastructural study showed that the findings were similar between the control and DF groups. Embryos vitrified with DF had higher rates of in vitro survival (53.33%) and in vivo (45%), the glazed with DMSO had an in vitro survival rate (26.66%) and in vivo (30%) and embryos frozen by the traditional method (33.33%) in vitro and (40%) in vivo. It can be concluded that the vitrification solution containing 20% ethylene glycol + 20% dimethylsulfoxide + 0.5 M sucrose is an effective method for cryopreservation of goat embryos produced in vivo. However, in sheep embryos, the combination of 20% ethylene glycol + 20% dimethylformamide + 0.5 M sucrose was the best cryoprotectant regarding embryo viability, demonstrating to cause less damage to thecytoskeleton and cell organelles, and presenting a satisfactory pregnancy rate. / A possibilidade de utilizar um protocolo de criopreservação prático, rápido e eficaz, como a vitrificação, estimularia a aplicação da técnica associada à transferência de embriões por um maior número de equipes em nível de campo. Porém, faz-se necessário o desenvolvimento de protocolos específicos que resultem no incremento da viabilidade embrionária. O objetivo deste trabalho foi identificar os danos causados pela criopreservação, avaliando a viabilidade morfológica e ultra-estrutural de embriões caprinos e ovinos submetidos a criopreservação pelo método clássico e pela vitrificação em OPS (Open Pulled Straw). No experimento 1, os embriões (N=246) foram obtidos de cabras da raça Boer superovuladas. Os embriões foram distribuídos aleatoriamente em três grupos: Grupo Controle (n= 75) - congelação pelo método clássico, Grupo DMSO (n= 74) – vitrificação e Grupo DF(n= 74) – vitrificação. Os embriões destinados ao congelamento clássico foram congelados utilizando congelador automático de embriões. Antes da congelação os embriões ficaram cinco minutos estabilizando nasolução de Etilenoglicol (EG). Os embriões do grupo DMSO foram equilibrados em solução de 10% de EG e 10% de Dimetilsulfóxido (DMSO) e depois transferido para solução de vitrificação com 20% EG e 20%DMSO +0,5 sacarose. Os embriões do grupo DF foram equilibrados em solução de 10% de EG e 10% de Dimetilformamida (DF) e depois transferido para solução de vitrificação com 20% EG e 20% DF+0,5 sacarose. No experimento 2, os embriões ovinos (N=186) foram obtidos de ovelhas da raça Santa Inês superovuladas. Os embriões foram distribuídos aleatoriamente em três grupos: Grupo Controle (n= 55) - congelação pelo método clássico, Grupo DMSO (n=54) – vitrificação e Grupo DF (n= 55) – vitrificação. Os embriões destinados ao congelamento clássico foram congelados utilizando congelador automático de embriões. Antes da congelação os embriões ficaram cinco minutos estabilizando na solução de Etilenoglicol (EG). Os embriões do grupo DMSO foram equilibrados em solução de 10% de EG e10% de Dimetilsulfóxido (DMSO) e depois transferido para solução de vitrificação com 20% EG e 20% DMSO+0,5 sacarose. Os embriões do grupo DF foram equilibrados emsolução de 10% de EG e 10% de Dimetilformamida (DF) e depois transferido para solução de vitrificação com 20% EG e 20% DF+0,5 sacarose. Os embriões foram avaliados por meio da análise da viabilidade embrionária pelo uso de sondas fluorescentes, utilizou-se Iodeto de Propídeo e Hoechst 33342, verificou-se nos embriões caprinos, que o grupo controle mantiveram grande parte das suas células integras após o descongelamento, 33,33% das amostras apresentaram-se lesionadas. Os embriões do grupo DMSO analisados, 26,66% estavam com suas células totalmente danificadas. O grupo DF apresentou 60% das amostras com lesões. O estudo ultra-estrutural por microscopia eletrônica de transmissão demonstrou que os embriões vitrificados revelaram uma maior preservação das células. Os embriões vitrificados com DMSO tiveram maiores taxas de sobrevivência in vitro (47,36%), os vitrificados com DF tiveram uma taxa de sobrevivência in vitro (31,58%), os congelados pelo métodoclássico obtiveram in vitro (25%). Nos embriões ovinos verificamos na análise por sonda fluorescente, que as células do grupo controle mantiveram viáveis em todos os embriões analisados, resultado semelhante ocorreu com o grupo DF, onde 80% das amostram foram consideradas viáveis, diferente do grupo DMSO, que tiveram 50% de viabilidade. O estudo ultra-estrutural demonstrou que os achados foram semelhantes entre os grupos controle e DF. Os embriões vitrificados com DF tiveram maiores taxas de sobrevivência in vitro (53,33%) e in vivo (45%), os vitrificados com DMSO tiveram uma taxa de sobrevivência in vitro (26,66%) e in vivo (30%) e os congelados pelo método clássico obtiveram (33,33%) in vitro e (40%) in vivo. Podemos concluir que, a solução de vitrificação contendo 20% de etilenoglicol + 20% de dimetilsulfóxido + 0,5M sacarose é um método eficiente para a vitrificação de embriões caprinosproduzidos in vivo. Entretanto em embriões ovinos, a associação de 20% de etilenoglicol + 20% de dimetilformamida + 0,5M de sacarose, foi o crioprotetor que apresentou melhor viabilidade embrionária, demonstrando causar menos lesões ao citoesqueleto e as organelas celulares, como isso apresentando um índice de gestação satisfatório.
17

Hydrosolubilizace skeletu BODIPY pro optické značení biomolekul / Hydrosolubilization of BODIPY for optical labelling of biomolecules

Bartoň, Jan January 2015 (has links)
1 Abstract This work aims at showing synthesis and potential use of water-soluble fluorescent probes based on BODIPY. The preparation of probes containing bioorthogonal mono- and heterobifunctional functional groups was demonstrated. Ground work was done at the optimisation of reliable, scalable and fast sulfonation of BODIPY in 2,6-positions. A protocol for handling sulfonated BODIPY has been established; especially for the exchange of counterions. In counterion se- lection, their relation to synthetic pathway and biocompatibility were taken into consideration. The second part of the work shows series of water-soluble fluorescent probes, into which can be easily introduced bioactive or bioorthogonal functional groups. This can be used for click chemistry in connection with turn off/on probes or fluorescent sensing of molecules or ions. All this can be done in aqueous solution without organic solvents, which is relevant for biochemical, analytical and imaging applications. Keywords BODIPY, bifunctional, water-soluble, fluorescent probe, solubilization, biocompa- tible probes, bioorthogonal reaction, BODIPY sulfonation
18

Controle da regiosseletividade de abertura de 2,3-epóxi-éster empregando selenolatos metálicos visando a obtenção de seleno-&#945;-hidroxi-éster / Regioselectivity control of the ring opening of 2,3-epoxy ester with selenolates metallics aiming to produce seleno-&#945;-hydroxy ester

Celante, Gizele 13 April 2017 (has links)
No presente trabalho foram realizados estudos de regiosseletividade das reações de abertura de 2,3-epoxipropanoato de etila (1) utilizando diferentes nucleófilos de selênio e algumas dessas reações foram desenvolvidas com a adição do ácido de Lewis trifluoreto de boro dietil éter (BF3&#183;Et2O). A abertura desse oxirano ao utilizar os nucleófilos MeSeMgCl e MeSeLi-BF3&#183;Et2O ocorreu seletivamente no Carbono C-3 formando o composto de interesse (3-metilseleno 2-hidroxipropanoato de etila), já ao utilizar MeSeLi (em ausência ácido de Lewis) a abertura procedeu-se seletivamente no carbono C-2 formando 2-metilseleno-3-hidroxipropanoato de etila. A reação com o nucleófilo (Na[PhSeB(OEt)3]) levou à mistura desses regioisômeros. O ácido de Lewis BF3&#183;Et2O em presença do selenolato levou a inversão de regiosseletividade da reação de abertura do epóxido 1 e a razão estequiométrica de BF3&#183;Et2O adicionada ao meio reacional correspondeu, proporcionalmente, a porcentagem de obtenção do produto de abertura em C-3 (Tabela 1). Os resultados obtidos sugeriram que BF3&#183;Et2O altera a nucleofilicidade do selenolato (RMN de 77Se) a partir de uma interação selênio-boro. A formação da ligação Se-B pode ocorrer com ou sem a liberação de fluoreto e esse mecanismo foi investigado por meio do emprego de uma sonda fluorescente seletiva desse haleto. O mecanismo dessas reações também foram investigados por cálculos teóricos, os quais mostram-se totalmente coerentes com os resultados experimentais. / In the present work was studied reactions of regioselective opening of 2,3-epoxyester using different selenolatos and some of this reactions were developed by adding Lewis acid BF3&#183;Et2O. The opening reaction of this oxirane using the nucleofilms MeSeMgCl and MeSeLi-BF3&#183;Et2O occurred selectively in carbon C-3 forming the compound of interest (ethyl 3-methylselene 2-hydroxypropanoato of ethyl), already using MeSeLi (in Lewis acid absence) the reaction was selectively on C-2 carbon to form ethyl 2-methylselene-3-hydroxypropanoate. The reaction with the nucleophile (Na[PhSeB(OEt)3]) formed a mixing of these regioisomers. The Lewis acid BF3&#183;Et2O in presence of selenolate reverses the regioselectivity of opening epoxide (1) reaction and the stoichiometric value of BF3&#183;Et2O added in the reaction corresponded proportionally with the percentage of C-3 product (Table 1). The results suggested that BF3&#183;Et2O alters the nucleophilicity of selenolate (77Se NMR) from a selenium-boron interaction. Se-B bond formation may occur with or without fluoride release and this mechanism has been investigated by the use of a selective fluorescent probe of that halide. The mechanism of these reactions was also investigated by theoretical calculations, which are fully consistent with the experimental results.
19

Synthesis and Applications of Dynamic Multivalent Nanostructures

Neranon, Kitjanit January 2015 (has links)
This thesis focuses on the design, synthesis and development of dynamic multivalent nanostructures such as supramolecular dendrimers, liposomes and gold-functionalized nanostructures. These structures can be used for drug delivery and molecular sensing applications. This thesis is divided into three parts: In part one, a general introduction to self-assembly, dynamic systems, metalligand exchange, nanostructured dendritic scaffolds, liposomes and gold nanostructures is given. In part two, a microwave approach is presented as an efficient method for the regioselective deuteration of bipyridine scaffolds. Dynamic systems based on transition metal-bipyridine coordination complexes were investigated. The compositional self-adaptation and kinetics of these dynamic systems were successfully assessed by ESI-MS. Based on this amphiphilic dendrimers/metallodendrimers were also designed and synthesized via  a convergent strategy. Their ability to self-assemble into supramolecular assemblies and their controlled disassembly was effectively demonstrated. In part three, two types of drug delivery systems based on dynamic multivalent nanostructures of glycodendrimers/metalloglycodendrimers and drugpresenting liposomes were developed. The dynamic self-assembly of these architectures into supramolecular nanostructures with site-specific functionality through interacting carbohydrate or cholesterol moieties was assessed. The host-guest interaction/encapsulation and controlled release with external stimuli were studied using a fluorescent probe, as well as selected drug molecules. The antibacterial property of the drug delivery systems was also evaluated, demonstrating an enhanced bactericidal activity. A new, rapid and simple approach for the functionalization of plasmonic gold nanostructured surfaces was also developed. The optical performance and light-specific sensitivity of the fluorescent probe on the resulting nanostructures were also presented. / <p>QC 20151119</p>
20

Controle da regiosseletividade de abertura de 2,3-epóxi-éster empregando selenolatos metálicos visando a obtenção de seleno-&#945;-hidroxi-éster / Regioselectivity control of the ring opening of 2,3-epoxy ester with selenolates metallics aiming to produce seleno-&#945;-hydroxy ester

Gizele Celante 13 April 2017 (has links)
No presente trabalho foram realizados estudos de regiosseletividade das reações de abertura de 2,3-epoxipropanoato de etila (1) utilizando diferentes nucleófilos de selênio e algumas dessas reações foram desenvolvidas com a adição do ácido de Lewis trifluoreto de boro dietil éter (BF3&#183;Et2O). A abertura desse oxirano ao utilizar os nucleófilos MeSeMgCl e MeSeLi-BF3&#183;Et2O ocorreu seletivamente no Carbono C-3 formando o composto de interesse (3-metilseleno 2-hidroxipropanoato de etila), já ao utilizar MeSeLi (em ausência ácido de Lewis) a abertura procedeu-se seletivamente no carbono C-2 formando 2-metilseleno-3-hidroxipropanoato de etila. A reação com o nucleófilo (Na[PhSeB(OEt)3]) levou à mistura desses regioisômeros. O ácido de Lewis BF3&#183;Et2O em presença do selenolato levou a inversão de regiosseletividade da reação de abertura do epóxido 1 e a razão estequiométrica de BF3&#183;Et2O adicionada ao meio reacional correspondeu, proporcionalmente, a porcentagem de obtenção do produto de abertura em C-3 (Tabela 1). Os resultados obtidos sugeriram que BF3&#183;Et2O altera a nucleofilicidade do selenolato (RMN de 77Se) a partir de uma interação selênio-boro. A formação da ligação Se-B pode ocorrer com ou sem a liberação de fluoreto e esse mecanismo foi investigado por meio do emprego de uma sonda fluorescente seletiva desse haleto. O mecanismo dessas reações também foram investigados por cálculos teóricos, os quais mostram-se totalmente coerentes com os resultados experimentais. / In the present work was studied reactions of regioselective opening of 2,3-epoxyester using different selenolatos and some of this reactions were developed by adding Lewis acid BF3&#183;Et2O. The opening reaction of this oxirane using the nucleofilms MeSeMgCl and MeSeLi-BF3&#183;Et2O occurred selectively in carbon C-3 forming the compound of interest (ethyl 3-methylselene 2-hydroxypropanoato of ethyl), already using MeSeLi (in Lewis acid absence) the reaction was selectively on C-2 carbon to form ethyl 2-methylselene-3-hydroxypropanoate. The reaction with the nucleophile (Na[PhSeB(OEt)3]) formed a mixing of these regioisomers. The Lewis acid BF3&#183;Et2O in presence of selenolate reverses the regioselectivity of opening epoxide (1) reaction and the stoichiometric value of BF3&#183;Et2O added in the reaction corresponded proportionally with the percentage of C-3 product (Table 1). The results suggested that BF3&#183;Et2O alters the nucleophilicity of selenolate (77Se NMR) from a selenium-boron interaction. Se-B bond formation may occur with or without fluoride release and this mechanism has been investigated by the use of a selective fluorescent probe of that halide. The mechanism of these reactions was also investigated by theoretical calculations, which are fully consistent with the experimental results.

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